OV During Acc

Regenerative overvoltage shut-off during acceleration

Mitsubishi Electric · FR-E500 Inverter

What does OV During Acc mean?

The inverter output is shut off due to regenerative overvoltage, meaning the internal main circuit DC voltage reached or exceeded a specified threshold during acceleration. This can occur if acceleration is too slow for the application, or due to external surge voltages on the power supply.

Common Causes

  • Acceleration time is set too slow, allowing regenerative energy to build up excessively.
  • Sudden deceleration or rapid changes in load during the acceleration phase (e.g. from an overhauling load).
  • Surge voltages or instability detected in the power supply system.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Decrease the acceleration time setting (e.g., Pr. 7 or Pr. 44) to reduce the potential for regenerative voltage build-up.

  2. 2

    Check the incoming power supply for voltage stability and potential surge conditions.

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Verified technical data. Last updated: March 2026

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Source: Mitsubishi Electric FR-E500 Inverter