Testing - TM-9-2920-258-30-P0051

TM 9-2920-258-30&P

Place the AC ammeter range selector (9) in the 400A position.

J Determine that the AC voltmeter range selector (11) is in the 50V position.

K Make sure the field current control (41) is fully counterclockwise.

L Ascertain that the battery selector (31) is in the OFF position.

b Testing

Start the varidrive by actuating the start button (28) and turn the drive speed control (42)

counterclockwise until the Alternator is operating at 2800 rpm.

Place the battery selector (31) in the 24V position.

Turn the master load switch (39) to the ON position.

CAUTION

Never allow the voltage (DC vottmeter) to exceed 32 volts or the ampere reading on the DC ammeter

(field and battery) to exceed 15 amperes or the rectifier maybe damaged.

Adjust the load current control (43) and the field current control (41) by turning clockwise

simultaneously until the reading on the DC ammeter (load and starter) reads 180 amperes and the

DC voltmeter reads 28 volts. The DC ammeter (field and battery charger) should read between 9

and 11 amperes.

Rotate the AC ammeter phase selector (10) through the A, B and C positions; the AC ammeter

should read approximately the same in all positions.

Rotate the AC voltmeter circuit selector (12) through the T1 -T2, T1 -T3, and T2-T3 positions; the

AC voltmeter should be approximately the same in all positions.

If the DC ammeter (field and battery charger) reads under 9 or over 12 amperes or other tests are

not conclusive, the Alternator will require repair.

Using a multimeter, place the red lead on terminal "ac" and ground the black lead. Check for 12-

16 volts AC.

Test Stand Shutdown

1 Turn the field current (0-30 amps) counterclockwise.

2 Turn the battery select switch OFF.

3 Turn the master load switch OFF.

4 Turn the speed control clockwise and reduce speed to 1000 rpm.

5 Depress the STOP button.

6 Return all switches to the base setting.

Testing Procedure With Regulator

D-3

Refer to TM 9-4910-485-12 for test stand general preparation and operation procedures. Use the

information contained below for testing procedures specific to the 180 amp Alternator.

D-3