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power of the lamps; and that when two or
teed as efficient in #! operation as any
| shall be guaran
of the direct-current types.
margin of safety that } hey | will not be in
jured if subjected to a temporary overload of
—— per cent. above such rating.
(See Note: p. 44., sec. 22.)
shall be built by the | COntractor | of −–,
laid —, or of other material subject to the
approval of the } o | and shall be of
sufficient length, width, and depth to safely
and firmly sustain "o" weight. (The
foundation(s) shall be capped with a framing
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 con- !. tact with the dynamo must be countersunk of s and covered with a moisture-proof insulating compound. r All necessary excavating and filling, and
the removal of all débris shall be done by the
}.} The height of the dynamo
baseframe(s) above the ground will be —.
(See Note: p. 45, sec. 23.) do
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 insu- lation 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.
so to . This contractor shall carry to the switchboard board 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.
Trade number or designation
(See Note: p. 47, sec. 27.)
Rating in volts at maximum load
(See p. 48, sec. 28.)
There shall be placed upon this switchboard, in addition to all the dynamo regulating apparatus, such switches, cut-outs, and other appliances as are necessary for the
41. Switchboard A ploaratus and ("onnections.
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).
(See p. 51, Sec. 32.)
Constant Potential, Alternating Current
This contractor shall furnish, and, unless otherwise specified, erect the following apparatus and material:
constant potential, alternating current dynamo(s) (each) having a capacity of —, -– c. p., -— volt incandescent lamps.