TM 5-3810-307-24-1-2
GENERATOR BENCH TEST
With carbon pile load turned off and with
battery or battery set fully charged, make
TEST EQUIPMENT NEEDED:
electrical connections as shown in Fig. 7.
Generator Test Stand (5000 rpm capability)
Battery voltage and ground polarity must be
Battery or Battery Set (fully charged)
same as system in which generator is used.
Variable Carbon Pile Load Test
Check and record battery voltage before
Ammeter (current capability at least 15 amps
proceeding with test.
higher than generator rating)
2. With carbon pile load "off," start test stand and
slowly increase generator speed to 5000 rpm.
Observe voltmeter.
This bench test procedure is used to verify that the
-
If voltage does not increase but remains at or
generator is functioning properly prior to
below previous reading (step 2), there is no
installation on the vehicle. This test checks the
generator output. Skip to step 5.
generator output in the same manner as the Rated
Output Check covered earlier in this procedure. If
-
If voltage increases above 31 volts on 24-volt
bench test equipment is not available, install the
system, voltage is uncontrolled. Recheck
generator
on
the
engine
according
to
generator for proper assembly. Assure that
manufacturer's instructions and repeat the Rated
test tab in "D" hole is not grounded. If
Output Check to verify generator operation. If
generator has been assembled properly,
bench test equipment is available, proceed as
replace regulator as described under "Unit
follows:
Repair".
1. Mount generator in suitable test stand,
-
If voltage is proper, proceed to next step.
according to test stand manufacturer's
3. With generator running at about 5000 rpm,
instructions. Test stand must be capable of
turn on carbon pile load and adjust to obtain
driving generator at speeds up to 5000 rpm.
maximum generator output on ammeter
NOTE
without allowing voltage on voltmeter to fall
below 25 volts on a 24-volt system
Battery or battery set must be fully
charged for test results to be valid.
-
If ammeter reading is within 15 amps of cold
output
shown
under
"Specifications",
CAUTION
generator is good. Turn off carbon pile and
When a 12-volt carbon pile load test is
stop test stand.
used to diagnose a 24-volt system,
-
If ammeter reading is more than 15 amps
attach load test only to 12-volt
below specification, generator is not
potential in battery set. Attaching a 12-
operating properly. Proceed to step 5.
volt load test to a 24-volt potential will
damage the load test.
Figure 7. Generator Bench Test
