second between the frame (ground ) and each
(4) At the end of the five-minute over-
terminal (A, B, D, and E) in turn. There must
speed run, reduce the speed to 6500 rpm. Apply
be no evidence of insulation breakdown or leak-
rated load of 300 amperes.
age current in excess of 2 milliamperes.
ute and check the electrical performance. The re-
(4) Reconnect capacitor terminals.
sults should compare with those observed in
g. Polarity Check.
(1) Operate the dc generator at rated speed
f. Dielectric Strength.
and load conditions. Connect the voltmeter leads
(1) Perform this test while the dc gener-
to stanter genenator terminals B and E, observing
ator is hat as a result of previous tests.
(2) Remove all external connections from
dc generator terminal board, and disconnect ter-
versed to obtain a reading, the polarity of the
dc generator is reversed. In this case, flash the
field in the proper direction as described in para-
(3) Using insulation breakdown test set
13700-1C, apply 300 volts ac (60 Hz) for one