Niagara Falls 100.000-Hp. Development

Niagara Falls 1 00,000 Up. Development [33 Unit Idea in lOO,OOO-Hp. Electrical Layout To Assure Reliability of Service and Simplicity of Operation Each Unit Has Been Dealt with As Separate Plant By J. Allen Johnson Electrical engineer Niagara Falls Power Company IN THE design of the Station No. 3 extension care- ful attention was given to the logical and orderly placing and grouping of apparatus. On account of its large size each unit was, to a great extent, con- sidered as a complete plant in itself, being provided with its own individual auxiliaries conveniently grouped about it. Thus, if one stands upon the operating gal- lery on the center line of a unit, in front is the passage to the thrust-bearing deck of the generator, with bearing thermometers and oil flow indicators in plain view. At the right hand, near the front of the gallery, is the turbine governor, with tachometer and pressure gages, and to the right of that a pedestal for the control of the penstock valve, which pedestal also carries an illuminated turbine gate-opening indicator. At the left hand is the exciter switchboard, containing exciter and fan-motor starting equipment, generator protective relays and generator field-circuit breakers. To the left of this switchboard stands the motor-gen- erator exciter. Thus practically all devices requiring constant oversight or frequent manipulation are con- centrated at one level where a minimum number of operators can attend them with a minimum of labor. On the main floor under the gallery, directly beneath the governor, are the governor accessories, comprising tanks, valves, piping, etc., and beneath the switchboard are the electrical switches for exciter and fan control, and beneath the exciter the ventilating fan. Below the main floor the hydraulic passages, valve, penstock, etc., occupy one side and the passages for electric wiring and ventilation the other. Piping connections for oil, water and compressed air are on the right, all electrical con- nections on the left. The first of the three generators, known as No. 16, was supplied by the Allis-Chalmers Manufacturing Company, the second, No. 17, by the General Electric Company, and the third, No. 18, by the Westinghouse Electric & Manufacturing Company. The three gen- erators are similar in design, dimensions and charac- teristics, each manufacturer, however, having been allowed considerable liberty in mechanical design and in the treatment of details. (These will be discussed in separate contributions by F. D. Newbury, W. G. Foster and R. B. Williamson.) The units are of the vertical- shaft type, three-phase, 25 cycles, 12,000 volts, 150 r.p.m., Y connected. They are given two ratings, one corresponding to the point of maximum efficiency of the hydraulic turbines, called the “normal” rating, and in addition a “maximum” rating. The ratings follow: ____________________________________ ____________ Rating Kw. Pf. Kva. Amperes Normal 24,000 .9 26,700 1,285 Maximum 26,000 .8 32,500 1,564 In addition it was specified that the generator should be capable of absorbing 36,000 hp. from the turbine. The principal dimensions of the generators are as follows: ________________________________________________________ Outside diameter of frame. . . Height to top of frame....... Height to thrust-bearing- deck .......... Height over all.............. Rotor diameter ............. 21 ft. 6 in. to 21 ft. 9 in. 9 ft. 5 in. 13 ft. 2g in. 20 ft. 2| in. 16 ft. 2| in. to 16 ft. 5J in. CC ,<u Generator a) To Gov. Pump No. 2'/. > 0 £ É «--7b Gov. Pump No.) 'Lightning Arresters ■V | f |Z.7ne Switch High VffSs 7b Lights Field Switch 2200/220 £ ai D.C. from Sta. 3 FIG. 46—SINGLE LINE DIAGRAM OF GENERATING STATION CIRCUITS 2200 Volt From Trans, in Sta.3 I To Gov. ^Pump No. S । z ,7b Con trot Room Neutral Resis- tance D.C. Bus Reserve Bus Exciter Bus Sta. Serv. Bus