What people are saying - Write a review
We haven't found any reviews in the usual places.
Other editions - View all
alternating current alternating-current amperes approved armored cable arrangement basement braid branch circuits building calculation capacity cartridge fuse cent center of distribution circular mils cleat connected Contractor controlled copper cost covering cut-out cabinet direct current direct-current distance distributing centers duct ductors Electrical Engineer electromotive force feeders and mains feet fiber conduit fire-proof fixtures flexible tubing formula gage given hall lights inches installed insulation resistance interior wiring iron conduit iron pipe junction boxes knife switches lamps length less lined conduit load main switchboard manhole metal method of wiring moisture molding motors National Electric Code necessary neutral conductor neutral wire number of lights obtain ohms outlet box overhead line panel-board placed plug outlets porcelain power factor protected push-button switch reactance receptacle rubber insulation rules self-induction separate feeder shown in Fig side skin effect sockets supplied terminals three-wire system two-wire system underground unlined conduit voltage voltmeter walls watts
Page 63 - Centigrade) they will carry indefinitely a current 10 per cent, greater than that at which they are rated, and at a current 25 per cent, greater than the rating, they will open the circuit without reaching a temperature which will injure the fuse tube or terminals of the fuse block. With a current 50 per cent, greater than...
Page 59 - Fuses should be stamped with about 80 per cent of the maximum current they can carry indefinitely, thus allowing about 25 per cent overload before the fuse melts. With naked open fuses of ordinary shapes and not over 500 amperes capacity, the maximum current which will melt them in...
Page 99 - The wiring in any building must test free from grounds; ie, the complete installation must have an insulation between conductors and between all conductors and the ground (not including attachments, sockets, receptacles, etc.) not less than that given in the following table...
Page 15 - 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.
Page 15 - The object of a tube or conduit is to facilitate the insertion or extraction of the conductors to protect them from mechanical injury and, as far as possible, from moisture. Tubes or conduits are to be considered merely as raceways, and are not to be relied upon for insulation between wire and wire, or between the wire and the ground.
Page 177 - The ground connection for central stations, transformer substations, and banks of transformers should be made through metal plates buried in coke below permanent moisture level, and connection should also be made to all available underground piping systems, including the lead sheath of underground cables. For individual transformers and building services the ground connection may be made to...
Page 16 - Department having jurisdiction, provided that the conduit ends are bushed and secured. e. Metal conduits, where they enter junctio'n boxes and at all other outlets, etc., must be provided with approved bushings fitted so as to protect...
Page 18 - Must not be drawn in until all mechanical work on the building has been, as far as possible, completed. p. Must, for alternating systems, have the two or more wires of a circuit drawn in the same conduit. It is advised that this be done for direct-current systems also, so that they may be changed to alternating systems at any time, induction troubles preventing such a change unless this construction is followed. For concealed ' ' knob and tube '
Page 43 - The lower limit is specified for rubber-covered wires to prevent gradual deterioration of the high insulations by the heat of the wires, but not from fear of igniting the insulation. The question of drop is not taken into consideration in the above tables.