Overvoltage Due to Generation Mode

What does Overvolt G mean?

This fault indicates an overvoltage condition when the VSD is operating in generation mode, meaning the motor is acting as a generator and feeding energy back to the drive. This typically happens with overhauling loads or when the motor is driven faster than its commanded speed by external forces. This condition can lead to damage to the drive's power components if the regenerative energy is not properly handled.

• External mechanical forces driving the motor (e.g., overhauling load, windmilling fan) generating energy back to the drive.
• Application requires continuous regeneration, but the VSD lacks a sufficiently sized braking resistor or active front end (AFE) unit.
• Incorrect VSD control mode or parameter tuning (e.g., P4-07 braking gain) causing unintended regenerative operation.
• Rapid deceleration commanded when the system has high kinetic energy, similar to 'Overvolt D' but sustained.
• Oversized motor or undersized VSD for the actual regenerative power generated by the load.

Click steps to track your progress.

1. 1

   Assess the mechanical system for any overhauling loads or external forces driving the motor. Implement mechanical braking if possible.

2. 2

   Install or upgrade the braking resistor to one with appropriate ohmic value and power rating for the calculated continuous regenerative power.

3. 3

   Review and adjust VSD control parameters related to braking (e.g., P4-07 braking gain, P1-03 deceleration ramp) for the specific application.

4. 4

   Consider implementing an active front end (AFE) regenerative unit if the application requires continuous and efficient energy return to the grid.

5. 5

   Verify the motor and VSD sizing, ensuring the system can handle the peak and continuous regenerative power requirements.