Class C.

INSIDE WORK.

(Light, Power and Heat. For Signaling Systems, see Class E.)

ALL SYSTEMS AND VOLTAGES

GENERAL RULES.

14. Wires.

(For special rules, see Nos. 18, 24, 35, 38 and 39.)

a. Must not be of smaller size than No. 14 B. & S. gage, except as allowed under Nos. 24 v and 45 b.

b. Tie wires must have an insulation equal to that of the conductors they confine.

c. Must be so spliced or joined as to be both mechanically and electrically secure without solder. The joints must then be soldered to insure preservation, and covered with an insulation equal to that on the conductors. Stranded wires must be soldered before being fastened under clamps or binding screws, and whether stranded or solid, when they have a conductivity greater than that of No. 8 B. & S. gage they must be soldered into lugs for all terminal connections.

d. Must be separated from contact with walls, floors, timbers or partitions through which they may pass by non-combustible, non-absorptive insulating tubes, such as glass or porcelain, except as provided in No. 24 u.

e. Must be kept free from contact with gas, water or other metallic piping, or any other conductors or conducting material which they may cross, by some continuous and firmly fixed non-conductor, creating a permanent separation. Deviations from this rule may sometimes be allowed by special permission.

f. Must be so placed in wet places that an air space will be left between conductors and pipes in crossing, and the former must be run in such a way that they cannot come in contact with the pipe accidentally. 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.

g. The installation of electrical conductors in wooden moulding or where supported on insulators in elevator shafts will not be approved, but conductors may be installed in such shafts if encased in approved metal conduits.

15. Underground Conductors.

a. Must be protected against moisture and mechanical injury where brought into a building, and all combustible material must be kept from the immediate vicinity.

b. Must not be so arranged as to shunt the current through a building around any catch-box.

c. 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.

d. No underground service from a subway to a building shall supply more than one building except by written permission from the Inspection Department having jurisdiction.

16. Table of Carrying Capacity of Wires.

a. The following table, showing the allowable carrying capacity of copper wires and cables of ninety-eight per cent conductivity, according to the standard adopted by the American Institute of Electrical Engineers, must be followed in placing interior conductors.

17. Switches, Cut-outs, Circuit-Breakers, Etc.

(For construction rules, see Nos. 51, 52 and 53.)

a. Must, for constant potential circuits, unless otherwise provided (for exceptions, see No. 8 c and No. 22 c), be so arranged that the cut-outs will protect, and the opening of a switch or circuit-breaker will disconnect, all of the wires; that is, in a two-wire system the two wires, and in a three-wire system the three wires, must be protected by the cut-out and disconnected by the operation of the switch or circuit-breaker.

b. Must not be placed in the immediate vicinity of easily ignitible stuff or where exposed to inflammable gases or dust or to flyings of combustible material.

c. Must, when exposed to dampness, either be enclosed in a waterproof box or mounted on porcelain knobs.

d. Time switches must be enclosed in an iron box or cabinet lined with fire resisting material.

CONSTANT-CURRENT SYSTEMS.

PRINCIPALLY SERIES ARC LIGHTING.

18. Wires.

(See also Nos. 14, 15 and 16.)

a. Must have an approved rubber insulating covering (see No 41).

b. Must be arranged to enter and leave the building through an approved double-contact service switch (see No. 51 b), mounted in a non-combustible case, kept free from moisture, and easy of access to police or firemen.

c. Must always be in plain sight, and never encased, except when required by the Inspection Department having jurisdiction.

d. Must be supported on glass or porcelain insulators, which separate the wire at least one inch from the surface wired over, and must be kept rigidly at least eight inches from each other, except within the structure of lamps, on hanger-boards or in cut-out boxes, or like places, where a less distance is necessary.

e. Must, on side walls, be protected from mechanical injury by a substantial boxing, retaining 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 must be attached by their insulating supports to the under side of a wooden strip not less than one-half an inch in thickness. Instead of the running-boards, guard strips on each side of and close to the wires will be accepted. These strips to be not less than seven-eighths of an inch in thickness and at least as high as the insulators.

