21.T YEAR. 1915 218T EDITION STANDARD WIRING FOR ELECTRIC LIGHT AND POWER AS ADOPTED BY THE FIRE UNDERWRITERS OF THE UNITED STATES TN ACCORDANCE WITH THE NATIONAL ELECTRICAL CODE, WITH EXPLANATIONS, ILLUSTRATIONS AND TABLES NECESSARY FOR OUTSIDE AND INSIDE WIRING AND CON- STRUCTION FOR ALL SYSTEMS, TOGETHER WITH A SECTION ON HOUSE WIRING. H. O. GUSHING, JR. Fellow )lm. Inst. Elecl. Engrs. WITH THE CO-OPERATION OF THE NATIONAL ELECTRIC LIGHT ASSOCIATION COMMITTEE ON WIRING EX- ISTING BUILDINGS, AND THE SOCIETY FOP ELECTRICAL DEVELOPMENT. *- INDEX TCT CONSENTS PAGE 216 PUBLISHED BY H. C. GUSHING, JR., PULITZER BLDG,, NEW YORK, U. S. A, PREFACE THE Author, with the collaboration of Mr. F. E. Cabot, Chairman of the Electrical Com- mittee of the National Fire Protection Associa- tion, and with the co-operation of the National Electric Light Association Committee on Wiring Existing Buildings, and the Society for Electrical Development, has made it his aim in compiling the following pages to set forth, as clearly as pos- sible, the essential rules and requirements for safe and economical exterior and interior wiring and construction, the object being to standardize, as much as possible, all work of this nature and to respectfully suggest to the Electrical Engineer, Architect, House-owner, Contractor and Wire- man just what is required by Fire Underwriters Inspectors throughout the TJaited States. Copyright, 1915, by A. B. Gushing. THE GENERATOR All generators, whether for central station or isolated lighting or power work, should be located in a dry place so situated that the surrounding at- mosphere is cool. If the surrounding air is warm it reduces the safe carrying capacity of the ma- chine, and is likely to allow such temperatures to Proper installation of dynamo or motor on filled wooden base frame. rise in the machine itself as to burn out either armature or field, or both. A generator should not be installed in any place whe/e any hazardous process is carried on, nor in places where they would be exposed to inflammable gases or flying combustible materials, as the liability of occasional sparks from the commutator or brushes might cause more or less serious explosions. 3O1 240 Foundations. Wherever it is possible, generat- ors should be raised or insulated above the sur- rounding floor on wooden base frames, which should be kept filled to prevent the absorption of moisture, and also kept clean and dry. When it is imprac- ticable to insulate a generator on account of its great weight or any other reason, the Inspection Department of the Board of Fire Underwriters having jurisdiction may, in writing, permit the omis- sion of the wooden base frame, in which case the frame should be permanently and effectively grounded. Generators operating at a potential of over 550 volts should always have their base frames permanently grounded. When a frame is, grounded the insulation of the entire system depends upon the insulation of the generator conductors from the frame, and if this breaks down the system is grounded and should be put in proper condition at once. Grounding Generator Frames can be effectually done by firmly attaching a wire to the frame and to any main water pipe inside the building, on the street side of the meter, if there is one. The wire should be securely fastened to the pipe by screwing a brass plug into the pipe and soldering the wire to this plug or by approved ground clamps. When the generator is direct driven an excellent ground is attained through the engine coupling and piping. Wherever high voltage machines have their frames grounded a small board walk should be built around them and raised above the floor on porcelain or glass insulators, in order that the at- 4 tendant may be protected from shock when adjust- ing brushes or working about the machine. Accessibility, Sufficient space should be left on all sides of the generator, or motor, and especially at the commutator end, so that there may be ample room for removing armatures, commutators, or other parts at any time. Circuit Breakers and Fuses. Every constant potential generator should be protected from ex- cessive current by a fuse, or equivalent device of approved design, such as a circuit breaker. Such devices should be placed on or as near the dynamo as possible. For two-wire, direct-current generators, single pole protection will be considered as satisfying the above rule, provided the safety device is located and connected that the means for opening same is actuated by the entire generator current thus com- pletely opening the generator circuit. When two-wire, direct-current generators are used in conjunction with balancer sets to obtain a neutral for three-wire systems, a protective device should be installed which will operate and discon- nect the three-wire system should an excessive un- balancing of voltage occur. If a generator, not electrically driven, in a two-wire system has one terminal grounded, the circuit breaker above men- tioned should be placed in the g/ounded lead. For three-wire direct-current generators, either compound or shunt wound, a safety device should be placed in each armature lead of sufficient ca- pacity and so arranged as to take care of the entire current from the armature. The safety devices for this service should be a double-pole, double-coil overload circuit-breaker, or a four-pole circuit-breaker connected in the main and equalizer leads and tripped by means of two overload devices, one in each armature lead. The safety devices thus required should be so inter- locked that no one pole can be opened without si- multaneously disconnecting both sides of the arma- ture from the system. Fuses should never be used for this class of protection. In general, generators should preferably have no exposed live parts and the leads should be well insu- lated and thoroughly protected against mechanical injury. This protection of the bare live parts against accidental contact would apply also to all exposed, uninsulated conductors outside of the gen- erator and not on the switchboard. Waterproof Covers, though not required, should be provided for every generator and motor and placed over each machine as soon as it is shut down. Negligence in this matter has caused many an arm- ature or field coil to burn out, as only a few drops of water are necessary to cause a short circuit, when the machine is started up again, that might do many dollars' worth of damage, to say nothing of the inconvenience of having to shut off light or power when it is most needed, and for an indefinite length of time. Name Plates. Every generator and motor should be provided with a name plate, giving the maker's name, the capacity in volts and amperes and nor- mal speed in revolutions per minute. This will show exactly what the machine is designed for, and how it should be run. Terminal blocks when used on generators should be made of approved non-combustible non-absorp- tive, insulating material, such as slate, marble or porcelain. Wiring from Generators to switchboards and thence to outside lines should be in plain sight or readily accessible, and should be supported entirely throughout upon non-combustible insulators (such as glass or porcelain) and in no case should any wire come in contact with anything except these insula- tors, and the terminals upon the generators and switchboard. When it becomes necessary to run these wires through a wall or floor, the holes should be protected by some approved non-combustible in- sulating tube, such as glass , or porcelain, and in every case the tube should be so fastened that it shall not slip or pull out. Sections of any conduit, whether armored or otherwise, that are chopped off for this purpose, should not be used. All wires for generator and switchboard work should be kept so far apart that there is no liability of their coming in contact with one another, nor of short circuit from metallic tools used about them. All wire used in this class of work should be the best quality of "rubber covered" (see page 66). Bus-bars on switchboards, may be made of bare metal, so that additional circuits may be readily attached. They should have ample carrying capacity, so as not to heat with the maximum cur- rent likely to flow through them under natural con- ditions. (See "Capacity of Wire Table/' page 81.) So much trouble in past years has arisen from faulty construction of switchboards, and the apparatus placed upon them, that strict requirements have been necessarily adopted by engineers as well as insurance inspectors, and the following suggestions, are recommended by the latter ; although it is advis- able, when possible, that all wires from generators to switchboards be in plain sight and readily accessi- ble, wires from generator to switchboard may, how- ever, be placed in a conduit in the brick or cement pier on which the generator stands, provided that proper precautions are taken to protect them against moisture and to thoroughly insulate them from the pier or foundation. If lead-covered cable is used, no further protection will be required, but it should not be allowed to rest upon sharp edges which in time might cut into the lead sheath, especially if the cables were liable to vibration. A smooth runway is desired. If iron conduit is provided, double braided rubber-covered wire will be satisfactory. In wiring switchboards with regard to their ground detectors, voltmeters, pilot lights, potential trans- formers or other indicating instruments. Nothing smaller than No. 14 B. & S. gage "rubber cov- ered" wire should be used, and no such circuit should carry over 660 watts. Such circuits should be protected by approved enclosed fuses. (See p. 124.) The Switchboard should be so placed as to re- duce to a minimum the danger of communicating fire to adjacent combustible material, and, like the generator, should be erected in a dry place and kept free from moisture. It is necessary that it should be accessible from all sides when the wiring is done on the back of the board, but may be placed against a brick, stone or cement wall when all wiring is on the face of the switchboard. The board should be constructed wholly of non- combustible material and never built up to the ceil- ing; a space of three feet, at least, should separate the top of the board from the ceiling and at least eighteen inches should separate the wall from the instruments or connections, when the wiring is done on the back of the board. Every instrument, switch or apparatus of any kind placed upon the switchboard should have its own non-combustible insulating base. This is required of every piece of apparatus connected in any way with any circuit. If it is found impossible to place the resistance box, rheostat, or regulator, which should, in every case, be made entirely of non-combustible material, upon the switchboard, it should be placed at least one foot from combustible material or separated there- from by a non-inflammable, non-absorptive insulat- ing material. This will require the use of a slab or panel of non-combustible, non-absorptive insulating material such as slate, soapstone or marble, some- what larger than the rheostat, which should be secured in position independently of the rheostat supports. Bolts for supporting the rheostat should be countersunk at least J /6 inch below the surface at the back of the slab and the holes over the heads of the bolts filled with insulating material. For proper mechanical strength, the slab should be of a thickness consistent with the size and weight of the rheostat, and in no case to be less than y*> inch. 9 If resistance devices are installed in rooms where dust or combustible flyings would be libale to accu- mulate on them, they should be equipped with dust- proof face plates. Where protective resistances are necessary in connection with automatic rheostats, incandescent lamps may be used, provided that they do not carry or control the main current nor con- stitute the regulating resistance of the device. When so used, lamps should be mounted in por- celain receptacles upon non-combustible supports, and should be so arranged that they cannot have impressed upon them a voltage greater than that for which they are rated. They should in all cases be provided with a name-plate, which should be per- manently attached beside the porcelain receptacle or receptacles and stamped with the candle-power and voltage of the lamp or lamps to be used in each receptacle. Wherever insulated wire is used for connection between resistances and the contact device of a rheostat, the insulation should be "slow burning." (See page 67.) For large rheostats and similar resistances, where the contact devices are not mounted upon them, the connecting wires may be run together in groups so arranged that the maxi- mum difference of potential between any two wires in any group shall not exceed 75 volts. Each group of wires should either be mounted on no-combust- ible, non-absorptive insulators giving at. least */ inch separation from surface wired over, or, where it is necessary to protect the wires from mechanical injury or moisture, be run in approved conduit or equivalent. Special attention is again called to the 10 fact that switchboards should not be built down to the floor, nor up to the ceiling, but a space of at least ten or twelve inches should be left between the floor and the board, and thirty-six inches be- tween the ceiling and the board, when possible, in order to prevent possible fire from communicating from the switchboard to the ceiling, and also to prevent the forming of a partially concealed space very liable to be used for storage of rubbish and oily waste. Where floor is of brick, stone or con- crete, the switchboard may go to the floor, but for cleanliness and safety space should always be pro- vided when possible. Lightning Arresters should be attached to each wire of every overhead circuit connected with the station. It is recommended to all electric light and power companies that arresters be connected at intervals over systems in such numbers and so located as to prevent ordinary discharges entering (over the wires) buildings connected to the lines (see p. 48). Arresters for Stations and Sub-stations should be located in readily accessible places away from combustible materials, and as near as practicable to the point where the wires enter the building. Station arresters are often placed in plain sight on the switchboard. The switchboard, however, does not necessarily afford the only location meet- ing these requirements. In fact, if the arresters can be located in a safe and accessible place away from the board, this should be done, for, in case the arrester should fail or be seriously damaged there 11 would then be no chance of starting arcs on the board. Fire Extinguishers. At least one, or more if the size of the installation demands it, good ap- proved extinguisher should be in plain sight and readily accessible, one which is capable of extin- guishing electrical fires or arcs without danger of transmitting a shock to the operator (see page 194). In all cases, kinks, coils and sharp bends in the wires between the arresters and the outdoor lines should be avoided as far as possible. They should be connected with a thoroughly good and permanent ground connection by metallic strips or wires having a conductivity not less than, that of a No. 6 B. & S. copper wire, and these should be run as nearly in a straight line as possible from the arresters to the earth connection. Ground wires from lightning arresters should not be attached to gas-pipes within the buildings. It is often desirable to introduce a choke coil in circuit between the arresters and the dynamo. In no case should the ground wire from a lightning arrester be put into iron pipes, as these would tend to impede the discharge. Unless a good damp ground is used in connection with all lightning arresters, they are little better than useless. Ground connections should be of the most approved construction, and should be made where permanently damp earth can be conveniently reached. For a bank of arresters such as is com- monly found in a power house, the following in- structions will be found valuable: First, dig a hole six feet square directly under the arresters until 12 permanently damp earth has been reached; second, cover the bottom of this hole with two feet of crushed coke or charcoal (about pea-size) ; third, over this lay 25 square feet of No. 16 copper plate; fourth, solder at least two ground wires, which should not be smaller than No. 4, securely across the entire surface of the ground plate ; fifth, now cover the ground plate with two feet of crushed coke or charcoal; sixth, fill in the hole with earth, using running water to settle. A practical and effective method of installing an outside line arrester is shown on page 48. All lightning arresters should be mounted on non-combustible bases, and be so constructed as not to maintain an arc after the discharge has passed. Testing of Insulation Resistance. All circuits except such as are permanently grounded, as de- scribed on pages 45 and 46, should be provided with reliable ground detectors. Detectors which indicate continuously and give an instant and permanent indication of a ground are preferable. Ground wires from detectors should not be attached to gas pipes within the building. Where continuously indicating detectors are not used, the circuits should be tested at least or^e per day (see page 65), and preferably oftener. Data obtained from all tests should be recorded and preserved for examination. Storage or Secondary Batteries should be in- stalled with as much care as generators, and in wiring to and from them the same precautions and rules should be adopted for safety and the preven- tion of leaks. The room in which they are placed 18 should not only be kept dry, but exceptionally well ventilated, to carry off all fumes which are bound to arise. The insulators for the support of the secondary batteries should be glass or porcelain, as filled wood alone would not be approved. The use of any metal liable to corrosion should be avoided in cell connections of secondary batteries of the lead or sulphuric acid type. Care of Generators. A few suggestions as to the care of the generator, as well as its installation, may be of value, and one of the important points under this head is that the driving power should have characteristics of steadiness and regularity of speed, and should always be sufficient to drive the generator with its full load, in additions to the other work which it may be called upon to sustain. Unsatisfactory results are always obtained if at- tempting to run a generator on an engine operating anything other than its own generator or gen- erators. Wooden bed plates are supplied, when ordered, for all generators, except in the larger or direct- connected machines. Most belt-driven generators and motors are fitted with a ratchet or screw bolt, so that they may be moved backward or forward on the bed plate in a direction at right angles to the armature shaft. By this means the driving belt may be tightened or loosened at will while the machine is in operation. Care should be taken in tightening the belt not to bind the bearings of the armature and force the oil from between the surface of the shaft and boxes. u Such practice will inevitably cause heating of the bearings and consequent injury. Generators are usually assembled, unless ordered otherwise, so that the armature revolves from left to right when the observer faces the pulley end of the shaft. All generators, however, may be driven in either direction by reversing the brush leads and changing field connections. The generator, if belt driven, is provided with a pulley of the proper size to take care of the power necessary to drive it, and one of different size should not be substituted unless approval be ob- tained from the generator makers. When driving from a countershaft which, at best, is bad practice, or when belted directly to the main shaft, a louse pulley or belt holder should be used, to admit of starting and stopping the generator while the shafting is running. Belts. A thin double or heavy single belt should be used, about a half -inch narrower than the face of the pulley on the generator. An endless belt, one without lacing, gives the greatest steadi- ness to the lights. For proper length of belts see formula on page 213. All Bolts and nuts should be firmly screwed down. All nuts which form part of electrical con- nections should receive special attention. When copper commutator brrshes are used, al- though now almost obsolete, they are carefully ground to fit the commutator, and they should be set in the holders so as to bear evenly upon its surface. On machines where two or more copper brushes 15 are supported on one spindle, the brushes on the same side of the commutator must be set so that they touch the same segments in the same manner. The brushes on the other side of the commutator must be. set so as to bear on the segments diamet- rically opposite. When the brushes are not so set it is impossible to run the machine without spark- ing. A convenient method of determining the proper bearing point for the brushes. is to set the toe of one brush at the line of insulation, dividing two segments to the commutator; then count the dividing lines for one-half the way around the sur- face, and set the other brush or brushes at the line diametrically opposite the first. Thus, on a forty- four segment commutator, after setting the tip of one brush at a line of insulation, count around twenty-three lines, setting the other brush at the twenty-third line, thus bringing the tips directly opposite each other. The angle which the brushes form with the surface of the commutator should be carefully noted, and the brushes should not be al- lowed to wear, so as to increase or decrease this angle. Careless handling of the machine is at once indicated by the brushes being worn either to a nearly square end or to a long taper, in which the forward wires of the brush far outrun the back or inside wires. Either condition cannot fail to be at- tended with excessive wear of both commutator and brushes. After copper brushes are set in contact with the commutator, the armature should never be rotated backward. If it is required to turn the armature back, raise the brushes from the commutator by the 16 thumb screw on the holder provided for that pur- pose, before allowing such rotation. Carbon Brushes are now almost universally used and require little or no adjustment or care other than keeping them clean. Bearings. See that the bearings of the ma- chine are clean and free from grit, and that the oil reservoirs are rilled with a good quality of lubricat- ing oil. The Oil Reservoirs should always be axamined before starting, and all loose grit removed. The oil should all be drawn off at the end of each day's run for the first three or four days and filtered, after which it can be assumed that any grit has been carried off with the filtration, and it will only be necessary to add a little fresh oil once in seven to ten days. These instructions apply only to ma- chines using loose ring oilers attached to each end of the armature shaft. In starting up a Generator or motor fill the oil reservoirs and see that the oiling rings are free to move. In the case of generators fitted with oil cups, start the oil running at a moderate rate. Too little oil will result in heating and injury of the bearing; but, on the other hand, excessive lubrica- tion is unnecessary, wasteful, and sometimes pro- ductive of harm. When the generator is ready to be started, place the driving belt on the pulley on the armature shaft, and then slip it from the loose pulley or belt holder on to the driving pulley on the counter-shaft. Tighten the belt, by means of the ratchet on the bed plate, just sufficiently to keep it from slipping. Care should be taken not to put more pressure than is necessary on bearings ; carelessness in this respect is often followed by heating of the boxes, and pos- sible permanent injury. The brushes may now be let down upon the com- mutator, if copper brushes are used. Move the brushes slowly backward or forward by means of the yoke handle, until there is no sparking at the lower brushes. Clamp the yoke in this position. If the top brushes then spark, move them slightly, one at a time, forward or backward in the brush holder until their non-sparking point is found. The spring pressure exerted upon the commuta- tor brushes should be just sufficient to produce a good ^contact without causing cutting. If the brushes cut, the commutator must be smoothed by the use of fine sandpaper, NOT emery cloth. The generator should run, without load, at the speed given by the manufacturer, and this speed should be closely maintained under all conditions. In the case of generators for incandescent light- ing, any increase of speed, above that given, nat- urally increases the voltage which is prejudicial to the life of the lamps, while a variation below causes unsatisfactory light (see table, page 116). Before starting a direct current generator, for the first time, if to be run in connection with another or more generators, it should be tested for polarity. TJiis may be done by holding a small pocket compass near the field or pole piece. If the dynamo is con- nected to be run in multiple with another machine and happens to be polarized wrong, it can be given 18 the right polarity by lifting the brushes from the commutator, closing the field switch, and then clos- ing the double-pole switch used to throw it in mul- tiple with the other machine, which is supposed to be now running. After the current has been al- lowed to pass through the fields for a few moments, the double-pole switch can be thrown open, and if a test with the compass is again made the polarity will be found to be the same as the other, machine, or machines, and is ready to be started in the usual manner in multiple. (See page 37.) If the dynamo is to be used in series with an- other on the three-wire system, and is found to be polarized wrong, it can be given the right polarity by making a temporary connection from the posi- tive brush of the new machine to the positive brush of the machine already in operation; and also a temporary connection from negative brush to neg- ative brush, having first raised the brushes from the commutator and closing the field switch. Keep this connection for a few minutes, then open the field switch and break the temporary connections. Another test with the compass will show that the polarity of the machine is now correct, and the dynamo is ready to be started in the usual manner in series. (See page 37.) Assuming that the lamps and lines are all ready, the following precautions should be observed when starting the dynamo : Be very careful that the brushes are properly set and diametrically opposite each other, as already stated. 19 Be sure that all connections are securely made, and all nuts or connections firmly set. In cases where two or more dynamos are con- nected in multiple by the use of the equalizing con- nection, care should be taken that the circuit wires from both positive brushes be connected to the same side of the main line, while those from the negative are connected to the other side. A neat arrangement of the equalizing connection can be made by using triple-pole switches on the switchboard, instead of double-pole switches, and making the equalizing connections through the cen- ter pole of the switch, instead of running a cable direct from one dynamo to the other. This method is especially desirable where three or more dynamos are run in multiple. When dynamos are connected in series, as in the cases where the three-wire system is in use, the leading wire from the positive brush of one ma- chine is connected to the negative brush of the other. The other two brushes (negative and pos- itive) are connected to the two main wires on the outside of the system, while the third or neutral wire is connected to the conductor between the two generators. Keep all commutator and brush holder insula- tions free from dust, gritty substances and oil. They should be carefully cleaned once a day. If any of the connections of the machine become heated, examination will show that the metal sur- faces are not clean or not in perfect contact. The Commutator should be kept clean and al- lowed to polish or glaze itself while running. No 20 oil is necessary unless the brushes cut, and then only at the point of cutting. A cloth slightly greased with vaseline is best for the purpose. Never use sandpaper on the commutator without first lifting the brushes. Otherwise, the grit will stick to the brushes and cut the commutator. Hot Bearings. The most natural thing to do is to shut the machine down, but this should never be done until the following alternatives have been tried and have failed: First Lighten the load. Second Slacken the belt. Third Loosen the caps on the boxes a little. Fourth- Put more oil in bearings. Fifth If all the above fail to remedy the heat- ing, use a heavy lubricant, such as vaseline or cyl- inder oil. Should the heating then diminish, the shaft must be polished with crocus cloth and the boxes scraped at the first opportunity. Sixth Under no conditions put ice upon the bearings unless you are perfectly familiar with such a procedure. Seventh If it is absolutely necessary to shut down, get the belt off as soon as possible, keeping the machine revolving meanwhile in order to pre- vent sticking, and at the same time take off the caps of the bearings. Do not stop the flow of oil to the bearings. When the caps "have been taken off, stop the machine and get the linings out imme- diately, and allow them to cool in the air. Do not throw the linings into cold water, as it would be apt to spring them. Scraping should be done only by an experienced 21 person, otherwise the linings may be ruined. Polish the shaft with crocus cloth, or, if badly cut, file with a very fine file, and afterward polish, with crocus. Wipe the shaft, as well as the boxes, very carefully, as perhaps grit has been the cause of the hot box. Inspect the bearings, see that they are in .line, that the shaft has not been sprung, and that the oil collar does not bear against the box. Oily Waste should be kept in approved metal cans (made entirely of metal, with legs raising them at least three inches above the floor, and with self- closing covers) and removed daily. Attendance. A competent man should always be kept on duty where generators are operating. MOTORS. The Installation of Motors. All direct-current motors for 550 volts or less, should be insulated on wooden floors or base frames, which should be kept filled to prevent absorption of moisture; and kept clean and dry. Where frame insulation is imprac- ticable the Inspection Department having jurisdic- tion may, in writing, permit its omission, in which case the frame should be permanently and effect- ively grounded. The use of motors operating at a potential in excess of 550 volts will only be ap- proved when every practicable safeguard has been provided. They should have no exposed live metal parts and their base frames, in every case, should be permanently and effectively grounded, as in the case of generators. Plans for such installations should be submitted, for approval, to the Inspection Department having jurisdiction before any work is begun. 22 A high-voltage machine which, on account of great weight or for other reasons, cannot have its frame insulated, should have its frame permanently grounded and should be surrounded with an insu- lated platform. This may be made of wood, mounted on insulating supports, and so arranged that a man must stand upon it in order to touch any part of the machine. Motors operating at a potential of 550 volts or less should be wired with the same precautions as required for lighting wires carrying a current of the same volume. Motors operating at a potential between 550 and 3,500 volts should be wired with approved multiple conductor, metal sheathed cable in approved metal conduit firmly secured in place. The metal sheath should be permanently and effectively grounded, and the construction and installation of the conduit should conform to rules for interior conduits, ex- cept that at outlets approved outlet bushings should be used in place of the outlet box. The leads or branch circuits from the source of supply should be designed to carry a current at least 25 per cent, greater than that required by the rated capacity of the motor to provide for the in- evitable excess current used by the motor at times, especially when starting, without overfusing the wires. Where the wires would be ovtrfused, in order to provide for the starting current, as in the case of many of the alternating current motors, the wires should be of such size as to be properly pro- tected by these larger fuses. The insulation of the several conductors for high voltage motors, where leaving the metal sheath at 23 outlets, should be thoroughly protected from mois- ture and mechanical injury. This may be accom- plished by means of a pot head or some equivalent device. The conduit should be substantially bonded to the metal casings of all fittings and appa- ratus connected to the inside high tension circuit. It would be much preferable to make the conduit system continuous throughout by connecting the conduit to fittings and motors by means of screw joints, and this construction is strongly recom- mended wherever practicable. High voltage motors should preferably be so located that the amount of inside wiring will be reduced to a minimum. The Inspection Department having jurisdiction may permit the wire for high voltage motors to be installed according to the general rules for high voltage systems when the outside wires directly enter a motor room. Under these conditions there would generally be but a few feet of wire inside the building and none outside the motor room. The motor and the rheostat should be protected by a cutout or circuit breaker, and controlled by a switch (see illustrations on pages 33 to 37), said switch plainly indicating whether "on" or "off." Small motors may be grouped under the protection of a single set of fuses, provided the rated capacity of the fuses does not exceed 6 amperes. Where one-fourth horse-power or less is used on circuits where the voltage does not exceed 300, a single- pole switch will be accepted. The switch and rheo- stat should be located within sight of the motor, except in such cases where special permission to 24 locate them elsewhere is given, in writing, by the Inspection Department having jurisdiction. In connection with motors the use of circuit- breakers, automatic rheostats with automatic un- der-load switches is recommended, wherever it is possible to install them. Where the circuit-breaking device on the motor- starting rheostat disconnects all wires of the circuit, the switch called for in this section may be omitted. Overload-release devices on motor-starting rheostats should not be considered to take the place of the cut-out required by this section if they are inopera- tive during the starting of the motor. The switch is necessary for entirely disconnecting the motor when not in use, and the cut-out to pro- tect the motor from excessive currents due to acci- dents or careless handling when starting. An automatic circuit-breaker disconnecting all wires of the circuit may, however, serve as both switch and cut-out. The use of circuit-breakers with motors is recommended, and may be required by the In- spection Department having jurisdiction. To be safe, a rheostat should have as great a carrying capacity as the motor itself, or else the arm should have a strong spring-throw 7 attachment, so arranged that it cannot remain at any intermediate position unless purposely held there. See cut on page 27. Auto starters, unless equipped with tight casings enclosing all current-carrying parts, should be treated about the same as knife switches, and in all .wet, dusty or linty places, should be enclosed in dust-tight, fireproof cabinets. If a 'special motor 25 room is provided, the starting apparatus and safety devices should be included within it. Where there is any liability of short circuits across their exposed live parts being caused by accidental contacts, they should either be enclosed in cabinets, or else a rail- ing should be erected around them to keep unau- thorized persons away from their immediate vicinity. Motors should not be run in series-multiple or multiple-series, except on constant-potential sys- tems, and then only by special permission of the Inspection Department having jurisdiction. Like generators, they should be covered with a waterproof cover when not. in use, and, if neces- sary, should be incjosed in an approved case. When it is necessary to locate a motor in the vicinity of combustibles or in wet or very dusty or dirty places, it is generally advisable to enclose it in a dust-tight fireproof cabinet. Such enclosures should be readily accessible and sufficiently ventilated to prevent an excessive rise of temperature. The sides should preferably be made largely of glass, so that the motor may be al- ways plainly visible. This lessens the chance of its being neglected, and allows any derangement to be more readily noticed. k The use of the enclosed type of motor is recom- mended in dusty places, being preferable to wooden boxing. Motors, when combined with ceiling fans, should be hung from insulated hooks, or else there should be an insulator interposed between the motor and its support. 26 Every motor should be provided with a name- plate, giving- the maker's name, the capacity in volts and amperes, and the normal speed in revolutions per minute. Starting and Stopping Motors (Direct Current) One rule at all times to be remembered in starting and stopping motors is, switch first, rheostat last, which means, in starting, close the .switch first, and then gradually cut out all resistance as the motor speeds up. To stop the motor open the switch first and then cut in all the resistance of the rheostat Motor Starting Rheostat or "Resistance Box" with No-Voltage Release. Slate front carries lever, contacts and release spool, mounted on a ventilated box of pressed steel which serves as a container for the resistance. which is in series with the motor armature. When starting any new motor for the first time, see that the belt is removed from the pulley and the motor started with no load. Never keep the rheostat handle on any of its coils longer than a moment, as they are not designed to regulate the speed of the motor, but to prevent too large a flow of current into the armature before the latter has attained its full speed. 