Internal fault (power stage)

What does H07 mean?

During the initialisation of the controller, an incorrect power stage was detected. This signifies a critical internal hardware issue related to the power conversion circuitry.

• Failure of power stage components (e.g., IGBTs, rectifiers) detected during self-test, indicating internal short circuits or open circuits.
• Incorrect hardware variant or mismatched power board detected by the control unit during initialization.
• Faulty gate driver circuit preventing proper switching of the IGBTs.
• Internal communication error between the control board and the power board, potentially due to a loose internal ribbon cable (e.g., between X100 on control board and power board).
• Overvoltage or overcurrent transient event previously damaging the power stage components.

Click steps to track your progress.

1. 1

   Completely power cycle the drive (disconnect all power, wait 5 minutes for capacitor discharge) to attempt a full hardware reset of the power stage.

2. 2

   Measure the resistance between the motor output terminals (U, V, W) and between each output terminal and ground (PE) with the motor disconnected, looking for short circuits (should be open circuit).

3. 3

   Inspect internal power stage connections (e.g., ribbon cables, busbar connections) for looseness, corrosion, or damage.

4. 4

   Check the rating of the drive against the application requirements to ensure it was not exposed to conditions exceeding its design limits.

5. 5

   Contact manufacturer support with the drive's serial number and model to determine if there's a known incompatibility or specific diagnostic procedure for this power stage error.