19. Series Arc Lamps.

(For construction rules, see No. 57.)

a. Must be carefully isolated from inflammable material.

b. Must be provided at all times with a glass globe surrounding the arc, and securely fastened upon a closed base. Broken or cracked globes must not be used.

c. Must be provided with a wire netting (having a mesh not exceeding one and one-fourth inches) around the globe, and an approved spark arrester (see No. 58), when readily inflammable material is in the vicinity of the lamps, to prevent escape of sparks of carbon or melted copper. It is recommended that plain carbons, not copper-plated, be used for lamps in such places.

d. Where hanger-boards (see No. 56) are not used, lamps must be hung from insulating supports other than their conductors.

e. Lamps when arranged to be raised and lowered, either for carboning or other purposes, shall be connected up with stranded conductors from the last point of support to the lamp, when such conductor is larger than No. 14 B. & S. gage.

20. Incandescent Lamps in Series Circuits.

a. Must have the conductors installed as required in No. 18, and each lamp must be provided with an automatic cut-out.

b. Must have each lamp suspended from a hanger-board by means of rigid tube.

c. No electro-magnetic device for switches and no multiple-series or series-multiple system of lighting will be approved.

d. Must not under any circumstances be attached to gas fixtures.

CONSTANT-POTENTIAL SYSTEMS.

GENERAL RULES—ALL VOLTAGES.

21. Automatic Cut-outs (Fuses and Circuit-Breakers).

(See No. 17, and for construction, Nos. 52 and 53.)

a. Must be placed on all service wires, either overhead or underground, as near as possible to the point where they enter the building and inside the walls, and arranged to cut off the entire current from the building.

b. Must be placed at every point where a change is made in the size of wire [unless the cut-out in the larger wire will protect the smaller (see No. 16)].

c. Must be in plain sight, or enclosed in an approved cabinet (see No. 54), and readily accessible. They must not be placed in the canopies or shells of fixtures.

d. Must be so placed that no set of incandescent lamps requiring more than 660 watts, whether grouped on one fixture or on several fixtures or pendants, will be dependent upon one cut-out. Special permission may be given in writing by the Inspection Department having jurisdiction for departure from this rule in the case of large chandeliers, stage borders, and illuminated signs.

e. The rated capacity of fuses must not exceed the allowable carrying capacity of the wire as given in No. 16. Circuit-breakers must not be set more than 30 per cent above the allowable carrying capacity of the wire, unless a fusible cut-out is also installed in the circuit.

22. Switches.

(See No. 17, and for construction, No. 51.)

a. Must be placed on all service wires, either overhead or underground, in a readily accessible place, as near as possible to the point where the wires enter the building, and arranged to cut off the entire current.

b. Must always be placed in dry, accessible places, and be grouped as far as possible. Single-throw knife switches must be so placed that gravity will tend to open rather than close them. Double-throw knife switches may be mounted so that the throw will be either vertical or horizontal as preferred.

c. Must not be single pole when the circuits which they control supply devices which require over 660 watts of energy, or when the difference of potential is over 300 volts.

d. Where flush switches or receptacles are used, whether with conduit systems or not, they must be enclosed in boxes constructed of iron or steel. No push buttons for bells, gas-lighting circuits, or the like shall be placed in the same wall plate with switches controlling electric light or power wiring.

e. Where possible, at all switch or fixture outlets, a ⅞-inch block must be fastened between studs or floor timbers flush with the back of lathing to hold tubes, and to support switches or fixtures. When this cannot be done, wooden base blocks, not less than ¾-inch in thickness, securely screwed to lathing, must be provided for switches, and also for fixtures which are not attached to gas pipes or conduit.

23. Electric Heaters.

a. Must be protected by a cut-out and controlled by indicating switches arranged as required for electric power devices employing the same current and potential.

b. Must never be concealed, but must at all times be in plain sight.

c. Flexible conductors for smoothing irons and sad irons, and for all devices requiring over 250 watts, must comply with Rule 45, section g.

d. For portable heating devices the flexible conductors must be connected to an approved plug device, so arranged that the plug will pull out and open the circuit in case any abnormal strain is put on the flexible conductor. This device may be stationary, or it may be placed in the cord itself. The cable or cord must be attached to the heating apparatus in such manner that it will be protected from kinking, chafing, or like injury at or near the point of connection.

e. Smoothing irons, sad irons, and other heating appliances that are intended to be applied to inflammable articles, such as clothing, must conform to the above rules, so far as they apply. They must also be provided with an approved stand, on which they should be placed when not in use.

f. Stationary electric heating apparatus, such as radiators, ranges, plate warmers, etc., must be placed in a safe location, isolated from inflammable materials, and be treated as sources of heat.

g. Must each be provided with name-plate, giving the maker's name and the normal capacity in volts and amperes.

