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shall be provided for the installation one ground detector, or if the circuits have no common junction one ground detector for each circuit which shall continuously indicate the insulation from the ground maintained on both sides throughout the system, and one pair of lightning arresters for the common circuits, or for each circuit if they are kept separate; there shall also be provided such brush jigs, switches, cut-outs, belts and other appliances as are requisite and proper for the operation of the system; all switches and cut-outs to be of the double pole type and mounted on incombustible bases.

For alternating systems there shall be 57, overt.

provided the following numbers and sizes
of converters:
Number. Sizes.

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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 ampere, and no wire Smaller than — B. & S. or —B. W. G. shall be used. All regulator, exciter, and for systems carrying over volts all auxiliary and main wires, shall be insulated with —; all wires of systems carrying over — volts shall be run—; where 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 —.

For systems carrying less than — volts the main wires shall be of

bare copper wire Supported on porcelain insulators.

carefully cleated to the ceiling, carried on porcelain insulators, concealed in a moulding consisting of a backing —thick and a Cappling thick, run in conduit, wires of opposite polarity being separated

not less than —.

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

— insulated wire

(See p. 51, sec. 25.) #.i. Struction.

(See p. 51, sec. 26.) onewal

(See Note: p. 52, sec. 27.) 61. Summary.

Each bidder shall fill out completely, so far as it pertains to his apparatus, the following summary: Number of direct-current dynamos Trade number or designation . . —

Number of alternating-current
dynamos . . . . . . —
Trade number or designation . . —
Number of exciter dynamos . . —
Trade number or designation . . —
Rating of dynamos in volts . . – —
Rating of dynamos in amperes . ——
Rating of exciters in volts . . . ——
Rating of exciters in amperes . . ——

Self or separately excited . . .

62 SWitch. board.

63. Switchboard Apparatus and Con

nections.

Shunt or compound . . . . . —

Reduction recommended in convert-
€I'S . . . . . . . . .

H. P. required to be delivered at pulley
at full load . . .

(See p. 53, 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 proper and convenient manipulation of the circuits, such appliances to be named by each bidder in his proposal.

For the two-wire, direct-current system the appliances and connections shall be such as will permit any dynamo to be added to or taken from parallel circuit without in any manner affecting the operation of the dynamos remaining in circuit, or the candle-power and steadiness of the lamps.

For the three-wire, direct-current system the appliances and connections shall be such as will permit any dynamo on either side to be added to or taken from parallel circuit without in any manner affecting the operation of the dynamos remaining in circuit on that side, or the candle-power and steadiness of the lamps; and a breakdown switch for connecting the two outside wires in case it shall be. come necessary or desirable to operate on the two-wire system.

For the alternating-current system the appliances and connections shall be such as will permit the operation of any dynamo on any circuit or number of circuits, and the cutting in or out of any dy

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