Overcurrent Fault

What does OC mean?

This fault indicates an excessive current draw, which can lead to motor and drive damage if not promptly addressed. It can occur during momentary power loss recovery, DC Injection Braking, or during acceleration if the mechanical load is too large or the acceleration time is set too short. The drive will trip and stop operation upon detection of this fault.

• Sudden increase in motor load or a mechanical jam causing a motor stall condition.
• Motor winding insulation breakdown, causing a phase-to-phase or phase-to-ground short circuit.
• Drive output phase-to-phase or phase-to-ground short circuit on U, V, W terminals or motor cable.
• Incorrect tuning of motor parameters (e.g., E1-01, E1-04, E1-05) or current loop gains.
• Rapid acceleration (C1-01) with a high inertia load, causing excessive current demand during startup.

Click steps to track your progress.

1. 1

   1. Inspect the mechanical system for any binding, obstructions, or damage that could impede motor rotation.

2. 2

   2. With power removed, measure the motor winding resistance (U-V, V-W, W-U) and insulation resistance to ground with a megohmmeter.

3. 3

   3. Using a clamp meter, monitor motor current (U, V, W) during startup and operation to identify peak currents.

4. 4

   4. Increase the acceleration time (e.g., parameter C1-01 or C1-03) to reduce startup current demand.

5. 5

   5. Check all wiring from drive output terminals (U, V, W) to the motor for signs of damage or short circuits.