Overcurrent Protection (Other Causes)

What does E04. mean?

This overcurrent fault occurs due to conditions not directly tied to constant speed, acceleration, or deceleration, often observed during startup or when the motor is operating at 0 Hz with DC injection braking. It means the inverter's protection circuit was activated unexpectedly, typically around 200% of the rated output current, due to various external or tuning factors.

• Sudden short circuit between inverter output phases (U, V, W) or to ground during startup or 0 Hz operation (DC injection braking).
• Motor winding insulation breakdown (inter-turn short or phase-to-ground fault) detected at power-on.
• Internal inverter output stage (IGBT) failure or gate driver fault causing a short circuit condition.
• Incorrect DC injection braking parameters (e.g., P1-10, P1-11) leading to excessive current during static braking.
• Severe electromagnetic interference (EMI) or power line transients causing false current readings and a trip.

Click steps to track your progress.

1. 1

   Disconnect the motor from inverter output terminals (U, V, W) and re-apply power; if the fault clears, the issue is with the motor or cable.

2. 2

   Perform an insulation resistance test (megohmmeter) on the motor windings (phase-to-phase and phase-to-ground) to detect shorts.

3. 3

   Visually inspect inverter output cables for physical damage, pinching, or signs of insulation breakdown.

4. 4

   If DC injection braking is used, verify parameters (P1-10 DC braking current, P1-11 DC braking time) are set correctly and within limits for the motor.

5. 5

   Check for proper grounding of the inverter chassis (ground terminal) and shielding of control wiring to mitigate EMI.