tion. All single conductors shall be insulated 121. InsulaAll duplex conductors shall with be insulated with. Duplex con ductors and all single conductors larger From the switchboard (or centre of dis- 123. Sub division of (riser, groups of risers, and main shall be feeder, provided with an independent tube. Riser Group No. 1 shall feed all lights (lo- thence upward in (channels, elevator shaft, etc., with location) to their respective junction boxes. ate in sec ondary june-mains shall be carried to secondary junc tion boxes). (Note.-In certain cases it is advisable 126. Taps. to run the circuits in such a manner that no room shall be dependent on one circuit only; if so desired, it should be added under this heading.) From the riser feeder junction boxes dis- tributing circuits shall be run to the vari- amperes. risers mains and taps shall be brought together in junction boxes at the points designated in this specification and on the plans [and connected with their respective cut-outs and switches; (unless the wiring contractor does not furnish cut-outs and switches, in which case add, in such a way as to permit the easy and convenient insertion of the cut-outs and switches specified.)]. 127. Junction Boxes. 131. Fixture Supports. 132. Sizes of Tubes. 133. Fastenings. 134. Joints. Where no gas pipe or other support for the fixture exists, the special form of terminal box designed to furnish such support shall be employed and shall be substantially fixed to a suitable foundation in the ceiling or wall. All tubes shall be of sufficient size to allow the wires to be readily drawn in, withdrawn and reinserted at will. Tubes, whether concealed or on the surface, should be held in place by the fastenings especially designed for use with this conduit. The tubes shall be cut squarely, reamed out smoothly, and the ends joined by the use of the coupling designed for that purpose. Where more than three elbows are unavoidable an intersection box shall be inserted to relieve both the wires and the tubes of strain when the wires are being drawn in. All tubes shall emerge at outlets in 136. Outlets. terminal boxes leaving the outlets so protected as not to be injured by the plasterers. To guard against mechanical injury and the destructive action of cement all floor conduits shall be made of double tube, one telescoped within the other, and both the outer and inner tubes joined in the usual manner. The outer tube shall, in the case of contact with cement, be alkali proof. As a further protection floor tubes shall be covered, during construction, with a light board. Such other precautions shall be taken to insure the safety of the tubes as the character of the building and work require. 137ork Floor Work with armored Conduit. Each side of circuits carrying more than 138. Separa tion of Wires. |