ESAB PCM-875 - SEQUENCE OF OPERATION

SECTION 5 TROUBLESHOOTING
25
5.3REFERENCE VOLTAGE CHECKS
A. Control Board Assembly (PCB1)
1. LEDs
LED-1 - Torch Switch
LED-2 - High Frequency
LED-3 - Gas Solenoid Valve
2. Voltage Test Points
Tests are made with power on - no arc.
Disable High Frequency by disconnecting blue wire with black sleeve
TP-0 - Ground
TP-1 - +15 vdc
TP-2 - +12 vdc
TP-3 - -12 vdc
TP-4 - +5 vdc
TP-9 - IGBTs driving signal - switching frequency = 20 KHz
TP-10 - IGBTs driving signal - switching frequency = 20 KHz
0
-13 vdc
13 vdc
40 usec - LPG50
50 usec - LPG80
6 usec - LPG50
9 usec - LPG80
For 208/230 VAC input, the IGBT off time is 3µsec.
For 400/460/575 VAC input, the IGBT off time is 6µsec.
Figure 5.1 IGBT Gating Signal
50 µsec