27 The illustration (p. 27) shows a rheostat which is designed to automatically protect the armature of a motor. The contact arm is fitted with a spring which constantly tends to throw the arm on the "off-point" and open the circuit, but is prevented from so doing, while the motor is in operation, by the small electro-magnet, shown on the face of the rheostat, which consists of low resistance coil con- nected in series with the field winding of the motor. This magnet holds the contact arm of the rheostat in the position, allowing the maximum working cur- rent to flow through the armature while it is in operation. If, for some reason or other, the current sup- plied to the motor be momentarily cut off, the speed of the armature generates a counter current which also tends to hold the arm in position as long as there is any motion to the motor armature, but as soon as the armature ceases to revolve all current ceases to flow through the electromagnet, thereby releasing the rheostat handle, which flies back to the "off" point, as shown in the illustration, and the motor armature is out of danger. Such a de- vice is of great value where inexperienced men have to handle motors, and are unaware that the first thing to be done when a motor stops for any reason whatever is to open the circuit, and then cut in all the resistance in the rheostat to prevent too large an in-rush of current when the motor is started up again. The Circuit Breaker for under and over loads is also a most valuable protection in such cases. Motor Wiring Formulae (Direct Current). To find the proper size of wire for direct-current motors proceed as follows : e voltage of motor, d = single distance from generator to motor in feet. v = volts loss in lines, k = efficiency of.motor. (See table below.) 10.8 Resistance in ohms of a wire I ft long and .001 inch diameter. Then in size or wire circular mils (cm) horsepower X 746 X 2d X 10.8 c.m. = - e X v ;X k horsepower X d X 16113.6 or simplified cm _ - e X v X k Compare the size of wire thus found with that al- lowed by the underwriters for full load current of motor, -|- 25%. If it be smaller it must be increased to at least that figure to be approved and the re- sulting lower line loss accepted. (See table, p. 81.) THE AVERAGE MOTOR EFFICIENCY (K). I h.p. and under 75 per cent. 3 h.p. to 5 h'.p 80 per cent. 5 .h.p. to 10 h.p 85 to 90 per cent. Over 10 h.p 90 per cent. The tables and examples worked out on pages 52-54 and 69-71 will give the desired results, in many cases of smaller installations without having to use the above direct current formulae. 29 CURRENT REQUIRED BY MOTOR (Direct Current.) To find current required by 'a motor when the horse-power, efficiency and voltage are known, use the following formula : Let C current to be found. H. P horse-power of motor. E voltage of motor circuit. K efficiency of motor intper cent. H. P. X 746 X ioo E X K The table of "amperes per motor" given on the following page, will, in many cases, prevent the trouble of working out the above formula. By adding the volts indicated in the (page 32) table to the voltage of the lamp or motor, the re- sult shows the voltage at the dynamo for losses in- dicated. Thus, 10 per cent, on no volt system is: 12.22 volts added to no equal 122.22, showing that the dynamo must generate 122.22 volts to take care of a 10 per cent, loss in the line (for A. C., see pp. 70-78). SIZES OF FUSES, IN AMPERES, FOR MOTORS EQUIPPED WITH OVERLOAD STARTING RHEOSTATS. Horsepower. 115 Volts. 230 Volts. 500 Volts. 0.5 8 4 2 1 15 8 4 2 30 15 7 3 40 20 10 4 50 25 12 5 60 30 15 7.5 90 45 20 10 115 60 25 15 175 90 40 20 225 115 50 25 300 150 60 30 350 175 76 35 400 200 90 40 450 225 100 50 600 300 125 '^o 10 g CD gj co - oj g gg g 2 g t^COOi^^C^lQOiC oo t: ? ? S ?- o o cq OT S b- t' od o co' i ' r-i tW !M' W W C *' 5 >' l> 00 OS* O jH N CO *' LO O g5 An approved installation in every detail, and wiring connection* for fthunt-wound, four-pole motor, using two enclosed fuse* instead of circuit breaker. IRON FRAME STARTING RHEOSTAT An approved installation in every detail and wiring connections for shunt-wound multipolar slow speed ceiling motor for direct Connection to line shafting, using both circuit bieaker and double-pole fuse cut-out. An approved installation in every detail, and wiring connections, for shunt-wound bipolar motor, using circuit breaker instead of double-pole fuse cut-out. 86 CONNECTIONS FOR DIRECT CURRENT MOTORS SERIES MOTOR. 4-POLE SHUNT MOTOR 4-POLE 36 CONNECTIONS FOR DIRECT CURRENT DYNAMOS. Rheostat 1 Rheostat THREE WIRE DISTRIBUTION ^heostat Rheostat at i ' 4 [ Equalizer T r c * MULTIPLE JDISTRIBUTION-TWO WIRE 37 CONNECTIONS FOR DIRECT CURRENT MOTORS & DYNAMOS C - P - A Enclosed fuse COMPOUND MOTOR 2 POLE COMPOUND DYNAMO 2-POLE COMPOUND MOTOR 4- POLE COMPOUND DYNAMO 'l-POLE OUTSIDE WIRING AND CONSTRUCTION Service Wires (those leading from the outside main wire to the buildings and attached to same) should be "Rubber Covered,'' as described on page 66, under that heading. Line Wires, other than service wire, should have an approved "weatherproof" covering. (See page 67.) Bare Wires may be used through uninhabited and isolated territories free from all other wires, as in such places wire covering would be of little use, as it is not relied on for pole insulation. For Insulated Wires. For Bare Wire or Cable. Insulator Clamps. Tie Wires should have an insulation equal to that of the conductors they confine, within city limits, or some permanent clamp that wilt not injure the insulation. Space between Wires for outside work, whether for high or low tension, should be at least one foot, and care should be exercised to prevent any possi- bility of a. cross connection by water. Wires should never come in contact with anything except their insulators.- Roof Structures. If it should become neces- sary to run wires over a building, the wires should 39 be supported on racks which will raise them from 7 to 12 feet above flat roofs, as shown on page 43, or at least one foot above the ridge of pitched roofs, and should be strongly made. Guard Arms. Whenever sharp corners are turned, each cross arm should be provided with a dead insulated guard arm, or guard iron, to pre- vent the wires from dropping down and creating trouble, should their insulating support give way. (See Fig. 2, page 64.) Petticoat Insulators (See illustrations on page 41) should be used exclusively for all outside work, and especially on cross arms, racks, roof structures and service blocks. Porcelain knobs, cleats or rub- ber hooks should never be used for this heavy outside work. In fact, rubber hooks are not now approved for any form of electric light or power work. The Dossert Solderless Cable Connector approved for use on stranded wires and cables without the use of solder. Splicing of two pieces of wire or cable should be so done as to be mechanically and electrically secure without solder. They should then be sol- dered, unless made with some form of approved splicing device. This ruling applies to joints and splices in all classes of wiring. All joints whether soldered or made with an approved splicing device should be covered with an insulation equal to that of the conductors. 40 6000 Volts 4000 Volts 15000 Volts Types of Petticoat Insulators for high voltages. Construction Work Tree Insulation. 41 Tree Wiring. Whenever a line passes through the branches of trees, it should be properly sup- ported by insulators, as shown on page 41, to pre- vent the chafing of the wire insulation and ground- ing the circuit. The tree insulators shown on the previous page have proved themselves to be the most practical and permanent insulators for all kinds of tree con- struction, allowing the free swaying of limbs without chafing the insulation of the wires. Service Blocks which are attached to buildings should have at least two coats of waterproof paint to prevent the absorption of moisture. Size of Wire. To find the required size of wire in circular mils for any alternating current system, to carry any required current any distance at any voltage and. with any required loss, use the for- mulae and examples on pages 69 to 78, and for di- rect currents the formulae on. pages 198 and 199. When possible, however, refer to tables No. I or No. 2 on pages 52 and 69, respectively, as they will be found much simpler when within their limita- tions. Service Wires. Where service wires enter a building they should have drip loops outside and the holes through which the conductors pass should be bushed with non-combustible, non-absorptive in- sulating tubes, such as glass or porcelain, slanting upward toward the inside. Where metal conduit is used the conduit should be curved downward at its outer end and carefully sealed or, a much better method is to use an ap- proved service-head to prevent the entrance of moisture. (See illustration below.) The inner end should extend to the service cut- out. If a cabinet is used the conduit should be properly carried within the cabinet. G-V Universal An Approved Service Head for Service or Entrance Wires. It may be used in either a Horizontal or Vertical Position. Telegraph and Telephone wires should nevei , be placed on the same cross arm with light or power wires, especially when alternating currents are used, as trouble will arise from induction, un- less expensive special construction, such as the transposing of the lighting circuits, be resorted to at regular intervals. Even under these conditions it is bad practice, as an accidental contact between the lighting or power circuit might result in start- ing a fire in the building to which the telephone line is connected. If, however, it is necessary to place telegraph and telephone wires of the same poles with lighting and power wires, the distance between the two inside pins of each cross arm should not be less than twenty-six inches. The metallic sheaths to cables should be thoroughly and per- manently connected to earth. Transformers should not be placed inside of any building excepting central stations or sub-sta- tions, and should not be attached to the outside walls of buildings, unless separted therefrom by 44 substantial supports as shown on page 49. In cases where it is impossible to exclude the transformer and primary wiring from entering the building, the transformer should be located as near as possible to the. point where the primary wires enter the building, and should be placed in a vault or room constructed of or lined with fire-resisting material, and should contain nothing but the transformers. It is, of course, the safest practice to place all transformers on poles away from the building that is to be wired, as illustrated on page 49. Where transformers are to be connected to high- voltage circuits, it is necessary in many cases, for best ^protection to life and property, that the sec- ondary system be permanently grounded, and pro- vision should be made for it when the transformers are installed. Grounding of Low-Potential Circuits. The grounding of low-potential circuits is only recom- mended when such circuits are so arranged that under normal conditions of service there will be no appreciable passage of current over the ground wire. In Direct-Current 3-Wire Systems, the neutral wire should be grounded, and when grounded the following suggestions should be complied with: i They should be grounded at the central sta- tion on a metal plate buried in coke beneath per- manent moisture level, and also through all avail- able underground water and gas pipe systems. 2 In underground systems the neutral wire should also be grounded at each distributing box through the box. 45 3 In overhead systems the neutral wire should be grounded every 500 feet. , In Alternating-Current Secondary Systems. All transformer secondaries of distributing sys- tems should be grounded, and the following sug- gestions should be complied with: i The grounding should be made at the neutral point or wire, whenever a neutral point or wire is accessible. 2 When no neutral point or wire is accessible one side of the secondary circuit should be ground- ed. 3 The ground connection should be at the trans- former or on thej individual service and when transformers feed systems with a neutral wire, the neutral wire should also be grounded at least every 500 feet. Inspection Departments having jurisdiction may require grounding if they deem it necessary. Ground Connections. When the ground con- nections is inside of any building, or the ground wire is inside of, or attached to any building (ex- cept central or sub-stations) the ground wire should be of copper and have an approved rubber insulating covering. The ground wire in direct-current 3-wire sys- tems should not at central stations be smaller than the neutral wire and not smaller than No. 6 B. & S. gage elsewhere, The ground wire in alternating- current systems should never be less than No. 6 B. & S. gage. On 3-phase systems, the ground wire should 46 have a carrying capacity equal to that of any one of the three mains. The ground wire should, except for central sta- tions and transformer sub-stations, be kept out- side of buildings as far as practicable, but may be directly attached to the building or pole by cleats or porcelain knobs. Staples should never be used. The wire should be carried in as nearly a straight line as practicable, avoiding kinks, coils and sharp bends, and should be protected when exposed to mechanical injury. This protection can be secured by use of an ap- proved molding, and as a rule the ground wire on the outside of a building should be in moulding at all places where it is in within seven feet from the ground. Conduit may be used for this purpose. The ground connections for central stations, transformers, sub-stations, and banks of transfor- mers should be made through metal plates buried in coke below permanent moisture level, and con- nection should also be made to all available under- ground piping systems, including the lead sheath of underground cables. For individual transformers and building ser- vices, the ground connection may be made to water piping systems running into buildings. This con- nection may be made by carrying the ground wire into the cellar and connecting on the street side of meters, main cocks, etc. Where it is necessary to run the ground wire through any part of a building it should be pro- tected by approved porcelain bushings through walls or partitions and should be run in approved mould- 47 Installation of Lightning Arrester on outside lines, showing method of obtaining a good "ground." ing, or conduit, except that in basements it may be supported on porcelain. In connecting a ground wire to a piping system, the wire should be sweated into a lug attached to an approved clamp, and the clamp firmly bolted to I Construction Work Installation of Transformers. the water pipe after all rust and scale have been removed; or be soldered into a brass plug and the plug forcibly screwed into a pipe-fitting, or, where the pipes are cast iron, into a hole tapped into the pipe itself. For large stations, where connecting to underground pipes with bell and spigot joints, 49 it is well to connect to several lengths, as the pipe joints may be of rather high resistance. Where ground plates are used, a No. 16 Stubbs' gage copper plate, about three by six feet in size, with about two feet of crushed coke or charcoal, about pea size, both under and over it, would make a ground of sufficient capacity for a moderate-sized station, and would probably answer for the ordinary sub-station or bank of transformers. For a large central station, a plate with considerably more area might be necessary, depending upon the other un- derground connections available. The ground wire should be riveted to the plate in a number of places, and soldered for its whole length. Perhaps even better than a copper plate is a cast-iron plate with projecting forks, the idea of the fork being to dis- tribute the connection to the ground over a fairly broad area, and to give a large surface contact. The ground wire can probably best be connected to such a cast-iron plate by soldering it into brass plugs screwed into holes tapped in the plate. In all cases, the joint between the plate and the ground wire should be thoroughly protected against cor- rosion by painting it with waterproof paint or some equivalent. Ground Detectors. The cuts on page 65 illus- trate a few practical methods of detecting grounds on alternating and direct current circuits which have not been purposely grounded, as described on pages 45 and 46. In using any one of these methods for detecting grounds always see that the circuit TO GROUND is 50 left open after testing the outside circuits. Some central station men are in the habit of leaving the ground circuit closed on one side constantly in or- der that any ground that might occur on the other side may he instantly noticed. This, however, is bad practice, as it greatly reduces the insulation of the whole system. Test all circuits once a day. MEASURING RESISTANCE It is frequently necessary to know just what the insulation resistance of a line, or the wiring in a building, is in ohms. The "Megger" for Measuring Resistance. Heretofore such tests have been made with some form of portable testing set (Wheatstone Bridge), or by the voltmeter method; inconvenient calcula- tions being necessary in either case. Now, however, there is on the market a new instrument, called the Evershed Megger, by means of which conductor or insulation resistance can be measured as quickly and as accurately as volt- si age is measured with a voltmeter. A small hand generator is mounted in the case, so that no out- side source of current is required. Tests by the "Megger-method" are made as fol- lows : Connect a wire from one side of the circuit to binding post of the Megger marked "Line," and with another piece of wire connect a water pipe to the "earth"- binding post of the Megger. Turn the generator handle at one end of the Megger case, and the pointer of the instrument will instantly show the correct resistance the scale being grad- uated in ohms. As the generator voltage is usually TOO or 250 volts, there is the added advantage that tests by the "Megger-method" are practically made under working conditions. Wiring Table No. 1. For Direct Current Work. Size of Wire, Feet per B. & S. Gauge. Volt-Ampere. 0000 10068.4 000 7998.7 00 6389.5 5025.1 1 3974.5 2 3166.5 3 2495.0 4 1980.0 , 5 1347.0 6 1248.7 7 986.7 8 779.6 9 618.4 10 495.0 11 394.0 12 312.3 13 246.7 14 194. 52 How to Use the Wiring Table No. i. The col- umn entitled size of wire B. & S. gage gives the various sizes used in wiring. The column entitled feet per volt-ampere gives the number or feet that the adjacent size of wire will transmit one ampere with a lost of one volt; this is a constant quantity for each size of wire. The distance that a wire will transmit a given current is directly proportional to the volts lost. The distance that a wire will transmit a cur- rent with a certain volt loss is inversely propor- tional to the current. If, therefore, it is desired to know how far a given wire will transmit a given current at a cer- tain given line loss, select from the second column opposite the ize of the wire constant in the feet? per-volt-ampere column and multiply this figure by the desired loss and divide by the current to be transmitted. If it is desired to know how much current can be transmitted a given distance with a certain line loss multiply this constant by the line loss and divide by the distance. If it is desired to know what line loss will oc- cur when transmitting a certain current through a certain size of wire multiply the distance and current together and divide by f he constant for the size of wire which it is desired to use. Take a Practical Example. Let it be asked, "How far will a No. 6 wife transmit 20 amperes with a line loss of 15 volts?" The constant for No. 6 wire is 1248.7; multiply this by the line loss 53 of 15 volts and we have 18730.5, and dividing this by the current, 20 amperes, we have 936.5. Con- versely, suppose we have a distance of 936.5 feet and must transmit over it 20 amperes, how much line loss will obtain ? Multiply this distance of 936.5 by the current to be transmitted, and we obtain 18/30, dividing this by the constant for No. 6 wire, 1248.7, we obtain 14.999 v l ts lme l ss > or practically 15 volts. Similarly : Suppose we have, a distance of 936.5 feet, and the conditions are such that at most it must not exceed a line loss of more than 15 volts. How many amperes can we transmit with a No. 6 wire ? To do this we multiply the constant of No. 6 wire, 1248.7 by the line loss of 15 volts, obtaining .18730.5, and dividing this by the distance, 963.5 feet, we obtain 20.0005, or practically 20 amperes. Finally, and as is more often the case, the dis- tance and line loss and current are given ; we have to multiply the distance by the current and divide . by the line loss which will give us the constant of the wire to use. In the preceding case of 936.5 feet, we multiply by the current of 20 amperes and obtain 18730.; dividing this by the line loss of 15 volts we obtain 12486.6, which is practically 12,- 487, the constant for No. 6 wire. If this constant had been larger still, but not so large as the constant for No. 5 wire, it would be proper to select the nearest constant. Wires for Outside Use have in most cases a " weather-proof" (see page 67) insulation, except service wires, which should be "rubber covered" 54 see page 66). Any insulating covering for wires exposed to the weather on poles is in time ren- dered useless. The real insulation of the system is dependent upon the porcelain or glass insulat- ors on which the wires are supported. Constant-Potential Currents of over 5,000 volts should be given special care and attention as to their installation and location with respect to ad- joining or near-by property or other outside wiring. Accidental crosses between such lines and low- potential lines may allow the high-voltage current to enter buildings over a large section 'of adjoining country. Moreover, such high-voltage lines, if carried close to buildings, hamper the work of fire- men in case of fire in the building. It is fully understood that it is impossible to frame rules which will cover all conceivable cases that may arise in construction work of such an ex- tended and varied nature. Every reasonable precaution, however, should be taken in arranging routes so as to avoid exposure to contacts with other electric circuits. On exist- ing lines, where there is a liability to contact, the route should be changed by mutual agreement be- tween the parties in interest wherever possible. Such lines should not approach other pole lines nearer than a distance equal to the' height of the taller pole line, and such lines "hpuld not be on the same poles with other wires, except that signal- ing wires used by the company operating the high- pressure system, and which do not enter property other than that owned or occupied by such com- pany may be carried over the same poles. Where such lines must necessarily be carried near other pole lines, or where they should neces- sarily be carried on the same poles with other wires, extra precautions to reduce the liability of a break- down to a minimum should be taken, such as the use of wires of ample mechanical strength, widely spaced cross arms, short spans, double or extra heavy cross arms, extra heavy pins, insulators, and poles thoroughly supported. If carried on the same pole with other wires, the high-pressure wires should be carried at least three feet above the other wires. Where such lines cross other lines, the poles of both lines should be of heavy and substantial con- struction. Whenever it is feasible, end insulator guards should be placed on the cross arms of the upper line. If the high-pressure wires cross below the other lines, the wires of the upper line should be dead-ended at each end of the span to double- grooved, or to standard transposition insulators, and the line completed by loops. When it is necessary to carry such high-voltage lines near buildings, they should be at such height and distance from the building as not to interfere with firemen in event of fire; therefore, if within 25 feet of a building, they should be carried at a height not less than that of the front cornice, and the height should be greater than that of the cor- nice, as the wires come nearer to the building. It is evident that where the roof of the building continues nearly in line with the walls, as in Man- sard roofs, the height and distance of the line 56 should be reckoned from some part of the roof instead of from the cornice. POLES FOR LIGHT AND POWER WIRES It is very essential. to a proper installation that the poles receive due consideration, a fact that is too often overlooked. In selecting the style of pole necessary for a cer- tain class of work, the conditions and circumstances should be considered. They may be arranged in three classes, the size of wire they are to carry being one of the important regulating circum- stances. First Class. Alternating-current plants for lighting small towns. Main line of poles should consist of poles of from 30 to 35 feet with 6-inch tops. These are strong enough for all the weight that is placed upon them. No pole less than 30 feet with 6-inch top should be placed on a corner for lamps. The height of trees, of course, will have to be considered in many cases. For the Edi- son municipal system, where more than one set of wires are used for street lighting, a 6-inch top should be the size of the poles, the length being not less than 30 feet, and more if the streets be hilly and filled with trees. Second Class. Town lighting by arc lights. All poles should be at least 6-inch tops. The cor- ner poles should be 6^2 -inch tops, and wherever the cross arms are placed on a pole at different angles, the pole should be at least a 6^/2 -inch top. A 3O-foot pole is sufficiently large for the main 57 line, but it would be advisable to place 35-foot poles on corners. Third Class. Where heavy wire, such as No. oo, is used for feeder wire, the poles should be at least 7-inch tops. Where mains are run on the same pole line the strain is somewhat lessened, and poles of smaller size will answer all purposes. Cull Poles. The question as to what is a cull pole is something on which many authorities dif- fer. Of course, if specifications call for a certain- sized pole, parties supplying the 'poles should be compelled to send the sizes called for. All poles that are smaller at the top than the sizes agreed upon, are troubled with dry rot, large knots and bumps, have more than one bend, or have a sweep of over twelve inches, should certainly be classed as cull poles. Specifications for electric light and power work should be, and in many cases are, much more severe than those required by telegraph lines. A cull pole, one of good material, is the best thing for a guy stub, and is frequently used for this pur- pose. A cedar pole is always preferable to any other, owing to the fact that it is very light in comparison to other timber, and is strong, durable, and very long lived. Pole Setting. In erecting poles, it seems to be the universal opinion of the best posted construc- tion men that a pole should be set at least five feet in the ground, and six inches additional for every five feet additional length above thirty-five feet. Also additional depths on corners. Wherever there is much moisture in the ground, it is of much value to pain or smear the butt ends of the pole 58 with pitch or tar, allowing this to extend about two feet above the level of the ground. This protects the pole from rot at the base. The weakest part of the pole is just where it enters the ground. Never set poles further than 125 feet apart; spac- ing not over no feet is good practice. Pole Holes should be dug large enough so that the butt of the pole can be dropped straight in without any forcing, and when the pole is in posi- tion only one shovel should be used, to fill in, the earth being thoroughly tamped clown with iron tampers at every step until the hole is completely filled with solidly packed earth. Where the ground is too soft for proper tamping, a grouting com- posed of one part of Portland cement to two parts of sand mixed with broken stone may be used to make an artificial foundation. Painting. When poles are to be painted, a dark olive green color should be chosen, in order that they may be as inconspicuous as possible. One coat of paint should be applied before pole is set, and one after pole is set. Tops should be pointed to shed water. All poles 35 feet long and over are usually loaded on two cars. For chestnut poles add 50 per cent, to weights as given above. Cross Arms. The distance from the top of the pole to the cross arm should be equal to the diam- eter of pole at the top. All cross arms should be well painted with one coat of paint before plac- ing, and must be of standard size. Cross arms of four or more pins should be 59 braced, using one or two braces as occasion de- mands. Cross arms on one pole should face those on the next, thereby making the cross arms on every other pole face in one direction. All wooden pins should have their shanks dipped in paint and should be driven into the cross arm while the paint is wet. The upper part of the pin should also be painted. Iron pins can be furnished for corners where there is a heavy strain, but are not advised, it being preferable to use the construction as shown in the diagrams. Put double arms on the pole where feeder wires end. (See p. 64.) Guard Irons. Guard irons should be placed at all angles in lines and on break arms. (See p. 64.) Steps. All junction and lamp poles should be stepped so that the distance between steps on the same side of the pole will not be over 36 inches. Poles carrying converters should also be stepped. Guys. All poles at angles in the line should be properly guyed, using No. 4 B. & S. galvanized iron wire, or two No. 8 wires twisted. All junction poles should also be guyed. Never attach a guy wire to a pole so that it prevents a cross arm from being removed. For alternating current work, double or triple petticoat insulators are recommended. (See cuts on page 41.) Primary Wires on Poles. When running more than one alternating current, single-phase primary circuit upon the same line of poles the wires of each circuit should be run parallel and on adjacent pins, as shown below, so as to avoid any fluctuation in the lamps due to induction. The lines lettered A 60 and A are for circuit No. i, and B and B for cir- cuit No. 2, etc.' A A B B Underground Conductors should be protected against moisture and mechanical injury where brought into a building, and all combustible material should be kept from the immediate vicinity. They should not be so arranged as to shunt the current through a building around any catch-box. Where underground service enters building through tubes, the tubes shall be tightly closed at outlets with asphaltum or other non-conductor, to prevent gases from entering the building through such channels. CEDAR POLES FOR ELECTRIC LIGHT WORK. SIZE. Average weight, pounds each. No. of Poles to a Car SIZE. Average weight, pounds each. No. of Poles tn a Car 25- ft., 5-inch top 200 150 35-ft., 7-inch lop 650 90 25 " 5^ " " 225 130 40 " 6 " " 800 80 25 " 6 !' " 250 100 40 " 7 " " 900 75 28 " 7 " " 400 80 45 " 6 " " 900 70 30 " 5 " " 300 110 45 " 7 " " 1000 65 30 " 6 " " 350 90 60 " 6 " " 1200 55 30 " 7 " " 420 75 65 " 6 " " 1400 45 35 " 6 " " 550 100 61 POLE LINE DATA Gauge No. B. & i Diam. Bare wire, i Ohms Res. B. wire Wt. (lbs.)perl,00( Wt. " u Mile Poles per Mile 4-0 .460 .2622 775 4092 3-0 .40964 .33 630 3326 2-0 .3648 .4164 490 2587 1-0 .3249 .5252 400 2112 1 .2893 .6642 306 1616 2 .2576 .8337 268 1415 n Thousandths at 75 per mile ) ft. Triple B . . Dist. bet. Poles Ft. Approximate Wt. of Weatherproof Wire between Poles i 20 ... 264.00 251.40 240.10 229.56 220.00 211.20 203.07 195.55 188-55 182.09 176.00 170.30 165.00 160.00 155.29 150.85 146.66 142.70 138.96 135.38 132.00 128.78 125.71 122.79 120.00 117-33 114.78 112.34 110.00 107.75 105.60 103.52 101.53 99.64 97.77 96.00 210-73 200.66 191.64 183.24 175-60 168.59 162.07 156.10 150-46 145.34 140.50 135.92 131.71 127.72 123-96 120-38 117-07 113.90 110.93 108-05 105.37 102-79 100.35 98-01 95-79 93-66 91-61 89-67 87-80 86.01 84.30 82-63 81.04 79.54 78-04 76-63 171.31 163.14 155.81 148.96 142.76 137-04 131.76 126.90 122.35 118.16 114.21 110-51 107.07 103-82 100-76 97-89 95-15 92.60 90.17 87-84 85.65 83 56 81.58 79.68 77-87 76-15 74.48 72.89 71.38 69-92 68.53 67-18 65.89 64.65 63.44 65-29 133.24 126-87 121.17 115.85 111.03 106.58 102.48 98.69 95.16 91.89 88.83 85.95 83.28 80-75 78-37 76.14 74.02 72.02 70.13 68-33 66-62 64.99 63.44 61-97 60.56 59.21 57-93 56-70 55.52 54.38 53 29 52.24 51.24 50.29 49.34 48-45 108-78 103-58 98.91 94.57 90-64 87-01 83.65 80.56 77-68 75.01 72.51 70-16 67.98 65.92 63-98 62-15 60.43 58-79 57-25 55.77 54-38 53.05 51.79 50-59 49.47 48.38 47 27 46 28 45.32 44.39 43.50 42-65 41-83 41.05 40.28 39-55 83-21 77.24 75-67 72.36 69.34 66.56 64.00 61-64 59.43 57.39 55.47 53.67 52.01 50.43 48.94 47.55 46-23 44.98 43.88 42-67 41 61 40.59 39.62 38-70 37-82 36.98 36.18 35.40 34.67 33*96 33.28 32.63 32.00 31.40 30.82 30-25 72.87 69.39 66.27 63.36 60.72 58.29 56.05 53.97 52.05 50.26 48.58 47.00 45.55 44.16 42.86 41.64 40.48 39.39 38-36 37-37 36.43 35-54 34.70 33-89 33-12 32.38 31.68 31 01 30.36 29.74 29-15 28-57 28.02 27-50 26.98 ^6-50 21 22 23 24 25 26 27 28-.. Oq 30 31. 32 . . 33 34 OC 3g 07 3g 39 40 ... ..... 41 42 43 44 45 46 47 4g 49 .... 50 .. . 51 CO 53 ... c4 55 62 POLE LINE DATA. Continued. Gauge No. B. & S. Diam. Bare Wire, Res. B. Wire, per Wt. 1,000 ft. Tripl \Vr. Mile No. 3 .2294 1.058 210 1109 App No. 4 .2043 1.333 164 866 roxima Wii No. '5 .1819 1.6748 145 766 te Wt. e betw No. 6. .1620 2.114 112 591 of We een PC No. 7 .1442 2.673 atherpr )les No. 8 .1285 3.387 78 412 oof Thousandths... . mile at 75 e Braid Poles Per Mile Distance Between Poles Feet 20 264.00 251.40 240.10 229-56 220.00 211.20 203.07 195-55 188-55 182.09 176.00 170.30 165.00 160.00 155.29 150.85 146.66 142.70 138.96 135.38 132.00 128.78 125-71 122.79 120.00 117-33 114.78 112.34 110.00 107-75 105.60 103-52 101.53 99.64 ? 97.77 98 00 57.10 54.38 51.93 49.65 47.59 45.68 43.92 42-29 40.78 39.39 38.07 36.83 35.69 34.61 33-59 32.63 31.72 30-87 30-06 29.28 28.55 27-85 27.19 26.56 25.96 25.38 24.83 24-30 23-79 23.31 22-84 22.39 21.96 21.55 21.15 20-76 44.59 42.46 40.55 38.77 37.16 35.68 34.30 33.03 31.85 30-76 29.73 28.77 27.87 27.03 26.23 25.48 24.78 24.10 23.47 22.86 22.30 21.75 21.24 20.74 20.27 19.82 19.39 18.98 18.58 18.20 17.84 17.49 17.15 16-83 16.51 16.21 39.43 37.54 35.86 34.28 32.86 31.54 30.33 29.21 28.16 27.19 26.29 25.43 24.64 23.90 23.19 22.53 21.90 21.31 20.76 20.22 19-71 19-23 18-78 18.34 17.92 17.52 17-14 16-78 16.43 16.09 15.77 15.46 .5.16 14.88 14.60 1434 30.45 29.00 27.70 26.48 25.38 24.36 23-42 22-56 21.75 21.00 20-30 19.64 19.03 18.46 17.91 17.40 16.92 16.46 16-03 15.62 15.23 14.85 14.50 14.17 13.84 13.53 13.24 12-96 12,69 12-43 12.18 11.95 11.71 11.49 11.28 11.07 .':;:. 21.21 20.20 18.29 18.44 17.67 16.97 16.32 15.71 15-15 14.63 14.14 13-68 13.26 12.85 12.47 12.12 11.78 11.46 11.16 10.88 10.61 10-34 10.10 9.86 9.64 9.43 9,22 9.02 8-84 8.66 8.48 8-32 8-16 8.00 7.85 7.71 21 22 23 24 25 26 27 28 29 30 31 .... 32 33 34 35 36 37 .... 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 ... 54 55 G3 ANGLES OF BRACES WILL BE GOVERNED BY CIRCUMSTANCES BLOCK *vu. X VARIES AS THE DIAMETER OF THE POLE CONSTRUCTION WORK Position of Cross-Arms when Turning Corners When running a heavy line where it is necessary to use two cross arms fastened as shown in Fig. 2. If lines are not heavy, only one cross arm will be necessary. In case lines cross the street diag- onally, the arms where the wires leave and those to which they run are both set at an angle. When turning an abrupt cor- ner, only one arm is turned. The above cannot be used where feeders tap into double branches. In such cases the method as given in Fig. 1 is used. 64 CONNECTIONS OF GROUND DETECTORS , ALTERNATING GROUND DETECTOR FOR ONE CIRCUIT ALTERNATING GROUND DETECTOR FOR TWO CIRCUITS DIRECT CURRENT GROUND DETECTOR NEUTRAL WIRE IN 3-WIRE SYSTEM TO GROUND IF THE LAMP BURNS A GROUND IS INDICATED ON THE OPPOSITE SIDE OF THE CIRCUIT FROM THAT TO WHICH THE SWITCH IS CONNECTED INSIDE WIRING General rules for all systems and voltages for light, power and heat, when protected by service cut-out and switch. Approved "Rubber-Covered Wire" should be used exclusively in all interior wiring. Although the Fire Underwriters allow "Slow Burning" wire to be used in dry places when wiring is entirely exposed to view and rigidly supported on porce- lain or glass insulators. The copper conductors before being rubber cov- ered should be thoroughly tinned and the thickness of the rubber covering should correspond to the following table for voltages up to 600: From No. 14 to No. 8 inclusive ,\ in " 6 to " a I's in i to ' oooo 6 \ in Over oooo to ' 500000 c. m. 3 3, in 500000 c. m. to " i oooooo * & in Larger than " i oooooo " I in For voltages above 600 the rubber covering is correspondingly thicker. Consult your supply dealer or any of the following manufacturers who will furnish the proper insulation for the voltage required. Complete list of Manufacturers of Approved "Rubber Covered" Wires : A. A. Wire Co., Inc Newark, N. J. American Electrical Works Providence, R. I. American Steel & Wire Co Worcester, Mass. Atlantic Insulated Wire & Cable Co New York. Bay State Insulated Wire & Cable Co Hyde Park, Mass. Belden Mfg. Co Chicago, 111. Bishop Gutta Percha Co New York. Boston Insulated Wire & Cable Co Boston. Bourn Rubber Co Providence, R. I. Collyer Insulated Wire Co Pawtucket, R. I. Crescent Insulated V/ire & Cable Co Trenton, N. J. Detroit Insulated Wire Co , Detroit, Mich. 66 Klectric Cable Co Bridgeport, Conn. General Electric Co Schenectady, N. Y. Goodrich Co., B. F Akron, Ohio. Goodyear Rubber Insulating Co New York. Habirshaw Wire Co Yonkers, N. Y. Hazard Mfg. Co Wilkes-Barre, Pa. Indiana Rubber & Insulated Wire Co". Jonesboro, Ind. Kerite Insulated Wire & Cable Co New York. Lowell Insulated Wire Co Lowell, Mass. Marion Insulated Wire Co Marion, Ind. National India Rubber Co New York. New York Insulated Wire Co New York. The Okonite Co New York. Phillips Insulated Wire Co Pawtucket, R. I. Roebling's Sons Co., John A t Trenton, N. J. Rome Wire Co Rome, N. Y. Safety Insulated Wire & Cable Co New York. Simplex Wire & Cable Co Boston. Standard Underground Cable Co Pittsburg. \Vaterbury Company New York. Chicago Insulated Wire & Mfg. Co Chicago. (Slow-Burning and Weatherproof.) "Slow-Burning" Wire should have an insula- tion consisting of three braids of cotton or other thread with the interstices well filled with a fire- proofing compound. The outer braid should be designed to resist abrasion and have its surface finished smooth and hard. The complete covering should be of a thickness not less than that given in the following table: Form No. 14 to No. 8 inclusive, 3/64 inch 7 to ' 2 " 1/16 " 1 to ' 0000 " 5/64 " 250000 to ' 500000 c. m. " 3/32 " 500000 to ' 1000000 c. m. " 7/64 " Larger than 1000000 c. m. " 1/8 " "Weatherproof" Wire is for out-door use, and should have a covering of at least three braids thoroughly impregnated with a dense moisture re- pellent which should stand a temperature of 160 Fahrenheit without dripping. The thickness should correspond to that of "Slow Burning" wire, and 67 the outer surface should be thoroughly slicked down. Carrying Capacity of Wires. The table on page 8 1 gives the safe carrying capacity of wires from No. 18 B. & S. to cables of 2,000,000 circu- lar mils. No wires smaller than No. 14 should be used except for fixture wiring and pendant cords. For fixtures as small as No. 18 may be used. (Sec page 99.) Tie Wires should have an insulation equal to that of the conductors they confine. All wires of the size of No. 8 B. & S. gage or larger when used in connection with knobs should be securely tied thereto with tie wires having equal insulation. Solid porcelain knobs should be used at the end of runs where circuits are terminated. Split knobs or cleats should be used for conductors small- er than No. 8 B. & S. gage, except at the end of runs: All knobs or cleats should be fastened by screws of generous length and should have washers under their heads to prevent the screw from cracking the porcelain. Splicing should be done so as to make the wires mechanically and electrically secure without solder; then they should be soldered to insure pre- servation from corrosion and consequent heating from poor contact. Then thoroughly taped. All joints should be soldered unless made with some form of approved splicing device such as Dos- sert joints. (See page 40.) This ruling applies to joints and splices in all classes of wiring. 