TM 9-4940-568-20
2-103
Table 2-17. ARC Welder Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
6. GREEN AC POWER INDICATOR OFF; FAN NOT OPERATING.
Input line disconnect switch in OFF position.
Place input line disconnect switch to ON position.
Power supply MAIN CIRCUIT BREAKER (MCB) in OFF position.
Place MCB to ON position.
7. RED WARNING INDICATOR ON; NO WELD OUTPUT.
Thermal sensor TH1 open (thermal shutdown)
Allow the unit to cool for five minutes before turning the power supply ON.
Input voltage fluctuation causing protection circuits to activate.
Monitor input power for spikes and high voltage condition.
8. FRONT PANEL 24V OR 115V CIRCUIT BREAKER(S) TRIPS WHEN REMOTE
CONTACTOR POINTS ARE CLOSED OR, WHEN THE AMPERAGE/VOLTAGE
SELECTOR IN PANEL POSITION.
Faulty feeder/remote device.
Verify operation of external feeder device and replace if necessary.
9. NO WELD OR OUTPUT; FAN OPERATING; WARNING INDICATOR OFF.
OUTPUT CONTACTOR selector in REMOTE 14 position with no remote contactor connected.
Set OUTPUT CONTACTOR selector to ON position.
Line voltage is too high.
Verify that input voltage matches setting on rear panel INPUT SELECTOR switch.
