Table 2-2. Troubleshooting - CONT - TM-55-1905-223-24-40047

TM 55-1905-223-24-4

Table 2-2. Troubleshooting - Cont

Malfunction

Test or Inspection

Corrective Action

13. Generator set not producing voltage.

STEP 1.

Check to see if circuit breaker is open. Correctly apply load.

Verify frequency and voltage are correct. Close circuit breaker and apply load

Refer to operator's manual, TM 55-1905-223-24-10 for automatic transfer.

STEP 2.

Check for malfunctioning voltmeter. Measure line voltage at the generator circuit breaker as follows:

WARNING

Line voltage is present at the regulator board and the terminal strip when

the generator is running.

Connect a frequency meter to terminals V7 and VO (120 volts AC).

Start the generator set.

Verify that the generator set output frequency is correct (63 Hz or 53 Hz for droop; 60 Hz or 50 Hz for

isochronous). Adjust the frequency if necessary.

If the frequency is correct, turn off the generator set.

Disconnect the frequency meter from terminals V7 and VO and connect a voltmeter to terminals L1 and

L2 on the generator set circuit breaker.

Start the generator set.

Carefully rotate the VOLTAGE adjustment to obtain the desired line voltage output (clockwise to

increase).

If voltmeter gauge readings are still incorrect. Replace defective gauge. (Refer to TM 55-1905-223-24-

18.)

STEP 3.

Check for defective voltage regulation on SCR module.

Check SCR module as follows:

Check SCR Module on RX1 scale.

Connect ohmmeter from (=) to (-). You should read high resistance in one direction and low resistance in

the other.

Connect ohmmeter from AC1 to (+). You should read high resistance in both directions. Repeat for AC2.

Connect ohmmeter from AC1 to (-). You should read high resistance in one direction and low resistance

in the other. Repeat for AC2.

C1 to (+) should see low resistance in one direction and high resistance in the other. Reeat for G2.

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