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.

Complete Troubleshooting Guide

1. 1

   Check the external braking resistor for correct resistance value and proper wiring to the inverter's braking terminals.

2. 2

   Inspect the braking unit (if external) for any fault indicators or signs of damage.

3. 3

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

4. 4

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

5. 5

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