LOW-POTENTIAL SYSTEMS.

550 VOLTS OR LESS.

Any circuit attached to any machine, or combination of machines, which develops a difference of potential between any two wires, of over ten volts and less than 550 volts, shall be considered as a low-potential circuit, and as coming under this class, unless an approved transforming device is used, which cuts the difference of potential down to ten volts or less. The primary circuit not to exceed a potential of 3,500 volts unless the primary wires are installed in accordance with the requirements as given in No. 12 A, or are underground.

Before pressure is raised above 300 volts on any previously existing system of wiring, the whole must be strictly brought up to all of the requirements of the rules at date.

24. Wires.

GENERAL RULES.

(See also Nos. 14, 15, and 16.)

a. Must be so arranged that under no circumstances will there be a difference of potential of over 300 volts between any bare metal parts in any distributing switch or cut-out cabinet, or equivalent center of distribution.

b. Must not be laid in plaster, cement, or similar finish, and must never be fastened with staples.

c. Must not be fished for any great distance, and only in places where the inspector can satisfy himself that the rules have been complied with.

d. Twin wires must never be used, except in conduits, or where flexible conductors are necessary.

e. Must be protected on side walls from mechanical injury. When crossing floor timbers in cellars, or in rooms where they might be exposed to injury, wires must be attached by their insulating supports to the under side of a wooden strip, not less than one-half inch in thickness, and not less than three inches in width. Instead of the running-boards, guard strips on each side of and close to the wires will be accepted. These strips to be not less than seven-eighths of an inch in thickness, and at least as high as the insulators.

f. When run in unfinished attics, will be considered as concealed and when run in close proximity to water tanks or pipes, will be considered as exposed to moisture.

SPECIAL RULES.

For Open Work.

In dry places.

g. Must have an approved rubber or "slow-burning weatherproof" insulation (see Nos. 41 and 42).

h. Must be rigidly supported on non-combustible, non-absorptive insulators, which will separate the wires from each other and from the surface wired over in accordance with the following table:—

In damp places, or buildings specially subject to moisture or to acid or other fumes liable to injure the wires or their insulation.

i. Must have an approved insulating covering.

j. Must be rigidly supported on non-combustible, non-absorptive insulators, which separate the wire at least one inch from the surface wired over, and must be kept apart at least two and one-half inches for voltages up to 300, and four inches for higher voltages.

k. (Stricken out.)

For Moulding Work

l. Must have an approved rubber insulating covering (see No. 41).

m. Must never be placed in moulding in concealed or damp places, or where the difference of potential between any two wires in the same moulding is over 300 volts.

For Conduit Work.

n. Must have an approved rubber insulating covering (see No. 47).

o. Must not be drawn in until all mechanical work on the building has been, as far as possible, completed. Conductors in vertical conduit risers must be supported within the conduit system in accordance with the following table:— No. 14 to 0 every 100 feet. No. 00 to 4-0 every 80 feet. 0000 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. A turn of 90 degrees in the conduit system will constitute a satisfactory support, as per above table.

The following methods of supporting cables are recommended :—

1. Junction boxes may be inserted in the conduit system at the required intervals, in which insulating supports of approved type must be installed and secured in a satisfactory manner so as to withstand the weight of the conductors attached thereto, the boxes to be provided with proper covers.
2. Cables may be supported in approved junction boxes on two or more insulating supports so placed that the conductors will be deflected at an 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 suspended may be additionally secured to these insulators by tie wires. Other methods, if used, must be approved by the Inspection Departments having jurisdiction.

p. Must, for alternating systems, have the two or more wires of a circuit drawn in the same conduit.