68 Stranded Wires, except flexible cords, should have their tips soldered before being fastened under clamps or binding screws. Both solid and stranded wires having a conductivity greater than No. 8 B. S. gage should be soldered into lugs for all ter- minal connection unless Dossert lugs are used. Wiring Table, No. 2 (See page 70.) The fol- lowing examples show the method of using the table on the following page. 1. What size of wire should we use to run 50 5O-watt carbon lamps, of no volts, a distance of 150 feet to the center of distribution with the loss of 2 volts? First multiply the amperes, which will be 22.75 (5-5 watt no-v. lamps take 22.75 am - peres, see table on page 115), by the distance, 150 feet, which will equal 3,412 ampere feet. Then refer to the columns headed "Actual Volts Lost/' and as we are to have only a loss of two volts look down the column headed 2 until you come to the nearest corresponding number to 3,412 and we find that 3,900 is the best number to use. Put your pen- cil on the number 3,900 and follow that horizontal column to the left until you come' to the vertical vcolumn headed "Size B. & S." and you find that a No. 4 B. & S. wire will be the proper size to use in this case. 2. What size wire should we use to carry cur- rent for a motor that requires 30 amperes and 220 volts, and is situated 200 feet from the distributing pole, the "drop" in volts not to exceed 2 per cent.? First multiply 30 amperes by 200 feet, as we did in the first example, and we get .6,000 ampere feet. Now look at the upper left hand corner of the table 69 o o O rH C4 *< OS C5 o' O rH rH oi *< 05 00 f. O O O O rH CO 10 C* TJ< OO OO IO rH O O O T-4 03 bl iO O O rH T(< OO. eo ?o w t~o*eo i OOrHNlOO \ r 1 IO fa COI>THIHOOO 1 Q rH CO CO rH w rH $ H S; T( oo o 'O oo H u Oo'rHOOSO Ci ^i OS OO OS O O rH CO t-I iO O O * * r-t OJ f 00 rH 0* CO 00 10* rHCA8eSO rH CM T* CS t- iH rH U Til O 00* a O O O O O i>eocoooO'ccMco iomcoi>t>. i-.oo^.koo5 -v 05 1- I- 05 CO 00 * rH OS t- * Si rH rH - 00 O rH t- O (M IO lO iH OS OS CO ^f rHOOiOlO CO t-(NOOOO CO COi-HCO C5 **< CO <*< l> rH t- CO O QO lO CO C* l-t OOOOOOOOOOOOOOO * w oj * oo o oo o o * z> -^ o* oo o o * oo T-H oo < 10 C50J050irH^OJiOOt05DCO(?*i-l > ?O <* CO CO 00 OO co'^O5O-^ioio OOOo -ts rHiOiOgvj t^ v^Z 2 w > O 5 S ^<0osot-osioeo-t-oo ** I- CO rH OO O lO * M C* rH rH 03 'c? o o o o rH c co -a* o < oo o e* ^ o 70 and you will see a vertical column headed "Volts." Go down this column until you come to 220 and follow the horizontal column to the right until you come to the figure 1.8 which is the nearest we can come to a 2 per cent, loss without a greater loss or "drop." Place your pencil on a figure 1.8 and fol- low down the vertical column of figures until you come to the nearest corresponding figure to 6,000, which we find to be 6,200. Then with your pencil on this figure follow the horizontal column to the left and we find that a No. 5 B. & S. wire is a prop- er size to use for the above conditions. 3. Supposing we have occasion to inspect a piece of wiring, and find a dynamo operating 50-50 watt no-volt lamps at a distance of 150 feet, and our wire gauge shows that wire in use is a No. 12 B. & S., at what loss, or "drop," are these lamps be- ing operated ? First multiply the amperes, which will be 22.75 (5~5 watt no-volt lampfs take 22.75 amperes (see table on page 115), by the distance, 150 feet and we get 3,412 ampere feet. As we find in use a No. 12 B. & S. wire we look for the verti- cal column headed "Size B. & S." and follow it down until we come to 12. With our pencil on the figure 12 we travel along the horizontal line to the right until we come to the nearest corresponding number to 3,412, which we find to be 3,050. Then starting at this number we travel up the vertical column and we find a loss of about 10 actual volts, or at an 8 per cent, loss, which would greatly re- duce the candle-power or brilliancy of his lamps. A larger wire should, therefore, be used. 71 LOTORS. th tables c^ 8 Phase E rHrHWN^^Wt, ^ V C '? H 3 I r-l I PH eo a OOlO *0 INDUC n eonne iQ eo 1010 ^ j r-nHi-HOJ* W ^ S CO * U8 . 2 * i '* eo iHrHC4(M -*10 Sr-lff40M 2 - _S CO S "3 u O S s ' 40 VOLTS 2 Phase ~~ "ft -3 C6 lO O OO lO lO y ll s s |l Phase " * 00 OJ lO *> t^ i-l W 10 t-' I* 2 "Sco5s i ^ M- s: 1 oo ^S -o SS2weo-*SS *S ^ S -3 I 1 5 "o H .2 Phase t- lO 5 1C a a w w oo 8 S iHrHOi-^S-f^SSSSM CO iH iH |H CJ f^ W c PH eo t-io c fc W? rt^CO g o cu *o 3 1 . LO VOLTS n o* eo vo S *** l-l rH CN | P H .S"c < 3 8 a is rt CO ^"* Ji g -ss MH cO OH 1-1 Q o ^0 ^ ^ S C-2 . . rH rH (7i-C* CO ** +H ^ 72 Wiring Calculations for Alternating Current. When figuring wire sizes for Alternating Current, except in cases of long distances, the following methods of calculating should be used. As compared with the circular mileage of each conductor of a two wire system, that of each con- ductor of other systems, transmitting same power with the same distance, volts lost, and lamp voltage is, for: 3 wire, single phase 25.0% 4 wire, single phase 11.1% 4 wire, two phase 50.0% 3 wire, two phase 50.0% with middle wire 75 % 4 wire, three phase, with neutral. . 1 6.6% 3 wire, three phase 50.0% All wires of each system ; except 3 wire two phase ; considered of same size. We will now take an example in each system and show how to calculate the wire size. Three Phase, Three Wire. What size wire should we use to run 1-220 volt, 30 horsepower in- duction motor; and light 102-220 volt, 60 watt mazda lamps ; a distance of 400 feet to the center of distribution with the loss of 7 volts? Let us refer to the table on page 72. Here we see that the amperes per phase (same as amperes per terminal) of a 3 phase, 220 volt, 30 H.P. motor is 81. We must calculate the amperes per phase for the lamps by using this formula : total watts of lamps Amperes - 1-73 X volts 73 w H I S 3 B s 3 s s$ 1 O CO o 30 CO n o 35 o CO o C5 5 ro JO CO O f 3 05 i> * co CO CO H * o 5 n o o n o CO CO o o o 00 o CO o CO i o CO :: JC CO 00 2 S 05 t~ m * g w rH 1-1 o o o o O o T* CO o C5 o m CO co o CO * CO O CO o in rr rH CO so CO 1-1 i-i 1 1 1 o co o CO o o o ~. rH 1 9 m CO 00 -tf 1 1 00 O5 m co CO Tjt CO co CO 1-1 i ^ o 3 o 01 o 1 o o o o 1 o o n 1 O 1 CO rH 3O CO -H CO CO t i 1 CO CO CO :o o CO 1 CO O CO N 00 1 1 O CO M 00 CO CC 1 CC o CO c CO m CO CO g CO C5 a O3 1 C-; CO O5 CO "* a oo CO in :o CO CO _ o c - ^ ^ o oo o o 2 ^ s ^> ^ o o CO CO CO CO o 3 CO g :; m CO 00 CO Ci OC S ^" * CV r-l 1-1 N 1 OJ i 5 E S Bi Q 1 a g CO 1 ci s OC -O * CO CO - c QC (M m a m K S CO t- 1 oc 1 1 O CO C5 O 1C c O s 3^ g O g co o CO CO CO 0- 1 CC CO 1 s ^ 5 CO CO ul ^ oo CO CO c S o o O CO CO CO o 00 o CO CO CO I- CO CO X) ": X ?! C^ ^ r~ \ CO OS . t-l'OO C * re re ?i iH r^' *3 js t- ^ H * i co O oo 1 c; O <4< S ~ /- o Ji '- O4 O c - 5 X 1 o i- o r re c: o 00 i- CO Ci c ~ 00 04 ^^a^ 13 e ^ < ? H O X O O CM O c c~. OS M * pS x -4 - ' A i-t I* eo t O4 ^* 00 -^ eo CO CO r! 4> ^ L| ^ M r: CO ^ eo # ce ?! ?1 !_: ;! c X IO eo " O r r ?^ = = O X o c o oo c r o r c X c 00 C eo .Sj^ ^ QO O < - / eo t X 00 to j3 > ,L, cr. ex CO re ?/ I*-M 1 j t- C' M^ re ? r^ i m *^ ^o eg U ^ ^ nj rt *5 2* ^ ^ _, o f- U r. s l~ o CO OS ce r r a o g o t- cr. to CO M r .s!> *>% n5 w eo 01 O * fl> 2 o o o ~ ~ o o o oo o o m 3 co o 1 o CO 1 ^ rt r " / S m e ct \ 1 1-1 ^ / l> ?! CO 06 CO re -f ~ J2 t- M *ll w o o iO O O o . S o O 10 Iff in ~ S>^ ^ 2 o iO m co t- CO 13 c I-H /' CO t* ,:'? r. 7 ';2 S e'i 04 to ? X c : " : " ^ af* r; s ^L! os t- CO r? 04 IH c C 2 ^ .h 3 c ( , ia 10 o C iO iO m t- e 04 C5 3 c ~ '**' !/) J X 1 V ^* (M Ct | ?! I 1 b- os <- os tO IO co m at re 00 re eo B i CO CO r? 8^1 o S. ?! W ^"^ O o o o Q O ^ IO tO .10 O o eo j ce i- X -1- ^^ ""' On c: * ?^ T '~~ ^ "ftC ""* o El: ^_; - o .S|.2 us *w 1* i|s U o ~ U 1 O g O i-d 1 eo -* CO CO s S ** 4>"3 III o r |O 7 rt ^'u "3^3 4*^ 2IH <5 00 91 ^ SH .^1 > i -4^ .< c <^ .^, 1 1 09 eo ' ^1 *ft CO CO s G4 ^t W ^ ^ ^ ^ (W 'f t . 3> ^x ^ o ^^ T-l C* in 3 3 5< ?^ g.* *!? > *- : fi^ us ia k"v g i o fci g S l-t. CO s 64 s it ll 3.5 s> 71 r-< ^ ""* ^ t *,a Turning to page 76 and following the directions given at the top of the table there given : 34.09 X ioo = 3409; under the column of 3 volts loss, we find opposite the nearest number (3690) that we are to use No. 6 wire for the two outside lines and No. 4 wire for the middle one. Two Phase, Four Wire. For this system of wiring calculate the amperes per phase the same as for 2 phase, three wire, and use the table on page 70 to find the size of wire. In the above problem under 2 phase, three wire, if we were to run a 2 phase, four wire service, we would use No. 6 wire for each line. Three Phase, Four Wire, With Neutral. This system is very little used and therefore no table is given, but the sizes can be calculated in this way : Calculate the circular mils necessary for a two wire system of the same total wattage, distance, volts lost and applied voltage and take as size for each wire 1 6.1%. For example, a system using a total of 10,000 watt, at 220 volts, 500 feet, and 10 volt drop, circular mils for two wire system = 10.8 X 2 X 500 X 45-5 - ( formula given on page 10 160) 49,000. 16.1% of th^s is 49,000 X .161 = 8,170. From table on page 74 we find that the nearest size (larger) is No. 10 wire, therefore we must use four wires of this size. Single Phase, Two Wire. Calculate for this the same as for two wire D. C, using the table on page 77 70. In the case of motors, obtain the amperes re- quired from table on page 72. Single Phase, Three Wire. Calculate the size necessary for a two wire system of same power, voltage, volts lost, and distance, and take three wires of one-quarter the size thus calculated for this sys- tem. The same general method as given above un- der Three Phase, Four Wire. Single Phase, Four Wire. Calculate the size necessary for a two wire system of same power, voltage, volts lost, and distance, and take 11.1% of the result for each wire in this system. The same general method as given above under Three Phase, Four Wire. A convenient type of pocket wire gauge, one- half actual size, for measuring wire from No. 18 to No. ooo B. & S. gauge. On the front is given the safe carrying capacity of copper wires in am- peres, and on the reverse side the approximate decimal equivalent of the various sizes of wires. 78 Installation of Wires. All wiring, when not en- closed in approved conduit, moulding or armored cable, should be kept free from contact with gas, water or other metallic piping, or any other conduct- ors or conducting material which they may cross, by some continuous and firmly fixed non-conductor, creating a separation of at least two inches, and in wet places should be arranged so that an air space will be left between conductors and pipes in cross- ing, and the former should be run in such a way that they cannot come in contact with the pipe ac- cidentally. Where one wire crosses another wire the best and usual means of separating them is by a porcelain tube on one of the wires. The tubing should be prevented from moving out of place either by a cleat or knob on each end, or by taping it. The same method may be adopted where wires pass close to iron pipes, beams, etc., or, where the wires are above the pipes, as is generally the case, ample protection can frequently be secured by sup- porting the wires with a porcelain cleat placed as nearly above the pipe as possible. Wires should be run over rather than under pipes upon which moisture is likely to gather, or which by leaking might cause trouble on a circuit. No smaller size than No. 14 B. & S. gauge should ever be used for any lighting or power work, not that it may not be electrically large enough but on ac- count of its mechanical weakness and liability to be stretched or broken in the ordinary course of usage. Smaller wire may be used for fixture work, if pro- vided with approved rubber insulation. Wires should never be laid in or come in contact 7t with plaster, cement or any finish, and should never be fastened by staples, even temporarily, but always supported on porcelain or glass insulators or cleats which will separate the wires at least one-half inch from the surface wired over and keep the wires not less than two and one-half inches apart; three wire cleats may be used when the neutral wire is run in the center and at least two and one-half inches sep- arate the two outside or -j- and wires. This style of wiring is intended for low voltage systems (300 volts or less), and when it is all open work, rubber covered wire is not necessary as "weatherproof" wire may be used. Weatherproof wire should not be used in moulding. Wires should not be fished between floors, walls or partitions or in concealed places. Twin wires should never be used, except in con- duits; they are always unsafe for light or power circuits on- account of the short distance between them. All wiring should be protected on side walls from mechanical injury. This may be done by putting a substantial boxing about the wires, allowing an air space of one inch around the conductors and closed at the top (the wire passing through bushed holes) and the boxing extending about five feet above the floor. Sections of metal conduit may be used (the wire being protected by approved flexible tubing), and in most cases this practice is preferable. All bushings should be made of non-combustible, non- absorptive insulating material such as glass or por- celain and should be used wherever wires go through walls, floors, timbers or partitions. They 80 CARRYING CAPACITIES AND DIMENSIONS OF WIRES AND CABLES. As adopted by the National Board of Fire Underwriters of the United States. For further dimensions of bare and insulated wires, see Index. an 1 6 M 5 S c u v . w <_, t- V c/i , 5 rt QJ u S N P j; | M "^ V *! " 4> 4/^> 5 and 6 inches. Each size has its correspond- ing size elbow, coupling, etc. The specifications for the construction of metal conduit are numerous, but the con- tractor or wireman need not bother about these details just see that it is of the proper size and bears the name or initials of an approved maker. Flexible Steel Conduit is made for use on odd or irregular bends or for inaccessible places "where the rigid conduit could only be installed with great difficulty. It is furnished in any lengths desired and in nine different diameters (inside), 5/16, 3/6, ]/2, %, i, i, T 4? I'/^j 2 an d 2/4 inches. No metal conduit with an inside diameter of less than one-half inch should be used. All conduit work should be continuous from outlet to outlet or to junction boxes or cabinets, and the conduit should properly enter, and be secured to all fittings, and the entire system mechanically secured in position. In case of service connections and main runs, this involves running each conduit continuously into a main cut-out cabinet or gutter surrounding the panelboard, as the case may be. It should be first installed as a complete conduit system, without the conductors. It should be equipped at every outlet with an ap- proved outlet box or plate. At exposed ends of conduit (but not at fixture outlets) where wires pass from the conduit system without splice, joint or tap, an approved fitting having separately bushed holes for each conductor should be used. Outlet plates should not be used where it is prac- ticable to install outlet boxes. For concealed work in walls and ceilings com- posed of plaster on wooden joists or stud construe 93 tion, outlet boxes or plates and also cut-out cab- inets should be so installed that that the front edge will not be more than one-fourth inch back of the finished surface of the plaster, and if this surface is broken or incomplete it should be repaired so that it will not show any gaps or open spaces around the edges of the outlet box or plate or of the cut-out cabinet. On wooden walls or ceilings, outlet boxes or plates and cut-out cabinets should be so installed that the front edge will either be flush with the finished surface or project there- from. This will not apply to concealed work in walls or ceilings composed of concrete, tile or other non-combustibile material. In buildings already constructed where the con- ditions are such that neither outlet box nor plate can be installed, these appliances may be omitted, providing the conduit ends are bushed and secured. It is suggested that outlet boxes and fittings hav- ing conductive coatings be used in order to secure better electrical contact at all points throughout the conduit system. Metal conduits where they enter junction boxes, and at all other outlets, etc., should be provided with approved bushings or fastening plates fitted so as to protect wire from abrasion, except when such protection is obtained by the use of approved nipples, properly fitted in boxes or devices. The metal of the conduit should be permanently and effectually grounded to water piping, gas pip- ing or other suitable grounds, provided that when connections are made to gas piping, they are on the street side of the meter. If the conduit system 94 consists of several separate sections, the sections should be bonded to each other, and the system grounded, or each section may be separately grounded, as required above. Where short sections of conduit (or pipe of equivalent strength) are used for the protection of exposed wiring on side walls, the conduit or pipe need not be grounded. Conduits and gas pipes should be securely fast- ened in outlet boxes, junction boxes and cabinets, so as to secure good electrical connections. If conduit, couplings, outlet boxes, junction boxes, cabinets or fittings, having protective coat- ing of non-conducting material such as enamel are used, such coating should be thoroughly removed from threads of both couplings and conduit, and such surfaces of boxes, cabinets and fittings where the conduit or ground clamp is secured in order to obtain the requisite good connection. Grounded pipes should be cleaned of rust, scale, etc., at place of attachment of ground clamp. Connections to grounded pipes and to conduit should be exposed to view or readily accessible, and should be made by means of approved ground clamps to which the ground wires should be sol- dered. Ground wires should be of copper, at least No. 10 B. & S. gage (where largest wire contained in conduit is not greater than No. o B. & S. gage), and need not be greater than No. 4 B. & S. gage (where largest wire^ contained in conduit is greater than No. o B. & S. gage). They should be protected from mechanical injury. All elbows or bends should be so made that the 95 conduit will not be injured. The radius of the curve of the inner edge of any elbow not to be less than three and one-half inches. There should be not more than the equivalent of four quarter bends from outlet to outlet, the bends at the outlets not being counted. CONDUIT WIRING. All conductors for this class of work should be approved rubber covered. Single wire for conduits must comply with the requirements and in addition there should be a second outer fibrous covering, at least one thirty- second of an inch in thickness for wires larger than No. 10 B. & S. gage, and at least one sixty-fourth of an inch in thickness for wires No. 10 B. & S. gage' or less in size; this fibrous covering to be sufficiently tenacious to withstand abrasion of being hauled through the metal conduit. For twin or duplex wires in conduit each con- ductor must comply with requirements and in addi- tion there must be a second outer fibrous covering, at least one thirty-second of an inch in thickness for wires larger than No. 10 B. & S. gage, and at least one sixty-fourth of an inch in thickness for wires No. 10 B. & S. gage or less in size; this fibrous covering to be sufficiently tenacious to with- stand abrasion of being hauled through the metal conduit. For concentric wire, the inner conductor should comply with the requirements and there should be outside of the outer conductor the same insulation as on the inner, the whole to be covered with a sub- stantial braid, which should be at least one thirty- 96 second of an inch in thickness, and sufficiently tenacious to withstand the abrasion of being hauled through the metal conduit. The braids or tapes should be properly saturated with a preservative compound. The braid or tape required around each conductor in duplex, twin and concentric cables is to hold the rubber insulation in place and prevent jamming and flattening. No wires should be drawn into conduits until all mechanical work on the building has been done. Conductors in vertical conduit risers should be supported within the conduit system in accordance with the following table: No. 14 to o every 100 feet. No. oo to oooo .every 80 feet. oooo to 350,000 C. M. every 60 feet. 350,000 C. M. to 500,000 C. M. every 50 feet. 500,000 C. M. to 750,000 C. M. every 40 feet. 750,000 C. M. every 35 feet. The following methods of supporting cables are recommended : 1. A turn of 90 degrees in the conduit system will constitute a satisfactory support. 2. Junction boxes may be inserted in the con- duit system at the required intervals, in which in- sulating supports of approved type must be installed and secured in a satisfactory manner so as to with- stand the weight of the conductors attached thereto, the boxes to be provided with proper covers. 3. Cables may be supported in approved junc- tion boxes on two or more insulating supports so placed that the conductors will be deflected at an 97 angle of not less than 90 degrees, and carried a distance of not less than twice the diameter of the cable from its vertical position. Cables so sus- pended may be additionally secured to these insu- lators by tie wires. For alternating systems, the two or more wires of a circuit should be drawn in the same conduit. It is suggested that this be done for direct cur- rent systems also, so that they may be changed to alternating systems at any time, induction troubles preventing such a change if the wires are in sepa- rate conduits. Fixtures should, when supported from the gas piping of a building, be insulated from the gas pipe system by means of approved insulating joints (see page 107) placed as close as possible to the ceiling, and the wires near the gas pipe above the insulating joint should be protected from possible contact by the use of porcelain tubes. All burrs or fins should be removed from the fix- tures before the wires are drawn in. The tendency to condensation within the pipes should be guarded against by sealing the upper end of the fixture. In combination fixtures, where the wiring is con- cealed between the inside pipe and outer casing, the space between pipe and casing should be at least a quarter of an inch to allow plenty of room for the insulation of the wires without jamming. Fixtures should be tested for "contacts" between conductors and fixtures, for "short-circuits" and for ground connections before it is connected to its supply conductors. Ceiling blocks of fixtures should be made of in- sulating material ; if not, the wires in passing through the plate should be surrounded by porce- lain tubes, which should extend below the insulating joint. When fixtures have canopies against plaster in fireproof buildings, or where wire lath or metal ceiling or metal wall finish is used, the canopies should be thoroughly and permanently insulated from such walls or ceilings by approved canopy insulators. (See illustration on page 107.) Rosettes. These fittings should not be located where inflammable flyings or dust will accumulate on them. Bases should be high enough to keep the wires and terminals at least one-half inch from the surface to which the rosette is attached. Terminals with a turned up lug to hold the wire or cord should be used, and in no case must the wire be cut or injured. Fused rosettes are not ad- vised for use where cords can be properly protected by line cut-outs, and where necessary those equipped with enclosed fuses are recommended. If fused rosettes are used the next fuses back should not be over 25 amperes capacity. Fixture Wiring should be done with approved fixture wire. The voltage should never exceed 300 on wires in fixtures. Although No. 18 "rubber covered" is allowable in fixture work, it is preferable to use nothing smaller than No. 16, if practicable, for mechanical reasons. Supply conductors, and especially the splices to fixture wires, should be kept clear of the grounded part of gas pipes, and where shells are used the latter should have area enough to prevent 99 pressing the wires against the gas pipe when finally in place. Flexible Cord should be made of stranded cop- per conductors, no single strand should be larger than No. 26 or smaller than No. 36 (B. & S. gauge) and each conductor should be covered by an ap- proved insulation and be protected from mechanical injury by a tough braided outer covering. When used for pendant lamps it should hang freely in air and so placed that there is no chance of its coming in contact with anything excepting the lamp socket to which it is attached and the rosette from which it hangs. Each stranded conductor should have a carrying capacity equivalent to not less than a No. 1 8 (B. & S. gauge) wire. The covering of the stranded wires for flexible cord should first have a tight, close wind of fine cotton, which is intended to prevent any broken strand from piercing the insu- lation and causing a short circuit or ground. Sec- ondly it should have a solid waterproof insulation at least one thirty-second of an inch thick. The outer protecting braiding should be so put on and sealed in place that when cut it will not fray out. Approved flexible cord may be had from any of the makers mentioned on pages 66 and 67. Flexible cord should not be used as a support for clusters, as it is not strong enough; and it should never be used for anything other than pendants, wiring of fixtures and portable lamps, portable motors or small light electrical apparatus. Where used for "portables" it should have a special outer covering. Flexible cord should never be used in show win- 100 dows, as a defective- piece might cauce a -short cir- cuit and set fire to flints}' 'material or decorations. Many fires have been caused by the use of flexible cord in show windows, where handkerchiefs, deco- rations, etc., have been pinned to the cord. When the current is "turned on" short circuits are caused by the pins, and a fire is the result. Armored cables, however, may be used for this class of work and are made by the following companies : Boston Ins. Wire & Cable Co., Boston; Columbia Metal Hose Wks., Bayonne, N. J. ; Eastern Flexible Conduit Co., Brooklyn, N. Y. ; Flexible Conduit Co., Pen Yan, N. Y. ; National Metal Molding Co., Pittsburg, Pa.; Pratt Chuck Co., Frankfort, N. Y. ; Safety-Armorite Conduit Co., Pittsburg, Pa.; Sprague Electric Wks. of G. E. Co., New York; Trenton Electric & Conduit Co., Trenton, N. J. ; Western Conduit Co., Youngstown, O. Insulating bushings should be used where cords enter lamp sockets and desk stand lamps. Flexible cord should be so suspended that the entire weight of the socket, lamp and shade will be borne by knots under the bushing in the socket, and above the point where the cord comes through the ceiling block or rosette, in order that the strain may be taken from the joints and binding screws. It is good practice to always solder the ends of flexible cords which are going under binding screws, as it holds the strands together and pre- vents the pressure of the screws from forcing the strands from under them, and against the shell of the socket, causing a ground on the shell, or shore circuit. Where it becomes necessary to solder a great number of ends, as may be required when wiring a factory, use a small pot of melted solder and dip the ends of the wire, which have all been previously cut to the proper length and fluxed with a good soldering paste or solution. 101 Standard, L4n>p .SocketsshouM be plainly marked with the' watts and volts which apply to their class and with either the manufacturer's name or regis- tered trade mark. The inside of the shell of the socket should have an insulating lining which should absolutely prevent the shell from becoming a part of the circuit even though a wire or strand inside the socket should become loose or come out from under a binding screw. This insulating lin- ing should be at least one-thirty-second of an inch thick and of a tough and tenacious material. Special Lamp Sockets. In rooms where inflam- Waterproof Keyless Socket to be user in dye houses and damp places. mable gases may exist, both the socket and lamp should be enclosed in a vapor-tight globe and sup- ported on a pipe-hanger and wired with "Rubber Covered" wire, soldered directly to the circuit. No fuses or switches of any sort should be used in the room in such cases as the slightest arc might pro- duce dangerous explosions or fires. 102 Splicing should be done as described on page 40, in fact all wires, for this class of work, should be joined in this thorough manner and soldered. In damp or wet places, such as dye houses breweries, etc., a waterproof socket such as shown on page 91, should be used. Waterproof sockets should be hung by separate stranded rubber-cov- ered wires, not smaller than No. 14 (B. & S.). These wires, should be soldered direct to the circuit wires, but supported independently of them. All sockets for the above conditions should be keyless. Stranded Wires in every case should be sol- dered together before being clamped under binding screws, and when they have a conductivity greater than No. 10 (B. & S.) copper wire, they should be soldered into lugs. Stranded wires if not thus stiffened before being clamped under binding posts are liable to be pressed out or easily worked loose, making a poor contact, which causes heating, a possibility of arcing or a complete burn out. Dos- sert approved solderless lugs may be used. Automatic Cut-Outs such as circuit breakers and fuses should be placed on all service wires as near as possible to the point where they enter the building, on the inside of the walls, and arranged to cut off the entire current from the building. The cut-out or circuit breaker should always be the first thing that the service wires are connected to after entering the building; the switch next, and then the other fixtures or devices in their order. This arrangement is made so that the cut-out or circuit-breaker will protect all wiring in the build- 103 ing, and the opening of the switch will disconnect all the wiring. (See cuts on pages 33-38.) These automatic cut-outs should not, however, be placed in the immediate vicinity of easily ignit- ible stuff, or where exposed to inflammable gases or dust, or to flyings of combustible material, as the arcing produced whenever they break the circuit Circuit Breaker. The New I-T-E Circuit Breaker with Time Limit Feature. might cause a fire or explosion. When they are exposed to dampness they should be inclosed in a waterproof box or mounted on porcelain knobs. All cut-outs and circuit-breakers should be sup- ported on bases of non-combustible, non-absorptive insulating material. Link fuses should never be used, they are obsolete and have been the cause of 104 no end of fires and troubles. Enclosed fuses are always preferable. Cut-outs should operate successfully under the most severe conditions they are liable to meet with in practice, on short circuits with fuses rated at 50 per cent, above, and with a voltage 25 per cent, above the current and voltage for which they are designed. Circuit breakers should also be designed to successfully operate under the severe conditions liable to be met with in practice, and when designed to carry less than 100 amperes must be able to op- erate successfully on a short circuit with a supply system having a capacity of 1,000 amperes. They must also stand 2,000 volts A. C. for one minute between ground and live metal parts. All cut-outs and circuit breakers should be plainly marked, and where it will always be visible, with the name of the maker, and current and voltage for which the device is designed. Cut-outs or circuit breakers should be placed at every point where a change is made in the size of wire, unless such a device in the larger wire will protect the smaller. They should never be placed in canopies or shells of fixtures, but should be so placed that no set of incandescent lamps, whether grouped on one fixture or several fixtures or pend- ants, requiring more than 660 watts should be de- pendent upon one cut-out. Special permission may be given in writing by the Inspection Department having jurisdiction in case extra large or special chandeliers are t9 be used. Fuses for cut-outs should not have a capacity to exceed the carrying capacity of the wire, and where circuit breakers- 105 are used they should not be set more than 30 pel cent, above the allowable carrying capacity of the wire, unless a fusible cut-out is also installed in the circuit as shown in the illustration on page 33. Excepting on main switchboards, or where they are at all times subject to expert supervision, circuit, breakers should never be used as a protection to a circuit without the additional use of enclosed fuse cut-outs. Circuit breakers open at exactly the current they are set for and instantly, therefore it is necessary to set them considerably above the ordinary amount of current required to keep them from constantly opening on slight fluctuations. When this is the case a double-pole fusible cut-out should be added to protect the wire from a heavy, steady current, which may be maintained just below the opening point of the circuit breaker. The fuse requires a little time to heat, and would not therefore blow out with a momentary rise of current which might open the circuit breaker if set as low as necessary to protect the wire, which may be of a size only large enough for the figured amount of current under ordinary conditions of operation. If, how- ever, in the case of motor-wiring, the size of wire is 25 per cent, above the figured size for the motor's average current, as it should be, then the intro- duction of a fusible cut-out in addition to the cir- cuit breaker is unnecessary, as is shown in the illustration on page 35. Insulating Joints should be made entirely of material that will resist the action of illuminating gases, and will not give way or soften under the 106 heat of an ordinary gas flame, or leak under a moderate pressure and able to withstand 4,000 volts for five minutes. They should be so arranged that a deposit of moisture will not destroy the insulating effect, and should have an insulation resistance of at least 250,000 ohms between the gas pipe attachments, and be sufficiently strong to resist the strain they will be liable to be subjected to in being installed. Insulating joints should not contain any soft rubber in their composition. The insulating mate- A Macallen Insulating Joint. B Macallen Canopy and Insulating Joint in Position. C Macallen Canopy Insulator .rial should be of some hard and durable material such as mica. Insulating Resistance. The wiring in any build- ing should test free from grounds, i. e., the com- plete installation should have an insulation between conductors and between all conductors and the ground (not including attachments, sockets, recep- tacles, etc.) of not less than the following: Up to 5 dinperes 4,000.000 ohms. 10 " 2,000,000 " 25 ' " , 800,000 " 107 Up to 50 amperes 400,000 ohms. 100 " 200,000 200 " 100,000 400 " 50,000 800 " 25,000 " 1,600 " and over... 12,500 Al cut-outs and safety devices in place in the above when the tests are made. Where lamp sockets, receptacles and electroliers, etc., are connected, one-half of the above will be sufficient. (See page 51 for method.) Knife Switches (Specifications). Hinges of knife switches should not be used to carry current unless they are equipped with spring washers, held by locked nuts or pins so arranged that a firm and secure connection will be maintained at all positions of the switch blades and unless they are connected in circuit so that the blades will not be alive when the switch is open. The bases of all switches should be made of non- combustible, non-absorptive insulating material, such as slate, marble or porcelain. Switches for currents of over 30 amperes should be equipped with lugs firmly screwed or bolted to the switch and into which the conducting wires should be soldered. For J:he smaller size switches simple screws can be employed provided they are heavy enough to stand considerable hard usage. Holes for inserting screws for supporting the switch should not be placed between contacts of opposite polarity. Pieces carrying the contact jaws should be se- cured to the base by at least two screws or else 108 rnade with a square shoulder or equipped with dowel pins to prevent possible turnings and the nuts or screw heads on the under side of the base should be countersunk not less than one-eighth inch and covered wifli a waterproof compound which will not melt below 150 degrees Fahrenheit. All cross-bars less than three inches in length should be made of insulating material. Bars of three inches and over which are made of metal to insure greater mechanical strength should be suffi- ciently separated from the jaws of the switch to prevent arcs following from the contacts to the bar on the opening of the switch under any circum- stances. Metal bars should preferably be covered with insulating material. All switches should have ample metal for stiff- ness and to prevent rise in temperature of any part of over 50 degrees Fahrenheit at full load, the con- tacts being arranged so that a thoroughly good bearing at every point is obtained with contact sur- faces advised for pure copper blades of about one square inch for each 75 amperes; the whole device should be mechanicaly well made throughout. The following table shows minimum break dis- tances and separation of nearest metal parts of opposite polarity for different voltages and differ- ent currents. The values given are correct for switches to be used on direct cuirent systems and can therefore be safely followed in devices designed for alternating currents. All switches should be plainly marked, where it can be read, when the switch is installed, with the name of the maker and. the current and voltage for which the switch is designed. 