Applicable Systems
WJ200
Symptoms
The WJ200 reports a main device protection trip. The main power semiconductor device activated its self-protection function.
Possible Causes
- IGBT junction temperature exceeding the internal protection limit
- IGBT short circuit or desaturation fault detected by the gate driver
- Gate driver circuit fault causing improper IGBT control
Troubleshooting Steps
- Step 1: Check the drive cooling system for proper operation
Cooling system operates normally - Step 2: Verify the IGBT is not shorted by measuring output terminals
IGBT shows no short circuit - Step 3: If the IGBT is damaged, replace the drive unit
New unit operates without main-device trips
How to Reset
To reset: Fix the main-device fault or replace the unit, then restart.
Source: Hitachi WJ200 Inverter Manual, Hitachi Industrial Equipment
Category: PLC & VFD