For Concealed "Knob and Tube" Work.

q. Must have an approved rubber insulating covering (see No. 41).

r. Must be rigidly supported on non-combustible, non-absorptive insulators which separate the wire at least one inch from the surface wired over. Must be kept at least ten inches apart, and, when possible, should be run singly on separate timbers or studdings. Must be separated from contact with the walls, floor timbers and partitions through which they may pass by non-combustible, non-absorptive insulating tubes, such as glass or porcelain.

s. When, in a concealed knob and tube system, it is impracticable to place any circuit on noncombustible supports of glass or porcelain, approved metal conduit or approved armored cable must be used (see No. 24 t), except that if the difference of potential between the wires is not over 300 volts, and if the wires are not exposed to moisture, they may be fished on the loop system if separately encased throughout in continuous lengths of approved flexible tubing.

t. Mixed concealed knob and tube work as provided for in No. 24 s, must comply with requirements of No. 24 n to p, and No. 25, when conduit is used, and with requirements of No. 24 A, when armored cable is used.

u. Must at all outlets, except where conduit is used, be protected by approved flexible insulating tubing, extending in continuous lengths from the last porcelain support to at least one inch beyond the outlet. In the case of combination fixtures the tubes must extend at least flush with outer end of gas cap.

For Fixture Work

v. Must have an approved rubber insulating covering (see No. 46), and be not less in size than No. 18 B. & S. gage.

w. Supply conductors, and especially the splices to fixture wires, must be kept clear of the grounded part of gas pipes, and, where shells or outlet boxes are used, they must be made sufficiently large to allow the fulfilment of this requirement.

x. Must, when fixtures are wired outside, be so secured as not to be cut or abraded by the pressure of the fastenings or motion of the fixture.

y. Under no circumstances must there be a difference of potential of more than 300 volts between wires contained in or attached to the same fixture.

24 A. Armored Cables.

(For construction rules, see No. 48.)

a. Must be continuous from outlet to outlet or to junction boxes, and the armor of the cable must properly enter and be secured to all fittings.

b. Must be equipped at every outlet with an approved outlet box or plate, as required in conduit work. (See No. 49 A.)

c. Must have the metal armor of the cable permanently and effectively grounded.

d. When installed in so-called fireproof buildings in course of construction or afterwards if concealed, or where it is exposed to the weather, or in damp places such as breweries, stables, etc., the cable must have a lead covering at least one thirty-second inch in thickness placed between the outer braid of the conductors and the steel armor.

e. Where entering junction boxes, and at all other outlets, etc., must be provided with approved terminal fittings which will protect the insulation of the conductors from abrasion, unless such junction or outlet boxes are specially designed and approved for use with the cable.

f. Junction boxes must always be installed in such a manner as to be accessible.

g. For alternating current systems must have the two or more conductors of the cable enclosed in one metal armor.

25. Interior Conduits.

(See also Nos. 24 n to p, and 49.)

a. No conduit tube having an internal diameter of less than five eighths of an inch shall be used. Measurements to be taken inside of metal conduits.

b. Must be continuous from outlet to outlet or to junction boxes, and the conduit must properly enter, and be secured to all fittings.

c. Must be first installed as a complete conduit system, without the conductors.

d. Must be equipped at every outlet with an approved outlet box or plate (see No. 49 l to o).

e. Metal conduits where they enter junction boxes, and at all other outlets, etc., must be provided with approved bushings 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.

f. Must have the metal of the conduit permanently and effectually grounded.

g. Junction boxes must always be installed in such a manner as to be accessible.

h. All elbows or bends must be so made that the conduit or lining of same 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. Must have not more than the equivalent of four quarter bends from outlet to outlet, the bends at the outlets not being counted.

26. Fixtures.

(See also Nos. 22 e, 24 v to x.)

a. Must when supported from the gas piping or any grounded metal work of a building be insulated from such piping or metal work by means of approved insulating joints (see No. 50) placed as close as possible to the ceiling or walls.

b. Must have all burs, or fins, removed before the conductors are drawn into the fixture.

c. Must be tested for "contacts" between conductors and fixture, for "short circuits" and for ground connections before it is connected to its supply conductors.

27. Sockets.

(For construction rules, see No. 55.)

a. In rooms where inflammable gases may exist the incandescent lamp and socket must be enclosed in a vapor-tight globe, and supported on a pipe-hanger, wired with approved rubber-covered wire (see No. 41) soldered directly to the circuit.

b. In damp or wet places, or over specially inflammable stuff, waterproof sockets must be used.

