Applicable Systems
WJ200
Symptoms
The WJ200 reports an overcurrent fault detected at the output. The drive trips to protect the power semiconductor devices.
Possible Causes
- Motor cable short circuit or ground fault in the Hitachi output wiring
- Motor winding insulation failure causing excessive current
- Accelerated too rapidly causing inrush current beyond the drive capacity
Troubleshooting Steps
- Step 1: Inspect the motor cable and motor windings for short circuits or ground faults with a megger
Insulation resistance is above the minimum threshold - Step 2: Reduce the acceleration time parameter to limit inrush current
Peak current stays within the drive rated value - Step 3: If the motor is defective, repair or replace the motor
New motor draws current within rated range
How to Reset
To reset: Resolve the overcurrent root cause, then reset the fault via the keypad or cycle power.
Source: Hitachi WJ200 Inverter Manual, Hitachi Industrial Equipment
Category: PLC & VFD