Switch and Control Positions - TM-9-2920-258-30-P0063

TM 9-2920-258-30&P

A Connect the test cable from the Alternator to the test stand's alternator section.

B Connect the test cable from the rectifier's left connector receptacle to the test stand's connection

points T1, T2 and T3 (rectifier section).

C Connect the test cable from the rectifier's right connector receptacle to the test stand's

connection point +C (both leads) (rectifier section).

D Connect rectifier ground to D-.

NOTE

Before the Alternator can be tested, a regulator must be connected. The regulator does not require

special mounting; simply set it on any flat surface, such as a workbench beside the test stand.

E Connect the regulator to the test stand as shown in Figure D-4.

Switch and Control Positions

1 From the base setting, turn the:

A DC load ammeter switch to X 10.

B Field circuit switch to the REGULATOR position.

C DC field ammeter switch to X 6.

D DC voltmeter output voltage select switch to REC/GEN (on model 7458-4 only).

NOTE

With the new model United test stand (part number 7458-4), be sure that the D-sensing switch in ON.

d Testing

1 Turn the master switch ON.

2 Depress the START button and hold for 3 to 5 seconds.

3 Turn the speed control counterclockwise until the tachometer reads 2800 rpm.

4 Turn the master load switch ON.

5 Turn the battery circuit select switch to 24 VOLTS.

6 Turn the ignition switch ON.

7 The voltmeter will show output voltage. Adjust voltage to 28 volts.

8 Turn the 100-amp fixed, 50-amp fixed, 25-amp fixed and 0- to 25-amp variable load switches ON.

9 Turn the variable load increase control until a drop of approximately 1 or 2 volts is indicated on the DC

voltmeter. Then, increase the voltage back to 28 volts. The load amperage will increase as the voltage is

increased. Do these steps until 180 amperes are indicated on the load ammeter.

D-15