1 18-3. 200~AMPERE DUAL VOLTAGE ALTERNATOR TESTING AND REPAIR (Contd)
Ensure auxiliary measuring equipment is properly grounded to test
stand. Failure to do so may lead to erroneous readings or damage to
Prior to operation of test stand, ensure all switches and controls are in
initial positions as referenced in Operator and Maintenance Manual,
TM 9-4910-663-12 (UMC Model GSAR-5001, or Operator and
Maintenance Manual, TM 9-4910-485-12 (Sun Model AGT-99A).
Set 500-amp test stand as follows:
(a) DC ammeter load and starter selector
(b) DC ammeter field and battery charge selector
(cl Field circuit switch
(d) DC voltmeter circuit selector
(e) Connect DC voltmeter (0-5OVDC) from point between regulator 14 VDC output and load in
14 volt circuit (or 14 volt battery).
(0 Connect ammeter (O-75ADC) in load line from 14 V regulator to 14 V load.
Turn 500-amp test stand master power switch and master load switch to ON, and turn battery
switch to 24 VDC. Green lamp on 500-amp test stand must illuminate.
Perform no-load test. Set test stand battery circuit selector to 24 VDC, IGN switch to ON, and start
varidrive. Observing the DC voltmeter output voltage and tachometer rpm, increase speed until
tachometer reads 5,000 rpm. Record voltmeter reading and refer to table 18-1 for diagnosis.