1 Output Phase Loss

What does OPF1 mean?

Detection of a single phase loss on the motor output. This can lead to unbalanced currents, motor vibration, and potential damage to the motor windings if operated in this condition. It is a critical fault indicating a broken connection or internal issue.

• Open circuit in one of the motor output phases (U, V, or W) between the drive and the motor due to a wire break.
• Loose connection or damaged terminal at the drive output (U, V, W) or the motor terminal box for a single phase.
• Internal fault in the drive's output power stage (e.g., a single IGBT failure) causing one phase to drop out.
• Motor winding failure (e.g., open circuit in one phase winding) causing an electrical imbalance.
• Incorrect connection of motor output terminals during installation, leading to an open phase.

Click steps to track your progress.

1. 1

   With power isolated, measure the resistance of each motor phase winding (U-V, V-W, W-U) at the drive's output terminals; compare values for balance (e.g., within 5%).

2. 2

   Visually inspect the motor output cables (U, V, W) for any breaks, kinks, or signs of damage from the drive to the motor.

3. 3

   Tighten all connections at the drive's output terminals (U, V, W) and the motor's terminal box.

4. 4

   Perform a continuity test on each individual cable conductor from the drive output terminal to the corresponding motor terminal.

5. 5

   If resistance checks and cable continuity are good, disconnect the motor and attempt to run the drive; if the fault persists, the drive's output stage is likely faulty.