TM-9-2920-257-30-P
GENERATOR, ALTERNATING CURRENT, 200 AMPERES
TECHNICAL MANUAL; DIRECT SUPPORT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS
MAY 1987
TM-9-2920-257-30-P - Page 24 of 111
TM 9-2920-257-30&P
2-6.
GENERAL TEST PROCEDURES
CAUTION
If voltmeter reading exceeds 30.5 volts for 24 volt systems, STOP engine
immediately and refer to Table 2-3.
a.
Start engine and accelerate to high idle.
Refer to TM 9-2350- 261-10, or TM 9-2350-277-10, or
TM 9-2350-247-10 Operator TM's.
b.
Observe ammeter and voltmeter readings on multimeter.
If battery is sufficiently discharged, amps should be
"high" within +1- 10% of output specified by performance curve (generator RPM = engine idle RPM X pulley ratio).
Volts
should be within or below the "normal range" of Table 2-2.
As battery approaches full charge, amps should fall as volts
rise.
When amps and volts stabilize, note readings and refer to Table 2-3.
Table 2-3.
TROUBLESHOOTING DIAGNOSIS
AMPS
VOLTS
DIAGNOSIS
CHARGING SYSTEM GOOD.
BATTERY NOT FULLY
CHARGED.
WAIT FOR CHARGING SYSTEM TO BRING
BATTERY TO FULL CHARGE.
AMPS SHOULD FALL
AND VOLTS SHOULD STABILIZE WITHIN NORMAL
HIGH
LOW
RANGE PER TABLE 2-2.
HIGH
NORMAL
NOTE IF AMPS FALL OR VOLTS EXCEED NORMAL
RANGE PER TABLE 2-2.
IF AMPS FALL AND VOLTS
REMAIN NORMAL, CHARGING SYSTEM IS GOOD.
IF
VOLTS EXCEED NORMAL, REGULATOR AND/OR FIELD
COIL SHOULD BE REPLACED.
GO TO STATIC TESTS.
STOP TEST.
REGULATOR AND /OR FIELD COIL
SHOULD BE REPLACED.
GO TO STATIC TESTS.
HIGH
HIGH
IF BOTH AMPS AND VOLTS ARE LOW, CHECK TO BE
SURE MULTIMETER LEADS ARE PROPERLY
ATTACHED.
IF OKAY, REPLACE EITHER GENERATOR
OR REGULATOR.
REFER TO GENERATOR AND
LOW
LOW
REGULATOR TEST PROCEDURE.
LOW
NORMAL
CHARGING SYSTEM GOOD.
LOW
HIGH
STOP TEST.
IF BATTERY AND VOLTMETER ARE BOTH
GOOD, REPLACE REGULATOR AND/OR FIELD COIL.
c.
Discover the cause for failure then disassemble and repair the generator before proceeding with prescribed tests.
Performing additional operational tests on a damaged generator will only increase the damage.
Change 1
2-17
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