Overcurrent Trip During Acceleration

What does E.OC1 mean?

An excessive current condition has been detected while the inverter is accelerating the motor. This can be caused by an abnormally high load, a short circuit between phases, or a ground fault on the inverter's output side, potentially leading to damage if not resolved.

• Motor acceleration time (Pr. 07, Pr. 08) set too short for the connected load's inertia.
• Mechanical binding or jamming in the driven load, requiring excessive torque during acceleration.
• Short circuit between output phases (U, V, W) or a phase-to-ground fault in the motor or motor cable.
• Inverter output current limit (Pr. 02) set too low compared to motor FLC (Full Load Current).
• Incorrect motor parameters (e.g., Pr. 03, Pr. 09, Pr. 71) entered, leading to poor motor control.

Click steps to track your progress.

1. 1

   Increase the acceleration time parameters (Pr. 07, Pr. 08) by 10-20% and re-test acceleration.

2. 2

   Disconnect the motor from the load and attempt to run the motor unloaded to isolate mechanical issues.

3. 3

   Use a multimeter to measure resistance between motor phases (U-V, V-W, W-U) and from each phase to ground (expect open circuit to ground).

4. 4

   Verify motor parameters (Pr. 03, Pr. 09, Pr. 71) match the motor nameplate data (Voltage, Amps, RPM).

5. 5

   Perform an auto-tuning procedure (Pr. 96 set to 1 or 2) to optimize motor control parameters.

6. 6

   Check for loose connections at inverter output terminals (U, V, W) and motor terminal box.