ESAB PCM-1125 Instruction Manual page 25

SECTION 5
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 -
TP-1 -
TP-2 -
TP-3 -
TP-4 -
TP-9 -
TP-10 -
Ground
+15 vdc
+12 vdc
-12 vdc
+5 vdc
IGBT's driving signal - switching frequency = 16 KHz
IGBT's driving signal - switching frequency = 16 KHz
Frequency - 16.0 KHz
13 vdc
0
6 usec - LPG50
9 usec - LPG80
Figure 5.1 IGBT Gating Signal
62.5 µs
40 usec - LPG50
50 usec - LPG80
Off Time
5 µs
-13 vdc
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TROUBLESHOOTING