Overcurrent

What does OC mean?

The Drive's output current has exceeded its overcurrent detection level, typically around 200% of the Drive's rated output current. Common causes include phase-to-phase shorts in the motor or cables, a locked rotor, an excessively heavy load, or insufficient acceleration/deceleration times. Repeated overcurrent can cause damage to the Drive's power components or the motor.

• Sudden heavy mechanical load applied to the motor shaft, causing excessive current draw.
• Phase-to-phase short circuit in the motor windings or motor cable insulation breakdown.
• Drive acceleration time (C1-01) set too short for the connected load inertia.
• Motor bearing failure or mechanical binding causing motor current to spike during operation.
• Incorrect motor nameplate data (P2-02, P2-05) entered, leading to miscalculation of current limits.

Click steps to track your progress.

1. 1

   1. Power down the Drive. Disconnect motor leads from the Drive output terminals (U, V, W).

2. 2

   2. Use a multimeter to measure resistance between motor phases U-V, V-W, and W-U. Look for very low resistance (near zero ohms) indicating a phase-to-phase short.

3. 3

   3. Manually rotate the motor shaft to check for excessive mechanical binding or seized bearings.

4. 4

   4. Increase parameter C1-01 (Acceleration Time 1) by 20-50% to allow for smoother acceleration and reduce current spikes.

5. 5

   5. Verify the motor's rated current (P2-02) and Drive's rated current are correctly matched, and ensure the Drive is adequately sized for the motor and load.