Зображення сторінки

156. Circuits. No distributing circuit shall carry more

than -- ampères. In buildings requiring a greater supply of current the lights shall be divided into circuits; these circuits shall be brought together at convenient and accessible centres of distribution, where all branch cut. outs shall be placed.

157. Cut-Outs aud Switches.

! Each branch circuit shall be provided with

a double-pole cut-out. The switches specified below shall be furnished and installed. All cut-outs and switches shall be mounted on incombustible bases.

(List of numbers and sizes of switches.)

[blocks in formation]

159. Suspen

sion of Lamps.

(All) lamps shall be suspended with flexible cord pendants from double-pole ceiling cutouts, the average length of the pendants to be -- This contractor is to furnish all necessary -- cord, ceiling cut-outs, and socket bushings. In both cut-outs and sockets the cord shall be knotted so that no weight shall come on the binding screws.

[blocks in formation]


(See p. 83, sec. 102.)

163. Hanging of Fixtures.

(See p. 83, sec. 103.)
(May require slight modification.)
(See p. 81, sec. 104.)
(May require slight modification.)

164. Wiring and Attachiny Sockets to Fixtures Already in



Low PotentialDirect Current System-Two

or Three-Wire.

chises and

(The purchaser) shall secure all franchises, 165. Fran rights of way, and permits from the --- Permits. authorities and abutting property owners for the erection and guying of poles and stringing of wires along the routes on the map hereto attached and made a part of this specification, shall make all necessary arrangements with cornpanies already having pole lines on any part of the same route for crossing, raising, lowering, or otherwise moving their wires, and for using, moving, or changing their poles, cross-arms, etc.; shall do all necessary trimming of trees; and in every reasonable way shall secure and furnish facilities for the uninterrupted continuance of the work to its completion.

The lights shall be supplied by circuits 166. Division divided as follows: -- --, etc.

All circuits shall be controlled by switches 167. Point of placed (location.)


168 Poles.

The pole line shall be composed of straight, select, shaved -- poles, sound and free from shakes, checks or large knots; poles subject to extra strain shall be specially selected and of ample strength to bear the strain.

[blocks in formation]

All poles must be set -- of their length in the ground and solidly tamped, must measure not less than -- in diameter at the top, and the distance from the ground line to the lowest cross-arm shall be not less than –– Corner, terminal, and other poles subject to extra strain shall be securely guyed wherever possible; where impossible to guy them. they shall be set with such rake and to such extra depth that the strain shall not pull them beyond the vertical position, allowance being made for the action of water and frost.

170. Distances. No two consecutive poles shall be set at a

greater distance apart than --, except by special permission from _-, and all poles carrying heavy feeders or mains shall be set not more than -- apart.

[blocks in formation]

172. Gains and Cross-Arms.

172. Gains and Gains shall be carefully cut so that the

cross-arms make a snug fit and stand at right angles to the pole.

Cross-arms shall be of —–, thoroughly seasoned, sound and free from large knots; painted --; the vertical distance between

cross-arms shall not be less than -- Double cross-arms must be placed on terminal poles and corner poles carrying wires larger than

B. & S. 1 C B .W.G. S

At all corners making an angle greater than -- two sets of cross-arms shall be used placed at the proper angle to each other.

173. Pins and Iusulators.

Pins shall be of selected --, shall fit closely 173. Pins and in the cross-arms and be nailed in place.

Insulators shall be of glass, —- pattern, and of a size suitable for the wire they are to hold.

All poles on which cut-outs are placed shall 174. Steps. be stepped.

175. Soil.

(Note.—Specify character of soil, as loam, sand, etc.; also whether rock will be met with, marsh land, quicksands, etc., requiring special work.)

All feeder, main, and pressure wires shall be 176. Wiring. Sof bare copper wire; } all service wires 7 insulated with - ;s shall be insulated with .--.

All wires shall be so handled as to avoid kinking; wagons, drays, etc., shall not be allowed to drive over them; they shall not be dragged along the ground, over cross-arms er through trees in such a way as to injure the insulation; and shall not be allowed to sag

unduly between supports, allowance being made for expansion and contraction with changes of temperature. All necessary and proper precautions shall be taken in passing over, through, or near buildings of every description, through trees, crossing other lines, turning corners, etc.

Pressure wires shall be carried from the (switchboard) to each centre of distribution unless such centres are connected by an equalizing main, in which case the pressure wires shall be carried to a point on the equalizing main electrically equidistant from the centres of distribution which it connects.

177. Joints

Joints shall be mechanically strong and secure so that no movement of the two ends relatively to each other is possible, and shall be carefully sweat-soldered, the joint being wiped free from any excess of flux; the solder shall be relied on only to give good electrical connection.

178. Lightning Arresters.

tetning An efficient lightning arrester shall be

placed on the pole, connected to the line and to a permanent ground for every -- of conductor.

Fall of

179. Maximum The mains shall be so proportioned that the Potential. maximum fall of potential between the centre

of distribution and any service cut-out, including the loss in any transforming device, shall not exceed --— per cent. under full load.

« НазадПродовжити »