. Electrical world. t of Load.—The electrical load was applied by meansof a large adjustable w-ater rheostat, which also forms part of theregular testing outfit. As the generator pressure of 11,000 voltsmight prove a source of danger to the attendants if passed directlyinto a water rheostat, the voltage was reduced by step-dow-n trans-formers to about 550 volts. All electrical measurements were, how-ever, made between the generator and the transformers. Voltage was measured by two voltmeters, one being used as acheck on the other, the pressure on the instruments being reducedby potential trans
. Electrical world. t of Load.—The electrical load was applied by meansof a large adjustable w-ater rheostat, which also forms part of theregular testing outfit. As the generator pressure of 11,000 voltsmight prove a source of danger to the attendants if passed directlyinto a water rheostat, the voltage was reduced by step-dow-n trans-formers to about 550 volts. All electrical measurements were, how-ever, made between the generator and the transformers. Voltage was measured by two voltmeters, one being used as acheck on the other, the pressure on the instruments being reducedby potential transformers having a ratio of 100 to I. Each of thesevoltmeters was arranged so that it could be plugged in between anyof the three terminals of the generator. Current was measured by a duplicate set of long-scale, dead-beat pump, which is geared to the turbine in the ratio of 31 to 4. Atachometer was used to detect sudden small variations of speed, ifsuch should occur, as well as to show the speed regulation when the. FIG. 4.—rotating field. load was suddenly increased and decreased. The records of speed,however, did not enter as factors in the measurement of power, whichwas ascertained entirely by observations of the electrical output. Regulation Test of Speed.—At the conclusion of the economy tests,a load of 1,309 kw was thrown ofT by opening the exciter circuit,with a resulting increase of 2 per cent, in speed. A load of 1,342 kw 358 ELECTRICAL WORLD anl ENGINEER. Vol. XLIII, No. 8. S r r »lO i^- ! I . I a- Is was then thrown on and a speed variation of per cent, in theopposite direction was shown. This load on being thrown oftshowed a speed variation of per cent. Test of Safety Stop.—The speed of the turbine was increased bj-holding down the main governor lever, thus preventing the governor 30 40,000 29 33,000 pl / / \ / i 27 34,000 ^ 20—133,000 A / / i ? / W / / 1 34—^»1 ^ 22-231,000=? 21—332,000 3 50— A y c^ y \\\ Z ^^ \
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
