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power of the lamps; and that when two or more are operating on the same circuit the load may be divided between them in proportion to their respective capacities under all conditions from no load to full load; if of the alternate current, constant-current or con. stant-potential type,

they e,

{ shall be guaran.

teed as efficient in
of the direct-current types.

The dynamo(s) shall be rated with such margin of safety that 3

otv thot they will not jured if subjected to a temporary overload of -- per cent. above such rating.


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34. Founda


(See Note: p. 44., sec. 22.)

The foundation(s) for the(se) dynamo(s) shall be built by the 3


7 purchaser Ċ of -M, laid --, or of other material subject to the approval of the engineer: į and shall be of

o architect, s an
sufficient length, width, and depth to safely
and firnily sustain
ulv sustain

Stheir l weight Thi

I its weight. The foundation(s) shall be capped with a framing of well seasoned timber securely fastened thereto, the dynamo base-frame(s) being securely fastened to the framing or to the foundation through the framing, both framing and baseframe being secured in such a manner as to prevent lateral motion in either direction

and to give an even bearing surface at every point. If metal is used to fasten framing or baseframe to the foundation it must be thoroughly insulated where it passes through them, and at all places liable to come in contact with the dynamo must be countersunk and covered with a moisture-proof insulating compound.

All necessary excavating and filling, and the removal of all débris shall be done hy the | contractor. / The height of the dynamo 7 purchaser. 5 baseframe(s) above the ground will be -

35. Instra Ments.

(See Note: p. 45, sec. 23.)

There shall be provided with each dynamo one voltmeter or pressure indicator which shall remain constantly in circuit so as to indicate at all times the pressure at the point to which it is connected; one brush jig for trimming the brushes; one insulating baseframe provided with rails and a suitable device for shifting the position of the dynamo to alter the belt tension; if of the constant potential type, one hand regulator made entirely of incombustible material, a headboard switch for cutting off the current at the dynamo, a compensator or suitable balancing device for keeping the current in each circuit practically constant; if of the constant current type an automatic regulator for so controlling the potential as lights are turned on or off that the current shall not vary appre

ciably from its normal value under any condition of load. There shall be provided for each circuit one ampère meter for indicating the current in said circuit, one ground detector which shall continuously indicate the insulation from the ground maintained at both poles and approximately the distance of any ground from the station, and one pair of efficient lighting arresters. There shall also be provided one testing magneto capable of ringing through -- ohms.

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This contractor shall carry to the switchboard location at -- all regulator, exciter, auxiliary, and main wires, leaving the ends coiled up neatly, properly tagged and sufficiently long to make the necessary switchboard connections. All main wires shall have a capacity of at least —- C. M. per ampère and no wire smaller than –– B. & S. or —B. W. G. shall be used. All wires shall be insulated with -- ; shall be run ——; when of opposite polarity shall be separated at least ---; and where crossing each other, wires of other circuits, or passing near metal pipes, girders, etc., shall be further protected by

- In no case shall insulated wires be carried in such proximity to heated surfaces, vapors, or air as to endanger their insulation.

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38. Summary.

(See Note: p. 47, sec. 27.)

Each bidder shall fill out completely the
following summary:
Number of dynamos . . .
Trade number or designation
Rating in volts at maximum load
Rating in ampères at maximum load
Direct or alternating current . .
Constant or varying current . .
Constant or varying potential .
Series, shunt, compound, self or sepa-

rately excited . . .
Rating of exciter in volts .
Rating of exciter in ampères .
Trade number or designation
Regulation by hand or automatic ..
Number of fully loaded circuits possi-

ble to operate per dynamo . Make of lamp recommended for use . Number of —- C. p. lamps of above

make per circuit . . .
Volts per —- C. p. lamp . . .
Ampères per —— c. p. lamp . .
H. P. required to be delivered at the pul-

ley at full load with no loss in the
feeders but including exciter

(See p. 48, sec. 28.)

40. Switch


There shall be placed upon this switch- 41. Switchboard, in addition to all the dynamo regula- atiisana Com. ting apparatus, such switches, cut-outs, and other appliances as are necessary for the

board Apar


proper and convenient manipulation of the circuits, such appliances to be named by each bidder in his proposal. For systems operating dynamos and circuits in parallel, the appliances and connections shall be such as will permit adding to or taking from the circuit any dynamo without in any manner affecting the operation of the remaining dynamos in circuit or the candle power of the lamps, and will permit the cutting in or out of any circuit without affecting the stability of other circuits. For systems operating one dynamo for each circuit or series of circuits the connections shall be such as will permit any circuit to be connected to or disconnected from any dynamo with certainty and rapidity. (For switchboard connections see secs. 30 and 31, p. 50).

42. Circuits.

(See p. 51, sec. 32.)

Alternating Current

Constant Potential,


This contractor shall furnish, and, unless otherwise specified, erect the following apparatus and material:

43. Dynamo(s). - constant potential, alternating cur

rent dynamo(s) (each) having a capacity of --, -- c. p., -- volt incandescent lamps.

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