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and precaution, to add to or take away from the circuit any dynamo without in any manner affecting the operation of the remainder, or causing any change in the candle-power or steadiness of the lamps; and that when two or more are operating on the same circuit in parallel the load may be divided between them in proportion to their respective capacities under all conditions, from no load to full load; and that with the proper connections any number of pairs, a pair consisting of two similar dynamos, may be manipulated in the same manner and with the same effect as single dynamos, as indicated above.

The dynamo(s) shall be rated with such margin of safety that they shall not be injured if subjected to an overload of per cent. above such rating for a period of

22. Founda- (Note.—The following specification is

for foundations for belted dynamos; while

tions.

the dynamo foundation need not be as massive as the engine foundation it should, nevertheless, be of ample dimensions.

For direct-connected outfits the foundation is the engine foundation sufficiently enlarged to also support the dynamo and therefore is properly included under the head of engine foundation.

For either purpose the foundation should be entirely separated from walls, floor or sub-stratum of rock by some deadening material such as felt, cork, or sand.)

The foundation(s) for the(se) dynamo(s) shall be built by the purchaser you choll ho built by the contractor Lee

{oflaid - , or other material subject to the approval of the engineer, { and shall be

7 architect, sa of sufficient length, width and depth to safely and firmly sustain

in their ,

its

weight.

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in the following manner:- , so that no vibration or noise whatsoever shall be transmitted to any part of the building.

Above the floor line { they shall be faced with

All necessary excavating or filling and the removal of all debris shall be done by the contractor lo

uv) purchaser Ċ who shall also restore the floor in the following manner —

The height of the dynamo base-frame(s) above the floor line will be —

The dynamo base-frame(s) shall be firmly and securely fastened to the(se) foundation(s) in such a way as to prevent lateral motion in either direction, and to give an even bearing surface at every point.

23. Instru.

ments.

(Note.—This specification simply provides for such instruments as are actual. ly necessary for operating the dynamo; if extra instruments are desired such as portable voltmeters, portable ammeters,

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

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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 carried 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. Regulator wires shall be covered with insulation, and shall be

cleated to the ceiling, )
| carried on insulators,
y concealed in molding,

{main wires run in conduits;

of bare copper wire supported shall be of/ on porcelain insulators,

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