ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. T 
the maximum mechanical output and the normal output, 
the former being the greatest energy which can be devel- 
oped by the motor with a normally excited field before it 
falls out of step. 
Within the practical limits of excitation the overload capac- 
ity increases with the exciting current, but this feature is 
not important. 
o 2000 4000 6000 es eT. 
i 
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Fic. 94.—CHARACTERISTICS OF 450 H. P., 500 Revs., 50-CYCLE 
SYNCHRONOUS 3-PHASE Moror. 
435. Practical Ratio.—The designer considers it sufficient to 
know, that there is an ample margin of overload capacity, 
which is directly indicated by the ratio between the short 
circuit current, which corresponds to the normal excitation, 
and the normal armature current. 