28. Flexible Cord.

a. Must have an approved insulation and covering (see No. 45).

b. Must not be used where the difference of potential between the two wires is over 300 volts.

c. Must not be used as a support for clusters.

d. Must not be used except for pendants, wiring of fixtures, portable lamps or motors, and portable heating apparatus.

e. Must not be used in show windows.

f. Must be protected by insulating bushings where the cord enters the socket.

g. Must be so suspended that the entire weight of the socket and lamp will be borne by some approved device 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.

29. Arc Lamps on Constant-Potential Circuits.

a. Must have a cut-out (see No. 17 a) for each lamp or each series of lamps.

b. Must only be furnished with such resistances or regulators as are enclosed in non-combustible material, such resistances being treated as sources of heat. Incandescent lamps must not be used for this purpose.

c. Must be supplied with globes and protected by spark arresters and wire netting around the globe, as in the case of series arc lamps (see Nos. 19 and 58).

d. Lamps when arranged to be raised and lowered, either for carboning or other purposes, shall be connected up with stranded conductors from the last point of support to the lamp, when such conductor is larger than No. 14 B. & S. gage.

30. Economy Coils.

a. Economy and compensator coils for arc lamps must be mounted on non-combustible, non-absorptive insulating supports, such as glass or porcelain, allowing an air space of at least one inch between frame and support, and must in general be treated as sources of heat.

31. Decorative Lighting Systems.

a. Special permission may be given in writing by the Inspection Department having jurisdiction for the temporary installation of approved Systems of Decorative Lighting, provided the difference of potential between the wires of any circuit shall not be over 150 volts and also provided that no group of lamps requiring more than 1320 watts shall be dependent on one cut-out.

b. Incandescent lamps connected in series must not be used for decorative purposes inside of buildings except by special permission in writing from the Inspection Department having jurisdiction.

32. Car Wiring and Equipment of Cars.

a. Protection of Car Body, etc.

1. Under side of car bodies to be protected by approved fire-resisting insulating material, not less than 1-8 inch in thickness, or by sheet iron or steel, not less than .04 inch in thickness, as specified in Section a, 2, 3, and 4, This protection to be provided over all electrical apparatus, such as motors with a capacity of over 75 H. P. each, resistances, contactors, lightning arresters, air brake motors, etc., and also where wires are run, except that protection may be omitted over wires designed to carry 25 amperes or less if they are encased in metal conduit.

2. At motors of over 75 H. P. each, fire-resisting material or sheet iron or steel extend to not less than 8 inches beyond all edges of openings in motors, and not less than 6 inches beyond motor leads on all sides.

3. Over resistances, contactors, and lightning arresters, and other electrical apparatus, excepting when amply protected by their casing, fire-resisting material or sheet iron or steel to extend not less than 8 inches beyond all edges of the devices.

4. Over conductors, not encased in conduit, and conductors in conduit when designed to carry over 25 amperes, unless the conduit is so supported as to give not less than 1-2 inch clear air space between the conduit and the car, fire-resisting material or sheet iron or steel to extend at least 6 inches beyond conductors on either side.

5. In all cases fireproof material or sheet iron or steel to have joints well fitted, to be securely fastened to the sills, floor timbers and cross braces, and to have the whole surface treated with a waterproof paint.

6. Cut-out and switch cabinets to be substantially made of hard wood. The entire inside of cabinet to be lined with not less than 1-8 inch fire-resisting insulating material which shall be securely fastened to the woodwork, and after the fire-resisting material is in place the inside of the cabinet shall be treated with a waterproof paint.

b. Wires, Cables, etc.

1. All conductors to be stranded, the allowable carrying capacity being determined by Table "A" of No. 16, except that motor, trolley and resistance leads shall not be less than No. 7 B. & S. gage, heater circuits not less than No. 12 B. & S. gage, and lighting and other auxiliary circuits not less than No. 14 B. & S. gage. The current used in determining the size of motor, trolley and resistance leads shall be a per cent of the full load current, based on one hour’s run of the motor, as given by the following table:—

2. To have an insulation and braid as called for by No. 41 for wires carrying currents of the same potential.

3. When run in metal conduit, to be protected by an additional braid as called for by No. 47.

4. When not in conduit, in approved moulding, or in cables surrounded by 1-8 inch flameproof covering, must comply with the requirements of No. 41—except that tape may be substituted for braid—and be protected by an additional flameproof braid, at least 1-32 inch in thickness, the outside being saturated with a preservative flameproof compound.

