Overcurrent Protection During Constant Speed

What does E01. mean?

This fault occurs when a large current flows through the inverter while the motor operates at a constant speed, typically due to sudden load fluctuations or brake application. The inverter's protection circuit activates at approximately 200% of the rated output current, causing a trip to prevent damage to the inverter components.

• Sudden, heavy mechanical load applied to the motor during constant speed operation (e.g., conveyor jam, sudden material feed).
• Motor winding insulation breakdown causing phase-to-phase or phase-to-ground short circuit, increasing current draw.
• Incorrect inverter current gain or PID controller tuning (e.g., P0-06, P3-01) causing unstable current regulation.
• Mechanical brake engagement while the motor is still actively driven by the inverter, leading to high current.
• Inverter output phase imbalance due to a faulty IGBT or current sensor, resulting in excessive current on one phase.

Click steps to track your progress.

1. 1

   Measure the motor's actual running current on all three phases (U, V, W) using a clamp meter and compare to inverter display (d004) and motor nameplate FLA.

2. 2

   Inspect the mechanical system for binding, blockages, or excessive friction that would cause a sudden increase in load.

3. 3

   Verify motor winding integrity by performing an insulation resistance test (megohmmeter) between each phase and ground (>1 MOhm).

4. 4

   Review and adjust inverter current limit parameters (e.g., P2-01, P2-02) to match motor FLA and application requirements.

5. 5

   Confirm that mechanical brakes are properly disengaged before motor run command and only engage after inverter stop command and motor has slowed.