Check the thermal relay input path and whether unplugging it clears the indicator.
Fault route
LGK60L Power-On O.C Light Diagnostic
A protection-light route for LGK60L plasma cutters using temperature relay and phase-loss evidence before main-board replacement.
Quick Answer
For LGK60L power-on O.C light, first separate temperature relay evidence from phase-loss protection evidence before replacing the main control board.
- If unplugging the temperature-relay path clears the O.C light, inspect or replace the temperature relay.
- If unplugging the phase-loss protection path clears the O.C light, inspect three-phase input and phase-loss circuit behavior.
- Replace the main control board only after the external protection inputs are proven normal.
Use this page when
- O.C / abnormal indicator is on after power-up.
- The machine has control power and can be checked at control-board connectors.
- You need to separate thermal, phase-loss and board-decision layers.
Do not use this page when
- The machine is completely dead.
- The breaker trips before the control board powers.
- O.C light appears only after cutting load starts.
LGK60L power-on O.C route
External protection inputs first; main control board last.
Check three-phase input and phase-loss circuit misoperation on the bottom-board path.
If protection inputs are normal but O.C stays on, inspect the main control-board decision layer.
Protection evidence table
| Evidence point | Expected / abnormal evidence | Repair direction |
|---|---|---|
| Temperature relay input | O.C light clears after related connector is unplugged. | Inspect or replace temperature relay/wiring. |
| Phase-loss protection input | O.C light clears after phase-loss protection path is removed from the main control board. | Check three-phase input, bottom-board phase-loss circuit and wiring. |
| Main control board | External protection inputs normal but O.C light remains. | Repair/replace main control board after confirming rails and connectors. |