TM-9-2920-257-30&P Maintenance and Parts Manual for 200 Amp M113 Generator Download
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