ESAB EPP-400 - Page 41

41
SECTION 6 TROUBLESHOOTING
Problem Possible Cause Action
Very high Output current ac-
companied by either a left or
right over current (LED 6)
Shorted IGBT Replace the IGBTs
Current pot set too high Lower the current setting
Faulty left PWM / Drive PCB Replace left PWM / Drive PCB
High remote current signal Decrease remote current signal
Faulty PCB1 Replace PCB1 P/N 0558038287
LED 10 - (red) Left IGBT Un-
saturated
Black wire connecting IGBT (Q2) collector to P3 of the
left PWM / Drive PCB (PCB2) is disconnected.
Secure connector
Shorted Freewheeling Diode(s) Replace freewheeling diode(s)
Loose or unplugged P1 connector at the left PWM /
Drive PCB
Secure P1
Loose or unplugged P10 connector at PCB1 Secure P10
Faulty PCB1 Replace PCB1 P/N 0558038287
Faulty left PWM / Drive PCB Replace PCB2 P/N 0558038308
LED 11 - (red) Right IGBT
Unsaturated
Black wire connecting IGBT (Q5) collector to P3 of the
right PWM / Drive PCB (PCB3) is disconnected.
Secure connector
Shorted Freewheeling Diode(s) Replace freewheeling diode(s)
Loose or unplugged P1 connector at the left PWM /
Drive PCB
Secure P1
Loose or unplugged P10 connector at PCB1 Secure P11
Faulty PCB1 Replace PCB1 P/N 0558038287
Faulty right PWM / Drive PCB Replace PCB3 P/N 0558038308