Hitachi WJ200 Error Code E04

Hitachi PLC & VFD Major Overvoltage

Model: WJ200 | Code: E04

Applicable Systems
WJ200

Symptoms

The WJ200 reports a DC bus overvoltage fault during acceleration detected. The drive trips to protect the capacitor bank and switching devices.

Possible Causes

  • Regenerative energy from the motor exceeded the braking resistor capacity
  • Deceleration time too short causing excessive regenerative voltage
  • Input power supply voltage at the upper limit of the drive range

Troubleshooting Steps

  1. Step 1: Increase the deceleration time to reduce regenerative energy
    DC bus voltage stays below the trip threshold
  2. Step 2: Check if a braking resistor is installed and correctly rated
    Braking resistor absorbs regenerative energy adequately
  3. Step 3: Measure the input supply voltage and verify it is within range
    Input voltage is within the drive rated range

How to Reset

To reset: Reduce the DC bus voltage below the threshold, then reset the fault.

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Source: Hitachi WJ200 Inverter Manual, Hitachi Industrial Equipment

Category: PLC & VFD