109 KNIFE SWITCH DIMENSIONS Minimum Separation of Minimum Nearest Metal Parts of Break- Opposite Palarity. Distance. 125 VOLTS OR LESS: For Switchboards and Panel Boards: 10 amperes or less H inch y 2 inch. 11-30 amperes 1 ' H ' 60 " 1J4 " 1 For Individual Switches: 30 amperes 1 1 A inch 1 inch. 60-100 " l l / 2 " 1J4 " 200-300 " 2% " 2 400-600 " 2}4 " 2*/ 2 ' 800-1000 " 3 " 2& " 250 VOLTS D. C, AND NOT OVER 500 VOLTS A. C: For all Switches: 31-100 amperes 2J4 inch 2 inch. 200-300 " 2y 2 " 2J4 " 400-600 " 2^ " 2J4 " 800-1000 " 3 " 2J4 " A 300-ampere switch with the spacings of the 200-ampere switch above may be used on switchboards. Cut out terminals on switches for over 250 volts must be designed and spaced for 600-volt fuses. 600 VOLTS : For all Switches: 30-60 amperes 4 inch 3 l / 2 inch. 100 " 4J4 " 4 Auxiliary contacts of either a readily renewable or a quick-break type or the equivalent are recom- mended for D. C. switches, designed for over 250 volts, and should be provided on D. C. switches de- signed for use in breaking currents greater than 100 amperes at a voltage of over 250. For 3-wire direct current and 3-wire single phase systems the separation and break distances for plain 3-pole knife switches should not be less than those required in the above table for switches designed for the voltage between neutral and outside wires, no Knife Switches (Installation). Switches should be placed on all service wires, either overhead -or underground, in the nearest readily accessible place to the point where the wires enter the build- ing, and arranged to cut off the entire current. Service cut-out and switch should be arranged to cut off current from all devices including meters. In risks having private plants the yard wires running from building to building are not consid- ered as service wires, so that switches would not be required in each building if there are other switches conveniently located on the mains or if the generators are near at hand. Switches should always be placed in dry, acces- sible places, and be grouped as far as possible. Single-throw knife switches should be so placed that gravity will not tend to close them. Double- throw knife switches may be mounted so that the throw will be either vertical or horizontal as pre- ferred, but if the throw be vertical a locking device should be provided, so constructed as to insure the blades remaining in the open position when so set. When practicable switches should be so wired that blades will be "dead" when switch is open. When switches are used in rooms where com- bustible flyings would be likely to accumulate around thefn, they should be enclosed in dust-tight cabinets. Up to 250 volts and thirty amperes, approved in- dicating snap switches are suggested in preference to knife switches on lighting circuits. Single pole switches should never be used as service switches nor for the control of outdoor 111 signs or circuits located in damp places, nor placed in the neutral wire of a three-wire system, except in the two-wire branch or tap circuit supplying not more than 660 watts. Three-way switches are considered as single pole switches. Where flush switches or receptacles are used, whether with conduit systems or not, they should An Approved Double Pole Knife Switch, Showing Terminals for Approved Enclosed Fuses. Always install so that the handle will be up when circuit is closed. be enclosed in an approved box constructed of iron or steel, in addition to the porcelain enclosure of the switch or receptacle. Where in floor outlets attachment plugs are liable to mechanical injury, or the presence of moisture is probable, floor outlet boxes especially designed for this purpose should be used. Where possible, at all switch or fixture outlets, 118 unless outlet boxes which will give proper support for fixtures are used, a seven-eighths inch block should be fastened between studs or floor timbers flush with the back of lathing to hold tubing, and to support switches or fixtures. When this cannot be done, wooden base blocks, not less than three- fourths inch in thickness, securely screwed to lath- ing, or approved fittings or plates -designed for the service, should be provided for switches, and also for fixtures which are not attached to gas pipes or conduit. Sub-bases of non-combustible, non-absorptive, insulating material, which will separate the wires at least one-half inch from the surface wired over, should be installed under all snap switches used in exposed knob and cleat work. Sub-bases should also be used in moulding work, but they may be made of hardwood or they may be omitted if the switch is approved for mounting directly on the moulding. Flush Switches. Where gangs of flush switches are used, whether with conduit systems or not, the switches should be enclosed in boxes con- structed of, or lined with, fire-resisting material. Where two or more switches are placed under one plate, the box should have a separate compart- ment for each switch. No push buttons for bells, gas-lighting circuits, or the like, should be placed in the same wall plate with switches controlling electric .light or power wiring. Snap Switches like knife switches, should al- ways be mounted on non-combustible, non-absorp- tive insulating bases, such as slate or porcelain, and 118 should have carrying capacity sufficient to prevent undue heating. When used for service switches they should in- dicate at sight whether the current be "on" or "off." Indicating switches should be used for all work to prevent mistakes and possible accidents. The fact that lights do not burn or the motor does not run is not necessarily a sure sign that the current is off. Every switch, like every other piece of electrical apparatus, should be plainly marked where it is always visible with the maker's name and the cur- rent and voltage for which it is designed. On constant potential systems, these switches, like knife switches, should operate successfully at 50 per cent, overload in amperes with 25 per cent, excessive voltage under the most severe conditions they are likely to meet with in practice. They should have a firm contact, should make and break readily, and not "stop when motion has once been imparted to the handle. On constant current systems, they should close the main circuit and disconnect the branch wires when turned "off"; should be so constructed that they will be automatic in action, not stopping be- tween points when started and should prevent an arc between the points under all circumstances. LAMP DATA The illumination given by one candle at a dis- tance of one foot is called the "candle foot," and is taken as a unit of intensity. In general, inten- sity of illumination should nowhere be less than one candle-foot, and the demand for light at the- 114 INCANDESCENT LAMP DATA CARBON I.AMPS Volts Watts C. P. W. P. C. Amps. Hot Res 110 10 20 30 50 60 2-0 4.8 9.3 16.8 20-2 5.00 4-15 3.23 2.97 2.97 0.191 0-182 0.273 0.455 0.546 1210.00 605.00 403.00 242.00 201 .80 220 30 - 35 60 5.1 8.0 16.3 5.90 4-40 3-69 0. 1363 0.159 0-273 1613.3 1382.00 806-00 GEM LAMPS (METALLIC FILAMENT) Volts Watts C. P. W. P. C. Amps. Hot Res. 110 20 30 40 50 60 80 100 5.0 10.0 156 20.0 24.0 325 40.7 4.00 3.00 2.56 2.50 2.50 2.46 2.46 0.1818 0.273 0.364 0.455 0.546 1.727 1.909 605.0 403.3 302.0 242.0 201.5 151.4 121.0 MAZDA (VACUUM) LAMPS Volts Watts C. P. W. P. C. Amps. Hot Res. 110 10 7.7 1.30 0.0909 1210.0 15 13.0 1.15 0.1363 807.0 20 18.2 1.10 01818 605.0 " 25 23.8 1.05 0.227 484.0 40 38.8 1.03 0.364 302.5 60 60.0 1.00 0.546 201.7 100 105.0 .95 0.909 121.0 150 167*.0 .90 1.363 80.7 " 250 278.0 .90 2.272 48.4 " 400 444.0 .90 3.640 30.2 " 500 556.0 .90 4.550 24.2 MAZDA (TYPE C) LAMPS (GAS FILLED) Volts Watts C. P. W. P. C. Amps. Hot Res. 110 200 300 400 500 750 1000 250.0 385.0 533.0 714.0 1250.0 1820.0 0.80 0.78 0.75 0.70 0.60 0.55 1.82 2.73 3.64 4.55 6.82 9.09 60.5 40.3 30.3 24.2 16.1 12.1 220 25 40 60 100 150 250 500 19.2 33.3 50.0 90.9 143.0 250.0 556.0 130 1.20 1.20 1.10 . 1.05 1.00 1.00 0.1136 0.1818 0.273 0.455 0.682 1.136 2.273 1936.0 1210.0 807.0 484.0 322.0 193.6 96.7 115 The tables below show the variation in the life and candle-power of incandescent lamps with various percentages of decrease and increase -of rated voltages CARBON FILAMENT LAMP VARIATIONS. % Volts % C. P. % Amperes % Ohms % Watts % W. P.C. % Ufe 10 69.8 10.8 21.9 28.2 85.5 9 61.4 9.7 19.5 25.9 82.6 8 534 8.5 172 23.5 79.0 > 1 5.4 1.2 jB 2.1 3.6 22.5 2 10.6 2.1 **3 4.1 7.3 50.5 3 15.5 3.2 a 6.1 11.2 85.3 % 4 g *03 % 4 ' 2 % 8 -l o 15.3 v 1289 8 5 S 24.8 5.4 3 10.1 19.6 < 180.0 b 6 g 29 o: S 6.4 12.0 24.1 250.4 8 8 33.2 O 37.1 7.4 8.4 13.9 Q 158 o 28.8 S 33.8 336.0 5 442.0 9 40.7 9.5 17.7 39.0 578.0 10 44.3 10.7 19.6 44.4 747.0 METAL FILAMENT LAMP VARIATIONS. % Change in Voltage % C. P. Mazda [Vacuum) % Watts Mazda (Vacuum) % C. P. Mazda (Type C.) % Watts Mazda (Type C.) % C. P. Gem % Watts Gem 10 39.7 16.3 36.3 15.9 58.0 18.4 9 35.3 14.6 32.3 14.3 51.3 16.5 8 31.0 12.9 28.4 12.7 44.7 14.6 7 v 26.8 4> 11.3 a, 24.6 A S 5 I 7 | r i S i*2 61-100 IOI-2OO 201-400 126 CURRENT REQUIRED TO FUSE WIRES OF COPPER, GERMAN SILVER AND IRON. B. &S. Gauge. 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 2P 30 31 32 33 34 35 36 37 38 39 40 German Copper, Silver, Iron, Amperes. Amperes. Amperes. 333. 169. 101. 284. 146. 86. 235. 120.7 71.2 200. 102.6 63. 166. 85.2 50.8 139. 71.2 42.1 117. 60. 35.5 99. 50.4 32.6 82.8 *2.5 25.1 66.7 34.2 20.2 58.3 29.9 17.7 49.3 25.3 14.9 41.2 21. 1 12.5 34.5 17.7 10.9 28.9 14.8 8.76 24.6 12.6 7.46 20.6 10.6 6.22 17.7 9.1 5.36 14.7 7.6 4.45 12.5 6.41 3.79 30.25 5.26 3.11 8.75 4.49 2.65 7.26 3.73 2.2 6.19 3.18 1.88 5.12 2.64 1.55 4.37 t.24 1.33 3.62 1.86 1.09 3.08 1.58 .93 2.55 1.31 .77 2.20 1.13 .67 1.86 .95 .56 The above cut illustrates the manner in which harder metal tips should be attached to fuse wire. 127 LINK FUSES. Should have contact surfaces or tips of harder metal, having perfect electrical connections with the fusible part of the strip. The use of the hard metal tip is to afford a strong mechanical bearing for the screws, clamps, or other devices provided for holding the fuse. They should be stamped with about 80 per cent, of the maximum current which they can carry in- definitely, thus allowing about 25 per cent, overload before the fuse melts. With naked open fuses, of ordinary shapes and with not over 500 amperes capacity, the minimum current which will melt them in about five minutes may be safely taken as the melting point, as the fuse practically reaches its maximum temperature in this time. With larger fuses a longer time is necessary. Fuse terminals should be stamped with the mak- er's name or initials, or with some known trade- mark. Cabinets. Should in all cases be made amply strong and rigid to keep their shape, permitting their doors to close tightly, and making it possible to install the wiring and conduit properly. Cabi- nets may be constructed of cast or sheet metal, wood or approved composition. Wood or com- position cabinets should not be used when con- nected with metal conduit, metal moulding, or armored cable systems. All metal cabinets should be thoroughly painted or treated to prevent rust or corosion. 128 Wooden Cabinets. Wood should be well sea- soned and at least three-fourths inch thick, and be thoroughly filled and painted, and should be lined with a non-combustible material. In all cabinets, linings of slate, marble or ap- proved composition should be at least one-fourth inch thick and firmly secured in place; when metal is used for the lining it should be at least No. 16 U. S. gage in thickness. For lining wooden cabi- nets one-eighth inch rigid asbestos board may be used when firmly secured in place by screws or tacks. Metal Cabinets. If cast metal is used a thick- ness of at least one-eighth inch should be provided. Sheet metal should not be less than .0625 inch thick (No. 1 6 U. S. gage). In steel cabinets having an area of more than 360 square inches for any sur- face, or having a single dimension greater than 2 feet, sheet metal should be used at least No. 14 U. S. gage in thickness; in those having an area of more than 1,200 square inches for any surface, or having a single dimension greater than 4^-2 feet, the sheet metal should be at least No. 12 U. S. gage in thickness. Doors should shut closely at all edges against a rabbet formed as a part of the door or trim or have turned flanges at all edges. Hinges should be of strong and durable design. A substantial Jatch or catch should be provided so as to keep the door closed, and a lock may be used in addition to the catch if desired. When doors have glass panels the glass should 129 be at least one-eighth inch thick (commercial thick- ness), and should not have a greater area than 450 square inches unless plate glass at least one-fourth inch in thickness is used. Every cabinet should be marked with manufac- turer's name, where the name can be plainly seen when the cabinet is installed. Arc Lamps should be carefully isolated from in- flammable material, should be provided at all times with a glass globe surrounding the arc and se- curely fastened upon a closed base. No broken or cracked globes should be used, as they are designed to prevent hot bits of' carbon or even an entire carbon from falling to the floor should it fall from the carbon holder. All globes for inside work should be covered with a wire netting 'having a mesh not exceeding one and one-quarter inches, to retain the pieces of the globe in position should the latter become broken from any cause. A globe thus broken should be replaced at once. When arc lamps are used in rooms containing readily in- flammable material they should be provided with approved spark arresters, which should be made to fit so closely to the upper orifice of the globe that it will be impossible for any sparks thrown off by the carbons to escape. It is safe to use plain carbon and not copper-plated ones in such rooms, or better still, an enclosed arc lamp, one having its carbons enclosed in a practically tight glass globe which is inside the outer globe. Where hanger-boards are not used arc lamps should be 130 hung from insulating supports other than their con- ductors. All arc lamps should be provided with reliable tops to prevent carbons from falling out in case the lamps become loose, and all exposed parts should be carefully insulated from the circuit. Each lamp for constant current systems, should be provided with an approved hand switch, and also an auto-, matic switch that will shunt the current around the carbons, so that the lamp will thus cut itself out of circuit should the carbons fail to feed properly. If the hand switch is placed anywhere except on the lamp itself it should comply in every respect with the requirements for switches on hanger- boards as described under the latter heading. Arc Light Wiring (High Potential). All wir- ing for high potential arc lighting circuits should be done with "Rubber Covered" wire. The wires should be arranged to enter and leave the building through an approved doubled contact service switch which should close the main circuit and disconnect the wires in the building when turned "off" and be so constructed that they will be automatic in their action, not stopping between points when started and to prevent arcing between points under any circumstances, and should indicate plainly whether the current is "on" or "off." Never use snap switches for arc lighting circuits. All arc light wiring of this class should be in plain sight and never enclosed, except when required, and should be supported on porcelain or glass insulators which separate the wires at least one inch from the sur- 131 face wired over. The wires should be kept rigidly at least eight inches apart, except of course within the lamp, hanger-board or cut-out box or switch. On side walls the wiring should be protected from mechanical injury by a substantial boxing, retain- ing an air space of one inch around the conductors, closed at the top (the wires passing through bushed holes), and extending not less than seven feet from the floor. When crossing floor timbers in cellars or in rooms, where they might be exposed to injury, wires should be attached by their insulating sup- ports to the under side of a wooden strip not less than one-half an inch in thickness. Arc Lamp on Low Potential Circuits should have a cut-out for each lamp or series of lamps. The branch conductors for such lamps should have a carrying capacity about 50 per cent, in excess of the normal current required by the lamp or lamps to provide for the extra current required when the lamps are started or should a carbon be- come stuck without over-fusing the wires. If any resistance coils are necessary for adjustment or regulation, they should be enclosed in non-combus- tible material and be treated as. sources of heat ; it is preferable that such resistance coils be placed within the metal framework of the lamp itself. Incandescent lamps should never be used for re- sistance devices. These lamps should be provided with globes and spark arresters, as in the case of arc lamps on high-potential series circuits, except when the enclosed arc lamps are used. Economy Coils or compensator coils for arc lamps should be mounted on glass or porcelain, al- 132 lowing an air space of at least one inch between frame and support, and in general to be treated like sources of heat. Hanger Boards should be so constructed that all wires and current-carrying devices thereon will be exposed to view and thoroughly insulated on non- combustible, non-absorptive insulating substance, such as porcelain. All switches attached to the hanger-board should be so constructed that they will be automatic in their action, cutting off both poles to the lamp, not stopping between points under all circumstances. Electric Heaters should always be treated as sources of heat and kept away from inflammable materials. Each heater should have a cut-out and indicating switch and all attachments from the feed wires to the heater should be kept in plain sight, easily accessible arid protected from interference. Each heater should have a name plate giving the maker's name, and the normal capacity in volts and amperes. Car House Wiring. All trolley wires in car houses should be securely supported on insulating hangers. The trolley hangers should be placed close enough together to prevent the trolley wire, should it break from any cause, from coming in contact with the floor or rails within the building, or even in contact with the ironwork on the trucks or wheels of the car, as it hangs down. A broken trolley wire in this way would produce dangerous arcing and probably start a fire. All the wires in the car house should be con- 133 trolled by a cut-out switch, located on a pole at least 100 feet from the building, so that in case of fire or for other reasons all wires could be con- trolled from that point. The current should al- ways be cut out of the car house when the same is not in use or the road not in operation. All lamps and stationary motors used in car houses should be installed in such a way that one main switch can control the whole of each installation independently of the main feeder switch. No port- able incandescent lamps or twin wire should be used, except in the car pits, where they may be used when connections are made by two approved rub- ber-covered flexible wires, . properly protected against mechanical injury, and all such pit wiring be controlled by a separate switch for each pit placed outside of the pit. All wiring for lights or motors within the car house should be with ap- proved rubber-covered wire and supported on sin- gle porcelain or glass insulators which separate the wires from surface wired over by one inch. No system of feeder distribution should center in the car house. All rails within the building should be bonded at each joint with annealed copper wire, not smaller than No. oo B. & S. gage. When cars are run in the house they should not be left with their trolleys in contact with the trol- ley wire, as frequent fires have been caused by the motorman or conductor forgetting to turn off the car heater current or other car wiring, and during the course of the night, or other times, "burn-outs" 1S4 have occurred, followed by fire, and, as once hap- pened in the course of the writer's experience, the total loss of a large car house and a number of valuable cars and other stock. Current from trol- ley systems, having a grounded return wire, should never be used for any purpose in or on buildings other than car houses or their power stations. Approved Apparatus and Supplies. Every ar- ticle or fitting intended for use in electrical wiring or construction or in connection therewith should, before being manufactured or placed upon the mar- ket, be submitted to the Underwriters' Laboratories, 207 East Ohio street, Chicago, for examination and report. Branch offices are located in thirty-two other cities of the United States and Canada. The New York office, at 135 William street, is equipped for the conduct of examinations and tests of all electrical devices under the same conditions as those afforded at the principal office and testing station in Chicago. The amounts of the fees are in proportion to the nature and extent of the work required in exam- inations and tests. When such article or device is approved and found safe and suitable for the use intended, it is placed on the List of Electrical Fit- tings issued semi-annually by the National- Board of Fire Underwriters, for use in accordance with the rules and requirements of the National Elec- trical Code as given in the foregoing pages of this book. When buying electrical supplies of any descrip- tion make sure that they have been approved, or that their use will be permitted. If there is any 135 question about it, make your supply dealer, or the manufacturer give you a guarantee that they will be approved by the Fire Underwriters' Inspector if installed in accordance with the rules and require- ments of the National Electrical Code. Electrical Inspection. The principal points re- garding the safe installation of dynamos, motors, ^ outside and inside wiring, as required by the insur- ance underwriters, have been briefly set forth in this little book, which has been compiled simply for reference and not as a teacher a book designed to settle most of the doubtful questions which might arise on the mind of the engineer or contractor as to just what will be considered safe by insurance inspectors. There will probably arise questions which cannot be settled by reference to the sugges- tions herein contained, and, therefore-, a great deal has to be left to the judgment of the constructing engineer and inspector. In every such case the Inspection Department having jurisdiction should be consulted with perfect assurance that nothing unreasonable will ever be demanded in the way of special construction. Every piece of wiring or electrical construction work, whether open or concealed, should be in- spected, and notice, therefore, should always be sent by the contractor or engineer to the board hav- ing jurisdiction immediately upon completion of any work. Negligence in this matter has frequent- ly caused 'floors to be torn up when doubtful work- has been suspected, and at the cost of the parties who installed the wiring. 136 WIRE TABLE, STANDARD ANNEALED' COPPER. Case No. B. & S. Diameter in Mils at 20 C Cross Section Circular Mils Ohms per 1000 Feet * C (=32" F) 20 C (=68 F) 50 C (=122 F) 0000 000 00 460.0 409.6 364.8 211 600. 167 800. 133 100. 0.045 Ib .0.36 .3 5.615 50 . 13 39.57 31.52 90.6 40.4 03.1 206.9 260.9 329.0 231.3 291.7 367.8 * Resistance af the stated temperatures of a wire whose length is 1000 feet at 20 C. (Bureau of Standards) 137 WIRE TABLE, STANDARD ANNEALED COPPER. . CONTINUED. Gage No. B. &S. Diameter in Mils at 20 C Pounds per 1000 Feet Feet per Ohm * C (=32 F) 20 C (=68 F) 20 400. 16 180 12 830. 50 C (=122 F) 18 250. 14 470. 11 480. 000 000 00 460.0 409.6 3t>4.8 340.5 507.9 402.8 22 140. 17 5fiO. 13 930. 1 2 324.9' J2S9.3 257.6 319.5 253.3 200.9 11 040. 8758. 6946. 10 180 8070. 6400. 9103. 7219. 5725. 3 4 5 229.4 204.3 181.9 159.3 126.4 100.2 5508. 4368. 3464. 5075. 4025. 3192. 4540. 3600, 2855. 6 7 8 162.0 144.3 128.5 79.46 63.02 49.98 2747. 2179. 1728. 2531. 2007. 1592. 2264. 1796. 1424. 9 10 11 114.4 101.9 90.74 39.63 31.43 24.92 1370. 1087. 861.7 1262. 1001. 794.0 1129. 895.6 710.2 12 13 14 80.81 71.96 64.08 19.77 15.68 12.43 683.3 541.9 429.8 629.6 499.3 396.0 563.2 446.7 354.2 15 16 17 57.07 50.82 45.26 9.858 7.818 6.200 340.8 270.3 214.3 314.0 249.0 197.5 280.9 2.2.8 176.7 18 19 20 40.30 35.89 31.96 4.917 3.899 3.092 170.0 134.8 106.9 156.6 124.2 98.50 140.1 111.1 88.11 21 22 23 28.46 25.35 22.57 2.452 1.945 1.542 84.78 67.23 53.32 78.11 61.95 49.13 69.87 55.41 43.94 24 25 26 20. JO 17.90 15.94 1.223 0.9699 .7692 42.28 -S3. 53 26.59 38.96 30.90 24.50 34.85 27.64 21.92 27 28 29 14.20 12.64 11.26 .6100 .4837 .3836 21.09 16.72 13.26 19.43 15.41 12.22 17.38 13.78 10.93 30 31 32 10.03 8.928 7.950 .3042 .2413 .1913 10.52 8.341 6.614 9.691 7.68") 6.095 8.669 6.875 5.452 33 34 35 7.0RO 6 . 305 5.615 .1517 .1203 .095 42 5.245 4.160 3.299 4.833 3 . 83^ 3.040 4.323 3.429 2.719 * Length at 20 C of a wire whose resistance is 1 ohm at the stated temperatures. (Bureau of Standards). 138 WIRE TABLE, STANDARD ANNEALED COPPER. CONTINUED. Gage No. B. &S. Diameter in Mils at 20 C Ohms per Pound C (=32 F) 20 C (=68 F) 50 C (=122 F) 0000 000 00 460.0 409.6 364.8 0.000 070 51 .000 1121 .000 1783 0.000 076 52 .000 1217 .000 1935 0.000 085 54 .000 1360 .000 2163 1 2 324.9 289.3 257.6 .000 2835 .000 4507 .000 7166 .000 3076 .000 4891 .000 7778 .000 3439 .000 5468 .000 8695 3 4 5 229.4 204.3 181.9 .001 140 .001 812 .002 881 .001 237 .001 966 .003 127 .001 383 .002 198 .003 495 6 7 8 162.0 144.3 128.5 .004 581 .007 284 .011 58 .004 972 .007 905 .012 57 .005 558 .008 838 .014 05 9 10 11 114.4 101.9 90.74 .018 42 .029 28 .046 56 .019 99 .031 78 .050 53 .022 34 .035 53 .056 49 12 13 14 80.81 71.96 64.08 .074 04 .1177 .1872 .080 35 .1278 .2032 .089 83 .1428 .2271 15 16 17 57.07 50.82 45.26 .2976 .4733 .7525 .3230 .5136 .8167 .3611 .5742 .9130 18 19 . 20 40.30 35 . 89 31.96 1.197 1.903 3.025 1.299 2.065 3.283 1.452 2.308 3.670 21 22 28 28.46 25.35 22.57 4.810 7.649 12.16 5.221 8.301 13.20 5.836 9.280 14.76 24 25 26 20.10 17.90 15.94 19.34 30.75 48.89 20.99 33.37 53.06 23.46 37.31 59.32 27 28 29 14.20 12.64 11.26 77.74 123.6 196.6 84.37 134.2 213.3 94.32 150.0 238.5 CO 31 32 10.03 8.928 7.950 312.5 407.0 790.3 339.2 539.3 857.6 379.2 602.9 958.7 33 34 35 7.080 6.305 5.615 1256. 1998. 3177. 1364. 216S. 3448. 1524. 2424. 3854. (Bureau of Standards) 139 WIRE TABLE, STANDARD ANNEALED COPPER CONTINUED Gasre No. B. &S. Diameter in Mils at 20 C Pounds per Ohm C (=32 F) 20 C (=68 F) 50 C (=122 F) 0000 000 00 460.0 409.6 364.8 14 180. 8920. 5610. 13 070. 8219. 5169. 11 690. 7352. 4624. (; 1 2 324.9 289.3 257.6 3528. 2219. 1395. 3251. 2044. 1286. 2908. 1829. 1150. 3 4 5 229.4 ?04.3 181. 9 877.6 551.9 347.1 .808.6 508.5 319.8 723.3 454.9 286.1 6 7 S 182.0 It4.3 128.5 218.3 137.3 86.34 201 .1 126.5 79 . 55 179.9 113.2 71.16 9 JO 11 114.4 101.9 90.74 54.30 34.15 21.48 50.03 31.47 . 19.79 44.75 28 . 1 5 17.70 12 13 14 80.81 71.96 64.08 13.51 8.495 5.342 12.45 7.827 4.922 11.13 7.001 4.403 15 16 17 57 . 07 50.82 45.26 3.360 2.113 1.329 3.096 1.947 1.224 2.769 1.742 1.095 18 19 20 40.30 35.89 31.96 0.8357 .5256 .3306 0.7700 .4843 .3046 0.6888 .4332 .2725 21 22 23 28.46 .2079 25.35 .1307 22.57 j .08222 .1915 .1205 .075 76 .1713 .1078 .067 77 24 25 26 20.10 .05171 17.90 .03252 15.94 ; .02045 .047 65 .029 97 .018 85 .042 62 .026 80 .016 86 27 28 29 14.20 ' .01286 12.64 .008090 11.26 .005088 , Oil 85 .007 454 .004 688 .010 60 .006 6C8 .004 193 30 31 32 10.03 8.928 7.950 .003200 .002 012 .001 266 .002 948 .001 854 .001 166 .002 637 .001 659 .001 043 33 34 35 7.080 6.305 5.615 .000 7959 .000 5005 .000 3148 .000 7333 .000 4612 .000 290" 1 .000 6560 ' .000 4126 .000 2595 (Bureau of Standards) 140 HOUSE WIRING. Special Suggestions and Recommendations to the House Owner, Architect, Contractor and Wweman, with the co-operation of the Na- tional Electric Light Association Committee on Wiring Existing Buildings and the Society for Electrical Development, in Accordance with the Rules and Requirements of the National Board of Fire Underwriters. Obtaining Service. In every case where the electric wires have not been introduced into a house, it is necessary to con- sult the central station as to the terms on which service can be obtained. When the wires are not even on the street it will always be necessary for the central station to make an extension, involving additional mains, as the electric wires in the street are called, and usually additional poles for overhead wires, or digging for conduits for underground wires. It may be noted here that the current for trolley service is not suitable for house lighting, nor is such service allowed by the insurance interests in any part of the country. No one but the central station representative can determine the cost of making an extension, and all that can be said in this general treatise is that some- times the central station will extend its wires with- out any guarantee, on the chance that the new busi- ness will be profitable. In other cases the prospec- tive customer is asked to guarantee a definite in- come for a term of years, or to make a deposit towards the cost of the extension, to be returned 141 out of the income ; or in extreme cases, even to pay the whole cost. Each case has to be considered separately; but in this country a somewhat general rule is to make extensions when the annual income, either estimated or guaranteed, is equal to about half the cost of the additional investment, or cost of the extension beyond the point to which the lines have been already built. In regard to whether the service is overhead or underground, this usually depends on the character of the neighborhood, dense city districts being sup- plied underground, and suburban or country dis- tricts overhead. If in a district where the wires are underground, the central station extends the mains along the street, and usually branches from the mains to the lot line without further charge for the branch. Sometimes the street construction is such that the house service comes from the wire directly oppo- site. In other cases there are manholes in the street at convenient intervals, and the wires run directly from such manhole to the house. Sometimes a charge is made by the central sta- tion for the whole of the branch to the house, but more usually there is no charge for the work in the public streets, and often the wire is carried free to the house wall, especially if the house is close to the street. If, however, there is a wide lawn a charge is often made, running from 75 cents to $1.50 per foot, according to circumstances. In the case of new houses it is often convenient to use the same trench or conduits for the telephone wires also, and sometimes even for the water pipe. 141 As the central station will always either do this underground work itself or furnish definite and complete specifications, no further reference need be made to it here. In the case of overhead wires questions about the extension of the central station wires in the street come up. The householder should appreciate that overhead wires are installed only in districts where the cost of underground is prohibitive, so that if the central station cannot obtain the right to set the necessary poles in such districts it may not be able to extend the wires at all. When the necessary poles are near enough the central station will usually run the wires from the pole to the house without further charge. In other cases, as when the house sets far back, or when for some special reason the wires have to enter the house in the rear, it may be necessary to set poles on the private property, for which work the central station will frequently make a charge, which should run from say $10 to $50, about $25 for each pole together with the wire, cross arms, insulators, etc. Of course, when the customer is willing to pay for it, the central station will run its wires down the pole into the ground and supply the house by an underground service, even in overhead districts. The Code rules governing outside work for both overhead and underground are as follows : ; a. Line wires must have an approved weather- proof or rubber insulating covering (see p. 67). That portion of the service wires between the main cut-out and switch and the first support from the 143 cut-out or switch on outside of the building must have an approved rubber insulating covering, but from the above-mentioned support to the line, ex- cept when run in conduit, may have an approved weatherproof insulating covering if kept free from awnings, swinging signs, shutters, etc. b. Must be so placed that moisture cannot form a cross connection between them, and except when run in conduit, not less than a foot apart] and not in contact with any substance other than their in- sulating supports. Wooden blocks to which insu- lators are attached must be covered over their entire surface zuith at least two coats of waterproof paint. For conduit work, zvires must be placed so as to conform to rules for unlined conduit except that conduit system must be waterproof (see p. 96). c. Must be at least seven feet above the highest point of flat roofs (see p. 43) and at least one foot above the ridge of pitched roofs over which they pass or to which they are attached and roof struc- tures must be substantially constructed. d. Must, zvhere exposed to the weather, be pro- vided with petticoat insulators of glass or porce- lain (see pp. 40 Mid 41); porcelain knobs or cleats and rubber hooks will not be approved. Wires on the exterior walls of buildings must be supported at least every fifteen feet, the distance between sup- ports to be shortened if wires are liable to be dis- turbed. Where not exposed to the weather, low poten- tial wires may be supported on glass or porcelain knobs which zvttl separate the wires at least one inch from the surface ivired over, supports to be 144 placed at least every four and one-half feet. e. Must be so spliced or joined as to be both mechanically and electrically secure without * sol- der (see p. 40). The joints must then be soldered, to insure preservation, and covered ixnth an insula- tion equal to that on the conductors. All joints must be soldered, unless made with some form of approved splicing device (see p. 40). f. Must, ivJiere they enter buildings, have drip loops outside, and the holes through which the con- ductors pass must be bushed with non^combustible, non-absorptive, insulating tubes slanting upward toward the inside. For low-potential systems the service wires may be brought into buildings through a single iron con- duit. The conduit to be equipped with an approved service-head (see pp. 42 and 44). The inner end must extend to the service cut-out, and if a cabinet is required by the Code must properly enter the cabinet. g. Electric light and power wires must not be placed on the same cross-arm with telegraph, tele- phone or similar wires, and when placed on the same pole with such zvires the distance between the two inside pins of each cross-arm must not be less than twenty-six inches. h. The metallic sheaths of cables must be per- manently and effectively connected to "earth' (see pp. 46-50). Although not specified in the Code, bare wires are sometimes used, especially through uninhabited and isolated territories, free from other wires (see tables, pp. 62, 63, 210, 211). 