Cause : OverVoltage comes when DC bus voltage exceeded maximum value. If you're encountering overvoltage issues with an Allen-Bradley PowerFlex 400 drive, it's crucial to address them promptly to prevent damage to the drive and associated equipment. Here are some steps to troubleshoot and mitigate overvoltage problems:

1. Check Power Supply Specifications: Verify that the input power supply to the drive meets the specified voltage and frequency requirements as outlined in the drive's documentation. Ensure that the power supply is within the acceptable range and not exceeding the maximum voltage rating of the drive.

2. Inspect Wiring and Connections: Examine the wiring and connections between the power supply and the drive for any signs of damage, loose connections, or improper termination. Ensure all connections are secure and tight to prevent voltage fluctuations.

3. Voltage Monitoring: Utilize the drive's built-in voltage monitoring features, if available, to monitor the input voltage levels in real-time. This can help identify any spikes or surges in voltage that may be causing the overvoltage issue.