5. Must be so spliced or joined as to be both mechanically and electrically secure without solder. The joints must then be soldered and covered with an insulation equal to that on the conductors.

6. All connections of cables to cut-outs, switches and fittings, except those to controller connection boards, when designed to carry over 25 amperes, must be provided with lugs or terminals soldered to the cable, and securely fastened to the device, by bolts, screws, or by clamping; or, the end of the cable, after the insulation is removed, shall be dipped in solder and be fastened into the device by at least two set screws having check nuts. All connections for conductors to fittings, etc., designed to carry less than 25 amperes, must be provided with turned-up lugs that will grip the conductor between the screw and the lug, the screws being provided with flat washers; or by block terminals having two set screws, and the end of the conductors must be dipped in solder. Soldering, in addition to the connection of the binding screws, is strongly recommended, and will be insisted on when above requirements are not complied with.

c. Cut-outs, Circuit Breakers and Switches.

1. All cut-outs and switches having exposed live metal parts to be located in cabinets. Cut-outs and switches, not in iron boxes or in cabinets, shall be mounted on not less than 1-4 inch fire-resisting insulating material, which shall project at least 1-2 inch beyond all sides of the cut-out or switch.

2. Cut-outs to be of the approved cartridge or approved blow-out type.

3. All switches controlling circuits of over5 ampere capacity shall be of approved single pole, quick break, or approved magnetic blow-out type. INSIDE WORK. Switches controlling circuits of 5 ampere or less capacity may be of the approved single pole, double break, snap type.

4. Circuit breakers to be of approved type.

5. Circuits must not be fused above their safe carrying capacity.

6. A cut-out must be placed as near as possible to the current collector, so that the opening of the fuse in this cut-out will cut off all current from the car.

d. Conduit.

1. Metal conduits, outlet and junction boxes to be constructed in accordance with No. 49, except that conduit for lighting circuits need not be over 5-16 inch internal diameter and 1-2 inch external diameter, and for heating and air motor circuits need not be over 3-8 inch internal diameter and 9-16 inch external diameter, and all conduits where exposed to dampness must be water tight.

2. Must be continuous between and be firmly secured into all outlet or junction boxes and fittings, making a thorough mechanical and electrical connection between same.

3. Metal conduits, where they enter all outlet or junction boxes and fittings, must be provided with approved bushings fitted so as to protect cables from abrasion.

4. Except as noted in Section i, 2, must have the metal of the conduit permanently and effectively grounded.

5. Junction and outlet boxes must be installed in such a manner as to be accessible.

6. All conduits, outlets, or junction boxes and fittings to be firmly and substantially fastened to the framework of the car.

e. Moulding.

1. To consist of a backing and a capping and to be constructed of fire-resisting insulating material, except where circuits which they are designed to support are nominally not exposed to moisture, they may be constructed of hard wood.

2. When constructed of fire-resisting insulating material, the backing shall be not less than 1-4 inch in thickness and be of a width sufficient to extend not less than 1 inch beyond conductors at sides. The capping, to be not less than 1-8 inch in thickness, shall cover and extend at least 3-4 inch beyond conductors on either side. The joints in the moulding shall be mitred to fit close, the whole material being firmly secured in place by screws or nails, and treated on the in-inside and outside with a waterproof paint.

3. Wooden mouldings must be so constructed as to thoroughly encase the wire and provide a thickness of not less than 3-8 inch at the sides and back of the conductors, the capping being not less than 3-16 inch in thickness. Must have both outside and inside two coats of waterproof paint. The backing and the capping shall be secured in place by screws.

f. Lighting and Lighting Circuits.

1. Each outlet to be provided with an approved porcelain receptacle, or an approved cluster. No lamp of over 32 candle power to be used.

2. Circuits to be run in approved metal conduit, or approved moulding.

3. When metal conduit is used, except for sign lights, all outlets to be provided with approved outlet boxes.

4. At outlet boxes, except where approved clusters are used, porcelain receptacles to be fastened to the inside of the box, and the metal cover to have an insulating bushing around opening for the lamp. When approved clusters are used, the cluster shall be thoroughly insulated from the metal conduit, being mounted on blocks of hard wood or fire-resisting insulating material.

