Wiring for Light and Power: A Detailed and Fully Illustrated Commentary on the More Important Portions of the National Electrical Code

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McGraw-Hill book Company, Incorporated, 1917 - 426 стор.
 

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Сторінка 173 - Bushings must be long enough to bush the entire length of the hole in one continuous piece, or else the hole must first be bushed by a continuous waterproof tube. This tube may be a conductor, such as iron pipe, but in that case an insulating bushing must be pushed into each end of it, extending far enough to keep the wire absolutely out of contact with the pipe.
Сторінка 177 - In wet places it should be arranged so 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.
Сторінка 60 - Must 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.
Сторінка 343 - 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 resistance devices.
Сторінка 197 - The switch must be so constructed that it shall be automatic in its action, not stopping between points when started, and prevent an arc between the points under all circumstances; it must indicate on inspection whether the current be "on
Сторінка 286 - Rigid supporting requires under ordinary conditions, where wiring along flat surfaces, supports at least every four and one-half feet. If the wires are liable to be disturbed, the distance between supports should be shortened. In buildings of mill construction, mains of No.
Сторінка 397 - Volts. Any circuit attached to any machine or combination of machines which develops a difference of potential between any two wires, of over...
Сторінка 103 - Storage or Primary Batteries. a. When current for light and power is taken from primary or secondary batteries, the same general regulations must be observed as apply to similar apparatus fed from generators developing the same difference of potential.
Сторінка 378 - SPECIAL ELECTRICAL EFFECTS. Where devices are used for producing special effects such as lightning, waterfalls, etc., the apparatus must be so constructed and located that flames, sparks, etc., resulting from the operation cannot come in contact with combustible material.
Сторінка 104 - No. 24, i and j). (d). All secondary batteries must be mounted on non-absorptive, noncombustible insulators, such as glass or thoroughly vitrified and glazed porcelain. (e). The use of any metal liable to corrosion must be avoided in cell connections of secondary batteries.

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