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or insulated wire

f 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 oper- 25. starting

r "1 Plant and Ill

ation the dynamo(s)shall be operated for a Btructlon

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

This contractor shall furnish such re- *e. Kenewai

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 . . .

Trade number or designation .

Rating in volts ....

Rating in amperes . . .

Shunt or compound . . .

Speed

Dimensions of pulleys . .

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 "-i^jjf*" 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

not only should questions of convenience be considered, but also questions of its relation to economy in the wiring.

The switchboard shall be made of ,

neatly and substantially built, of sufficient size to accommodate all the regulating apparatus, switches, bus bars, etc., named below without crowding, supported

on a stout framing of . , and set out not

less than from the wall.

29. Switchboard Apparatus.

(Note.—This specification includes only the instruments used in the simplest of installations. The instruments required for any particular installation must be determined by its individual purposes and necessities.)

There shall be placed upon this switchboard all the dynamo regulating apparatus and the following appliances:

main ampere meters.

—ampere meters for risers.

dynamo galvanometers.

dynamo galvanometer switches.

dynamo switches.

[graphic][merged small]

change-over switches.

break-down switches.

main cut-outs.

(switches, cut-outs, etc., for purely local conditions).

All switches carrying over amperes

shall be knife switches; all other switches shall have sliding contacts, and shall make and break contact automatically beyond the control of the operator, who shall simply set the switch at the point of making or breaking.

Cut-outs shall be so protected that the molten metal cannot be spattered about on the fusing of the strip.

All switches and cut-outs shall be mounted on incombustible bases.

All connecting wires shall be carried

30. Connections (oon

back of the switchboard using only oealed>

wire. All joints shall be soldered.

All connections to switches, cut-outs, etc., shall be soldered or made with an

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