INSIDE WIRING.

GENERAL RULES.

17. At the entrance of every building there shall be an approved switch placed in the service conductors by which the current may be entirely cut off. (See Definitions).

18. CONDUCTORS:

a. Must have an approved insulating covering, and must not be of sizes smaller than No. 14 B. & S., No. 16 B. W. G., or No. 4 E. S. G., except that in conduit installed under Rule 22, No. 16 B. & S., No. 18 B. W. G., or No. 4 E. S. G., may be used. (See Definitions).

b. Must be protected when passing through floors; or through walls, partitions, timbers, etc., in places liable to be exposed to dampness by waterproof, noncombustible, insulating tubes, such as glass or porcelain.

Must be protected when passing through walls, partitions, timbers, etc., in places not liable to be exposed to

dampness by approved insulating bushings specially made for the purpose.

c. Must be kept free from contact with gas, water, or other metallic piping, or any other conductors or conducting material which they may cross (except high potential conductors) by some continuous and firmly fixed non-conductor creating a separation of at least one inch. Deviations from this rule may sometimes be allowed by special permission.

d. Must be so placed in crossing high potential conductors that there shall be a space of at least one foot at all points between the high and low tension conductors.

e. 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 all pipes upon which condensed moisture is likely to gather, or which by leaking might cause trouble on a circuit.

f. Must be so spliced or joined as to be both mechanically and electrically secure without solder. They must then

be soldered, to insure preservation, and covered with an insulation equal to that on the conductors. (See Definitions).

SPECIAL RULES.

19. WIRING NOT ENCASED IN MOLDING OR APPROVED CONDUIT:-

a. Must be supported wholly on noncombustible insulators, constructed so as to prevent the insulating coverings of the wire from coming in contact with other substances than the insulating supports.

b. Must be so arranged that wires of opposite polarity, with a difference of potential of 150 volts or less, will be kept apart at least two and one-half inches.

c. Must have the above distance increased proportionately where a higher voltage is used.

d. Must not be laid in plaster, cement or similar finish.

e. Must never be fastened with staples.

IN UNFINISHED LOFTS, BETWEEN FLOORS AND CEILINGS, IN PARTITIONS, AND OTHER CON

CEALED PLACES.

f. Must have at least one inch clear air space surrounding them.

g. Must be at least ten inches apart when possible, and should be run singly on separate timbers or studding.

h. Wires run as above immediately under roofs, in proximity to water tanks or pipes, will be considered as exposed to moisture.

i. When from the nature of the case it is impossible to place concealed wire on non-combustible insulating supports of glass or porcelain, the wires may be fished on the loop system, if encased throughout in approved continuous flexible tubing or conduit.

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

k. Twin wires must never be employed in this class of concealed work.

20. MOLDINGS:

a. Must never be used in concealed work or in damp places.

b. Must have at least two coats of waterproof paint or be impregnated with a moisture repellant.

c. Must be made of two pieces, a backing and capping, so constructed as to thoroughly encase the wire, and maintain a distance of one-half inch between conductors of opposite polarity, and afford suitable protection from abrasion. 21. SPECIAL WIRING:

In breweries, packing houses, stables, dye-houses, paper and pulp mills, or other buildings specially liable to moisture or acid, or other fumes liable to injure the wires or insulation, except where used for pendants, conductors

a. Must be separated at least six inches.

b. Must be provided with an approved waterproof covering. (See Definitions). c. Must be carefully put up.

d. Must be supported by glass or por