4-2
Table 4-2. Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
MVC 300 APPEARS TO BE DEFECTIVE.
Step 1. Verify that wiring is correct and proper in accordance with Figure 3-3.
If wiring is defective or incorrect, repair as needed.
If wiring is not defective or incorrect, proceed to Step 2.
Step 2. Check that the AUTO-OFF-MAN front panel switch turns off the excitation.
If the excitation does not turn off, replace the MVC 300.
If the excitation shuts down, proceed to Step 3.
Step 3. With the AUTO-OFF-MAN front panel switch in MANUAL, verify that the generator
output voltage builds up.
If the generator output voltage builds up, proceed to Step 6.
If the generator output voltage does not build up, proceed to Step 4.
Step 4. Verify that internal fuses F1 and F2 are good.
If either fuse is defective or blown, replace fuse and proceed to Step 5.
If both fuses are not defective or blown, replace the MVC 300.
Step 5. Verify that the generator output voltage builds-up.
If the generator output voltage does not build-up, replace the MVC 300.
If the generator output voltage builds-up, proceed to Step 6.
Step 6. Verify that the generator output can be controlled by the MVC 300 front panel potentio-
meter.
If the generator output voltage cannot be controlled by the MVC 300, replace the MVC
300.
If the generator output voltage can be controlled by the MVC 300, proceed to Step 7.
Step 7. Verify that the generator works in the front panel switch AUTO position.
If the generator fails to operate with the front panel switch in the AUTO position, trou-
bleshoot the voltage regulator.