Cause : Overvoltage comes when voltage in the DC bus has exceeded the overvoltage detection level. When a Yaskawa L1000A drive indicates an "Overvoltage" fault, it means that the voltage supplied to the drive exceeds the specified limit.

Overvoltage faults can occur due to various reasons, including fluctuations in the power supply, regenerative energy from the motor, or issues with the drive itself.

Voltage in the DC bus has exceeded the overvoltage detection level.
• For 200 V class: approximately 410 V
• For 400 V class: approximately 820 V

Follow these steps to solve problem:

1. Immediate Action: If the overvoltage fault occurs, stop the operation of the drive immediately to prevent potential damage to the drive or connected equipment.

2. Check the voltage: Verify that the power supply to the drive is stable and within the specified voltage range. Fluctuations or spikes in the power supply can lead to overvoltage faults. Consider installing voltage regulation or surge protection devices if necessary.

3. Inspect Motor Regeneration: If the motor is operating in a regenerative mode (e.g., during braking or deceleration), excessive energy generated by the motor can cause overvoltage conditions. Consider implementing regenerative braking resistors or other energy dissipation methods to handle excess energy.

4. Review Drive Parameters: Check the drive parameters related to voltage limits and protection settings. Ensure that these parameters are set correctly for your application and adjust them if necessary to provide adequate protection against overvoltage conditions.

5. Check Grounding: Verify that the drive and associated equipment are properly grounded according to electrical codes and standards. Poor grounding can lead to voltage imbalances and contribute to overvoltage faults.

6. Inspect Wiring: Inspect all wiring and connections to the drive, ensuring they are secure and properly terminated. Loose or damaged wiring can cause voltage spikes and contribute to overvoltage faults.