Cause : Overcurrent trip during constant speed comes when the abrupt fluctuations in the load or abnormal load conditions. The inverter output current exceeds the rated current during constant-speed operation, the protection circuit is activated and the inverter trips.

An "OC3" fault code on a Fuji drive indicates overcurrent during constant speed operation. This means the motor is drawing more current than the drive is designed to handle while running at a steady speed.

Here are some potential causes of an OC3 fault in a Fuji drive:

1. Mechanical overload: The motor might be experiencing excessive mechanical load due to factors like:
2. Rapid load changes: Sudden increases in load on the motor can also trigger an OC3 fault.
3. Drive overload: The drive itself might be overloaded if it's undersized for the motor's current requirements.
4. Wiring issues: Loose or damaged wiring connections between the drive and the motor can cause unexpected current fluctuations.
5. Internal drive fault: In rare cases, the fault could be within the drive itself.

Here's how to troubleshoot an OC3 fault in a Fuji drive:

1. Check the load: Ensure the mechanical load on the motor is appropriate and within the specified operating parameters.
2. Inspect the motor and drive: Look for any signs of physical damage or overheating on the motor or drive.
3. Verify wiring: Make sure all wiring connections between the drive and the motor are secure and undamaged.
4. Review settings: Double-check that the drive's current limit settings are appropriate for the motor. Refer to the Fuji drive's user manual for specific instructions.
5. Consult Manuals: The Fuji Electric troubleshooting guide for your specific drive model might offer additional steps specific to the OC3 fault code.