145 Bare wire is also used for high tension wires, the theory being that only the insulators and not the 'covering are relied on for pole insulation. Hence, where there is no danger of other wires or trees coming near them, bare wire is satisfactory. If there are other wires or trees near, and the ten- sion is below say 5000, then weatherproof insula- tion saves enough trouble from crosses with other wires, branches, etc., to be worth the cost. When, however, the voltage is above 5000, the protection of the covering is so slight as not to be worth while. It should be noted that wires should be kept well clear of trees, as branches may blow onto the wires and cause trouble, even if clear of the wires in calm weather. Also, many companies consider it undesirable to attach wires to trees, but prefer to set independent poles, even at an added expense, on the ground that in the long run the cost is less. Where tree wiring may be necessary, suggestions are illustrated on page 41. Guard arms should be placed on all corner poles (see pages 40 and 64). This, however, applies more often to poles on street corners rather than from pole to house. In alternating current systems the wires in the street are usually of high voltage (2000 to 4000 volts) and a transformer is used for transforming the voltage to no or 220 volts. The rule governing transformer installation is given on page 147. Current Supply. Art. i : In designing a house wiring installation, 146 it is necessary to know whether the current is direct or alternating and the voltage of the supply serv- ice. If alternating it is also necessary to know the phase and cycle. In some large cities direct current is used and also in places where owners have private generat- ing plants. In most of the intermediate and smaller cities, however, and in practically all suburban dis- tricts, the supply is from alternating current. In practically all residences, except very large ones with large individual motors, the alternating current is delivered in what is known as single phase, requiring but one transformer, and this con- dition is assumed throughout this section of the book. The transformer for supplying a residence is generally located on a pole (see p. 49), or in an underground vault, near, or inside, the building and the transformer is designed with two or three wires, according to the system used, coming from it on the house or service side. The Code rule is as follows : Transformers must not be placed inside of build- ings without special permission. Must be located as near as possible to the point at which the primary wires enter the building. Must be placed in an enclosure constructed of fire-resisting material; the enclosure to be used only for this purpose, and to be kept securely locked, and access to the same allowed only to responsible parties. The transformer case must be permanently and effectually grounded, and the enclosure in which 147 the transformers are placed must be practically air- tight, except that it must be thoroughly ventilated to the outdoor air, if possible through a chimney or Hue. There should be at least six inches air space on all sides of the transformer. In equipments with not more than fifty lights and outlets many lighting companies deliver the current, from the transformer to the building, on a two-wire system at about 1 10 volts and without the use of the third or neutral wire. Voltage. Art. 2 : With the three-wire system the voltage between the two outside wires is generally about 220 volts and the voltage between the neutral (mid- dle) wire and either outside wire is about no volts. The no-volt outlets, for lights and small appliances are placed on two-wire branch circuits, balanced on each side of this neutral wire. Larger appliances are often wound for 220 volts and connected across the outside or 22O-volt circuit. For these larger power appliances and motors 22O-volt apparatus is used for the purpose of re- ducing the size of the wires supplying them. Small heating appliances where considerable heat must be generated are almost universally made for no volts. Bell and telephone systems require but low volt- age (4-6 volts) and small currents and therefore are seldom dangerous from a fire standpoint, when kept away from contact with light and power wir- ing. This portion of the installation is not inspected by insurance representatives, except to see that the wires do not come in contact at any point with 148 electric lighting or power circuits, from which they must be kept entirely separate. Service Feeders. Art. 3 : In most of the larger cities the feed wires come directly into the cellar underground and in many cases where the wires are overhead on poles, the owner prefers to have the wires brought into the house underground from the nearest pole, al- though in this case, the owner must pay for the underground portion of the work. Where the lighting companies' pole on the high- way is not over sixty or seventy .feet (60' or 70') from the residence, the service company will gen- erally bring its service wires overhead to the house without charge and in such cases it is good prac- tice to have the house wiring carried through the cellar wall to the outside of the house and then rise in a rigid iron conduit to meet the overhead wiring, the end of the conduit being turned over or fitted with an appliance such as a service head or pot-head which will prevent the entrance of water (see p. 44). At this point, insulators are placed on the side of the house to take the strain of the wires from the pole to the house, and then a loop is made, con- necting to the wires in the conduit arranged so that the wires come out of the conduit at a downward angle to prevent rain water from running along the wires into the conduit. Main Switch and Meters. Art. 4: The service switch (see pp. 108-112) for cutting off the entire electrical supply of the house and the meters furnished and installed by 149 the lighting company should be located at some accessible point as in the cellar close to where the wires come through the wall. This makes it un- necessary for the meter reader, who comes once a month, to go through the main living portion of the residence. Where a different rate is charged for different classes of service there should be a different meter for each class. Many service companies make dif- ferent rates for light, for power and for heating, cooking and refrigeration. Most companies will furnish and connect 3-wire meters for power and cooking, etc., as well as for light, so that both 110- volt and 22O-volt apparatus may be used on the same meter by balancing on each side of the neutral wire, as explained in Art. 2. The service company should be consulted as to meter arrangements. Current Costs. Art. 5 : The costs given below for operating vari- ous appliances are based on the ratio common with many companies throughout the United States, viz : Lighting, roc. per kilowatt-hour. Power, 8c. per kilowatt-hour. Heating, cooking and refrigeration, 5c. per kilo- watt-hour. Rates varying from the above will cause a like change in the operating costs. Electricity is sold at so much per kilowatt-hour. A kilowatt means 1000 watts (see pp. 195 and 200). A kilowatt-hour is the equivalent of 1000 watts continually consumed for one hour (see p. 201). Watts (see pp. 195 and 201) are the product of the volts by the amperes. Thus, 40 25-watt Mazda or 150 Tungsten lamps (each giving about 21 candle-pow- er) all continuously in use for one hour, or one such lamp burning for 40 hours would in either case consume one kilowatt-hour and cost about ice. at the above rate (see Lamp Data, p. 115). For cooking, current at 3c. per kilowatt-hour is about the equivalent of artificial gas at goc. Grounding. Art. 6: In two-wire system (see Art. i), one side of the service switch and in the three-wire system, the neutral (middle) of the service switch (in both cases on the incoming side), should be grounded by means of a copper wire to the water supply pipe on the supply side of the water meter. By grounding is meant a solid, permanent con- nection to the earth or ground by means of cen- nection to water pipes, or plates buried in the ground (see pp. 46-50). The result is that if either outside the house or in it anyone touches this neu- tral or grounded wire, as at a lamp socket, and also touches or makes connection with the ground, as through a gas pipe or radiator, there is no difference of potential, while if either the positive or negative wire is touched only, the system potential, as 120 or 240 volts, is felt, and is considered perfectly safe while pressures above 300 become dangerous. Without a ground connection, it is possible, in ofse of an accident in the street or during a thunder- storm, for almost any pressure to get on the wires. If this happens they are still safe so long as no connection is made by a person between the wires, and no ground connection made at all. If after such dangerous pressure gets on the wires a ground 151 connection is made somewhere by accident, still nothing happens, but then if a person touch the ungrounded wire and connect to ground, as through a radiator, etc., he gets the full pressure. On the other hand, with a ground connection made intentionally, whenever any dangerous press- ure gets on the wires it immediately flows to the ground, when contact is made, through any lamp socket, motor, or current-using devices on the sys- tem, and blows the fuses before any harm can be done. The result is that a ground connection, while making it possible for any person easily to get the normal voltage, makes it impossible for him to get any more. Where the wiring of the house is in conduit, the conduit system should be continuous or electrically connected by means of wires, and the conduit sys- tem also grounded in the cellar to the water pipe, in the same manner as described above for service switches. The two ground wires should be sepa- rate, although they may connect to the same water pipe (see pp. 92-98). House Mains. Art. 7 : From the service equipment the supply wires, called the mains, should be carried to the central distributing points (known as cut-out or panel equipments), there being one such main for each class of equipment that is separately metered (see Art. 4). These mains are carried to all panel equipments controlling the class of appliance which the mains are intended to supply. The branch cir- cuits which run to light and power outlets and to 162 the vario'us appliances radiating from these panel equipments, should be located in central and ac- cessible positions. (To find the proper size of wires for carrying any current any distance for any num- ber of lamps, or their equivalent, at any loss of voltage, see table and examples on pages 69 to 78.) Distributing Panels. Art. 8: In residence work it is good practice to place the distributing panels in cellars, servants' halls or corridors (not in clothes closets) so that workmen can get to them when necessary without disturbing the occupants of the house, and where possitffe dirty shoes and hands will do the least damage. The necessity, however, does not often occur in well designed and installed systems. These panel equipments may consist of groups of porcelain cut-outs and fuses or porcelain base knife switches and fuses. In the best class of work knife switches and enclosed fuses are mounted directly in two vertical rows on polished slate or marble panels and cross connected by metal straps to polished copper bus-bars rising up the middle of the panel. These bus-bars are fitted at their ends with lugs to which the mains connect. The cut-outs or panel are surrounded with slate edg- ings containing openings through which the circuit wires pass to connect to the branch switches. The slate frame thus formed is mounted in a metal box with from three to four inches (3" to 4") space around the slate, thus forming a gutter in which the circuit wires can be carried from the ends of the conduits terminating in the metal box, to the various switches. If a wooden door is used it 153 should be lined with slate and any wood trim which covers the gutter and overlaps the joint between the box and wall should be lined on the under sur- face covering gutter with metal. Where metal doors and trims are used only the slate door lining is re- quired. These trims are usually from 24 to 28 inches wide and of varying lengths to suit the num- ber of circuits. Each panel circuit or switch should be numbered by means of a metal stamp on the bus-bars opposite the switch and a directory sheet should be placed on the inside of the door giving the number of each switch and the number and location of the lights controlled. There should be a separate double pole cut-out or switch and fuses for each circuit con- suming 660 watts or less in the case of lamps or small power and heating devices; and a similar cut-out and switch for each outlet for motor, etc., where the capacity is greater than 300 or 350 watts (see Art. 9), (see illustrations, pp. 33-36). Where more than one main feeds a panel in bus- bar construction, the bus-bars are cut into the re- quired number of sections and each section carried out between switches to the edge of the panel that the main wires may be joined to the bus-bar ends just inside the slate edge and without the necessity of having the wires cross the panel. To limit the necessity of cutting away too much of walls, floors and supports, where circuit conduits come together, the number of circuits at any panel box should be limited to ten or twelve by placing as many boxes at separate locations as may be necessary to supply the residence. Where the con- 154 struction will* permit, however, as many as eighteen to twenty-four circuits may be grouped at a single panel equipment without undue size. Branch Circuits. Art. 9: The rules of the Fire Underwriters allow 660 watts distributed at sixteen sockets on each 2-wire lighting circuit. It is recommended, how- ever, that* the number of sockets be limited to twelve or thirteen on a circuit, as this does not greatly affect the cost of the work and will permit the use of No. 14 wire for practically all such branch circuits without undue loss in voltage and without appreciable variation in voltage between outlets on the same circuit under any condition of use. (See Carrying Capacity of Wires, p. 68.) Branch circuits for single phase power are also two-wire and vary in size depending on the horse- power of the motor or the watts of the appliance connected. In wiring for small motors from y 2 H.P. to I HLP. branch circuits should be No. 14 wire for 220- volt motors and No. 12 wire for no-volt motors. These sizes are made necessary because of the large inrush of current at the moment of starting the mo- tor. For either appliances where there are no mov- ing parts (such as electric soldering iron) the size of the wires vary with the watts consumed, but in no case may such wires be smaller than No. 14 Brown and Sharp gauge (see p. 81, 5th column). Where heating devices are of small capacity (as glue pot and soldering iron in basement workshop) two or more may be placed on one circuit. Where the watt- age of a single appliance is 350 watts or more, it is 155 better to carry a separate circuit to each such ap- pliance. The branch circuits to electric cooking ranges are generally three-wire; the size depending on the capacity of the range. The branch circuit for the vacuum cleaner outlets should be on the power section of the system and as but one outlet is used at a time, all the vacuum cleaning outlets in the residence may be placed on one No. 12 wire branch circuit and connected for 220 volts. Where the lighting companies make separate rates (as in Art. 4) branch circuits to lighting ap- pliances to power appliances and to heating ap- pliances must, of course, be kept separate and con- nected to the proper section of panel equipments. Knob Work With Flexible Non-Metallic Conduit. Art. 10: In frame residence with stud partitions, it is permissible to carry wires on porcelain insu- lators on the sides of the beams and studs and through them by enclosing in porcelain tubes with flexible non-metallic conduit (flexible tube) from nearest knob to outlet, keeping the wires as far as possible from the floor or ceiling to prevent injury. Outlet boxes should be used for flush switches and receptacles; but for ceiling and side fixture outlets where there are no gas pipes and for surface switches and receptacles, wood fixture blocks should be built into the walls and securely fastened to beams and studs to give adequate support for the fixtures and fittings. This type of construction is known as "knob and tube" work and is not only 166 the cheapest but also a very satisfactory method of installation for concealed wiring (see pp. 91-92). Armored Cable. Art. loa: Some architects and engineers specify armored cable for frame or semi-frame residences (pp. 91 and 101). This armored cable is made by wrapping steel tape or ribbon around the two or more wires of the mains or circuits, thus giving a heavy metal sheathed main or branch circuit. Such cable is made in lengths of from 50 to 250 feet. Armored cable may be laid or drawn between beams and studs or furring strips with practically no liabil- ity to mechanical injury from nails, etc. Armored cable should not be placed in brick or concrete walls unless imbedded in plaster-of-paris or other suit- able material to protect the sheath and wires from the corrosive action of the surrounding ingredients. For the same reason the best practice prohibits such armored cable being placed in brick or concrete walls where subject to considerable dampness. Out- let boxes in this construction are required at all outlets, and the metal armor should be grounded as called for in Art. 6. Armored cable construction is very satisfactory in residences where the permanent decorations are not expensive or where the construction is such that the concealed lengths between outlets may be withdrawn and new lengths drawn in (in case of trouble) without injury to the finished surface. This construction is a little more expensive than knob and tube work (see Art. 12). 157 Flexible Steel Conduit. Art. lob: Where the character of a residence is such that it would be expensive to make repairs or alterations in the concealed wiring, good practice calls for the use of concealed conduits for the re- ception of the wires. These conduits should be large enough to permit the easy drawing in and withdrawal of the wires without the use of tackle. The smallest conduit generally used for electric light branch work is about % inch inside diameter (see p. 93). Conduits should be securely fastened to building construction and have easy bends to facilitate the drawing in of the wires. Flexible steel conduit is frequently used for this purpose, the construction of which is practically the same as armored cable but in larger and tube form. These flexible conduits are made in lengths of from 25 to 100 feet for- lighting work and this type of wiring installation is more expensive than with armored cable (see Art. 12). Rigid Conduits. Art. ice: For the highest class of residence work, architects and engineers generally specify rigid con- duit construction (see p. 92). These rigid conduits are of gas-pipe thickness and are coated on the in- side with a tough elastic and very smooth enamel. The exterior may either be coated with the same enamel or galvanized. The conduits come in ten- foot lengths and all diameters from %-'mch to 6-inch and are joined by means of screw couplings of the same material and the joints are made tight by the use of red or white lead. This prevents the entrance of any moisture. This is the most ex- 158 pensive character of concealed wiring work (see Art. 12). Wood Moulding. Art. lod: This class of work, which is not per- mitted in concealed places, is frequently resorted to on account of the cheapness and where it is un- desirable, or. unnecessary for appearance, to run circuits inside of walls or ceilings. Wood moulding work is especially adapted to the cheaper class of cottages, bungalows, etc. For construction rules se-e page 88. Cleat Work. Art. loe : In dry places and where the wires are not liable to mechanical injury, or contact with other objects, circuits may be supported on porce- lain cleats or knobs. For this class of work the wires should be sepa- rated, by their insulating knobs or cleats, two and one-half inches from each other and at least one- half inch from the surface wired over (pp. 68 and 79), where the voltage does not exceed 300. Metal Moulding. Art. icf : Where it becomes necessary, for me- chanical reasons, to use metal moulding the sug- gestions given on pages 89 and 90 should be fol- lowed. Bell Conduits. Art. log: Bell and telephone cables and wires need not necessarily be in conduit nor need they be installed on knobs. In fireproof or semi-fire- proof residences where the cables come in contact with brick or concrete and would not last and in frame residences where it is desired to make re- 159 pairs to the concealed wiring without injury to the walls, such wires should be placed in concealed conduits, installed in the same manner as described above for electric light wiring. In the best class of residence work this is usually done. Conduit Fittings. Art. 1 1 : In both armored cable and metallic conduit construction special fittings are used to connect the metal to the outlet box or cut-out box. or other opening, and in the case of conduit work these bushings and nipples are so designed and in- stalled that the wire is drawn over smooth rounded surfaces to prevent abrasion of the braid covering of the conductors while they are being drawn in (seep. 93). Approximate Wiring Costs. Art. I2a: Due to the varied cost of labor and material and to varying methods of building con- struction, universal costs of electric light work for the several types of wiring hereinbefore described, cannot be given, but for the purpose of general comparison the following approximations may be a help: Knob and (Flexible) Tube Work $1.50 to $2.50 per outlet B. X. Cable Work 2.00 to 5.00 !' " Flexible Steel Conduit Work 3.50 to 5.50 " " Rigid Metallic Conduit Work 4.00 to 7.00 " " It must be borne in mind, however, that these proportions for the wiring work will not follow as proportions for the complete equipment, as the 160 cost of fixtures, appliances and lamps, etc., will be the same for any one of the systems, and as these fixed costs are generally the larger part of the com- plete total the above proportions would apply to perhaps one-half or less of the total cost of any given installation. Bell Costs. Art. i2b: Bell call or annunciator requirements differ for almost every family and attempts to give costs in this class of work would be misleading. In a general way, however, the equipments will range from $3.00 to $10.00 per call; and from $1.50 to $8.00 per extension bell or annunciator drop. The smaller costs are for the simpler systems with con- cealed wires not in conduits, and the higher costs for more or less complicated call systems with wires in concealed rigid conduits. House Telephone Costs. Art. i2c: A house telephone system intercom- municating between various rooms of the residence and arranged on what is known as metallic circuit connections (to prevent cross-talk) will cost from $20.00 to $50.00 per instrument, depending upon the number and finish of the instruments, and whether or not the concealed wire is in conduit. Most of the telephone manufacturers of this class of instrument make a standard telephone with ten (10) buttons, thus providing for intercommunica- tion between eleven (n) points. Wire for Light and Power. Art. i3a: All of the various fire underwriters organizations require "Rubber Covered" wire (see p, 66) for all classes of concealed residence wiring, 161 These wires may have a single impregnated braid in case of knob and tube work and a double braid in the other classes of concealed work hereinbe- fore described. The life of rubber insulation de- pends largely upon the amount of pure unreclaimed Para rubber used in the insulating compound and the method of applying it to the copper conductor. The very best class used in residence wiring as well as the most expensive contains about 30 per cent, pure Para rubber. In installations supplied by alternating current it is important that all the wires of any branch cir- cuit, main or feeder should be in the same conduit. In fact, this should be absolutely insisted upon to prevent trouble from induction (see p. 91). Joints in wires should not be allowed where they will be concealed in conduits or be at inaccessible points. Where splicing is necessary the joint should first be made mechanically strong, then soldered for per- fect electrical contact and insulated with rubber compound and tape and made equal in insulation to the rest of the wire (see p. 68). Bell and Telephone Wire. Art. i3b: Wire used in bell and telephone systems may be of the same quality as above described but need not be as large in size. For small bell sys- tems No. 18 B. & S. gauge is amply large for the section wires and No! 16 for the battery wires. These sizes are determined mainly by means of mechanical strength and in order to easily distin- guish between battery and section wire. Where there are a number of bell or telephone wires carried between two points a considerable 163 distance apart, it is quite customary to buy the cable already made up and these wires are often as small as No. 20 or No. 22 B. & S. gauge. The separate wires in such cables may be insulated with two silk and one cotton wrapping impregnated with beeswax to keep the ends of the yarns from un- raveling and the made-up cable encased in a heavy fireproof braided covering. The most approved type of house telephone con- tains two wires for each call, two wires for battery talking, two wires for battery ringing. Each pair of wires should be twisted to prevent "cross-talk." This refers to metallic circuit connections in house intercommunicating telephone systems. Where silk and cotton cables are used in damp places the cable should be encased in lead to prevent moisture de- veloping short circuits between the various wires. Voltage Loss in Conductors. Art. 14: The size of conductors given in the Na- tional Electrical Code for any given current is based only on the safe carrying capacity (see table, p. 81) without undue heating and does not necessarily de- termine, except where the distance is short, the size of conductor that good engineering practice requires. The proper size of conductors in any installation should be determined by the loss in volts between the service supply -\nd the furthest outlet or appliance (ekctrically speaking) when the entire equipment is in simultaneous operation. In residence work 2 per cent, loss between the above mentioned points is not excessive (see pp. 69-78). Conductors smaller than No. 14 Brown and Sharp gauge must never be used in electric 16? light work, except inside the lighting fixtures where a smaller conductor is permissible. In proportioning the total voltage losses of a residence installation between the mains and branch circuits not more than I per cent, loss should be permitted in the branch circuit panel. A simple table, with examples worked out, to show its use, is given on pages 69 to 78. By its use the proper size of wire is easily determined for carrying any current any distance at any desired loss in volts. There is a large rush of current at the moment of starting up single phase alternating current mo- tors and the loss in such wires should be based on this momentary large amount which may vary from 100 to 200 per cent, overload of current. If this condition is not provided for it is quite possible to install wires that would be large enough to operate the motor after it is in motion, but too small to take care of this starting current (see pp. 22-32). Room Switches. Art. i5a: A liberal use of switches in a residence invites economy by encouraging the putting out of lights when leaving rooms. They soon pay for themselves. The most satisfactory switches are of the flush type and should be placed in metal cut- out boxes sunk in the wall and should generally be located just inside of entrance doors. Large rooms with numerous outlets should be controlled by more than one switch, and in long living rooms it is often a good plan to place the lights of each end of the room on a different switch control, both for convenience of occupants and economy in bills. 164 For electroliers, switches are sometimes used, so designed that one turn of the handle lights one group of lights; the second turn lighting an addi- tional group without putting out the first group, and a third turn will put all out. Servants' rooms should have switches and high fixtures not only so that the lights will be more apt to be extinguished when not needed, but also to prevent the use of fixtures as clothes hangers. Hall Switches. Art. I5b: For hall and stairs it is customary to arrange lights that they may be turned on or off frqni any one of several switches known as 3-way and 4-way switches. A light in first floor hall and one on the second floor may be controlled by a switch at entrance door and also controlled from second floor. In the same manner an outlet on third floor may be controlled by a switch in second hall and one on third floor. This allows a person going to the third floor to come in late, light halls and stairs to room and put out lights again from above and thus do away with wasteful burning (see Hall Wiring, p. 166). The three-way arrangement for servants' stairs especially will keep down the monthly bills, because of the ease with which the servants can put out lights. Sometimes this 3-way switch arrangement is used in bedrooms, one switch at door and the other at bed. Master Switch. Art. i5c: A master switch may be placed in the owner's bedroom and so connected that the switch will control the first, second and third floors, main 165 hall and stairs, 3-way lights, either independent of whether the local switches have been used or not (see Master Bedroom, p. 167). J L 3- Way Switch for lighting Fixture A in Living Room 5- froni either side of entrance - T \ Living Room \ \ (3- Way Switch\ at head of Stairs for s lighting Fixture A) -s 3 Incfa A Newel Po Outlet fo (descent I 50 Wat) 'equivalei |Up jj 1 ^2 S:i f amps (.The \lf it also be 3-Way Switch for lighting Fixture at head of Stairs jhting Fixture should be controlled by :5-Way Switch at head of Stairs) Lighting of Fixture controlled by 3-Way Switch at head of Stairs and by 3-Way Switch at E Ceiling Outlet for 2 Incandescent Lamps To Watt eacli equivalent Dinin -S 3 3-Way Switch for lighting Fixture A in Dining Room VESTIBU ./ Light ing of ''Fixture 6 controlled by 3-Way Switch at E and by 3- Way Switch at F Lighting of Fixture C controlled by 3-Way Switch at F and by 3-Way Switch at G S?G DD Push to Kitchen Annunciator ENTRANCE Closet Switches. Art. i5d: Closet switches are often controlled by switches set in the door jambs and operated by 166 movement of door. As closets, however, are often left open for ventilation, wall switches are pref- erable (see cut of closet below). Pilot Switches. Art. 156: With switches operating lights hot visi- ble from the switch (as in case of cellar) it is 1=--==! ^ =\ -SeeB Outlet for LJ Dsk Lamp Y< b ^ See B -ji- \ ^^ LJ . MASTER E ED ROOM >Tr< n 4 Interior Telephone 4 Public Telephone Extension i Bracket Outlet for 2 \ Incandescent I^amps \ 50 Watt each equivalent Outlet for Ozonizer, i 1_ Vibrator, Vacuum lT Cleaner Ceiling Outlet for Closet Lamp Special Heating Outlet for Water Heat >r, Heating 1'ad, Radiator 1 ,_.~\\ / Push to Bell in CLOSET \\ Servants' Quarters S.P.Switch for oW \ CloS^ P rT?J^erSwitch^ 1 1 . X. S M Q Outlet for / Bed Reading / Lamp \ / Y~>( 3- Way Switch for lighting Fixture B from either Sidt- of Enti.incc economical to equip the switch with a small pilot light which burns when switch is in use. This same style of pilot switch should be used in connection with all heating or other appliances which are fixed in position and do not visibly indi- cate when current is on (see Art. 18). Motor Switches. Art. 16: Fused knife switches 1G7 (see p. TT2) in metal boxes should be used in connection with A. C. motors of y*. H.P. and larger. These switches should be double pole and located near the motor they control. Motor starting boxes are sometimes used with ^ H.P. to i H.P. A. C. single phase motors in order to cut down the momentary rush of current (described in Art. 14), but nearly every service company will permit motors to be operated directly from the switch. Small motors may be operated from flush switches of room type. Tank Switches. Art. 17 : When the house water tank in the attic is filled by an electric pump, a switch should be placed at the tank and connected to a float in the water, and so wired and connected as to automat- ically start and stop the pump by the fall and rise of the water in the tank. Combination Pilot Switch and Receptacle. Art. 18 : Where portable electrical appliances do not visibly indicate when the current is on, and where such appliances are connected by means of flexible wires, the wall outfit should consist of a switch pilot light and receptacle. All three (3) may be placed in the same outlet box and one (i) plate covers all. Base Receptacles. Art. ipa: Flush receptacles and plugs should be liberally distributed throughout the residence as they are very handy for a great variety of purposes and may be generally placed on or just above the baseboard. The plates may be painted to match surroundings and made very inconspicuous. Receptacles for the same voltage and class of 168 I hi Kb Bell Transformer or 1 1 Battery Outlet CELLAR Ceiling Outlet for 2 Incandescent Lamps 50 Watt each equivalent Special Power-Current Outlet (Wall Receptacle) for -\ Workshop Machinery ^ Lathe See A I I ^- S.P. Switch at Head of Stairs for lighting Fixture A Ceiling Outlet Furnace service should have interchangeable plugs to avoid the necessity of changing the plug on the flexible 160 cord attached to any lamp or appliance should its location he changed. Receptacles, however, should be so designed that Ceiling Outlet for 2 Incandescent Lamps 50 Watt each equivalent irculation Heater Special Heating Outlet for Electric Range or 'Oven Broiler, Hot Disc Stove 3- Way Switch for controlling Fixture C ither G or H See B ial Power- Current Outlet for small Motor or Power (ft. Table. - W Power Table Accessories, Ice Cream Freezer, Coffee Grinder, Metal Polisher, Bread Mixer, Egg Beater, Knife Sharpener, Meat Chopper 170 the plugs on apparatus of different voltage or class cannot be inadvertently connected to wrong recep- tacles. This may be accomplished by using the same make of receptacle with different openings for each voltage or class or by specifying a differ- ent make for each class. If this is not done, a 110- volt appliance might be easily connected to a 220- Outlet for Cigar Lighter, Reading Lamp Bracket Outlet for 2 Incandescent Lumps 50 Watt each equivalent LIBRARY See B Ceiling Outlet for 4 Incandescent Lamps 50 Watt each equivalent Outlet for |_ Vacuum Cleaner S:P. Switch for lighting Fixture A volt receptacle in which case the appliance would probably be destroyed to say nothing of the fire hazard involved. Receptacles for lighting purposes are usually no volts. In addition to the lighting receptacles which are usually installed for reading lamps, piano lamps, etc., there should be one or two spare receptacles 1 171 in each main room and hall. One of the receptacles in main living room or hall should be placed so as to be near a suitable location for a Christmas tree, so that this may be illuminated without unsightly wires showing in the room. A porcelain lamp receptacle, mounted in a con- dulet or outlet box, is often placed under the 1 "fT R YZ^\ Bracket Outlet for 2 X^< s a Outlet for *~* Incandescent Lamps XlX H Piano Player, 5 Watt "sh equivalent Vacuum Cleaner Special Floor Outlet /g for Heating and vR Cooking ) P-, Table Bell Push to L^-l Kitchen Annunciator rJJ LIVING ROOM Outlet for Moving Picture Lamp, Tea Table, Toaster, Tea Pot, Coffee Percolator A VV Ceiling Outlet for _ fij Incandescent Lamps *-* 50 Watt each equiva- lent Outlet for Tan, Cigar /Lighter, Portable / Lamp, etc. I S* 3- Way Switch for lighting .Fixture A from either Side of Entrance kitchen range-hood and the conduit run around under the hood to the side wall where the control- ling switch is located. Outdoor Decoration Receptacles. Art. igb: A waterproof receptacle and plug should be located outside the main entrance, con- trolled by a switch in hall for step and walk canr opy lighting. 179 A similar receptacle and plug may be placed high up on pillar or wall of porch for electric decora- tions. These receptacles should be on a separate circuit from panel and controlled by a switch at porch door. To Pantry 3 _ Way Switeh Ou ti et for lighting | _--"~' b Fixture B in Pantry 1<^" | ^~"~"~ 1 "-- Yv\ S 3 3- Way Switch ^* \ for lighting Fi See B \ 1 i \ Outlet npS B xture A ^ X Bracket Outlet for 2 Incandescent Lamps 50 Watt each equivalent Special Flooi Outlet /for Electric Cooking r Toaster, Egg Boiler, C^\ Chafing Dish, Percolator m Table Bell Push to ' ' Kitchen Annunciator Ceiling Outlet for i Incandescent Lamps 50 Watt each equivalent \ ROOM \ Special Outlet for \ Heater, Fan, \ Vacuum Cleaner, \rtsjTv Dutlet for O ( X^X B ^ 1 \ U- Serving 1 _bi Outlet for Elec. ?7\ "lJ Serving Tray, >>_X Drjnk Mixer v Table j ^ DININb See B K) 3- Way Switch ( ' Push to Annunciator r^~i in Kitchen L - J Porch Receptacles. Art. IQC: The living porch should have one or more flush wall receptacles placed in the side wall twelve or fifteen inches above the floor (to prevent water splashing on them). These receptacles for use of reading lamp, chafing-dish, percolator, etc. Bedroom porches may have a similar receptacle for reading light. Servants' or kitchen porches should have a re- 171 ceptacle pilot light and switch (see Art. 18), so that ironing may be done on the porch in hot weather. Should a receptacle should be on a separate circuit. Mantel Receptacles. Art. igd : Receptacles for mantel candles may be placed in the wall just above the shelf, or, where the design will permit, in the shelf itself. These J L Ceiling Outlet for 2 Incandescent La 50 Watt eac equivalent i Outlet for Plate Oven, 1 Hot Disc Stove PANTRY Outletfor Water Sterili " p3x~x .^ (V) B ^- A s- Plate Oven t Disc Stove Cf 3- Way Switch for lighting Fixture B To _+ Dining Room Bracket Outlet for 2 Incandescent Lamps 00 Watt each equivaU Outlet for Vibrator, Ha:r Dryer, Shaving Mirror, Elec. Bath Cabinet receptacles should be controlled by a switch at con- venient location. Bed Receptacles. Art. 196 : Two receptacles, one for reading lamp and one for heating pad or similar sick room appli- ance, should be placed at the side of each bed and connected to no-volt lighting circuit. , These may both be in the same outlet box and covered with one plate. Alongside of this equipment but not in con- 174 tact with same, may be placed a bell receptacle with removable portable cord and hand "pear push" for bell call. This bell receptacle and plug must be of entirely different design from the two before men- tioned so that by no possibility may the bell plug be attached to either of the other receptacles. These bell portables are connected to the same bell wires as the wall push button at door, so that either point Vacuum Cleaner <0 See B Bracket Outlet for 3 Incandescent Lamps (/* 50 Watt each equivalent SEWING ROOM i Outlet for -m Fan, Iron Ceiling Outlet for 3 Incandescent Lamps 50 Watt each equivalent S.P. Switch Push to for lighting Kitchen Fixture A ( S Q] Annunciator rings the same bell or drop on the annunciator. Floor Receptacles. Art. igi : Where receptacle outlets come in the floor, they should be placed in specially designed floor boxes which have cone shaped tops projecting above the floor to prevent water entering the box and to protect the wires. When these portables are not in use, the cone top can be removed and a flush top substituted. 