Check surface burn and diode/short behavior.
Fault route
LGK100L Power-On Breaker Trip Diagnostic
A high-energy path route for LGK100L breaker trip faults at power-on.
Quick Answer
For LGK100L power-on breaker trip, inspect the high-energy path: three-phase rectifier bridge, rectifier/filter capacitors, IGBT module and driver board evidence.
- A blackened or shorted rectifier bridge can trip the breaker.
- Burned or exploded rectifier/filter capacitors are a direct trip clue.
- If the IGBT is visibly burned or shorted, replace IGBT together with driver-board evidence checks, not as an isolated part.
Use this page when
- Breaker trips immediately or shortly after power-on.
- The machine is not simply dead with no input.
- Qualified technician can isolate high-energy components.
Do not use this page when
- Only O.C light is on while breaker holds.
- Fan runs but display is off.
- No-output fault occurs after normal power-up.
LGK100L breaker-trip route
High-energy short path before control-board troubleshooting.
Look for burned, bulged or exploded capacitors.
Visible burn or short suggests IGBT/power-stage failure.
When IGBT is damaged, driver board evidence must be checked together.
Breaker-trip evidence table
| Evidence point | Expected / abnormal evidence | Repair direction |
|---|---|---|
| Three-phase rectifier bridge | Output and input should not be directly shorted; surface burn is a clue. | Clean/inspect bridge and test diode characteristics. |
| Rectifier/filter capacitors | Burned or exploded capacitors cause power-on trip. | Replace failed capacitors/board section. |
| IGBT module | Blackened or shorted IGBT indicates power-stage short. | Replace IGBT and verify driver board. |
| Driver board | Bad drive can re-damage new IGBT. | Check driver before powering repaired stage. |