TM 55-6115-498-40
d. When brush seating is completed, remove,
3-3. The voltage must be between 1.9 and 2.1
volts.
(3) After completing the previous test, de-
crease the speed of the motor until the mini-
mum rated of 5000 rpm is measured on
the tachometer. Adjust the voltage regulator
until a 26-volt reading is obtained. The starter
generator must deliver rated current of 300 am-
peres, as read on the ammeter.
NOTE
(4) Readjust the regulator until a 30-volt
reading is obtained.
d. Commutation. Immediately following the
previous heat runs, and with the dc generator
hot, observe the commutation of the dc genera-
tor over the speed range 5000 to 8000 rpm for
no load (all load switches off), half load (suit-
able load switches turned on give 150 am-
peres), and rated load bud (suitable switches turned
on to give 300 amperes). Table 4-3 lists the
various conditions. There should be no sparking
except for the fine pinpoint sparking at the gen-
erator brushes.
NOTE
e. Overspeed.
(1) Perform this test while the dc gener-
ator is hot as a result of testing.
(2) Open all load switches and the field
switch. (Operaite the generator at no load
(3) Increase the speed of the driving motor
11,000 rpm. The generator must operate at this
speed for five minutes without mechanical fail-
ure, the throwing of varnish, or impairment of
electrical performance.
figure