175 Stereopticon Receptacles. Art. 20 : Stereopticon and moving picture ma- chines are now made for home use. The recep- tacles for some have a larger capacity than those for lighting and are usually placed at the end of the long living room or hall. They should be connected to i lo-volt power and by means of two No. 8 wires. Vacuum Cleaner Receptacles. Art. 21 : Flush receptacles ftfr portable vacuum cleaners should be so located that the thirty to fifty feet (30 to 50') of cord that goes with the cleaner will enable the operator to reach all parts of the house. They should be so arranged that the plugs are not interchangeable, except for the very small type as explained in Art. ipa. The momentary rush of current with many of the larger portable vacuum cleaners would blow the fuses of small cir- cuits and it is advisable to put these receptacles on a separate No. 12 wire, and as but one point is used at a time, all the vacuum cleaner receptacles in the residence may be placed on the same circuit. Dining Room Special Front Outlet. Art. 22 : There should be a receptacle and outlet box placed in the floor under the dining-room table, a little off the center, so as to clear the center leg of table. This should be fitted with a removable plug connected to permanent table wiring (which is car- ried up the center leg of the table along the under framework and out on the crossbars, where the wir- ing should terminate in three no-volt fused power receptacles. One of these may be used for electric chafing-dish or egg boiler, one for electric toaster and one for electric coffee percolator. This enables 176 the housewife to use the above appliances and dis- connect and remove them as desired, without reach- ing to the floor and with practically no exposed connections, -except the short ones over the edge of the table. The three receptacles under the edge of the table may, if desired, be mounted in a neat box to match the woodwork. (See Dining Room, p 173.) Other Power Receptacles. Art. 23 : Flush receptacles for power and heating appliances are of sizes depending on capacity, but for most residence work, the standard 10 ampere receptacle and plug manufactured by many com- panies, is satisfactory in the great majority of cases. For different classes of apparatus and voltage, these receptacles should not be interchangeable (see Art. I9a). For use with heating or similar appliances, they should be in connection with pilot lights and switches, as explained in Art. 18. This type of cortibined switch and receptacle should be used for laundry and pressing irons (and provision should be made at ironing table to hold up the cord con- necting the iron). A laundry iron receptacle should always be placed to the right of the laundress. Cellar Lighting. Art. 24: Usually 10 or 15 watt lamps are suf- ficient for cellar lighting except in case of work bench or lathe, which should be brightly lighted by 25 watt or 40 watt lamps. Outlets should be so located as to illuminate sinks, furnaces and any pumps or apparatus that need attention. Store rooms and vegetable rooms should be well lighted from ceiling with controlling switch at door. The wine room switch should pref- 177 erably be placed outside the door, so that the room may be inspected through glass or grating of door without unlocking. There should be at least one outlet in cellar con- trolled by pilot switch at the head of the stairs (see Art. 156), and where there are few lights in the cellar it is sometimes advisable to put all on such a sw r itch. (See Cellar, p. 169.) Porch Lighting. Art. 25 : Porches are usually lighted from ceil- ing outlets controlled by a switch at porch door with receptacles for reading lamps, etc. (See Art. IQC. (See Porch, p. 170.) Room Lighting. Art. 26: In addition to mantel lights (see Art. ipd), side or ceiling lighting should be so designed as to properly illuminate all portions of a room (see pages 114-119), in such a manner as to allow the shifting of furniture from time to time without destroying the harmony of the interior. For this reason residence outlets should not be limited to the fewest possible permissible with the original furniture layout, but should be planned with a view of any re-arrangement of furnishings. Outlets not needed with first scheme may be capped until re- quired. For economy as well as for convenience, room lighting should be controlled by switches (see Art. I5a). Most rooms require one or more recep- tacles for portable lights (Art. 19). A cigar lighter may be placed on the lighting cir- cuit of den or living room. It uses very little cur- rent and does away with burnt matches. It needs no switch beyond the self-contained one. 178 Dining room the table should be well lighted by ceiling domes or showers. For bedrooms, in addition to the above room lighting, there should be a receptacle for desk lamp and there should also be a reading lamp at bed. (See Art. 196.) Hall Lighting. Art. 27 : Halls require a soft general illumina- tion and the addition of portable table and vase lights is often advantageous. In addition to the wall switches for the regular lights, there should be up and down control between floors as mentioned in Art. i5b. (See Hall, p. 166.) Pantry Lighting. Art. 28: The pantry should be well lighted from a high center outlet so that contents of dress- ers and cupboards may easily be seen and this out- let should be controlled by a switch. (See Pantry, p. 174.) Kitchen Lighting. Art. 29 : Kitchens are generally lighted from ceiling outlet controlled by switch at door. When, however, there are appliances around side wall at which the cook works, there would be a shadow if only the center fixtures were used, and side out- lets should be added at such points and at the sink. The range-hood should have a light under same, as detailed in Art. 193. (See Kitchen, p. 170.) Laundry Lighting. Art. 30 : Laundries are usually finished in light color and need comparatively little general illumina- tion from ceiling fixture controlled by a switch at door. A drop light should be provided at ironing 179 table and a side light at laundry machine. (See Laundry, p. 170.) Bath Room Lighting. Art. 31 : Most bath rooms may be well lighted by means of a 2-light ceiling fixture or side outlets placed over the mirror, the fixtures projecting 8 to 15 inches from wall and with two inverted lights in such position as to light top of head and each side of face, controlled by a switch at door. Bath room lights should never be so placed as to throw the shadow of anyone in the room on the window shade. (See Bath Room, p. 174.) Sewing Room Lighting. Art. 32 : The general illumination of the sewing room may be from the ceiling with switch control. Side lights should be installed to brightly illuminate the sewing machine and cutting table and also the chair used for hand sewing. An outlet for electric pressing iron (see Art. 32), should be installed and when the room is used in hot weather an electric fan adds to comfort. An 8-inch fan takes very lit- tle current 20 to 40 watts, and can be used on lamp socket. (See Sewing Room, p. 175.) Closet Lighting. Art. 33: Closet lights are desirable unless room fixtures are so placed as to illuminate them. Es- pecially is this true of storage and servants' closets as it insures cleanliness. Closet lights should be controlled by wall or door switches. (See Art. I5d.) (See Closet, p. 167.) Play Room Lighting. Art. 34 : The play room should be brightly lighted from the ceiling and controlled by a switch at door. 180 This will prevent accidents to or from low side fix- tures. The play room should also be wired for use as a bedroom with side lights and receptacles with outlets capped up for future use. If receptacles for play toys are installed they should be of such a character as not to permit the toys being connected to other outlets. Servant Room Lighting. Art. 35 : It pays to light servants' room from high ceiling lights designed for wide distribution of lighting and install switch at door for control of same. The lights will be thus used more econom- ically and the fixtures cannot be carelessly mis- handled. Workshop Lathe. Art. 36: Many owners like to provide a small workshop for their own use. A small wood turn- ing lathe can be operated by a motor consuming about 200 watts. This lathe may be controlled by either a motor starter and switch, or by means of a switch only, as detailed in Art. 16. (See Cellar, p. i6 9 .) House Pump. Art. 37 : Where city water supply is not available and a well is used, a tank located on roof or attic can be filled by electric pump. The well pipe may be from i ^2-inch diameter up, depending on the quan- tity of water needed. The motor may be controlled by hand or it may be automatic in action, as noted in Art. 17. (See Cellar, p. 169.) If wiring is installed a double throw switch is usually placed in the basement or at the pump to permit hand operation so that tests may be made 181 from time to time to see that everything is working satisfactorily. Water cocks may be placed around the lawn and water pumped through them directly for watering lawn, or for fire purposes without us- ing up the water in the tank. Refrigeration. Art. 38: Where ice is expensive or difficult to obtain, an ice box refrigerator electrically operated can be installed. These outfits require little atten- tion and in addition to keeping the box cool, can be used to make a small amount of ice for table and sick room use. Stereopticon. Art. 39 : Stereopticon and moving picture ma- chines are now made for residence use and are fast becoming an important part of the equipment of every home, especially where there are young peo- ple. Special receptacle should be provided as de- tailed in Art. 20. Vacuum Cleaner. Art. 40 : Portable vacuum cleaners are well known and much used. They should not be con- nected to the branch circuits feeding lights and small appliances (see Art. 9), but should be pro- vided with a special circuit and their own outlets. (See Art. 21.) Sometimes a permanent machine is installed in the basement with pipes carried con- cealed in the walls and with convenient outlets on each floor to which hose may be attached. In such a case it is advisable to place near the motor an au- tomatic distant control switch and carry one No. 14 wire branch circuit to flush receptacles placed close to each hose outlet. The plug is attached to the 182 end of the hose with a small chain. The connections are such that when the hose is in use and the plug inserted into the receptacle, the cleaner will start up and when the hose is removed thus pulling out the receptacle plug the motor stops, preventing waste of current. The receptacles that are used for connection to portable machines and their circuit are not used in this case. Plate Warmer. Art. 41 : Plate warmers are very convenient and add much to the ease of service and success of din- ners. They may be placed under dressers or pantry table and should be fitted with 2 or 3 heat switch and pilot light. When the first set of cold plates is placed in warmer, the switch is turned to high heat and left on for fifteen (15) minutes, when the lower heat is turned on and keeps the contents hot. Dish Washer. Art. 42: Electric dish washers are of many makes occupy small space do their work quickly and well and need little attention. They may be fitted with a switch on machine or at wall. (See Art. 16.) Metal Polisher. Art. 43 : An electric silver and metal polisher consists of a l /\ h.p. or l / 2 h.p. or Irrger. The ends of the motor shaft are arranged to receive various brushes, buffers, felt wheels and other fittings, all of which can be obtained with the outfit. By using such a machine the knives, forks, spoons and silver- ware may be kept in the best condition with a small expenditure of time and energy. Should have 183 switch and receptacle on wall, omitting pilot light. (See Art. 18.) Ice Cream Freezer. Art. 44: An electric ice cream freezer insures the best and purest home product with but little trouble. TJie electric current expense is negligible. Should have switch on machine with receptacle on wall or combined switch and receptacle on wall, omitting pilot light. (See Art. 18.) Electric Cooking Range Art. 45 : Cooking by electricity is fast coming into more general use. The freedom from odors and escaping gas, the cleanliness and the application of heat only where needed, appeals strongly to the housekeeper and in many parts of our country, such cooking may now be done as cheaply as with gas. (See Art. 5.) An electric range for a family of six would oc- cupy a floor space of about 22 inches by 28 inches. It is generally fitted with a number of separate switches for the various parts and utensils and should be on a separate 3-wire feeder with 3-pole main switch and pilot light. (See Kitchen, p. 170.) Ironing Table. Art. 46: Laundry ironing tables may be pur- chased complete with swinging arms to take care of the cords and with two (2) irons for different classes of work and so arranged with automatic stands that the iron when not in actual use takes only enough current to keep it hot. (See Art. 23.) Clothes Washer and Wringer. Art. 47 : The simplest type of electric clothes washer and wringer may be mounted on the tubs 184 and removed when not in use. Other types have all parts mounted on one stand which may be on roll- ers to bring it to the tubs on wash days and remove it at other times. Such a machine for a family of six would occupy a floor space of about 28 inches by 32 inches and the washing would be done better than by hand and with no danger of tearing laces and lingerie. Has switch on the machine and should connect to receptacle on wall. (See Laundry, p. 170.) Starch Cooker. Art. 48 : A convenient and inexpensive appliance in the house laundry is an electrically heated pot for cooking starch. Should be connected to pilot switch and receptacle. (See Art. 18.) Sewing Machine Motor. Art. 49: Every home should have the sewing machine fitted with a motor which may be very small in size and can be arranged to start and stop by pressing a contractor with the foot. It is very inexpensive to operate and saves many a doctor's bill where much sewing is done. The motor may be no volts and should be connected to a base receptacle. Bath Room Heater. Art. 50: Heating rooms by electricity is not yet an economic fact, but for special cases where not in continual use, they are very convenient and not too expensive to operate. When taking a bath on a winter morning when the hot water is turned on an electric heater may also be turned on and by the time the tub is ready, the chill will be taken out of the air. For this purpose the heaters should have 185 a capacity of four watts per cubic foot of room, al- though this is much greater than would be needed for continuous heating. These heaters should be on separate circuits and be supplied with combina- tion pilot switches and receptacles. (See Art. 18. ) (See Math Room, p. 174.) Other Bath Room Appliances. Art. 51: Curling iron heaters may be mounted on the surface of the wall and are very small in size and consume current only when the iron is in- serted into the heater. Hot water cups or stoves are much used, take up little space and should be connected to a combination pilot switch and recep- tacle. (See Art. 18.) Entrance Ball Calls. Art. 52: The push button at the main entrance door should not ring on the annunciators, but should be a distinctive call, ringing a separate bell in kitchen or pantry. An extension bell should be placed in servant's room or corridor and a second extension may be placed in a sewing room that is much used. These extensions are controlled by small lever switches for cutting them off in time of sick- ness. The push button at rear entrance should ring a buzzer in the kitchen, but without the extensions. Bell Annunciators. Art. 53 : An annunciator should be placed in the kitchen with bell different in sound from adjacent bells and fitted with an indicating drop from each of the rooms, porches and 'baths in the house. A second annunciator is often placed in servants' corridor and a third annunciator may be placed in the sewing room. 186 These two or three annunciators ring and indicate simultaneously for each call and are connected to- gether by two or three wires more than the total number of calls or drops on each. When a call is answered from any annunciator, a push at bottom of the annunciator resets all the annunciators, thus letting others know that the call is being attended to. Wall Pushes. ' Art. 54: \Yall pushes are placed in the door trims of the various rooms, porches, bath, etc., and connected to the nearest annunciator. Bath room pushes are sometimes placed over tub rather than at the door. Table Pushes. Art. 55 : In some rooms such as the living room, it is often desirable to have. a table push on a flex- ible cord connected to a floor receptacle. These portable pushes are usually connected to the same wires as the wall push in such rooms. In case of the dining room, the table push rings a separate buzzer in the pantry. while the wall push rings the annunciator. Bed Pushes. Art. 56: Portable push buttons are frequently located at beds and they connect to the same wires as the wall pushes. (See Art. iQe.) When the mistress of the house has a special maid, her bed portable push is usually connected to a buzzer in the maid's room. Battery and Cabinet. Art. 57: The bell system may be operated from six to eight cells of dry battery, placed in a cabinet 187 which may be located in the cellar. It is often well to use these batteries in duplicate with a throw- over switch so that while one set is being replaced or renewed, the other set is in use. (See Cellar, p. 169.) Bell Ringing Transformer. Art. 58: Where alternating current is used for lighting, the bell system can be operated by a small bell ringing transformer which may be placed in the cellar and connected to one of the lighting cir- cuits. These transformers may also be used for house intercommunicating telephone ringing, when the telephones are on metallic circuit. They cannot be used for telephone talking, which requires bat- tery or direct current. (See Cellar, p. 169.) Public Telephone. Art. 59: It is quite usual to put conduits in a residence for use of the Public Telephone Co. and thus keep their wires out of sight. A Public Tele- phone outlet may be placed in the kitchen or pantry with extensions to living room, owner's bedroom and to still other points if desired. A ^4-inch con- duit is ample for the above equipment. Standard Wiring Symbols. Art. 60 : Owners, architects and contractors would save much time and misunderstanding by familiarizing themselves with, and using, the stand- ard symbols as recommended by The National Elec- trical Contractors' Association and The American Institute of Architects, when indicating on plans just what is desired in the way of outlets, fixtures, receptacles, etc., etc., as given on the next page. 188 STANDARD SYMBOLS FOR WIRING PLANS As adopted and recommended by The National Electrical Con- tractors Association of the United States and The American Institute of Architects w Ceiling Outlet; Electric only. Numeral in center indicates number of Xl< Standard 16 C. P. Incandescent Lamps. fm<4 Ceiling Outlet; Combination. % indicates 4-16 C. P. Standard Incandes- >4<5 cent Lamps and 2 Gas Burners. Q If gas only. |>5< Bracket Outlet; Electric only. Numeral in center indicates number of I>6< Standard 16 C. P. Incandescent Lamps. |>^<4 Bracket Outlet; Combination. % indicates 4-16 C. P. Standard Incandes- I>*<2 cent Lamps and 2 Gas Burners. IK If gas only. Ij-, Wall or Baseboard Receptacle Outlet. Numeral in center indicates num- rt^J her of Standard 16 C. P. Incandescent Lamps. M Floor Outlet. Numeral in center indicates number of Standard 16 C. P. Incandescent Lamps. ~$Q Outlet for Outdoor Slandard or Pedestal; Electric only. Numeral indicates number of Standard 16 C. P. Lamps. XX Outlet for Outdoor Standard or Pedestal; Combination. % indicates 6-16 =* 6 . C. P. Standard Incandescent Lamps; 6 Gas Burners. 5J Drop Cord Outlet. (^) One Light Outlet, for Lamp Receptacle. (J Arc Lamp Outlet. fo Special Outlet, for Lighting, Heating and Power Current, as described in Specifications. C2QO Ceiling Fan Outlet. S 1 S. P. Switch Outlet. S' D. P. Switch Outlet. S 3 3-Way Switch Outlet. S" 4-Way Switch Outlet. S" Automatic Door Switch Outlet S Electrolier Switch Outlet. Show as many . Symbols as there are Switches. Or m case of a very large group of Switches, indicate number of Switches by a Roman numeral, thus: S 1 XII, meaning 12 Single Pole Switches. Describe Type of Switch in Specifica- tions, that is, Flush or Surface, Push Button or Snap. Meter Outlet. Distribution Panel. Junction or Pull Box. Motor Outlet; Numeral in center indicates Horse-Power. Motor Control Outlet. = y~y = Transformer. Main or Feeder run concealed under Floor. Main or Feeder run concealed under Floor above. Main or Feeder run exposed. Branch Circuit run concealed under Floor. Branch Circuit run concealed under Floor above. Branch Circuit run exposed. 189 STANDARD SYMBOLS (Continued) ^ Pole Line. Riser. W Telephone Outlet; Private Service. M Telephone Outlet; Public Service. Q Bell Outlet. D/ Buzzer Outlet. 02 Push Button Outlet; Numeral indicates number of Pushes. <|> Annunciator; Numeral indicates number of Points. -^ Speaking Tube. - Watchman Clock Outlet. I Watchman Station Outlet. Hg Master Time Clock Outlet. D Secondary Time Clock Outlet. [J] Door Opener. 12] Special Outlet, for Signal Systems, as described in Specifications. l|||l| Battery Outlet. ( Circuit for Clock, Telephone, Bell or other Service, run under Floor, J concealed. ( Kind of Service wanted ascertained by Symbol to which line connects. (Circuit for Clock, Telephone, Bell or other Service, run under Floor < above, concealed. ( Kind of Service wanted ascertained by Symbol to which line connects. NOTE If other than Standard 16 C. P. Incandescent lamps are de- sired. Specifications should describe capacity of Lamp to be used. When in Doubt. Art. 6 1 : Be guided by the sections on " Approved Apparatus and Supplies" (page 135), and by "Elec- trical Inspection" (page 140). 190 Resuscitation From Electric Shock. As recommended by The National Electric Light Association. Follow these instructions even if vic- tim appears dead. I. Immediately Break the Circuit. With a single quick motion, free the victim from FIG. i INSPIRATION; PRESSURE OFF. the current. Use any dry non-conductor (clothing, rope, board) to move either the victim or the wire. Beware of using metal or any moist material. While freeing the victim from the live conductor have every effort also made to shut off the current quickly. 101 II. Instantly Attend to the Victim's Breathing. As soon as the victim is clear of the conductor, rapidly feel with your finger in his mouth and throat and remove any foreign body (tobacco, false teeth, etc.). Then begin artificial respiration at once. Do not stop to loosen the victim's clothing now ; every moment of delay is serious. Proceed as follows : (a) Lay the subject on his belly, with arms ex- tended as straight forward as possible and with face to one side, so that nose and mouth are free for breathing (see Fig. i). Let an assistant draw for- ward the subject's tongue. (b) Kneel straddling the subject's thighs, and facing his head; rest the palms of your hands on the loins (on the muscles of the small of the back), with fingers spread over the lowest ribs, as in Fig. i . (c) With arms held straight, swing forward slowly so that the weight of your body is gradually, but not violently, brought to bear upon the subject (see Fig. 2). This act should take from two to three seconds. (d) Then immediately swing backward so as to remove the pressure, thus returnig to the position shown in Fig. i. (e) Repeat deliberately twelve to fifteen times a minute the swinging forward and back a complete respiration in four or five seconds. (f ) As soon as this artificial respiration has been started, and while it is being continued, an assistant should loosen any tight clothing about the subject's neck, chest, or waist. 192 2. Continue the artificial respiration (if neces- sary, two hours or longer), without interruption, until natural breathing is restored, or until a physi- cian arrives. If natural breathing stops after being restored, use artificial respiration again. c. Do not give any liquid by mouth until the sub- ject is fully conscious. 4. Give the subject fresh air, but keep him warm. III. Send for Nearest Doctor as Soon as Acci- dent is Discovered. Switchboard and Electrical Fires A liquid extinguisher, called Pyrene, has recently been put on the market. Experiment 'and accept- ance tests made by the largest electric light, power, railroad and transit companies in America and by the underwriters laboratories, indicate that it is of great value to the electrical industry. At several of the tests made short-circuit electrical arcs larger than any that have ever before been intentionally produced, were successfully handled by this extin- guisher, arcs of an indicated energy of 4OO-h.p. being snuffed out by a few ounces of the liquid. It was also found difficult to re-establish the arcs when put out by this preparation. The extinguisher is small and light, working on the principle of a double-acting syringe, can be conveniently located and is easily carried. As the liquid will not freeze at 60 below zero it can be left in exposed places during the winter. No peri- odic recharging is required, although they are re- fillable after use. 193 MISCELLANEOUS. DEFINITIONS OF ELECTRICAL UNITS. All electrical units are derived from the follow- ing mechanical units: The Centimeter is the unit of length, and equals 3937 inch, or .000000001 of a quadrant of the earth. The Gram is the unit of mass, and is equal to 1 5-43 2 grains, the mass of a cubic centimeter of water at 4 C. Tht Second is the unit of time and is the time of one swing of a pendulum, swinging 86464.09 times per day, or the i/864OOth part of a mean solar day. The Volt is the unit of electro-motive force [E]. Electromotive force, which is the force that moves electricity, is usually written E. M. F. (in formulae E)*and various writers use it to express potential, difference of potential, electric pressure and electric force. One volt will force an ampere of current through one ohm of resistance. Its value is purely arbi- trary, but fixed. The Ohm is the unit of resistance [R] and it is equal to the resistance of a column of pure mer- cury i square millimeter in section and 106.3 centi- meters long at the temperature of melting ice. One ohm is that resistance through which one ampere of current will flow at a pressure of one volt of E. M. F. The Megohm 1,000,000 ohms. The Ampere is the unit of current strength [C]. Its value may ,be defined as that quantity of elec- tricity which flows through one ohm of resistance when impelled by one volt of E. M. F. One ampere of current flowing through a bath will deposit 0.017253 grain of silver or 0.004085 grain of copper per second . The Coulomb is the unit of quantity [Q], and is the quantity of electricity passing per second, when the current is one ampere. The Farad is the unit of capacity [K], and is capacity that will contain one coulomb at a poten- tial of one volt. A condenser of one farad capacity, if charged to two volts, will contain two coulombs ; if to 100 volts, 100 coulombs, etc. The Microfarad [mfd] - - one millionth of a farad. The Joule is the unit of work |_\V]. It is the work done or heat generated, by a watt in a sec- ond. It is equal to .7373 foot-pound. The Watt is the unit of electrical power [P], is the energy contained in a current of one ampere with an electromotive force of one volt. 746 watts = one horsepower. A current of 7.46 amperes at 100 volts will do the work of the one horsepower. A Horse-Power in a steam engine or other mover is 550 Ibs. raised one foot per second, or 33,000 Ibs. one foot per minute. The Kilowatt [kw] equals to 1,000 watts. The E. M. F. is distributed according to the re- sistance of the various parts of the circuit, except where there is counter E. M. F. Counter E. M. F. is like back pressure in hy- draulics. Thus, to find the available E. M. F., or 195 the resulting current against a resistance where there is a counter E. M. F., the counter E. M. F. must be deducted. For example: Suppose a stor- age battery with a resistance of .02 ohm and a C. E. M. F. of 15 volts, and you wish to charge it with a dynamo which gives an E. M. F. of 20 volts at the battery binding posts. There are 20 15 - 5 volts working through a resistance of .02 of an ohm with consequently a current of 250 amperes. The impressed voltage is, however, 20 volts, and not 5 volts, and the power is 20 X 250 = 5000 watts, and not 5 X 250 = 1250 watts, as might per- haps be supposed. It is obvious that the C. E. M. F. has acted as a true resistance. In the above case 5 ;X 250 1250 watts were wasted in over- coming the resistance of the storage battery and the remaining 3750 watts were stored up in the chem- ical changes which they brought about in the active material of the storage battery. Mils = Thousandths of an inch. d 2 circular mils. The Circular Mil is now generally used as the unit of area when considering the cross-section of electric conductors, the resistance being inversely, and weight of copper directly, proportion to the circular mils. General Formulae Ohms Laws (Direct Current.) C. = current in amperes. E. ~ electromotive force in volts. R = resistance in ohms. W. = energy in watts. E. E. C = - E. C.R. R. - R. C. E 2 C. E. == W. VV. = - C 8 R. = W. R W. - = H.P. W. =746X H.P. 746 ' Formulae giving the volts or amperes necessary for a given horsepower on circuits of constant cur- rent, and constant potential, respectively: 746 X H.P. ir __ C. X K. . 746 X H.P. E. X K. E. = potential of circuit. C. = afnperes. K. = efficiency of machine. H.P. = horsepower. General Formulae for Direct Current Light and Power Wiring. When possible use the tables on pages 52 and 69, for conveniences. c.m. = circular mils. (See page 81). d. length of wire, in feet, on one side of circuit. n. = number of lamps in multiple. c. = current in amperes per lamp (see p. 115). v. volts lost in lines (see pp. 32 and 70). r. resistance per foot of wire to be used. 10.8 ohms resistance of one foot of commercial copper wire having a diameter of one mil and a temperature of 75 Fahrenheit. ivr It is an easy matter to find any of the above values by the following formulae for direct current: 10.8 X2d. X n- X c. c.m. = v. 10.8 X 2d. X n. X c. c.m. X v. c.m. 10.8 X 2d. X n. c.m. X v. c.m. X v. 2d. = 10.8 X 2d."X c. 10.8 X c. X n. v. - n. X c. X 2d. v. v. = n. X c. X 2d. X r. 2d. X n. X r. v. v. c. X 2d. X r. . n. X c. X r. To find the efficiency of incandescent lamps when : C. current in amperes. E. = electromotive force in volts. E R. = resistance of lamp, hot. C C.P. candlepower of lamp. W. c.p. = watts per candlepower (a measure of efficiency of lamp). (See p. 115.) One electrical H.P. 746 watts. 198 C.XE. Watts per C.P. = C.P. 746 Number candles per electric H.P. = W.c.p, As the efficiency of conversion of good dynamos is 90 per cent., the calculations of candles per elec- trical H.P. must be multiplied by this factor to give the number of candles per mechanical horse-power. The weight and resistance per mile of round wire, where d. is the diameter in mils, are : Weight. Resistance at 75^ d 2 380066 For copper wire Ibs. ohms. 62.5 d 2 d 2 56970 For iron wire Ibs. ohms 72 d 2 To ascertain the sectional area : Diameter = d. Sectional area in circular mils d 2 . Copper wire is 1.14 times the weight of an iron wire of the same size. A copper wire 334 circular mils in cross-section and 1000 feet in length weighs one pound. The percentage of conductivity of any wire is found by multiplying the resistance of a pure wire of the same length and weight at the same tem- perature by 100, and dividing the product by th<: resistance of the wire as measured. 199 Lull. Equivalent Value in Other Unit*. 1 H. P.=s< 746 watts. .846 K. W. 33,000 ft.-lbs. per minute. 550 ft.-lbs. per second. 2,545 heat-units per hour. 42.4 heat-units per minute. .707 heat-unit per second. .175 Ib. carbon oxidized per hr. 2.64 Ibs. water evaporated per hour from and at 212 F. 1 H. P. Hour 746 K. W. hours. 1,980,000 ft.-lbs. 2,545 heat-units. 273,740 k. g. m. .175 Ib. carbon oxidized with perfect efficiency. 2.64 Ibs. water evaporated from and at 212 F. 17.00 Ibs. water raised from 62 to 212" F. 1 KUo- watt 1 Watt per sq. = m. 4 1,000 watts. 1.34 H. P. 2,654,200 ft.-lbs. per hour. 44,240 ft.-lbs. per minute. 737.3 ft.-lbs. per second. 3,412 heat-units per hour. 56.9 heat-units per minute .948 heat-unit per second. .2275 Ib. carbon oxidized hour. 3.53 Ibs. water evaporated hour from and at 212 F. per per 8.19 _heat units per sq. ft. per minute. 6,371 ft.-lbs. per sq. ft. per minute .193 H. P. per sq. ft. 1 Kilo- gram = Metre 7.233. ft.-lbs. .00000365 H. P. hour .00000272 K. W. hour. .0093 heat-units. 1 Ib. Wat- er Evapo- rated =. from and at 212 F. . .283 K. W. hour. .379 H. P. hour. 965.7 heat-units. 103,900 k. g. m. 1,019,000 joules. 751,300 ft.-lbs. .0664 Ib. of carbon oxidized. 200 Unit. Equivalent Value in Other Units. 1 Heat- unit I Heat f unit per sq. it. =1 per mm. 1,055 watt seconds. 778 ft.-lbs. 107.6 .000293 K. W. hour. .000393 H. P. hour. .0000688 Ib. carbon oxidized. .001036 Ibs. water evaporated from and at 212 F. .122 watts per sq. in. .0176 K. W. per sq. ft. .0236 H. P. per sq. ft. 1 joule per second. .00134 H. P. 3,412 heat-units per hour. .7373 ft.-lb. .0035 Ib water evaporated per hour. 44.24 ft.-lbs. per minute. 1 K. W. Hour = 1,000 watt hours. 1.34 H. P. hours. 2,654,200 ft.-lbs. 3,600,000 joules. 3,412 heat-units. 367,000 kilogram metres. ,235 Ib. carbon oxidized with perfect efficiency. 3.53 Ibs water evaporated from and at 212 F. 11.75 Ibs. of water raised from 62 to 212 F. 1 Joule =- 1 watt second. .000000278 K. W. hour. .102 k. g. m. .0009477 heat-units. .7373 ft.-lb. 1 ft.-lb. = 1.356 joules. .1383 k. g. m. .000000377 K. W. hours. .001285 heat-units. 0000005 H. P. hour. 1 Ib. Car- bon Oxi- dized ^ with Per- * feet Ef- ficiency. 14,544 heat units. 1.11 Ib. anthracite coal ox. 2.5 Ibs. dry wood oxidized. 21 cu. ft. illuminating gas. 4.26 K. W. hours. 5.71 H. P. hours. 11,315;000 ft.-lbs. 15 Ibs. of water evaporated from and at 212 F. 201 CONDUIT SIZES FOR DIFFERENT SIZE WIRES. Size of Pipe No. B&S Circular Mills. Amperes Rubber. 1 Wire. 2 Wire. Wire. 18 1,624 3 54 54 54 16 2,583 6 X 54 54 14 4,107 15 54 54 34 12 6,530 20 54 34 34 10 10,380 25 54 34 l 8 16,510 35. 54 l 1 6 26,250 50. 34 l 154 5 33,100 55 34 154 154 4 41,740 70. 34 154 154 3 52,630 80. 34 154 154 2 66,370 90 34 154 2 1 83,690 100 l 154 2 105,500 125 l 2 2 2.0 133.100 150 l 2 2 3.0 167,800 175 154 2 254 4.0 211,600 225 154 2 254 200,000 200 154 2 254 250,000 235 154 254 254 300.000 275 154 254 3 350,000 300 154 ' 254' 3 400,000 325 154 3 3 450,000 380 2 3 354 500.000 400 2 3 354 In laying out a conduit job, first ascertain the size and number of wires required, then take the sizes of conduit from the above table. One-half inch is usually used for branch conduits and is the smallest size permitted by the National Electrical Code. In running several conduits together, a pull *box will be found more economical than elbows for making turns, as one pull box will take the place of several elbows. CONDUIT AND WIRE DIAGRAM SHOWING ACTUAL RELATION OP VARIOUS SIZES DOUBLE BRAID RUBBER COVERED WIRE TO CONDUIT. 203 Underground Conduit: The use of bitumin- ized fibre conduit for all underground work is rec- ommended on account of its simplicity and ease in installing. It is light in weight and practically water and gas proof and has high insulating quali- ties. Unlike metal conduit, for underground work, it is not affected by electrolytic action and may be purchased for one-third the cost of iron pipe. Bituminized conduit is furnished in convenient lengths, bends, elbows, tees and junction boxes in all sizes from one to four inches as per table given below. It may be laid in trenches with or without concrete and is especially adapted to running wires from street mains, to private residences. UNDERGROUND FIBRE CONDUIT. INSIDE THICKNESS BENDS DIAMETER OF WALL LENGTH RADIUS I inches i/4 inch 5 feet 8 inches iX inches 5/T6 inch 5 feet 10 inches 2 inches 3/8 inch 7 feet 12 inches 2 l /l inches 3/8 inch 7 feet H inches 3 inches 3/8 inch 7 feet 18 inches 3 T 4 inches 3/8 inch 7 feet 20 inches 3^2 inches 3/8 inch 7 feet 24 inches 4 inches 3/8 inch 7 feet 30 inches 204 - i- * * c* o O w co ^ c co c? US-^iCDCDCOeOrMCOCOCQrHCOitiCOrHCO o<; >s.\\-x.\\v x \\\ t x. > -vv ; .^.v. S fc ** S rH rH 1 " rH S > on " 'I 1 O O O O O O JU o O) S3 CD O CO CO Gt C* rH rH rH 10 O 00 ^ U-5 * rH ^ ilSw \ \ * " " jig w s ^ ^ ^ gpo o co co ^ CO ^ W rH CO oo t- rH I- V) 10 ? _J OOOOOOOOOOO>OO lOlOt-^OOOOiOtMt-KJrHC* kot-oi i ^ OOidOOOOtOb-lOOdOlO rHcoeo^iooeoeioeoow'*eoi-( t-iO-*COO* OJ OO o o eo o o rH ftg *. co >o ^ eo t- 10 eo o o o o o o o O t-OOOOOOO t-wsc^oosoot-oio ooooooiHCijeo^^oso ooo 206 Ss! ITS o O -* o c- US tf> * 00 t- a J5 ti 2 O CO 10 O CD ^* *o o f^- oo co 10 * O o O O r-l C* ill 8 COS I! IS "5> O 1-4 O> 1-4 f3 g^St-SSco ^ | g ec ^ t: JH oo oo $ J3 <* O 4) C 7 *5o 2 -J o> oo ^S o as 10 us us us .So co * t^ ci o d oo as o* o * in i> us' Hlt/Jrj tHiHCOTj0>OrHrH V "* W iHfHr j ... ._ o S s ft, O O .S u - Q fc ^ -O-M < uoaj W -o w &5 j 1 Pd c 'O 'M '8 'O ' OJJ p3 '3 M OO * vO CO PI u") O^ *t" ON O"" 1 ^ M M M M PI CM CO T*" vO^-CO O 6 ^ ' .' O 2>c co ^J* u~> %/> o co O d ID co co co r* o* u"i O O O I- M r^ M <>oo co PI M M -J- c^co O r^ PI PI o co i^ >-" PI CO vO ^ \n O co O PI O o % D d O O ^ *^ d O d co vO co rt-4tr>vOrAo N i-Icor-'''-'t---pi>-ir)* * " * ' co o^ d *D ^ o^ co 10 O r^ O O ^ O co f~** ^" co co O coco r^* o 1^** **"> ^ co *D co co o* Tf M co vO w") co c^i d ^dOOr^Omrtr-jddi-it-it-i M M M M i-l I I ' O" ^ MM O ^> 0*00 O coo "">co ^'O e^"^eod ir Oco meod Ocoo rl-tod O crco i~\o "~> T T co cOddddWMMMt-i^-MOOOOOOOO OcoCT-Tfdd^OrrdMi-idi-r-Mino^d ddddMi-iM>-M-Hoqoooo ) ooo 1 o O^^cOOcoOu^cOrfOcomeodiricOON w pi cn^fu">O t^co O>O M W tOTl'vrivO t^oo ^O no BREAKING WEIGHTS. ENGLISH SYSTEM. I 1J c Breaking Breaking ew Vji Weight Weight fen c?3 Hard Drawn "Phono- rt Copper. Electric." H Q Pounds Pounds OOOO 460 8310 II460 000 409.6 6580 9140 00 364.8 5226 7400 o 324.9 4558 6300 I 289.3 3746 5250 2 257^ 3129 4180 3 2294 2480 3300 4 204.3 1967 2700 5 l8l.9 1559 2080 6 l62 1237 1680 7 144-3 980 1350 8 128.5 778 1075 9 H4.4 6l 7 850 10 IOI-9 489 68 q ii 9O.74 388 545 12 80.81 307 420 13 71.96 245 340 14 64.08 270 15 57.07 153 220 16 50.82 133 180 17 45.26 97 135 18 40.30 77 107 ELASTIC LIMIT. s l .s Sfc-d Itj-g t a ja J a| Wire. W %l ^-s v g ' rt H Hard Drawn Copper . . . oo 364.8 52000 41775 "Phono-ElectnV" oo 364 8 7^^OO ^786o Hard Drawn Copper. . ,. o 324.9 /OO^ O/" 54000 39645 "Phono-Elect ric" . o 324.9 211 76500 55195 Length of Belting for Various Purposes. IT ( \ Open belting: L = - - S. -f 2C. 2 \ 8 L Length of belt. S = Sum of pulley diameters. C = Distance between centers of pulleys. D = Difference of pulley diameters. TT =3.141592, or, for practical purposes, 3.1416. For calculating the length of belting approxi- mately, add one-half the circumference of each pul- ley to twice the distance between centers of the pulleys. To find the horsepower strength of double leather belting when: d. '== diameter of small pulley in inches. r. = revolutions of small pulley per minute. b. = breadth of belting in inches. H.P. = horsepower to be transmitted. H.P. = 1925 "Double" belting is expected to transmit twice that of "single" belting, and "light double" one and one-half times that of "single." Strength of wrought iron or steel Shafting. (Formula as used by Pencoyd Iron Works.) sh ^ R p = 50 or d = V 7 R ' P ' for shafts carrying pulleys, etc., m Rd' or H.P. = 70 s * i = *y 720 d 2 for bare shafts, or d = V J 720 3 or i = V 140 d 2 for shafts carrying pulleys, etc.. 2 or d = V _il 140 H.P. = horse-power transmitted, d = diameter shaft in inches. R = revolutions per minute. 