Regenerative Transistor Fault

What does rr mean?

This fault indicates an issue with the regenerative braking transistor or its control circuit within the inverter. The regenerative transistor is responsible for dissipating excess energy from the motor during deceleration into a braking resistor. A fault here means the inverter cannot safely handle regenerative power, which can lead to overvoltage trips or damage to the DC bus capacitors.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Verify that deceleration times are not set too short, generating excessive regenerative energy.

2. 4

   Ensure the inverter's firmware is up to date and that braking parameters are correctly configured.

3. 5

   If an internal braking transistor is suspected, professional inverter service or replacement may be required.