Brake IGBT Fault

What does 27 mean?

A fault has been detected in the Insulated Gate Bipolar Transistor (IGBT) responsible for controlling the braking resistor. This indicates a hardware failure in the braking chopper circuit, rendering the braking function inoperable and potentially leading to drive overvoltage trips during deceleration.

• Internal hardware failure of the braking chopper IGBT module within the drive.
• Excessive current through the IGBT caused by a short-circuited braking resistor or external wiring.
• Overheating of the IGBT due to sustained overload or insufficient internal cooling within the drive.
• Failure of the IGBT gate driver circuit on the drive's control board.
• Repeated overvoltage trips stressing the braking chopper components.

Click steps to track your progress.

1. 1

   1. Power off the drive and disconnect the braking resistor wiring from terminals (e.g., R+ and R-).

2. 2

   2. Measure the resistance across the braking resistor terminals to confirm it is not short-circuited (refer to troubleshooting for Code 25).

3. 3

   3. Visually inspect the drive's internal braking chopper module for signs of thermal damage, discoloration, or component failure.

4. 4

   4. Verify the operation of the drive's internal cooling fans, especially those cooling the power section components (IGBTs).

5. 5

   5. If the external braking resistor and its wiring are confirmed healthy, the drive's internal braking chopper circuit (IGBT) has failed, requiring drive repair or replacement by a qualified technician.