1 = length between supports in feet. To find the horse-power of engines: in which : H.P. = indicated horse-power. Ps = travel of piston in feet per minute. A == area of piston in square inches. M. E. P. = mean effective pressure in pounds per square inch. Ip =r initial pressure, and: 34Xlp (a) M. E. P. = at VA, cut off. -57 ii Xlp (b) M. E. P. = at y 2 cut off. 13 An application of these formulae in an appropri- ate example may be considered in the following problem : 213 It is desired to determine the I. H. P. of an en- gine whose cylinder is 10 inches in diameter and whose stroke is 12 inches, operating at 300 revolu- tions per minute, the initial steam pressure being 100 pounds per square inch, cutting off at 'J/2 and l /2 stroke, respectively: 34 X Ip 34 X ioo (a) M.E.P. =- - = 59-65 at V 4 57 . 57 cut off. ii X Ip 34 X ioo (&) M.E.P. = = 84.6 at }/2 13 13 cut off. n A = X diameter 2 = .7854 X io 2 = 78.54 square 4 inches. Ps = .2 feet per revolution and 30 resolutions per minute = 600 feet per minute. Ps X A X M. E. P. I. H. P. at 54. cut off = - 33,000 600 x 78.54 x 59-65 - = 85.18 33,000 Ps X A X M. E. P. I. H. P. at */> cut off = - 33,000 600 X 78-54 X 84.6 33,000 214 To find the horse-power of a pulley: Multiply the circumference of the pulley in feet by the revolutions per minute, and the product thus obtained by the width of the belt in inches, and di- vide the result by 600. This rule is founded on the fact that good, ordi- nary, single leather belting, with a tension of fifty- five pounds per inch width, will require fifty square feet of belt surface passing over the pulley per min- ute for one horsepower. Fifty square feet per minute is equal to a belt one inch wide running 600 feet per minute. To find the speed of a belt, multiply the circum- ference of the driving pulley in feet by the revolu- tions per minute. Belts should always be run with the grain side next to the pulley. Rule for finding size of dynamo driving pulleys. DXS S l d required diameter of dynamo pulley. D = diameter of engine pulley. S = number of engine revolutions per minute. S 1 = required revolutions of armature per min- ute. The light cut-off by arc lamp globes is Ordinary glass ........................ 10% Light ground glass .................... 30% Heavy ground glass .................. 45 to 50% Strong opal glass ..................... 50 to 60% 215 INDEX TO CONTENTS. Appliances, Current Consuming, Sugges- tions % 181-186 Approval, of Apparatus and Supplies 135 Approved Apparatus and Supplies 135 Arc Lamps, Installation 130 Arc Lamps, Series 86 Arc Lamps, Series Wiring 85 Arc Lamps, Wiring, High Potential (Con- stant Current) 131 Arc Lamps, Wiring, Low Potential (Con- stant Potential) 132 Arms, Guard 40 Arresters, Lightning, Outside 48 Arresters, Lightning, Station . . . . v n Attendance, in Generator Room 22 Auto-Starters 25 Batteries, Storage, Installation of 13 Bearings, Care of 21 Belts, For Generators and Motors 15 Brushes, Copper and Carbon 15-1? Bus-Bars 7 Cabinets, General Specifications. . 128-130 Cabinets, Wood and Metal 129 Cables, Armored, Installation 157 Cables, Armored, Makers of 101 Circuit Breakers, For Generators 5 Circuit Breakers, For Motors 28 Circuit Breakers, Installation 104-106 Circuit Breakers, Where Required 84 Circuits, Branch I 55~i56 216 Coils, Economy 132 Commutators, Care of 20 Conduit, Bushings 94 Conduit Fitting, Use of 160 Conduit, Fittings . 95 Conduit, Flexible Steel, Installation 158 Conduits, For Bell Wiring 159 Conduit, Metal, Flexible Steel 93 Conduit, Metal, Rigid 92 Conduit, Non-Metallic Flexible 92 Conduits, Rigid, Metal, Installation 158 Conduit, Underground, Fibre 204 Conduit, Wiring 91 Connectors, Solderless for Wires and Cables 40 Covers, For Motors and Generators 6 Cross Arms 59 Current Supply 146-149 Cut-Outs, Automatic 103 Cut-Outs, Link Fuse 1 19-122 Cut-Outs, Protection and Care of 85 Extinguishers, For Electrical Fires 12, 193 Fires, Electrical, Extinguishing of 193 Fixtures, Lighting, Installation 98 Fixtures, Wiring of 99 Flexible Tubing, Installation of ("Knob" and Tube Work") 83 Formulae, See Index on Page 222 Fuse Blocks, Specifications 121 Fuses, Enclosed, Approved Makes 124 Fuses, Enclosed, Dimensions 125-126 Fuses, Enclosed, Cartridge and Plug Types 122-126 Fuses, For D. C. Motors 30 217 Fuses, Link, Specifications 128 Fuses, Open Link, Dimensions 122, 127 Fuses, Refillable (Unapproved) 124 Generators, Accessibility 5 Generators, Care of 14 Generators, Directions for Starting 17-20 Generators, Foundations 4 Generators, Installation . 3 Generators and Motors, Wiring Diagrams . . 33-38 Ground, Connections 46-51 Ground Detectors 13, 50 Ground Plates, Installation of 50 Ground Wires 12 Grounding 151-152 Grounding, A. C. Secondary 46 Grounding, Generator and Motor Frames . . 4, 22 Grounding, Low Potential Circuits 45 Grounding, 3~Wire D. C 45 Guard Irons, Where Required 60 Hanger Boards 133 Heaters, Electric, Installation , . . 133 High Voltage Circuits (5000) 55 House Wiring, Suggestions 141-190 Illumination, By Incandescent Lamps 117-118 Inspection, Of Wiring Installations . 140 Insulation Resistance, Testing 13 Insulators, Canopy, For Fixtures 107 Insulators, Petticoat 40-41 Insulators, Porcelain Knobs and Cleats.... 68 Insulators, Tree 41 Joints, Insulating 106-107 "Knob and Tube" Work 91-156 218 Lamps, Arc (See Arc Lamps) . . 216 Lamps, Incandescent, Arrangement... 118 Lamps, Incandescent, Data 114-117 Lamps, Mercury Vapor 1 17 1 .amp Wiring, Series Incandescent 87 Lighting, Arc and Incandescent Lamps.... 119 Lighting, Suggestions for Architect and ( hvner . . 177-181 Mains, For House Wiring 152 Motors, Current Required (D. C.) 3O-3 1 Motors, Efficiency of (D. C.) 29 Motors, Installation Diagrams 33~38 Motors, Installation of 22-38 Motors and Generators, Wiring Diagrams.. 33-38 Motors, Starting and Stopping Directions.. 27 Motors, Wiring Formula for D. C 29 Moulding, Metal 159 Moulding, Metal, Installation 90 Moulding, Metal, Specifications 89 Moulding, Wood, Installation . . . > 88 Moulding, Wood, Specifications 88 Moulding, Wood, Where Used 159 Xame Plates, for Generators and Motors .... 6 National Electric Light Association, Sugges- tions from 141-193 Ohm's Law, General Formulae (D. C.) . . . . 196-197 Outlets, Location of, Diagrams 166-175 Panels, Distributing 153-155 Poles,' Directions for Setting 58 Poles, For Light and Power Wires 57-64 Poles, Per Mile 62-63 Poles, Size and Weight 61 219 Rates, Current Costs 150 Receptacles, Flush, Distribution. 168 Resistance, Insulation of Wiring 107-108 Resistance, Measurement (Megger Method) 51 Rheostats or Controllers 9, 24 Roof Structures 39, 43 Rosettes, Wiring of 99 Service Blocks 42 Service Heads 44 Service, How to Obtain 141-143 Shock, Electric, Resuscitation from 191-193 Society for Electrical Development, Sugges- tions from 186-190 Sockets, Lamp, Construction of 102 Sockets, Lamp, Special 102 Splicing Devices, Approved 40 Splicing, Wires and Cables 40 Switchboards, Location of 8 Switches, Closet . 166-167 Switches, Cut-outs, Circuit Breakers 84 Switches, Flush 113 Switches, for Room, Convenience 164-165 Switches, Knife, Installation of 111-113 Switches, Knife, Specifications 108-110 Switch, Master 165 Switches, Motor 167 Switches, Pilot, Where Used 167 Switches, Snap 113-114 Symbols, Used for Wires, Outlets, Fixtures, Etc ....188-190 Tables, See Index on Page. . , 223 Tables, for Dimensions, Capacities, Etc 223 220 Telegraph and Telephone Wires 44 Terms, Electrical, Definition of 194-196 Transformers, Bell Ringing, Location 188 Transformers, Light & Power, Installation. 44, 49 Underground Wiring . . 61 Units, Electrical, Definition of 194, 200-201 Voltage, in House Wiring 148 Voltage, Loss in Conductors 163 W r hen in Doubt 190 Wire, Con 96 Wire, for Resistance Use 161 Wires, and Cable, Splicing 68 Wires, Carrying Capacity 68, 81 Wires, Dimensions (See Tables) 222 Wires, Entrance, Main Switch and Meters. . 149 Wires, For Outside Use 54 Wires, Installation of, Open Work 79-84 Wires, Insulation 66-67 W r ires, Line 39 Wires, List of Approved Makers 66-67 Wires, Protection on Walls 80 Wires, Rubber Covered 66 Wires, Service 39, 42 Wires, Slow-Burning and Weatherproof ... 67 .Wires, Stranded .69, 103 Wires, Tie 39 Wires, Tie, Inside 68 Wires, To Find Proper Size 69 Wires, Twin 80 Wiring, Alternating Current (A. C.) 70-78 Wiring, Car House 133 Wiring, Cleat Work, Open 159 221 Wiring, Concealed 90 Wiring, Conduit 91 Wiring, Costs, Approximate 160-161 Wiring, in Fixtures 100 Wiring, Inside, General Suggestions 66 Wiring, Flexible Cord 100-101 Wiring, for High Voltage 56-57 Wiring, for Telephone and Bell Service. . . . 162 Wiring, for Telephone and Bell, Sugges- tions 186-189 Wiring, from Generators and Switchboards 7 Wiring, from Service Mains to House. . . .143-146 Wiring, Primary A. C 60 Wiring, Special for Damp Places 87 Wires, Strength of 82 Wiring, Suggestions for Hall and Vestibule 166 Wiring, Suggestions to Architects and Owners 141-190 Wiring, Support in Conduits 97 Wiring Tables, (See Tables) 222 Wiring, Through Walls, Floors, Etc.. 80-84 Wiring, Tree 42 FORMULAE. To Find : Belting, Proper Length and Strength 166 Circulars Mils, Size of Wire 197 Current, in Amperes, D. C 197 Current Required, for D. C. Motors f 30 Efficiency, Lamps, Motors, Etc 198 Engines, Steam, Horse-power . .213-214 Ohms Law, All Values for D. C 196-197 Pulleys, Proper Sizes 215 Resistance, in Ohms, D. C 198 Shafting, Iron and Steel, Proper Size 212-213 Voltage, Electromotive Force, D. C 198 Watts, Per .Candle-power 199 Weight of Copper and Iron Wire. 199 Wire, Size for i -phase, 2-wire 77 Wire, Size for I -phase, 3-wire 78 Wire, Size for 2-phase, 3-wire, Lighting . . 75 Wire, Size for 3-phase, 3-wire, Motor .... 73 Wire, Size of, for A. C., General 73-?8 Wire, Size of, for D. C. Motors. . 29 TABLES. Amperes per Motor, A. C 72 Amperes, per Motor, D. C 31 Cables, Armored, Makers of 101 Cables, Stranded, Rubber Covered, Dimen- sions 208 ( ables, Stranded, Weatherproof , Dimen- sions 206 Conduit, Sizes for i, 2 and 3 Wires, or Cables 202-203 Conduit, Underground, Fibre, Dimensions. . 204 Efficiency, Motors, D. C 29, 31 Fuses, Approved Enclosed, Dimensions. . . .125-126 Fuses, Enclosed, Approved Makers 124 Fuses, Open Link, Dimensions 122 Fuses, Size of, for Motors, (A. C.) 72 Fuses, Size of, for Motors, (D. C.) 30 Insulation, of Wiring in Buildings 107-108 Lamps, Carbon, Gem, Mazda, Tungsten. . 115-116 293 Lamps, Mercury Vapor (Cooper Hewitt).. 117 Lamps, Variations with Voltage 116 Light, Cut Off by Various Glass Globes. ... 215 Poles, Cedar, Size and Weight . 61 Poles, No. per Mile and Distance Between. . 62-63 Switches, Knife, Dimensions no Symbols, for Wiring Plans 189-190 Unit-s, Electrical and Power, Values 200-201 Volts Lost at Different Per Cent. Drop 32 Wire, Approved Rubber Covered, Makers. . 66-67 Wire, Bare Copper, Strength of 82 Wire, Carrying Capacity, Dimensions, Etc. . 81 Wire, Current Required to Fuse 127 Wire, Equivalent Cross Sections 82 Wire, Insulation Thickness 66-67 Wire, Iron, Steel, Copper, Comparative. . . . 210 Wire, Magnet, Fine, Resistance and Weight 209 Wire, "Phono-Electric" and Hard Drawn, * Comparative Strength 211 Wire, Proper Size for Currents and Loss in Volts 70, 74, 76 Wire, Resistance and Weight, per 1000 feetSi, 137 Wire, Rubber Covered, Solid, Dimensions . . 207 Wire, Size for A. C. Systems 70-76 Wire, Supporting Distance in Conduits. ... 97 Wire, Weatherproof, Solid, Dimensions... Wire, Weatherproof, Weight Between Poles 62-63 Wiring Costs, Approximate, House 160 224 CLASSIFIED INDEX MANUFACTURERS OF OFFICIALLY APPROVED APPARATUS AND SUPPLIES (See Pages 4 and 5 for Addresses) ADJUSTERS, LAMP CORD Trumbull Electric Mfg. Co. AMMETERS AND VOLTMETERS General Electric Co. Hoyt Elecl. Inst. Co. L. M. Pignolet Westinghouse Elec. & Mfg. Co. Weston Elecl. Inst. Co. ASBESTOS H. W. Johns-Manville Co. ATTACHMENT PLUGS Bryant Electric Co. Cutler-Hammer Mfg. Co. General Electric Co. Pass & Seymour, Inc. Trumbull Elec. Mfg. Co. AUTO-STARTERS Cutler-Hammer Mfg. Co. General Electric Co. Monitor Controller Co. Westinghouse Elec. & Mfg. Co. BOOKS, ELECTRICAL John Wiley & Son, Inc. BUSHINGS, PORCELAIN General Electric Co. Pass & Seymour, Inc. CABINETS Frank Adam Electric Co. Bryant Electric Co. General Electric Co. Post-Glover Electric Co. Sprague Elec. Wks. of G. E. Co. Trumbull Elec. Mfg. Co. CABLES, ARMORED National Metal Molding Co. Safety-Armorite Conduit Co Sprague Elec. Wks. of G. E. Co. Western Conduit Co. CANOPY INSULATORS General Electric Co. The Macallen Co. CIRCUIT BREAKERS Condit Elecl. Mfg. Co. Cutter Electric & Mfg. Co. General Electric Co. Westinghouse Elec. & Mfg. Co. CLEATS, & KNOBS, PORCELAIN Cook Pottery Co. General Electric Co. Pass & Seymour, Inc. COMPOUNDS, INSULATING Walpole Tire & Rubber Co. CONDUIT, FLEXIBLE, NON- METALLIC Alphaduct Company American Circular Loom Co. American Conduit Mfg. Co. National Metal Molding Co. Tubular Woven Fabric Co. CONDUIT, FLEXIBLE STEEL National Metal Molding Co. Safety-Armorite Conduit Co. Sprague Elec. Wks. of G. E. Co. CONDUIT, RIGID METAL American Circular Loom Co. American Conduit Mfg. Co. National Metal Molding Co. Safety-Armorite Conduit Co. Sprague Elec. Wks. of G. E. Co. Western Conduit Co. CONDUIT BOXES Frank Adam Electric Co. Chicago Fuse Mfg. Co. Gillett-Vibber Co. Sprague Elec. Wks. of G. E. Co. CONNECTORS, SOLDERLESS Dossert & Company CURRENT TAPS Bryant Electric Co. General Electric Co. CUT-OUT BASES (For Edison Plug Type Fuses) Bryant Electric Co. General Electric Co. Trumbull Elec. Mfg. Co. Westinghouse Elec. & Mfg. Co. CUT-OUT BASES (For inclosed fuses) Bryant Electric Co. Chicago Fuse Mfg. Co. D & W Fuse Co. General Electric Co. H. W. Johns-Manville Co. Trumbull Elec. Mfg. Co. Westinghouse Elec. & Mfg. Co. EXTINGUISHERS, FIRE Pyrene Manufacturing Co. FIXTURES, ELECTRIC Frank Adam Electric Co. Gas Fixture & Brass Co. Post-Glover Elec. Co. Wakefield Brass Co. INSULATORS, POLE LINE Brookfield Glass Co. Hemingray Glass Co. KNOBS & CLEATS, PORCELAI] Cook Pottery Co. General Electric Co. Pass & Seymour, Inc. LAMP CLUSTERS Luminous Unit Co. FLEXIBLE CORDS (See Wires) FUSES, ENCLOSED Bryant Electric Co. Chicago Fuse Mfg. Co. Condit Elecl. Mfg. Co. Detroit Fuse & Mfg. Co. D & W Fuse Co. General Electric Co. H. W. Johns-Manville Co. Westinghouse Elec. & Mfg. Co. FUSES, PLUG TYPE, EDISON Bryant Electric Co. Chicago Fuse Mfg. Co. D & W Fuse Co. General Electric Co. ' H. W. Johns-Manville Co. FUSES, OPEN LINK Condit Elecl. Mfg. Co. Chicago Fuse Mfg. Co. General Electric Co. Walker Electric Co. Westinghouse Elec. & Mfg. Co. GAUGES, WIRE Novelty Electric Co. GENERATORS (See Motors) GROUND CLAMPS Condit Elecl. Mfg. Co. Fairmount Elec. Mfg. Co. General Electric Co. Gillette-Vibber Co. Hart Mfg. Co. Novelty Electric Co. Sprague Elec. Wks. of G. E. Co. HANGER BOARDS, ARC Bryant Electric Co. General Electric Co. HEATERS, ELECTRIC (Soldering and Flat Irons) Cutler-Hammer Mfg. Co. General Electric Co. Westinghouse Elec. & Mfg. Co. INSULATING JOINTS The Macallen Co. Trumbull Elec. & Mfg. Co. LAMPS, INCANDESCENT Buckeye Electric Division General Electric Co. Lux Mfg. Co. National Lamp Wks. of G. E. C Westinghouse Elec. & Mfg. Co. LAMPS, MERCURY VAPOR Cooper Hewitt Elec. Co. LAMP CLUSTERS General Electric Co. LIGHTNING ARRESTERS Electric Service Supplies Co. General Electric Co. Westinghouse Elec. & Mfg. Co. "MEGGERS" (For Measuring Resistance) James G. Biddle METERS, WATT General Electric Co. Westinghouse Elec. & Mfg. Co. MOTORS Emerson Elec. Mfg. Co. General Electric Co. Robbins & Myers Co. Sprague Elec. Wks. of G. E. Co Westinghouse Elec. & Mfg. Co. MOTORS, FAN (See Motors) MOULDING, METAL American Circular Loom Co. National Metal Molding Co. PANEL BOARDS Frank Adam Electric Co. Bryant Electric Co. General Electric Co. Post-Glover Electric Co. Sprague Elec. Wks. of G. E. Co. Trumbull Elec. Mfg. Co. Walker Electric Co. RECEPTACLES Bryant Electric Co. General Electric Co. Pass & Seymour, Inc. TrumbuU Elec. Mfg. Co. RTIEOSTATS Cutler-Hammer Mfg. Co. General Electric Co. Monitor Controller Co. Sprague Elec. Wks. of G. E. Co. Westinghouse Elec. & Mfg. Co. ROSETTES Bryant Electric Co. General Electric Co. Pass & Seymour, Inc. Trumbull Elec. Mfg. Co. SOCKETS, STANDARD Rryant Electric Co. General Electric Co. Pass & Seymour, Inc. SOCKETS, PORCELAIN Bryant Electric Co. Cutler-Hammer Mfg. Co. General Electric Co. Pass & Seymour, Inc. SOCKETS, WEATHERPROOF Bryant Electric Co. General Electric Co. H. W. Johns-Manville Co. Pass & Seymour, Inc. Trumbull Elec. Mfg. Co. SOLDERING FLUX Burnley Battery & Mfg. Co. M. W. Dunton Co. SOLDERING IRONS Vulcan Electric Heating Co. SWITCHBOARDS (See Switches, Knife) SWITCH BOXES Bryant Electric Co. Chicago Fuse Mfg. Co. Cutter Elecl. & Mfg. Co. Detroit Fuse & Mfg. Co. General Electric Co. Hart Mfg. Co. H. W. Johns-Manville Co. Machen & Mayer Elecl. Mfg. Co. Sprague Elec. Wks. of G. E. Co. SWITCHES, AUTOMATIC, TIME Reliance Automatic Lighting Co. SWITCHES, KNIFE Frank Adam Electric Co. Bryant Electric Co. General Electric Co. Post-Glover Elec. Co. Trumbull Elec. Mfg. Co. Walker Electric CD. Westinghouse Elec. & Mfg. Co. SWITCHES, OIL BREAK Condit Elecl. Mfg. Co. General Electric Co. Westinghouse Elec. & Mfg. Co SWITCHES, SNAP Bryant Electric Co. Cutler-Hammer Mfg. Co. General Electric Co. Pass & Seymour, Inc. Trumbull Elec. & Mfg. Co. SWITCHES, FLUSH, PUSH Bryant Electric Co. Cutler-Hammer Mfg. Co. Cutter Elecl. & Mfg. Co. General Electric Co. Hart Mfg. Co. Machen & Mayer Elecl. Mfg. Co. SWITCHES, FLUSH, ROTARY Bryant Electric Co. General Electric Co. Hart Mfg. Co. TAPE, FRICTION, INSULATING M. W. Dunton Co. The Okonite Co. Walpole Tire & Rubber Co. TRANSFORMERS, LIGHT AND POWER General Electric Co. Westinghouse Elec. & Mfg. Co. TRANSFORMERS, BELL RINGING General Electric Co. Westinghouse Elec. ?vlfg. Co. VEHICLES, ELECTRIC General Vehicle Co., Inc. WIRE, BARE, COPPER Bridgeport Brass Co. Phillips Ins. Wire Co. John A. Roebling's Sons Co. WIRE, RUBBER COVERED American Electrical Works American Steel & Wire Co. Atlantic Ins. Wire & Cable Co. Bishop Gutta-Percha Co. Electric Cable Co. General Electric Co. Habirshaw Wire Co. Indiana Rubber & Ins. Wire Co. Kerite Ins. Wire & Cable Co. Lowell Ins. Wire Co. National India Rubber Co. The Okonite Co. Phillips Ins. Wire Co. John A. Roebling's Sons Co. Rome Wire Co. Simplex Wire & Cable Co. Standard Underground Cable Co. WIRE, FLEXIBLE CORD (See Wire, Rubber Covered) WIRE, SLOW-BURNING American Electrical Works American Steel & Wire Co. Chicago Ins. Wire Co. General Electric Co. Chicago Ins. VVire Co. Phillips Ins. Wire Co. General Electric Co. John A. Roebling's Sons Co. National India Rubber Co. Standard Underground Cable Co. Phillips Ins. Wire Co. John A. Roebling's Sons Co. WIRE, SLOW-BURNING WEATH- Simplex Wire & Cable Co. ERPROOF Standard Underground Cable Co. Chicago Ins. Wire Co. General Electric Co. WIRE, "PHONO-ELECTRIC 1 ' Bridgeport Brass Co. WIRE, WEATHERPROOF American Electrical Works WIRE, RESISTANCE American Steel & Wire Co. Driver-Harris Wire Co. List of Advertisers of Standard Apparatus and Supplies Only Apparatus and Supplies that are officially approved, or per- mitted to be used, by the National Board of Fire Under- writers will be accepted in the following pages. ADAM ELECTRIC CO., FRANK 4<; ALPHADUCT CO 56 AMERICAN BRASS CO 42 AM. CIRCULAR LOOM CO 57 AMERICAN" CONDUIT MFG. CO 55 AMERICAN ELECTRICAL WO ; RKS 36 AMERICAN STEEL & WIRE CO 43 ATLANTIC INS. WIRE & CABLE CO 38 BIDDLE, JAMES G 47 BISHOP GUTTA-PERCHA CO 29 BRIDGEPORT BRASS CO 40 BROOKFIELD GLASS CO 22 BRYANT ELECTRIC CO 67 BUCKEYE LAMPS 61 BURNLEY BATTERY & MFG. CO 64 CENTURY ELECTRIC CO... 93 CHICAGO FUSE MFG. CO 74 CHICAGO INS. WIRE & MFG. CO 31 CONDIT ELECL. MFG. CO 76 COOK POTTERY CO 63 COOPER HEWITT ELECTRIC CO 14 CUTLER-HAMMER MFG. CO 19 CUTTER CO., THE 12 & 13 D & W FUSE CO 73 DETROIT FUSE & MFG. CO 75 DOSSERT & CO 52 DRIVER-HARRIS WIRE CO 71 DUNTON CO., M. W 81 ELECTRIC CABLE CO 32 ELECTRIC VEHICLE HAND-BOOK 82 ELBLIGHT CO. OF AMERICA 92 ELECTRIC SERVICE SUPPLIES CO 62 EMERSON ELECTRIC MFG. CO 20 4 FRANKLIN STEEL WKS 90 GAS FIXTURE & BRASS CO 85 GENERAL ELECTRIC CO 10 & 11 GENERAL VEHICLE CO 70 GILLETTE- VIBBER CO 78 HABIRSHAW WIRE CO 25 HART MFG. CO 45 IIASKINS GLASS CO 91 HEMINGRAY GLASS CO 23 HOYT ELECL. INST. CO 51 INDIANA RUBBER & INS. WIRE CO 30 JOHNS-MANVILLE CO., H. W 72 KERITE INS. WIRE & CABLE CO 26 LOWELL INS. WIRE CO 35 LUX MFG. CO 65 MACALLEN CO., THE 16, 17 & 18 MACHEN & MAYER ELECL. MFG. CO 44 MASS. ELEC. MFG. CO, 98 MONITOR CONTROLLER CO 79 MORGAN CRUCIBLE CO 89 NATIONAL INDIA RUBBER CO 41 NATIONAL LAMP WKS., OF G. E. CO 7 NATIONAL METAL MOLDING CO 60 XOVELTY ELECTRIC CO 53 THE OKONITE CO 27 OTTO GAS ENGINE WKS... 99 PASS & SEYMOUR, INC 77 PHILLIPS. INS. WIRE CO 34 PHOENIX GLASS CO 88 PIGNOLET, L. M 50 POST-GLOVER ELECTRIC CO 66 P YRENE MFG. CO 100 RELIANCE AUTOMATIC LIGHTING CO 24 ROBBINS & MYERS CO 21 ROEBLING'S SONS CO., JOHN A..' 28 ROME WIRE CO 37 SAFETY-ARMORITE CONDUIT CO 54 SIMPLEX WIRE & CABLE CO 39 SIMPLEX TIME RECORDER CO 84 SPRAGUE ELECTRIC WKS., OF G. E. CO 8&9 STANDARD UNDERGROUND CABLE CO 33 STAR EXPANSION BOLT CO 83 STAR PORCELAIN CO 86 TRUMBULL ELEC. MFG. CO 49 TUBULAR WOVEN FABRIC CO 58 VULCAN ELEC. HTG. CO 87 WAKEFIELD BRASS CO., F. W 68 WALPOLE TIRE & RUBBER CO 69 WALKER ELECTRIC CO 15 WESTERN CONDUIT CO 59 WESTINGHOUSE ELECTRIC & MFG. CO 6 WESTON ELECL. INSTRUMENT CO 48 WILEY & SON, INC., JOHN 80 5 Westinghouse Switchboards 'THE use of Westinghouse 7-inch Meters permits the panels of this board to be only 16-inches wide. The wiring at rear of board is complete. When in- stalling it is only necessary to connect the cables to the terminals provided, and everything is ready for imme- diate operation. The panels illustrated control a motor-generator set consisting of a 2200 volt Westinghouse synchronous Motor and a 275 volt Westinghouse Direct-Current Gen- erator for mining service. These boards can be shipped "rom stock in all usual capacities. Westinghouse Electric & Mfg. Co. Sales Offices in All Large Cities East Pittsburgh Pennsylvania IT ME dJTLJA LIT Y JL A M 3 MIAEJIE C KI A MI E K I C A WHEN you take a customer's money in ex- change for a lamp you are the one he holds responsible for its quality. The reputation of your house will profit or suffer in degree according to the kind of service that lamp will give. When, therefore, you place your name back of National MAZDA Lamps, you are per- fectly justified in demanding an assurance of their high quality. National MAZDA lamp quality is founded on the technical knowledge of experts. National MAZDA lamps are the culmination of years of effort on the part of the Research and Develop- ment Laboratories of the General Electric Com- pany at Schenectady and Cleveland laboratories that have access to every improvement produced in other leading laboratories of the world. But just as important as this basis of National Quality is the maintenance of that quality by careful methods of manufacture, by a rigid in- spection of all raw materials, by a constant test- ing of product and by a vigilant lookout for improvements that will still further raise the standard of quality. From factory to socket National MAZDA lamps mean satisfaction. Nela Park, Cleveland Member Society for Electrical Development "Do it Electrically" SPRAGUE FLOOR BOXES Adjustable. Non-Adjustable. Adjustable Gang. "ABSOiLyTELY WATERTIGHT." Sectional View of No. 6650 Adjust- able Floor Box, Showing Extreme Adjustment. No. 6860 Midget Non- Adj ustable Floor Box Sectional View of No. 6650 Adjustable Flooi Box Showing G. E. Receptacle No. GE700 and Cap No. 49487 in posi- tion. OUTLET AND SWITCH BOXES AND COVERS r No. 6200 Box with 6206 No. 6350 Octagon Box Canopy Cover with Ears with 6387 Pendant Cover, Drilled and Tapped. ^" Insulating Bushing. SIMPLE PRACTICAL Interchangeable with Boxes and Covers of other manufacture Clean cut knockouts FITTINGS AND TOOLS SPRAGUE ELECTRIC WORKS OF GENERAL ELECTRIC COMPANY Main Offices: 527-531 West 34th Street New York, N. Y. Branch Offices in Principal Cities TRADEMARK SPRAGUE BX CABLE UEG.U3.PAT.OFF. Hot Galvanized Flexible Steel Armored New Code Insulation Distinguishable Braids. GREENFIELD CONDUIT Flexible Steel Conduit with Coupling The Most Practical Form of Well Galvanized Unlined Metallic Conduit on the Market. GREENFIELDUCT The Only Hot Galvanized Rigid Iron Conduit The Standard by Which All Other Galvanized Conduits Are Compared SPRAGUE ELECTRIC WORKS OF GENERAL ELECTRIC COMPANY Main Offices: 527-531 West 34th Street New York, N. Y. Branch Offices in Principal Cities A Device for Every Use A few devices illustrating the great variety of G-E wiring supplies are shown in the above group. A complete stock of G-E reliable wiring devices includes every device for use in making installations or extending lighting or power lines in factories, stores, restaurants places of amusement or homes. In fact, all that is required by the up-to-date electrical contractor will be found in a G-E assortment. The careful construction of G-E Wiring Supplies insures absolute reliability. This careful construction, together with excellence of design and quality of material, result in a completed product fulfill- ing all requirements of the National Board of Fire Underwriters for electric wiring. Electrical contractors and electricians should specify G-E material for all electrical work under their direction. The large G-E assort- ment meets every wiring need, making standardization easy and insuring the highest possible quality throughout, coupled with per- manent satisfaction. G-E Wiring Devices are for sale by all leading jobbers of electrical material. General Electric Company Largest Fltctrical Manufacturers in the World Atlanta, Ga. General Office: Schenectady, N. Y. Omaha, Neb. Baltimore, Md ADDRESS NEAREST OFFICE 2SjS?pk F Birmingham, Ala. S 1 " 8 ,^, 8 ' A Boston, Mass. Buffalo, N. Y. Butte, Mont. Charleston, W. Va. Charlotte, N. C. Chattanooga, Tenn. Duluth, Minn. Chicago, 111. Elmira, N. Y. Cincinnati, Ohio. Erie, Pa. Cleveland, Ohio Columbus, Ohio Dayton, Ohio Portland, Ore. Providence. R. I. Richmond, Va. Rochester, N. Y. San Francisco, Cal. Salt Lake City, Utah St. Louis, Mo. Schenectady, N. Y. Louisville, Ky. Memphis, Tenn. Milwaukee, Wls. Fort Wayne, Ind. Minneapolis, Minn. Seattle, Wash. Indianapolis, Ind. Nashville, Tenn. Spokane, Wash. Jacksonville, Fla. New Haven, Ct. Springfield, Mass. Denver. Colo. Joplin, Mo. New Orleans, L*. Syiacuse, N. Y. Des Molnes, la. Kansas City, Mo. New York. N. Y. Toledo, Ohio Detroit, Mich. Knoxville, Tenn. ' Niagara Falls. Washington, D. C. (Office of Agent) Los Angeles, Cal. N. Y. Youngstown, O'hio For Texas, Oklahoma and Arizona business refer to Southwest General Elec- tric Company (formerly Hobson Electric Co.), Dallas, El Paso, Houston, and Oklahoma City. For Canadian business refer to Canadian General Electric Company, Ltd., Toronto, Ont. 4&24 MEMBER THE SOCIETY FOR ELECTRICAL DEVELOPMENT, INC. "DO IT ELECTRICALLY" 10 G-E Reliable Wiring Devices Adjustable Terminal Ground Clamps Attaching Plugs Automobile Wiring Acces- sories Cable Connectors and Plug Couplings, Push Button Switches, Sockets and Re- ceptacles, Snap Switches, Hand Searchlight, Battery Charging Plug and Recep- tacle, Cutouts, Glass Tube Fuses. Boards Arc Lamp Ceiling, Pilot Lamp Connector, Buzzer, Alternating Current; Buzzer, Combined Switch and Connectors Cord, Three-heat. Cutouts Combined Switch and Plug, Electrolier, Enclosed Fuse, 250 Volt; Enclosed Fuse, 600 Volt; Enclosed Fuse, 2500 Volt. Fuses Enclosed, Link, Plug, Plug and Reloads, Potential, Train Control Equipment, Fuse Wire, Fuse Clips and Ter- minals. Insulators Porcelain Clamp, Rack, In- , sulator Racks, Iron Boxes with Cutouts, Knockdown Panel Circuits, Knockdown Panel Circuit Parts, Lamp Guards, Portable. Lever Switches Miniature, Motor Starting and Running, Punched Clip, Type L Form D12, Type Q Form C2. Plugs Attaching, Combined Socket and _ Separable Attaching, Combined Switch and Sepa- rable Attaching. Fuse Minia- ture Swivel, Miniature Sep- arable, Separable Attaching, Socket, Swivel, Porcelain Specialties. Receptacles Automobile, Conduit, Con- duit Box, Double Door Flush, Indicating and Test- ing Lamp, Machine Shop, Marine, Metal Shell, Minia- ture and Candelabra, Porce- lain, Quick Make and Break 660 Watts, Remov- able Flush Wall, Separable, Sign. Rosettes Fused and Fuseless. Snap Switches Accessories and Cutouts, Ceiling, Conduit, Fan Mo- tor, For Automobile Light- ing, Moulding, Panel Board, Pendent, Porcelain, Remote Control, Series Parallel, Small Motor Control, With Extra Deep Bases, 600 Volt. Shadeholders Sockets Acorn Shell, Automobile, Candle, Electrolier, Exten- sion Kev. Extra Loner Key, Socket Handle and Adjuster, Brass Shell, Key and Kev- less; Locking Marine Weath- erproof, Miniature and Can- delabra, Porcelain, Key and Kevless: Pull, Quick Make and Break 660 Watts, Series, Special Designs, Spe- cial Finishes, Three-Way, Weatherproof, 650 Volt. Socket Handles and Adjusters Socket Plugs and Bushings Socket Rings Strips Battery, Interconnection. Switches Flush Push Button, Flush Rotary, Lever, Surface Snap, Pendent. Terminals Fuse Clips and Wrought Copper Cable. General Electric Company See facing page 3S4S ' Flush Plugs, Screw Plugs and Flush Switches The Cutter Co. PHILADELPHIA I-T-E Circuit Breakers for every service The next time a fuse blows replace it with an I-T-E Circuit Breaker. The Cutter Co. PHILADELPHIA Cooper Hewitt Light has been proving for ten years that it is equal to the best daylight for all in- dustrial purposes, and "Better Than Daylight" for many purposes. It is free from glare due to the fact that it comes from a long tube of lumin- ous vapor, not from a small glowing solid. It's soft blue-green color is rest- ful to the eyes, being free from the irritating red rays radiated from every other artificial light. It casts no deep shadows. Cooper Hewitt Lamps take less cur- rent, require less attention and cost less for upkeep. Read our Bulletin 4637 "Better Than Daylight." Type F Cooper Hewitt Lamp for Alternating Current Circuits Made for either 25, 40, 50 and 60 cycles Cooper Hewitt Electric Co. 8th and Grand Streets, Hoboken, New Jersey Boston 161 Summer Street. Chicago 215 Fisher Bldg. Cincinnati 1st Nat. Bank Bldg. Cleveland Engineers' Bldg. Detroit Ford Building Philadelphia 124 S. 8th Street Pittsburgh Westinghouse Bldg. St. Louis Central National Bank Building /fa/n0 ofr- Panel Boards Knife Switches and Switchboard Accessories Walker Electric Company PHILADELPHIA MACALLEN ARMORED MICA INSULATING JOINTS This ARMORED Joint is the result of over twenty years' experience in the manufacture of Insulating Joints. It has the greatest mechanical and electrical strength, and is ihe most compact joint ever made. These joints will be regularly inspected and labeled under the supervision of the Under- writers' Laboratories, Inc., under the direction of the National Board of Fire Underwriters. The Macallen Company Macallen & Foundry Streets Boston, Mass. Catalogues and Price Lists Furnished Upon Application 16 MACALLEN Solid Mica Insulating Joints Regularly inspected and labeled under the su- pervision of the Underwriters' Laboratories, Inc.; under the direction of the National Board of Fire Underwriters. We carry a large stock and can fill all orders promptly. The Macallen Company Macallen & Foundry Streets Boston, Mass. Catalogues and Price Lists Furnished Upon Application MACALLEN Canopy Insulators Patented July 13, 1897 Regularly inspected and labeled under the su- pervision of the Underwriters' Laboratories, Inc., under the direction of the National Board of Fire Underwriters. They are designed to go between the canopy and the wall or ceiling, where combination or straight electric fixtures are installed in buildings that are constructed with metallic lathing, or where there are metal ceilings or walls used. They are made of a special compound that is thoroughly waterproof, strong, durable, and of the highest insulating qualities. We manufacture these insulators to fit all stand- ard sizes of canopies. The Macallen Company Macallen & Foundry Streets Boston, Mass. Catalogues and Price Lists Furnished Upon Application " 18 CUTLER-HAMMER MOTOR CONTROLLERS Hand Operated and Automatic Types Hand Operated Type Motor Starter with No - Voltage and Automatic Starter. Overload Release. Cutler-Hammer Starters and Controllers are made for both direct and alternating current motors. When installing motors tell us what you wish to accomplish and we will send bulletin describing just the apparatus you need. PUSH BUTTON SPECIALTIES No. 7109 Push New No. 7500 No. 7007 Button Snap Switch Brass Shell "Acorn" Brass Push Button Socket Shell Pendent The C-H line of specialties includes Porcelain and Brass Shell Pendent Switches, Sockets, Surface Switches, Flash Switches, Fix- ture Canopy and Candelabra Switches. Door Switches, besides a complete line of Attachment Plugs and Attachment Plug Receptacles. Ask for Bulletin 8650. THE CUTLER-HAMMER MFG. CO., Milwaukee Largest Manufacturers of Electric Controlling Devices in the World NEW YORK BOSTON PITTSBURGH Hudson Terminal Columbian Life Bldg. Farmers' Bank Bldg. CHICAGO PHILADELPHIA CLEVELAND Peoples Gas Bldg. 1201 Chestnut St. Schofield Bldg. PACIFIC COAST AGENTS: H. B. Squires, 579 Howard St., San Francisco, and W. B. Palmer, 416 East Third St., Los Angeles. Emerson Small Motors 1/30 to 1/2 hp. For Alternating and Direct Currents J7ZI Glutchless Induction Motors Clutch Type Induction Motors Enclosed Direct Current Motors Ventilated Direct Current Motors A hundred types regularly carried in stock at St. Louis and New York Special Types developed for any purpose where quantities are required Write for Printed Matter The Emerson Electric Mfg. Co. 2032 Washington Ave., St. Louis Mo. 50 Church St., New York City -:- Makers of Emerson Fans -:- Type "K" A.C. Motor. Robbins & Myers Motors and "Standard" Fans The Robbins & Myers line of motors includes sizes from 1/40 to 15 horse-power, direct current and 1/40 to 7^/2 horse- power, alternating current for all services. In sizes from 1/40 to l /2. ^ horse-power inclusive, our direct current type "N" motors and single-phase, type "P" alternating current motors can be supplied with the frames the same in all important dimensions for the same speeds and capacities. Our line of direct current generators includes sizes ranging from 54 to 10 kilowatts capacity with plain or fly- wheel pulley as desired. "Standard" Fans are made in desk, bracket, oscillating and ceiling types in sizes to meet all re- quirements. They are furnished for operation on . all commercial direct and alternating cur- rent circuits. Model 11 Oscillator, Bracket Position. THE ROBBINS & MYERS COMPANY SPRINGFIELD, O. New York Philadelphia Cincinnati Cleveland Boston Chicago Rochester St. Louis INSULATORS 4000 volts THE STANDARD FOR OVER 50 YEARS FOR LOW AND HIGH VOLTAGES WITH OR WITHOUT DRIP POINTS The Brookfield Glass Company 2 RECTOR STREET, NEW YORK BRANCH OFFICE, 309 South Desplaines St., Chicago, III. EVERY STYLE FOR EVERY SERVICE SPECIAL DESIGNS DEVELOPED CORRESPONDENCE INVITED No. 135 10000 volts TRADE MARK REGISTERED. **&&$$i'*$$3^''' < 'j' s '* " ' * """*" ->" "^i'Ws^^P^^Hpl No. 19, Deep Groove No. 71, High Voltage Double Petticoat. Triple Petticoat. No. 2 Cable, Double Petticoat. For years the name "Hemingray" has been synonymous, not only with "glass insulators," but with "good glass insulators." The Hemingray insulators have been and are good insulators, be- cause they have been and are of good design and material sub- jected to proper processes of manufacturing, including especially perfect annealing. In a glass insulator, "good design" means more than proper lines electrically, it means a design which so dis- tributes the material that good annealing is possible. Given such a design and a proper proportioning of materials (including not too much cullet), it is possible to obtain, and the Hemingray Glass Company does produce a completed insulator, every part of which is perfectly annealed. Thorough annealing is of supreme importance in a glass insulator, and faults which have been found against glass as a material for line insulators have been due to the past practice of some other manufacturers who not only have used improper annealing methods, or material which was practically incapable of being properly an- nealed, but also have accepted for manufacture certain designs of insulators which so distributed the material as to make proper annealing practically impossible, no matter what materials or methods were used. The HEMINGRAY GLASS COMPANY has followed as one of its first principles the practice of not accepting for manufacture any design which their sixty-five years of experi- ence would indicate could not be properly and perfectly annealed. This is the prime reason for the uniform success of the Hemingray insulator; the reason for its superior mechanical quality of strength and capabilities to withstand the shocks of sudden blows or rapid and extreme temperature changes; the reason for its remarkable electrical qualities as a high voltage insulator. Insulators for Telephone, Telegraph, Light and Power HEMINGRAY GLASS CO. Established 1848 Incorporated 1870 COVINGTON, KY. Factories - - - MUNCIE, INDIANA Genuine "Reliance" Time Switches .The machine that will stand the test THIRTY DAYS FREE TRIAL Transportation prepaid GREATEST OFFER EVER MADE Manufactured by the sole inventor, Benj. F. Flegel. Beware of imitations Most simple, accurate, lowest price eight day Time Switch. Most complete line. All turn circuits both on and off. Cut shows open face. Also made with solid iron door