ESAB 0558001729, Installation, Operation And Maintenance Manual

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SECTION 6 Troubleshooting
ESP 400C and 600C Plasma Power Sources
6-7
Problem Possible Cause Action
Very high Output current
accompanied by either a left or
right over current (LED 6)
Shorted IGBT
Current pot set too high
Faulty left PWM/Drive PCB
High remote current signal
Faulty PCB1
Replace the pair of IGBTs containing
the shorted IGBT
Lower the current setting
Replace left PWM/Drive PCB
Decrease remote current signal
Replace PCB1 P/N 38032
LED 10 - (red) Left IGBT
Unsaturated Black wire connecting IGBT (Q4)
collector to P3 of the left PWM/Drive
PCB (PCB2) is disconnected.
Shorted Freewheeling Diode(s)
Loose or unplugged P1 connector at
the left PWM/Drive PCB
Loose or unplugged P10 connector
at PCB1
Faulty PCB1
Faulty left PWM/Drive PCB
Secure connector
Replace freewheeling diode(s)
Secure P1
Secure P10
Replace PCB1 P/N 38032
Replace PCB2 P/N 38030
LED 11 - (red) Right IGBT
Unsaturated Black wire connecting IGBT (Q4)
collector to P3 of the right
PWM/Drive PCB (PCB3) is
disconnected.
Shorted Freewheeling Diode(s)
Loose or unplugged P1 connector at
the left PWM/Drive PCB
Loose or unplugged P10 connector
at PCB1
Faulty PCB1
Faulty right PWM/Drive PCB
Secure connector
Replace freewheeling diode(s)
Secure P1
Secure P11
Replace PCB1 P/N 38032
Replace PCB3 P/N 38030