Motor Overcurrent

What does OCF mean?

The motor is drawing current that exceeds its rated capacity, indicating an excessive load, mechanical binding, or an electrical issue. This condition can lead to motor overheating and premature failure.

• Excessive mechanical load on the motor (e.g., jammed conveyor, seized pump bearing, clogged process).
• Incorrect motor parameters entered into the soft starter (e.g., P1-01 (Motor Rated Current) set too low compared to actual motor FLA).
• Short circuit or ground fault in the motor windings or motor cable (often precedes a GrdF fault).
• Mechanical binding in the driven equipment causing unusually high starting torque demand.
• Motor winding fault (e.g., turn-to-turn short) increasing current draw without immediately grounding.

Click steps to track your progress.

1. 1

   1. Measure actual motor current on all three phases (U, V, W) using a clamp-on ammeter during operation and compare to the soft starter display (e.g., F1-01).

2. 2

   2. Verify that the motor rated current parameter (P1-01) in the soft starter matches the motor nameplate FLA (Full Load Amps).

3. 3

   3. Disconnect motor from the driven equipment (if possible) and run the motor no-load to check for mechanical binding in motor bearings.

4. 4

   4. Manually check for mechanical freedom of the driven load (e.g., rotate shaft by hand, inspect for obstructions).

5. 5

   5. Perform a resistance check of motor windings (phase-to-phase) using a multimeter; compare readings for symmetry and against motor data.

6. 6

   6. Increase the soft starter's current limit parameter (e.g., P2-01) if initial current spikes are tripping the unit, ensuring it remains below motor/cable ratings.