for outdoor use. 52% more business in 1913 than 1912. Still more in 1914. There is a good reason, Lowest List, Greatest Discounts, Strongest Guarantee Write today for from one to ten on thirty days FREE TRIAL. IT MEANS HUNDREDS OF DOLLARS TO YOU. Reliance Automatic Lighting Co. 536 College Avenue RACINE, WIS. New Code ARE NATIONAL ELECTRIC NEW CODE STANDARD Habirshaw FOR ALL SERVICE Wi ire ANY PRESSURE Company OFFICES AND WORKS: YONKERS, N. Y. 25 Whether t h e wire or cable be large or small, for high or low tension, the most dura- ble, efficient and permanent i n - sulation known KERITE KEMTESSCOMPAHY OKONITE The STANDARD for RUBBER INSULATION TRADE MARK. REG. U. S. PATENT OFFICE INSULATE!) WIRES and CABLES are standard because of their unvarying reliabil- ity in service. CANDEE Pot Heads OKONITE Tape MANSON Tape Sole Manufacturers THE OKONITE CO. 253 Broadway, New York Willard L. Candee, Pres. Geo. T. Manson, Gen. Supt. H. Durant Cheever, Treas. Wm. H. Hodgins, Secretary Roebling Magnet Wire is carefully drawn and annealed to pro- duce a soft wire with a minimum varia- , tion in gauge, and is covered with a smooth and uniform insulation. The best metals obtainable and an ex- perience of many years in wire manu- facture are combined in the production of this and other Roebling wires which include rubber covered wire, weather- proof wire, lamp cord and all other wires used for electrical purposes. John A. Roebling's Sons' Co. TRENTON, N. J. Agencies and Branches New York Chicago Cleveland Philadelphia Pittsburgh Atlanta Seattle Los Angeles San Francisco Portland, Ore. JlllllllllHIWHIIItllHIIillllllllllltllffllillilllllltlllliltlllllllllllllHIfllHIill INDIANA RUBBER AND INSULATED WIRE CO. Paranite Rubber Covered Wires and Cables IF us PARANITE ITSRIGHT More Than Code Requires Underground, Aerial, Submarine and inside use Telephone, Telegraph and Fire Alarm Cables FACTORY AND GENERAL OFFICES JONESBORO, IND. Chicago Office, 210 So. Desplaines St Chicago, Illinois. Eastern Representatives, THOMAS & BETTS CO. 105 Hudson St., New York A Good Brand NATIONAL CODE STANDARD Reg. U. S. Patent Office of Electrical Wires and Cables There are none better Weatherproof Slow-Burning Weatherproof, either black inside or outside Slow-Burning (Old Underwriters), Magnet Wires, all sizes Annunciator, Office, Enamel, Signal Wires Telephone and Telegraph Wires Rubber- Covered Wires Bare Copper Wires and Strands Moving Picture Machine Cable Border Light Cable Elevator Lighting and Signal Cables. Quick shipments, reasonable prices. Chicago Insulated Wire & Mfg. Co. CHICAGO, ILL. ESTABLISHED 1885 THE PURPOSE of THE ELECTRIC CABLE COMPANY IS First: To produce Rubber Insulated wire and cables of a quality superior to that which it is pos- sible to obtain from any other manufacturer. Second: To make these products with such efficiency and economy as to permit of their sale at a price no higher than it is necessary to pay for inferior material. Third: To prove our appreciation of our customers' confidence by a conduct of business relations which shall always be courteous, fair and honest. We solicit your inquiries and orders for "INVINCIBLE" "ENGINEERS" New Code Standard. High Grade. Pure Para. LEAD ENCASED CABLES For any service and every voltage THE ELECTRIC CABLE CO. 17 Battery Place, New York Bridgeport Philadelphia Chicago Boston Cleveland San Francisco Works: Bridgeport, Conn. An Unchanged Standard The recent changes in the rules established by the Underwriters Laboratories specifying more severe tests for rubber insulated wire will neces- sitate putting a better grade of rubber into some code wires. "Sterling" N. E. C. Rubber Insulated Wire required no change in its manufacture to meet in every respect the new requirements. "Sterling" has always kept well in advance of Underwriters' requirements because it is made to meet a separate and independent standard based on maximum quality and durability at a reasonable and economical price. When buying v N. E. C. wire look for the Standard marking : One green thread or strand woven into the braid, which is our registered trademark. ll'riie our nearest office for "Sterling'' booklet. Standard Underground Cable Co. Pittsburgh, Pa, New York Philadelphia Chicago Hoston San Francisco St. Louis Manufacturers of Electric Wires and Cables of all kinds, all sizes, for all services, also Cable Accessories of all , kinds. For Canada: Standard Underground Cable Co. of Canada, Limited, Hamilton, Ont. 33 * Rubber Covered Lamp Cords Automobile Cable Show Window Cords : Telephone Wire Lowell Insulated Wire Co LOWELL, MASS. AMERICAN ELECTRICAL WORKS PHILLIPSDALE, R. I. "National Electrical Code Standard" Americanite Rubber Covered Wire Incandescent Lamp Cord Weatherproof Line Wire Slow Burning Wire Railway Feeder and Trolley Wire Galvanized Iron Wire and Strand NEW YORK, 165 Broadway CHICAGO, 112 West Adams St. BOSTON, 176 Federal St. CINCINNATI,. Traction Bldg. Montreal, Canada Rome Wire Company ROME, N. Y. U fctome-Wice Our Specialties Rubber Covered Code Wire Lamp Cord Telephone Wire ROUND-SQUARE-FLAT MAGNET WIRE YOU GET OUR PERSONAL ATTENTION ON ALL ORDERS 7 ATLANTIC WIRES AND CABLES RUBBER INSULATED NATIONAL ELECTRICAL CODE STANDARD [ Extra High Grade Three brands that mark the maximum of quality and ser- vice in their re- spective grades of insulated wire. WRITE FOR OUR PRICE LIST ~. , ,1 AND DISCOUNTS Commercial Code ] ' ATLANTIC INSULATED WIRE & CABLE CO. Sales Office: 125 Cedar Street, New York Factory: Stamford, Ct. TRADE MARK Nat'l Electrical Code Standard. Quality is indicated and measured by voltage tests. Long life and Superior Electrical Qualities are combined in our product. Size Underwriters r c p Voltage Simcore Voltage Tests 14 to 8 inc. 1500 2000 6 to 2 " 2000 3000 1 to 4-0 " 2500 5000 225,000 to 500,000 3000 6000 525,000 and larger .3500 7000 SIMPLEX IRE &CABLE (9 MANUFACTURERS 201 DEVONSHIRE ST.. BOSTON CHICAGO SAN FRANCISCO "PHONO -ELECTRIC" The Dependable Trolley Wire It's toughness that counts in an overhead wire, Tough- ness not implied either by tensile strength or elasticity, but a power to resist bending, kinking, wrenching, sudden blows or slow distortions without giving way. The Demand for better cars, better roadbeds and faster schedules is y an indirect demand for better overhead wires. "Phono-Electric" is tough; and is a wire that will give LONG SERVICE LIFE. You want a money-saving wire specify "Phono-Electric." It's tough. Bridgeport Brass Company Bridgeport Connecticut Catalogue Mailed Free All conductors carefully^tested] N. I. R. HIGH GRADE Rubber Covered Wires and Cables FOR EVERY SERVICE Electric Light, Power, Railway Telephone and Signal NATIONAL BRAND Weatherproof and Slow Burning WIRES AND CABLES National Electrical Code Standard NATIONAL INDIA RUBBER COMPANY Executive Office and Factory BRISTOL, R. I., U S, A. General Sales Office, 30 Church Street, NEW YORK Chicago San Francisco Clinton and Van Buren Sts. 579 Howard Street Boston, 201 Devonshire Street 41 Wires and Cables BARE COPPER WIRE for Power Transmission, Telephone and Trolley Lines FLAT COPPER WIRE for Armature and Field Coils ALLOYED TROLLEY WIRE for Extra High Tensile Strength Purposes GERMAN SILVER WIRE for Resistance Purposes INSULATED WIRE "K.K." Weather-proof Line Wire Slow Burning Weather-proof Wire Magnet, Office and Annunciator Wire BARE TRANSMISSION CABLE WEATHER-PROOF STRANDED CABLE Prices Quoted Upon Application. The American Brass Co. ANSONIA BRASS & COPPER BRANCH Ansonia, Conn. BENEDICT & BURNHAM BRANCH Waterbury, Conn. American IkWireCo AM RUBBER RE | WIRE THE QUALITY of Americore Wire is such as to make it an absolute standard for interior wiring and to give the best pos- sible fire protection. Eve4*y foot is carefully inspected by us in the various stages of manufacture, and when com- pleted, is finally inspected by an authorized representative of the National Board of Fire Underwriters. We are prepared to furnish this wire in all sizes of conductors, both solid and flexible, from warehouses con- veniently located for quick delivery to all parts of the Country. American Steel & Wire Company Chicago, New York, Worcester, Boston, Pittsburgh, Cincinnati Buffalo, . SALES OFFICES 72 W. Adams St. Cleveland, . . 30 Church St. Detroit, . . . . Western Reserve Building . . . Foot of First Street 94 Grove St. Oklahoma City, State National Bank Building 120 Franklin St. St. Louis, . . 3rd National Bank Building FrickBldg. Denver, ... 1st National Bank Building Union Trust Bldg. St. Paul-Minneapolis, Pioneer Bldg., St. Paul 337 Washington St. Salt Lake City, . . Walker Bank Building United States Steel Products Company Export Department, New York 30 Church Street Pacific Coast Dep't, San Francisco Rialto Building Portland Sixth and Alder Streets Seattle 4th Ave. South and Conn. Street Los Angeles Jackson and Central Avenues 48 Economy and Reliability M & M Shallowest Switch 1 7/ 16" deep M & M Sectional Wall Box Equipped with Loom Clamps 2", 2 1/2" or 3" deep Catalog and Discount Sheet on request MachenK Mayer Electrical Mfg. Co. PHILADELPHIA, PA. "Diamond H" Switches AND FLUSH RECEPTACLES PUSH BUTTON SWITCHES ROTARY FLUSH SWITCHES Rotary Surface Switches Remote Control Switches HART MFG. CO., Hartford, Conn: New York Boston Chicago Pittsburgh Denver Toronto REFLECTOLYTE The Unit of Quality and Efficiency Type P. F. Porcelain Enamel upper reflector. Will not crack, check or peel off. Made in three sizes, 16, 20 and 24 inch. Plain and ornamental, with one or three chains. A reflector with the qualities of Opal Glass and the strength of steel. Write for Catalog No. 26. FRANK ADAM ELECTRIC CO St Louis, Mo., U. S. A. 4ft "MEGGER" TESTING SETS For the use of Fire Underwriters, Government Inspectors, Consulting Engineers and Electrical Contractors we have developed a new Megger Testing Set, that can be supplied at moderate cost. The range of measurement is up to 5 megohms, and the generator develops 125 volts D. C. To any one who mentions "Standard Wiring" when placing order, we will supply one of these sets at special price of $120.00 net, f. o. b. Phila- delphia, during 1915. For rapid and accurate tests of insulation resist- ance, the "Megger-method" is far better than any other way. Approved and used by the U. S. Government. See text page 51 for description of the apparatus. James G. Biddle Electrical Measuring Instruments 1211-13 Arch St. Philadelphia The New Miniature Precision Instruments for Direct Current MODEL 280 ""(Portable)" They mark the highest development in very small Indicating In- struments, conforming in every way to the exacting W e s t o n standard. PORTABLE Volt-Meters, Millivoltmeters, Volt-Ammeters, Ammeters, Mil- Ammeters are supplied in single, double and triple ranges, the Triple Range Volt-Ammeter comprising six instruments in one. This group also includes BATTERY TESTERS. SWITCHBOARD Volt-Meters, Volt-Ammeters, Ammeters, Mil-Ammeters This new line of instruments represents the finest develop- ment of small size pivoted moving coil, permanent magnet type of instruments. They embody characteristics which have made the well-known Weston Standard famous throughout the world. They are accurate, dead beat and extremely sensitive. They may be left continuously in circuit at full load and are shielded against external electrical and magnetic influ- ences. They are substantially constructed and have the longest scale ever provided in instruments of similar size. The prices are surprisingly low for instruments of such quality. The several models and ranees offer a selection from over 300 different combinations. They are listed in BULLETIN No. 8, WHICH WILL BE MAILED UPON REQUEST. Weston Electrical Instrument Co., Newark, N. J. New York St. Louis Detroit Chicago Denver Cleveland Philadelphia San Francisco Buffalo Boston Atlanta Richmond Vancouver Toronto Winnipeg Montreal Berlin London " Circle T " Trumbull Switches Type "A" 30-5,000 amp. All styles Type "C" 30-200 amp. Front connections Plain finish Type "C" Large Sized Switches a Specialty Panel Boards, Switch Boards and Cabinets Comb Switches, Panel Cutouts, Plug Cutouts, Slate Base and Porcelain Fuse Blocks, Rosettes, Iron Service Boxes, Ironclad Switches, Battery Switches, Flush Receptacles, Panel Parts, Wire Connectors, Attachment Plugs, Mould- ing Branch Blocks, Moulding Receptacles, Snap Switches, Push Switches, Insulating Joints, Armored Cable, and Conduit, etc., etc., etc. Be sure to get our 1915 catalogue, No. 10. The Trumbull Electric Mfg. Co. PLAINVILLE, CONN. NEW YORK, 114-118 Liberty St. BOSTON, 76-78 Pearl St. PHILA., 138 No. 10th St. SAN FRAN., 84-88 Second St. CHICAGO, 15 So. Desplaines St. PIGNOLET INSTRUMENTS ACCURATE COMPACT INEXPENSIVE Voltmeters, Ammeters and Volt-Ammeters PORTABLE AND SWITCHBOARD TYPES FOR ALTERNATING AND DIRECT CURRENT. OUR NEW MODEL P. The handiest Direct and Alternating Current Portable Meter made; 6" long, 5" wide, 3" deep; weight less than 3 Ibs. We also make several styles of Pocket Meters; 4^' long, 3%" wide, i%" deep, with an extra long scale per- mitting close readings. Send for complete Catalog and Directions for Testing. L. M. PIGNOLET Cor. Cortlandt and Washington Streets NEW YORK, N. Y. 50 I. U. Volt Ammeter A distinguishing, we might almost say exclusive feature of the HOYT Une of Ammeters *> Voltmeters is their extreme flexibility adapting them to prac- tically every use required in modern practice. Ask for Bulletin SW Hoyt Electrical Instrument Works PENACOOK, N. H. 6" Type Pocket Ammeter DOSSERT CONNECTORS 2-Way Type A Showing: Details. Dossert Connectors eliminate entirely the use of solder in making electrical connections and splices, and are approved for use without solder by the National Board of Fire Underwriters for all classes of wiring. By their use much labor is saved and splices obtained that will withstand any overload. Many careful tests show that a splice made l>y means of a Dosserfc Connector will not heat as much as the cable which it connects when the cable is heavily overloaded. Type A Connectors are for use on cables, stranded, or solid wires, rods and tubing. They are simple and effective, and by their use splices can be quickly made in conductors of any size. Type A Connectors, however, should not be used on a cable that is to be subjected to heavy tensile strains. Part Cross-sectional View of Type B 2-Way Type B Connectors are for use on stranded wires or cables only, and are designed to make a joint which will withstand heavy tensile strains. They are not made for wires smaller than No. 0. The Cable Tap is used to connect a branch wire, rod, or bleeder, to a main wire, rod or feeder. It does not splice the main, but simply clamps on to it. Branch wire is connected to cable tap by means of a nut and sleeve as shown in Type A cut. With Dossert devices any combination 9f different sizes of cables, stranded and solid wires, rods and tubing can be connected to- gether. The cable tap will tap from any size main to any size branch. Terminal and switchboard lugs, front or back connected; angle and swivel lugs. Insulated connectors; two-ways, three-ways, equalizers, cable an- chors, reducers, elbows, Y's, service box lugs Cable Tap and plugs, grounding devices and stud connectors for threaded rods and flat strips or locks. Send for Tenth Year Catalogue. Dossert & Company H. B. LOGAN, President 242 West 41st Street New York, N. Y. "Griptite" and "Flexclamp" GROUND CONNECTION CLAMPS For Rigid and Flexibh Conduit National Electrical Code Standard Made of one piece of copper insuring perfect and permanent contact. Made for all Standard sizes of rigid and flex- ible metallic conduit. Patented Pat. Pending "NECO" Wire Gauge Our IMPROVED "NECO" POCKET WIRE GAUGE, for meas- uring wire from No. 18 to No. 000 B. & S. Gauge. On the front is also given the carrying capacity of cop- per wire in amperes and on the re- verse side the approx. decimal equivalent of the various size wires. Mailed to any address in the United States or Canada upon re- ceipt of 60 cents in cash or money order. Manufactured by Novelty Electric Company Wholesale Electrical Supplies 50-52-54 North 4th St., PHILADELPHIA Agents for Okonite Wires and Cables Holtzer Cabot Motors 53 CONDUIT WORK AT ODERN construction makes essen- 1VJ - tial the use of an armor or metal protection to electric wires; mechanical injury during construction or after completion of the work causes such annoyance, expense and damage, that the first cost of a conduit system over knob and tube work, exposed wir- ing, molding or non-metallic tubing construction is now considered of no consequence when safety by metallic conduit protection is secured. FIRST IN PROTECTIVE QUALITIES IS "Galvaduct" ] "Loricated" }- Rigid Conduits "S.-A.C.Co. Special" "Sterling" Flexible Steel Conduit Metallic Flexible "Sterling" Steel Armored Conductor (All Patented) THEY ARE THE BEST Literature and samples upon request Safety- Armorite Conduit Company PITTSBURGH, PA. Rigid Conduit Agent NATIONAL TUBE CO. 54 NON-METALLIC FLEXIBLE CONDUIT An Excellent Tubing ^V^ijf^ 7 MAfrK is scientifically constructed i-, 5-, 10- and so-lb. tins. The 2-oz. and 4-oz. sizes are packed 3 doz. in cardboard boxes. We are always ready to furnish samples FREE upon request. BURNLEY SOLDERING SALTS These SALTS are a combi- nation of pure chemicals so proportioned as to give the best results, as a FLUX, for all kinds of SOLDERING. Put up in y 2 - and i-lb. bot- tles, also y 2 - and i-lb. fric- tion top cans. Ask for prices. BURNLEY PASTE AND SALTS Manufactured and put up by THE BURNLEY BATTERY & MFG. CO Chas. E. Chapin Co. North East, Pa., 201 Fulton St., U. S. A. New York City, Agent. Lux Lamps Last Longest THE Drawn Wire Tungsten Nitrogen AND Concentrated Filament Lamps made by this company are strictly high grade and suitable for all purposes and conditions. Write for Prices. LUX MANUFACTURING CO HOBOKEN, N. J. 65 The Post -Glover Electric Co. CINCINNATI :-: :-: :-: OHIO Manufacturers of Switch Boards Standard and Special Boards for direct and alternating current. Panel Boards For 125, 125 to 250 and 250 volts for 2 to 2 wire, 3 to 2 wire and 3 to 3 wire systems, de- signed for open link fuses, N. E. C. S. enclosed fuses or plug fuses, with or without switches in mains. Approved by Underwriters. Cabinets, Flush or Surface types, constructed of steel or wood with or with- out wiring compartments, with wood or steel trims and with or without glass paneled doors. Approved. Knife Switches Type A 125, 250 and 600 volts front or back connected, with Or without fuse connections, 30 to 5,000 amperes, latest designs. Special switches. Approved by Underwriters. Write for catalogue. Perkins Dead Front Distributing Panel All connections and conductors are concealed and separated from the front of the panel by a continuous sheet of insulating material. There are no live parts exposed. With a quantity of these units in stock, the con- tractor is ready to make up lighting panels of any size, thus avoiding delays or expensive stock. Ease of assembling parts minimizes installation cost. Panels can be assembled for considerably less than $1.00 per circuit. Perkins Dead Front Panels may be installed in any standard steel or wood cabinet having a mini- mum depth of three inches. Panel units can be fur- nished with dull black cov- ers and black switch han- dles, or white enamel cov- ers and white handles. An eight-circuit Perkins Dead Front Distributing Panel in- stalled in a gutter box. THE BRYANT ELECTRIC COMPANY NEW YORK BRIDGEPORT, CONN. CHICAGO SAN FRANCISCO Wakefield Standard Universal Lighting Fixtures In Wakefield fixtures are combined two characteristics quality and substantial attractiveness of design. In every Wakefield design you get a fixture built for service first, then built in a design that will wear well; no extremes that quickly come in. style and as quickly go out again. The characteristic of quality is a broad one. It means first, good heavy gauge Brass ma- terial throughout. It means second, accurate mechanical construction. It means third, that troubles in handling have been anticipated and Wake- field Fixtures made with more special features to make them easier, to wire, easier to put together, easier to install, easier to carry in stock, than the ordinary lines. It means service First, Last and Always. When you buy Wakefield Fixtures you buy the experience of practical people to give you something that you can make just a little more money on than the aver- age and at the same time you can give your customer a sat- isfactory article. Whether you buy an attractive shower or an efficient "Mellowlite" Semi Indirect Fixture, you get some feature that means more profit for you in time saved, reputation saved and fixtures more easily sold. Send for complete catalog of electric designs. The F. W. Wakefield Brass Company Vermilion, Ohio ESSENTIALS FOR STANDARD WIRING f Guaranteed Durability 1 j ctlon I Reasonable Price lapel High Grade [ Perfect Insulation ALL EMBODIED IN OUR M. C. TAPE Snlirinrr f Perfect Insulation OpllCing I p erfect Adhesion Compound j P er [ e< * sfcty (Pure Rubber Tape) 1 PerfeCt J mt WIth Ut Heat For mending Insulation on Wire and all High Tension Work OUR THREE SELECTIONS "WALPOLE" "KEPONSEr-"UNION MOULDING VARNISH Our No. 4 is Approved by the Underwriter REASONABLE IN PRICE If your dealer doesn't handle our goods, write us Walpole Tire & Rubber Co. WALPOLE, MASS. Pioneers in Insulation Engineering Massachusetts Chemical Co.'s Products G. V. Electric Trucks Give you 10 or more years' life, odorless. Are clean, silent and Operate 297 days out of the 300. (Average statistics.) Show economy in tires, parts, replacements and general upkeep over a period of years. Promote the highest efficiency in systematic trucking, transfer work and light deliveries. Make possible undreamed-of economies in real estate investment covered by stables and wagon yards. Design standardized since 1907. All parts of each model interchangeable. Many new and exclusive refinements. Over 4,000 in use,, many ten years old. The ex-teamster and the simple Electric are a saving over the complex motor vehicle and the expert chauffeur- machinist. The Electric has economic law behind it and must domi- nate in its field. " Show your business acumen by getting the right machine for the right place. Six models; 1,000 Ibs. to 5 tons. Catalogue 35 on request. - ; . General Vehicle Company, inc. General Office and Factory Long Island City, N. Y. New York Chicago Boston Philadelphia 70 DRIVER-HARRIS WIRE CO. RESISTANCE ALLOYS ROUND OR AA7TT> T? RARE OR FLATTENED VV IJVIl/ INSULATED "NICHROME" For Electric Heaters "ADVANCE" For Controllers, Arc Lamps "CLIMAX" For Moving Picture Rheostats "No. 193 ALLOY" For Heavy Duty Rheostats "THERLO" For Instruments and Shunts A RESISTANCE WIRE FOR EVERY REQUIREMENT Armature Binding Wire Hercules ( T ^g? L D ) Phosphor Bronze Heater Cords Pure Nickel and Nickel Alloys Sheet Wire and Strip DRIVER-HARRIS WIRE GO. Main Office and Works: HARRISON, NEW JERSEY Branch: 565 West Washington Bldg., CHICAGO 71 Electrical Materials "Noark" Enclosed Fuses; Fuse, Service and Subway Boxes; Service Meter Protective Devices. Frink and J-M Linolite Systems of Electric Lighting, for Banks, Churches, Offices, Show Windows and Show Cases. Lighting Fixtures and Reflectors. Arc Lamp Hangers. Westinghouse Tungsten and Carbon Lamps. J-M Trolley Line Material, Cross-Overs, Rail Bonds and Tools. J-M Mine Supplies. J-M Electric Heaters. J-M Friction Tapes and Splicing Compounds. "Moulded Mica" Weatherproof Sockets. "Moulded Mica" J-P Bakelite Electrobestos and Vulcabeston Insulation. J-M Fibre Conduit. J-M Porcelain and Glass Insula- tors. J-M Niagrite Fireproof Cable Insulation. J-M Immovable Guy Anchor. J-M Insulated Coupler. J-M Pole Line Hardware. J-M Detail Supplies for Power Work. J-M Ebony Asbestos Wood. J-M Hard Fibre. J-M Dry Batteries; Battery Ammeters; Battery Connec- tors. J-M Indurated Fibre Specialties. J-M Transmission Ma- terials. J-M Victor Combination Meters. J-M Electrotherm Heating Pad. Write nearest Branch for Booklet. H. W. JOHNS-MAN VI LLE CO. Albany Baltimore Chicago Cincinnati Cleveland Columbus Denver Detroit Galyeston Indianapolis Kansas City Los Angeles Louisville Memphis Milwaukee Boston Minneapolis Newark New Orleans New York Omaha Philadelphia Pittsburgh Portland Salt Lake City San Francisco Seattle St. Louis Toledo Buffalo 2280 Every Blown Fuse Is An Expense Every fuse that blows under its rated capacity is an unwarranted expense. Many do not analyze the causes that add dol- lars to their fuse bills. Defective interior construction, weak joints and imperfect alignment of blades cost fuse con- sumers hundreds of dollars a year. Consider These Points In "D & W" Construction The links are scientifically designed. Every joint is riveted as well as soldered. They won't let go. The blades are properly aligned. Excessive heating is eliminated. All metal parts are ample and are securely fastened to the tube. "D & W" knife blade fuses may be refilled by the factory at an approximate saving of 63%. They are approved by the National Board of Fire Underwriters. SPECIFY "D & W" AND GET MORE FUSE VALUE D&W FUSE COMPANY Providence, R. I. Whether the Job Be Large or Small It will pay to use "UNION" Fuse and Box Material A Complete Line of Open and Enclosed Fuses, Cut-Out Blocks, Fittings, etc., for All Voltages. All "Union" Material is made in accordance with the re- quirements of the National Board of Fire Underwriters. "Union" Fuses, above 60 amperes, may be reloaded at our Factory at a large saving to the user, and are approved. Outlet Boxes and Covers to accom- modate all regular wiring devices. Switch Boxes that can be easily taken apart and rebuilt into gangs by the use of spacers. The Standard Line. Pat. Apr. 2, 1907; Mar. 1, ]910;Feb. 13, 1912. Gem X, Sectional Switch Box No. 106 O Box and No. 106 D Cover Write for Fuse Catalog No. 26 and Box Catalog No. 27. CHICAGO FUSE MFG. CO. CHICAGO NEW YORK "SQUARE D" Enclosed Entrance Switches and Distributing Cabinets A line of New Installation and Service Devices Un- equalled in Excellence of Design and Finish, in Quality, in Safety of Operation and in Low Price. "SQUARE D" Features All live parts enclosed Control outside "box Removable top and bottom end plates End plates interchangeable End plates Standard equipment Meter protective trim Meter trim and end plates inter- changeable Convenient knockouts Ground wire lugs Exclusive "locking off" device Roominess inside Connections easily made Not less than 30 Amp. capacity Made from 16 Ga. steel Corners electrically welded Finished in lustrous black enamel Switch and cutout mounted ready to install Satisfactory operation assured Prevents accidental contact with live parts Prevents tampering with service No. 5211E. With meter protective trim. Switch in "on" position, cabinet sealed. "ARKLESS" Fuses N.E.C.S. Only Guaranteed Mechanical Indicator Made All National Electrical Code Standard "ARKLESS" Fuses comply strictly with the requirements of the National Board of Fire Underwriters and are approved by the Underwriters' Laboratories after examination and test under the provisions of the National Electrical Code. We guarantee "ARKLESS" fuses to indicate, and will replace, free of charge, every "ARKLESS" fuse that fails to indicate when blown. Write for Catalog No. 22 S. W. DETROIT FUSE&MFG.CO. Detroit, Mich. "Shawmut" Fuses Exclusive Features Black Tube Copper Ends Ampere Capacity Stamped on Ferrule Efficiency Indicator "Shawmut" Bases All current carrying parts copper. Lugs flush with edge of slate. Clips have ample carrying capacity and being in perfect alignment afford maximum contact. Condit Electrical Mfg. Co. Boston, Mass. W. S. Brown Elec. Co., 3 W. 29th St., New York City F. V. L. Smith, 1206 Empire Bldg., Atlanta, Ga. Hendrie & Bolthoff Mfg. & Supply Co.. 1627 17th St., Denver, Colo. H. G. Behneman, 617 4th Ave., Seattle, Wash. T. G. Grier Co., 318 W. Washington St., Chicago, 111. Weiss-Bosley Co., 1403 Chestnut St., St. Louis, Mo. Holabird-Reynolds Co., 523-525 Mission St., San Francisco, Calif. "Insure Against Loss of Lamps" You cannot always prevent Incandescent lamps from being broken, but y u can p. re - vent their being stolen and 75% of those lost are stolen. The Socket that Locks will prevent this is LAMP INSURANCE Sell it to yourself by try- ing to remove the lamp, without the use of the Master key ~and then specify 5*^i<>H. on your next order. Sold by jobbers everywhere Descriptive booklet and sample gladly supplied on request. PASS & SEYMOUR, Inc., Solvay, N. Y., U. S. A. New York San Francisco Chicago 178 Fulton St. Rialto Bldg. 700 W. Jackson Blvd. 78 The MonitorSystem START SAFETY The Original "Just Press a Button" controller 'Just Press a Button' Affords simple but complete control of every movement required of any motor-driven machine. Prevents accidents, save motor, man and machine. There is a type of Monitor Control- ler for every need Either alter- nating or direct current. Ask particularly for details of our "Safety First" Station. MonitorControllerCompany III South Gay Street, Baltimore New York, 30 Church St. Philadelphia, 1533 Chestnut St. Boston, 77 Franklin St. Chicago, Old Colony Bid*. EVERY ONE OF THE 30,000 READERS OF " STANDARD WIRING " SHOULD HAVE THIS NEW BOOK "A Complete Reference Library in Itself" AMERICAN HANDBOOK FOR ELECTRICAL *t ENGINEERS EDITED BY DR. HAROLD FENDER, Professor of Electrical En- gineering, University of Pennsylvania, and 26 Asso- ciate Editors, each an authority in his field. A Really Practical Handbook In this book everything has been done to make it as useful as possible. For this reason, it has been necessary to break away from the usual handbook construction. As an example it is the first handbook to have an alphabetical arrangement, making it easy to find any subject desired. Then too, the Practical Data is grouped separately from discussions of Theory, a feature that should appeal to all busy men. These features and many others make this a book that you should not be without. 2023 Pages Thoroughly Illustrated Morocco $5 Postpaid Size 41/4x7 Send in your order to-day you have the privilege of returning the book within 10 days and your money re- funded. JOHN WILEY & SON, Inc. 432 FOURTH AVE. NEW YORK CITY NOKORODE SOLDERING PASTE Made with more care than nine-tenths of the druggists compound a doctor's prescription. Every particle contains all the ele- ments of the flux. Used exclusively by U S ' Gov>t 90% of the Elec- on the //O it trical Trade of telephone New York and X>v T * **.W|>t/irroi &>.,yy \ TVT T~* 11 1 circuits of / New England and for eleven the Panama |v_ rs b The Canal W N.E.Tel. &Tel. Co. PRICE LIST 2 oz. Cans, less than case lots - - $0.25 each. 2 oz. " 3 dozen (one case) 2.00 doz. 1 Ib. "1-2 " (one case) - - 1.00 Ib. 10 " 1.00 Ib. 25 Ib. and 50 Ib. Cans - .90 Ib. DISCOUNT IN CASE LOTS 50 PER CENT. Discount in less than Case Lots, 40 per cent. OUR PRODUCTS Uncoated Armature Tapes Sleevings Hose Frict'on Tapes Red Rope Paper Press Boards Rubber Gloves THEM.W. DUNTONCO. DDrt\/irhirkJSC- 150-152 NIAGARA o . PROVIDENCE, STREET R. I. "The Electric Vehicle Hand-Book" SECOND EDITION H. C. GUSHING, Jr. Fellow Am. Inst. Elec. Engrs., Publisher of "The Central Station," the offi- cial organ of the Electric Vehicle Association of America, and FRANK W. SMITH Ex-President Electric Vehicle Association of America and Vice Pres. United Electric Light & Power Co., New York: 362 pages, fully illustrated, flexible cover, pocket sizes, Price, $2.00 THE ONLY COMPLETE AND PRACTICAL BOOK ON THE OPERATION, CARE AND MAINTEN- ANCE OF all classes OF ELECTRIC VEHICLES, their Storage Batteries, Motors, Controllers, Tires and Accessories. Sent postpaid to any address on receipt of $2.00. by H. C. GUSHING, Jr. WORLD BLDG. NEW YORK, N. Y. Sebco Expansion Bolts For Fastening Conduit and Cables Made of Malleable Iron For Heavy Work Made of Lead Composition For Small Fastenings of All Kinds r The Five Points Make Drilling Easy CATALOG AND SAMPLES FREE Star Expansion Bolt Company 147 CEDAR STREET, NEW YORK BRANCHES 120 West Lake Street 579 Howard Street Chicago San Francisco 83 The SIMPLEX Magneto Watchman's Clock APPROVED BY UNDERWRITERS STYLE A, CAPACITY 25 STATIONS The Record is made on rectangular straight 24 hour sheet Requires no attention on Sundays and holidays Compare it with the common 12 hour round dials. Ask for Catalog SIMPLEX TIME RECORDER CO. 1-4 Sanborn Street GARDNER, MASS. T g E RAT E H "POPULAR QUALITY" LINE "MADE TO SELL AND SATISFY" ONE OF THE ty TJJJ!? HUNDRED DESIGNS ON WHICH WE MAKE HOUR SHIPMENTS 24 Your Name on Our Mailing List Will Keep You Supplied with Up- to-Date Designs. Net NOT WIRED FINISH BRUSHED BRASS] and BLACK , Correctly Displayed This Design Will Bring You Profitable Business. We Have 99 Other Designs Equally as Attractive on Which We Make 24 Hour Shipments. GAS FIXTURE & BRASS CO., 308 High St., Cleveland, Ohio The Star Oval Split Insulator Pat. Dec. 5, 1905. For the use of wire without tying The oval shape enables the hole to be placed in the center with less material than generally used, and holds the wire securely when in place by means of the curve be- tween the top and bottom. WRITE FOR OUR CATALOGUE AND PRICES The Star Porcelain Co. TRENTON, N. J. VULCAN Electric Soldering TOOLS Heat Quick ! Stay Hot ! You can heat Vulcan Electric Solder- ing Irons in less time than it takes to get a gas or charcoal furnace started and they stay hot all the time. Their use eliminates fire risk and increases output. Save Time-Labor-Money Furnace heated coppers are old-fash- ioned out-of-date. The Vulcan Elec- tric Iron does soldering quicker, better and cheaper. There are eight sizes for all kinds of work. Each tool has' a six- foot cord and plug. Tips are easily re- placed when worn out. SOLD BY ALL DEALERS WRITE FOR CATALOG AND FULL INFORMATION Vulcan Electric Heating Company DEPT. Z. BUFFALO, N. Y. PHEN1XLITE The Semi-Indirect Light of the Highest Efficiency Pat. Applied for. A Simple, Economical, Durable, practically Dustproof, absolutely Glareless Tungsten Arc, giving a large volume of illumination. Light is reflected from lower to upper reflector, thence outward and downward. Try it for better Illumination. Ask for Catalogue. THE PHOENIX GLASS COMPANY NEW YORK BOSTON CHICAGO PITTSBURG THE BEST BRUSH service for any condition is derived from the application of the proper type of Morganite or Battersea Carbon brushes. As only the high- est class of workmanship is used in manufacturing after thorough investi- gation of conditions by engineers, no better brush can be procured. The Morgan Crucible Co., Ltd. 114 Liberty Street New York City FRANKLIN STEEL WORKS FRANKLIN, PENNA., U. S. A. New York Office : 30 Church Street Denver Office: McPhee Bldg. Minneapolis Office: Phoenix Bldg. 90 REFLECTORS EFFICIENCY ARTISTIC EFFECT SCIENCE and DISTINCTIVENESS No. 1230 QJ2 are embodied in Haskins-Lucida reflectors, spheres and hemispheres. Lenticular reflectors for high efficiency are acknowledged the best. In addition to the scientific lines of reflectors, namely, Haskins-Lucida and Lenticular, \ve make a complete line of illuminating glassware in cut, etched, roughed inside, etc., etc. The Haskins Glass Co. WHEELING, W. VA. BRANCHES New York Philadelphia Chicago Atlanta Los Angeles 91 Elblight Lamps and Cables ARE BEST FOR Electrical Decorations EASY TO INSTALL EASY TO TAKE DOWN Economical and Artistic for Inside and Outside Effects Sold or Rented at Attractive Rates Send for Illustrated Catalog and Price List ELBLIGHT COMPANY OF AMERICA 133 W. 24th St. SSSi NEW YORK SINGLE PHASE MOTORS are being sold and recommended .by such a large number of Elec- trical Contractors and Central Station Operators because they know that when they are once properly installed they will give continued satisfactory service to the user. They possess those starting and oper- ating characteris- tics and accurate ru gged construc- tion so necessary for the develop- ment of power business and which will help to build a reputa- tion f or Y O U as a seller of apparatus possessing that much- sought for keep-a-running quality % to 40 H. P. 25 to 140 cycles. Quick shipments always from 26 Branch Stocks. CENTURY ELECTRIC CO. New York Office: Main Office and Works: Hudson Terminal, 19th, Pine and Olive Sts. 30 Church St. St. Louis, Mo. 93 The High Grade Insulation The Copper True to Gauge The Extreme Softness of Wire The Quality and Reliability of M assachusetts AGNET WIRE are well known Cotton Covered Mad f Silk Covered al1 Sizes Enamel Covered Massachusetts Elec. Mfg. Co, WEST LYNN, MASS. Gas and Gasoline Engines produce electric current at a lower cost than by steam and cheaper than other makes of internal combustion engines. They are world renowned for fuel economy and low cost of up-keep. Our special electric types operate with such close regulations that the cyclical variation in speed of the engine will be within 2 per cent, each way from mean rated speed under gradual change of load. Send for Catalogue No. 28 and Bulletin No. 10. THE OTTO GAS ENGINE WORKS 3417 Walnut St., Phil., Pa. er Gas PREPARE FOR FIRE FIRE EXTINGUISHERS Are the Most Efficient Known The Compound Pyrene Is a non-conductor of electricity. It can be used with perfect safety on the highest voltages. Does not deteriorate with age. Therefore cost of maintenance is entirely eliminated. Does not freeze. It is therefore service- able in the lowest temperatures. Does not contain acid, alkali or moisture. It is therefore non-damaging. Brass and nickel-plated Pyrene. Fire Extinguishers are included In the lists of approved fire appliances examined under the re- quirements of the National Board of Fire Underwriters, by the Underwriters' National Electric Association, after exhaustive tests by the Underwriters' Laboratories, and approved for use. The Double-Acting Pyrene Pump Is the most effective method of getting an extin- guishing agent on a fire. Pyrene Extinguishers are strongly constructed of the very best materials and carefully tested at the factory. Pyrene Manufacturing Co., New York, N. Y. Aberdeen, S, D. Alton Anderson, S. C. Atlanta Baltimore Birmingham Bridgeport Boston Buffalo Charleston, W. Va. Charlotte* N. C. Chicago Cincinnati Cleveland Dayton Denver Detroit Duluth Fargo, N. D. Jacksonville Ivouisville Memphis Milwaukee New Orleans Oklahoma City Phoenix Philadelphia Pittsburg Richmond St. Louis St. Paul Salt Lake City San Antonio York, Neb. Pacific Coast Distributors: Gorham Fire Apparatus Co. San Francisco Los Angeles Seattle Distributors for Great Britain and the Continent: The Pyrene Co., Ltd., 19-21 Great 'Queen St., London, W. C. 100 THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO $1.OO ON THE SEVENTH DAY OVERDUE. SEP 12 1! SEP 1 SENY Otf'2'3 U. C. BERKELEY VA 0?i98 301240 UNIVERSITY OF CALIFORNIA lylBRAR