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testing sets, etc., they should be distinctly specified as well as the make if a particular kind is preferred.)

There shall be provided with each dynamo one hand regulator for adjusting the pressure, made entirely of incombustible material; one ampere meter for indicating the current supplied by the dynamo and graduated to read amperes; one voltmeter or pressure indicator, which may remain constantly in circuit so as to indicate continuously the pressure at the point to which it is connected, and which shall be so constructed that the scale is plainly visible at a distance of at least —; one brush jig for trimming the brushes; and one insulating base frame provided with rails and a suitable device for shifting the position of the dynamo to alter the belt tension. There shall also be provided for the installation — ground detector(s), which shall continuously indicate the insulation from the ground maintained on both sides through

24. Cables to Switchboard.

out the system, and—lighting arresters
of the – type. -
(Note.—In the case of compound dy-
namos operating in parallel the equalizing
wire may often more conveniently be car-
ried direct from dynamo to dynamo in
which case this contractor should furnish
and connect a suitable equalizing switch
at each dynamo.)
This contractor shall carry to the
switchboard location at — all regulator
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. Regu

lator wires shall be covered with — insulation, and shall be

cleated to the ceiling,
carried on insulators,
concealed in molding,
run in conduits;

shall be of: bare copper wire supported |

main wires

on porcelain insulators,

or insulated wire

carefully cleated to the ceiling,

carried on porcelain insulators,

concealed in molding consisting of a backing — thick and a capping — 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.

When the plant shall be ready for operation the dynamo(s)shall be operated for a period of — consecutive days by competent engineers furnished by the contractor; all oil, waste, power, etc., to be furnished by (the purchaser). This contractorshall also give all necessary instruction to the engineer of (the purchaser) for the proper care, maintenance and operation of the dynamo (s), such instruction to be given during the trial period stipulated above.

This contractor shall furnish such re

25. Starting Plant and Instruction.

26. Renewal Parts.

newal parts as it is advisable to keep on hand, adding hereto an itemized list of Same.

(Note.—The object of this summary is to present in a concise, tabulated form, the essential data concerning the apparatus to be supplied, thus enabling the different bids to be easily and quickly compared. For complete plants a single form, systematically arranged, will be found extremely convenient both in making comparisons and in being able to see at a glance just what apparatus and appliances are called for, thus constituting a check on the specifications themselves.) Each bidder shall fill out completely the following summary: Number of dynamos . e Trade number or designation . Rating in volts . Rating in amperes Shunt or compound . Speed e e e Dimensions of pulley

27. Summary.

=

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

Switchboard and Appliances.

This contractor shall furnish and erect the following apparatus and material:

(Note.—In plants of any considerable size the switchboard specification is an extremely important one. Its general characteristics will be determined by questions of purpose, economy, utility, available space, beauty, etc., but the details of material, method of wiring, attachment of instruments, location, number of switchboards, etc., require the most careful study. It may be advisable in one instance to have a single switchboard controlling everything from a single centre, in another to have a dynamo switchboard and a separate circuit switchboard, while in yet another to even divide the dynamo switchboard into two or more parts and to have several circuit switchboards. In determining the location of switchboards

28. Switchboard.

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