5. Where conductors are run in moulding the porcelain receptacles or cluster to be mounted on blocks of hard wood or of fireproof insulating material.

g. Heaters and Heating Circuits.

1. Heaters to be of approved type.

2. Panel heaters to be so constructed and located that when heaters are in place all current carrying parts will be at least 4 inches from all woodwork. Heaters for cross seats to be so located that current carrying parts will be at least 6 inches below under side of seat, unless under side of seat is protected by not less than 1-4 inch fire-resisting insulating material, or .04 inch sheet metal with 1 inch air space over same, when the distance may be reduced to 3 inches.

3. Circuits to be run in approved metal conduit, or in approved moulding, or if the location of conductors is such as will permit an air space of not less than 2 inches on all sides except from the surface wired over, they may be supported on porcelain knobs or cleats, provided the knobs or cleats are mounted on not less than 1-4 inch fire-resisting insulating material extending at least 3 inches beyond conductors at either side, the supports raising the conductors not less than 1-2 inch from the surface wired over, and being not over 12 inches apart.

h. Air Pump Motor and Circuits

1. Circuits to be run in approved metal conduit or in approved moulding, except that when run below the floor of the car they may be supported on porcelain knobs or cleats, provided the supports raise the conductor at least 1-2 inch from the surface wired over and are not over 12 inches apart.

2. Automatic control to be enclosed in an approved metal box. Air pump and motor, when enclosed, to be in approved metal box or a wooden box lined with metal of not less than 1-32 inch in thickness. When conductors are run in metal conduit the boxes surrounding automatic control and air pump and motor may serve as outlet boxes.

i. Main Motor Circuits and Devices.

1. Conductors connecting between trolley stand and main cut-out or circuit breakers in hood, to be protected where wires enter prevent ingress of moisture.

2. Conductors connecting between third rail shoes on the same truck, to be supported in an approved fire-resisting insulating moulding, or in approved iron conduit supported by soft rubber or other approved insulating cleats.

3. Conductors on the under side of the car, except as noted in Section i, 4, to be supported in accordance with one of the following methods:—

a. To be run in approved metal conduit, junction boxes being provided where branches in conduit are made, and outlet boxes where conductors leave conduit.

b. To be run in approved fire-resisting insulating moulding.

c. To be supported by insulating cleats, the supports being not over 12 inches apart.

4. Conductors with flameproof braided outer covering, connecting between controllers at either end of car, or controllers and contactors, may be run as a cable, provided the cable where exposed to the weather is encased in a canvas hose or canvas tape, thoroughly taped or sewed at ends and where taps from the cable are made, and the hose or tape enters the controllers. Conductors with or without flameproof braided outer covering connecting between controllers at either end of the car, or controllers and contactors, may be run as a cable, provided the cable throughout its entire length is surrounded by 1-8 inch flameproof covering, thoroughly taped or sewed at ends, or where taps from cable are made, and the flameproof covering enters the controllers. Cables where run below floor of car may be supported by approved insulating straps or cleats. Where run above floor of car, to be in a metal conduit or wooden box painted on the inside with not less than two coats of flameproof paint, and where this box is so placed that it is exposed to water, as by washing of the car floor, attention should be given to making the box reasonably waterproof. Canvas hose or tape, or flameproof material surrounding cables after conductors are in same, to have not less than two coats of waterproof insulating material.

5. Motors to be so drilled that, on double truck cars, connecting cables can leave motor on side nearest to king bolt.

6. Resistances to be so located that there will be at least 6 inch air space between resistances proper and fire-resisting material of the car. To be mounted on iron supports, being insulated by non-combustible bushings or washers, or the iron supports shall have at least 2 inches of insulating surface between them and metal work of car, or the resistances may be mounted on hard wood bars, supported by iron stirrups, which shall have not less than 2 inches of insulating surface between foot of resistance and metal stirrup, the entire surface of the bar being covered with at least 1-8 inch fire-resisting insulating material. The insulation of the conductor, for about 6 inches from terminal of the resistance, should be replaced, if any insulation is necessary, by a porcelain bushing or asbestos sleeve.

