Cause : Output phase loss comes when one or more of the output phases have lost power due to broken, loose, or disconnected wires in the output circuit or component in the inverter's output stage is faulty.

"Opl" fault in Fuji FRENIC-VG drive indicate "Output phase loss". This means there is a problem with one or more of the output phases from the inverter to the motor. This fault typically occurs when the drive detects an imbalance or a loss of one phase in the three-phase output, which can lead to inefficient motor operation, potential damage to the motor, or failure to start.

Troubleshooting Steps:

1. Check Wiring Connections:

   • Inspect the wiring between the drive’s output terminals and the motor. Ensure all connections are secure and that there are no signs of damage, such as frayed wires or loose terminals.
   • If any wires are loose or damaged, repair or replace them as needed.

2. Inspect Fuses and Circuit Breakers:

   • Check the fuses and circuit breakers associated with the motor phases. Replace any blown fuses and reset any tripped breakers.
   • Ensure the correct fuse ratings are being used to avoid future issues.

3. Test the Motor Windings:

   • Use a multimeter to check the continuity of the motor windings. If a winding is open or shorted, the motor will need to be repaired or replaced.
   • Measure the resistance of each winding and compare it to the motor’s specifications to ensure they are within the expected range.

4. Examine Inverter Output:

   • If the wiring and motor appear to be in good condition, the issue may be within the inverter itself. Use diagnostic tools to check the drive's output phases.
   • If the drive is not producing one of the phases correctly, it may require repair or replacement.

5. Review Motor Load:

   • Check the mechanical load on the motor to ensure it is not excessive. Reduce the load if necessary to prevent overloading the drive and motor.