ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. 73 
behind the E.M.F., that is, has the power factor cos P 
= 0, counteracts A,, field ampere turns, then the same 
armature current on an inductive load with a power 
factor cos g = O will also counteract A,, field ampere 
turns. Therefore the application of this rule will take 
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LACTATION CURRENT LV AMPS, 
Fie. 35.—CHARACTERISTICS OF A 235 KVA., 50-CrcLE, STAR 
CONNECTED 3-PHASE ALTERNATOR. 
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SHORT CLRCULL CURRENT IN AMES. 
TERMINAL PRESSURE LW VOLTS. 
the form indicated in Fig. 35, which gives the test results 
of a 235 KVA. three-phase generator. 
The normal current of this alternator is 26 amperes with 
a terminal pressure-of 5,200 volts, and the excitation re- 
quired to obtain this current in the short circuited arma- 
ture is equal to A,, = 5.06 amperes. 
128. On Inductive Load.—If, on an inductive load, the alter- 
nator with an excitation A, of 30 amperes produees an 
armature current of 26 amperes, then the terminal voltage 
of 6,000 volts will correspond to 30 — 5.06 = 24.94 
amperes exciting current in the open circuit characteristic, 
see Fig. 35. . 
The tension of the armature on open cireuit, with 30 amperes 