7. Controllers to be raised above platform of car by a not less than 1 inch hard wood block, the block being fitted and painted to prevent moisture working in between it and the platform.

j. Lightning Arresters

1. To be preferably located to protect all auxiliary circuits in addition to main motor circuits.

2. The ground conductor shall be not less than No. 6 B. & S. gage, run with as few kinks and bends as possible, and be securely grounded.

k. General Rules.

1. When passing through floors, conductors or cables must be protected by approved insulating bushings, which shall fit the conductor or cable as closely as possible.

2. Moulding should never be concealed except where readily accessible. Conductors should never be tacked into moulding.

3. Short bends in conductors should be avoided where possible.

4. Sharp edges in conduit or in moulding must be smoothed to prevent injury to conductors.

33. Car Houses.

a. The trolley wires must be securely supported on insulating hangers.

b. The trolley hangers must be placed at such a distance apart that, in case of a break in the trolley wire, contact cannot be made with the floor.

c. Must have a cut-out switch located at a proper place outside of the building, so that all trolley circuits in the building can be cut out at one point, and line circuit-breakers must be installed, so that when this cut-out switch is open the trolley wire will be dead at all points within 100 feet of the building. The current must be cut out of the building whenever the latter is not in use or the road is not in operation.

d. All lamps and stationary motors must be installed in such a way that one main switch can control the whole of each installation—lighting or power—independently of the main feeder switch. No portable incandescent lamps or twin wire will be allowed, except that portable incandescent lamps may be used in the pits, the circuit to be controlled by a switch placed outside of the pit, and the connections to be made by two approved rubber-covered flexible wires (see No. 41), properly protected against mechanical injury.

e. All wiring and apparatus must be installed in accordance with rules for constant-potential systems.

f. Must not have any system of feeder distribution centering in the building.

g. The rails must be bonded at each joint with a conductor having a carrying capacity not less than that of a No. 2 B. & S. gage annealed copper wire.

h. Cars must not be left with the trolley in electrical connection with the trolley wire.

34. Lighting and Power from Railway Wires.

a. Must not be permitted, under any pretense, in the same circuit with trolley wires with a ground return, except in electric railway cars, electric car houses and their power stations; nor shall the same dynamo be used for both purposes.

HIGH-POTENTIAL SYSTEMS.

550 To 3,500 Volts.

Any circuit attached to any machine or combination of machines which develops a difference of potential, between any two wires, of over 550 volts and less than 3,500 volts, shall be considered as a high-potential circuit, and as coming under that class, unless an approved transforming device is used, which cuts the difference of potential down to 550 volts or less.

35. Wires.

(See also Nos. 14, 15 and 16.)

a. Must have an approved rubber-insulating covering (see No. 41).

b. Must be always in plain sight and never encased, except where required by the Inspection Department having jurisdiction.

c. Must be rigidly supported on glass or porcelain insulators, which raise the wire at least one inch from the surface wired over, and must be kept about eight inches apart.

d. Must be protected on side walls from mechanical injury by a substantial boxing, retaining 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 must be attached by their insulating supports to the under side of a wooden strip not less than one-half an inch in thickness.

36. Transformers. (When permitted inside buildings under No. 13.)

(For construction rules, see No. 62.) (See also Nos. 13 and 13 A.)

a. Must be located as near as possible to the point at which the primary wires enter the building.

b. 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.

c. Must be thoroughly insulated from the ground, or permanently and effectually grounded, and the enclosure in which they are placed must be practically air-tight, except that it must be thoroughly ventilated to the outdoor air, if possible, through a chimney or flue. There should be at least six inches air space on all sides of the transformer.

37. Series Lamps.

a. No multiple series or series multiple system of lighting will be approved.

b. Must not, under any circumstances, be attached to gas fixtures.

EXTRA-HIGH-POTENTIAL SYSTEMS.

OVER 3,500 VOLTS.

Any circuit attached to any machine or combination of machines which develops a difference of potential, between any two wires, of over 3,500 volts, shall be considered as an extra-high-potential circuit, and as coming under that class, unless an approved transforming device is used, which cuts the difference of potential down to 3,500 volts or less.

38. Primary Wires.

a. Must not be brought into or over buildings, except power stations and sub-stations.

39. Secondary Wires.

a. Must be installed under rules for high-potential systems when their immediate primary wires carry a current at a potential of over 3,500 volts, unles the primary wires are installed in accordance with the requirements as given in No. 12 A or are entirely underground, within city, town and village limits.