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123. Sub). division of (Risers Feeders s.

From the switchboard (or centre of distri- 123. Sub. ( risers

bisa Lohou bution) —~ 3 groups of risers shall be carfeeders

(Riser ) ried to the following points: Group { No. 1

(Feeder ( riser ) to —-, group No. 2 to —-, etc. ( feeder )

(riser Every conductor in each group of risers

( feeder
and main shall be provided with an inde-
pendent tube.

(Riser)
Group (No. 1 shall feed all lights (loca-
(Feeder )

(riser )
tion), 3 group No. 2 shall feed, etc.

(feeder)

124. Location

of Risers ? Feeders ) :

S switchboard From the

the centre of distributions S risers 1 y feeders /

{ shall be carried to --- and thence upward in (channels, elevator shaft, etc., with location) to their respective junction boxes.

125. Mains (if From the the Sriser Lunction h

· junction boxes mains taps terminate le feeders

iu secondary shall be carried to secondary junction boxes junction where all tap lines shall centre. From

Sriser,
3 feeders No. 1 shall be carried --- mains
terminating at ---; from feeder No. 2, etc.

126. Taps.

(Note.-In certain cases it is advisable 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.)

( riser From the feeder junction boxes distrib

( main uting circuits shall be run to the various outlets as specified in the schedule and located on the plans. For all taps duplex conductor requiring but one tube may be employed provided the current required does not exceed -- ampères.

(risers,

127. Junction

ļ mains

Boxes.

The terminals of a

10 feeders, 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.)].

128. Cut-Outs.

128. Cut-Outs.

(See p. 81, sec. 94.)

(See p. 81, sec. 95.)

129. Fuses.

(See p. 81, sec. 96.)

130. Switches.

Supports.

Where no gas pipes or other support for the 131. Fixture 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.

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All tubes shall be of sufficient size to allow the wires to be readily drawn in, withdrawn and reinserted at will. A quarter-inch tube will be permitted only where space is extremely limited.

Tubes, whether concealed or on the sur- 133. Clips. face, should be held in place by metal clips; the use of staples for such purpose will not be allowed where it can be avoided.

The tubes shall be cut squarely, reamed out 134. Joints. smoothly, and the ends joined by the use of the coupling designed for that purpose.

Where more than four elbows are unavoid- 135. Ellow able 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 termi- 136. Outlets. nal boxes, leaving the outlets so protected as not to be injured by the plasterers.

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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.

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Each side of circuits carrying more than -- ampères shall be run in a separate tube. Wires forming parts of two distinct circuits shall in no case be inclosed in the same tube.

[blocks in formation]

(See p. 85, sec. 107.)

147. ThreeWire System

Adapter to the Two-Wire

System.

Interior Wiring for Central Station Plants.

This specification contemplates the com- 148. Number

of Lights. plete installation of --, -- c. p., incandescent lamps located in blocks as designated on the plans hereto attached and made a part of this specification.

[blocks in formation]

(Note.-Specify whether bids for two-wire 152 System. direct-current systems only, for three-wire direct-current, for two-wire alternating current, or for any system will be considered.)

in Pressure.

The fall of potential between the service 153. Variation cut-out and the most distant lamp in any building shall not exceed -- per cent.

All wires used inside of buildings shall be 154. Insulainsulated with —-..

of the Work.

(open cleat) All wiring shall be molding { work, 155. Character

( concealed ) neat in its mechanical appearance and arrangement.

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