107. System. Three-Wire System Adapted to the Two- This specification is identical with the two-wire specification, except in "System," p. 94, sec. 84, in place of which insert the following: All risers, feeders } and mains shall consist of three wires, but the neutral wire shall consist of two wires each equal in cross-section to the outside wires, or of one wire equal in cross-section to the outside wires combined, in order that if desired all lights may be operated on the two-wire system; if two neutral wires are run they shall be permanently connected at each cut-out box. All distribution circuits shall consist of two wires only except to outlets for a group of c. p., lamps or more, and for special circuits specifically mentioned. In all three wire distribution circuits the neutral shall be equal in cross-section to the two outside wires combined. Care shall be taken in arranging the distribution circuits to have the same number of lamps on each side of the system and that no circuit shall be connected across the outside wires or between the neutral wires. The neutral shall in all cases be properly tagged and shall be run between the outside wires. 108. Circuits. 109. Insulation of Wire. Arc System. The lights shall be divided into the following circuits: Circuit No. 1 (Number of lights and location.) Circuit No. 2 (Number of lights and location), etc. All wire used in the installation shall be insulated with for inside circuits, and with for outside circuits. 110. Insulation Resistance. Each circuit shall test out with an insulation resistance of at least ohms. the highest possible insulation is obtained. All wiring shall be neat in its mechanical appearance and arrangement. All exterior wires shall be run In the interior of (the) building(s) the 113. Suspenlamps specified shall be suspended from securely fastened to the ceiling (and provided with a suitable device for raising and lowering). On the exterior of (the) building(s) the lamps specified shall be suspended from -, securely attached to (and provided with a suitable device for raising and lowering). (Add details concerning any posts, pole-steps, ornamental treatment desired, etc.) sion of Lamps. 114. Method of Wiring. 115. Appli ances. 116. Placing of Conduits. 117. Sealing Openings. Conduit System. Two- Wire. The building shall be wired according to the system of and using the conduit manufactured by All appliances employed shall be such as are especially adapted for use in conjunction with the conduit system. All conduits shall be placed in position before after } the plastering is done, and shall be firmly secured within and ceilings. } walls After the tubes are installed all openings in walls and floors shall be sealed so that it shall be impossible, in the event of fire, for smoke or flame to pass from one floor to another or from one room to another about the tubes. |