TM 9-2320-211-20
connections are correct. I f correct, replace the
output requirements of 30 volts and 30 amps at
1200 engine rpm cannot be reached, replace the
generator.
generator.
p. With the load bank knob in the fully CCW
position, turn on the load bank switch. Observe the
2-25. Regulator Testing
ammeter and slowly apply about a 5-amp load by
NOTE
turning the load knob clockwise. As the load is
Prior to making the following regulator
increased, the voltage will drop.
tests, the generator must be completely
q. With engine running at 1000 to 1200 rpm,
t e s t e d as in paragraph 2-24. The same
turn the field control knob, and maintain the 30-
a d a p t e r s used in generator testing are
volt output. Then turn the load control knob. The
required to test the regulator. The radio
amperage load should not exceed 30 amps. As the
ground strap must be connected to insure
amperage increases in this test, the voltage will
the grounding of the regulator (fig. 2-20).
drop. The field control knob must be turned to
a. Voltage Control Test (Fig. 2-20).
maintain proper voltage. Then turn the load control
(1) Select the 50-volt scale and turn the
knob to increase the amperage.
L O A D BANK SWITCH to OFF. The load bank
r. If 30 volts and 30 amps cannot be maintained,
control knob must be in the fully counterclockwise
check the belts for proper adjustment (para 2-113).
position.
(Loose belts can slip when a load is applied, giving
low readings.)
(2) W i t h t h e e n g i n e s t o p p e d , c o n n e c t t h e
regulator for defective wire (fig. 2-19). Repair as
meter to the adapters as shown in figure 2-18.
required.
( 6 ) If the wiring is not defective and the
Check to insure that cables are properly connected
and not touching vehicle metal (fig. 2-20).
regulator voltage is under 27.5 or exceeds 29 volts,
(3) With all adapter links closed, start the
replace the regulator (para 2-132).
engine and observe the voltmeter reading. This
b. Amperage Control Test.
CAUTION
should be 27.5 to 29 volts with the engine running
at 1000 to 1200 rpm.
T h e adapter link must be open for the
following test.
(4) Open the adapter link on the regulator and
CAUTION
check the voltage on open circuit. With the engine
at 1000 to 1200 rpm, the voltage should be 27.5 to
Do not allow the voltmeter to go below 22
29 volts (fig. 2-20).
volts while making this test.
(1) If the regulated voltage is 27.5 to 29 volts
(5) If the voltmeter shows less than 27.5 volts,
as in the voltage control test; then, with the engine
check the wiring between the generator and the
