Brake chopper supervision

What does 12 mean?

The brake chopper supervision has detected an issue, indicating either a missing or broken brake resistor, or a defective brake chopper unit. This fault prevents the drive from effectively dissipating regenerative energy, which can lead to overvoltage faults (Fault 2) during deceleration or when braking heavily.

• Open circuit in the external braking resistor due to element failure or a broken connection.
• Incorrectly wired braking resistor to the drive's R+/RB terminals, or loose connections.
• Braking resistor sized incorrectly (resistance too high or too low) for the drive.
• Defective internal brake chopper IGBT or its control circuit within the drive.
• Short circuit across the braking resistor terminals or wiring, causing excessive current and protection trip.

Click steps to track your progress.

1. 1

   Disconnect power to the drive and allow DC-link capacitors to discharge. Measure the resistance of the external braking resistor using a multimeter, verifying it matches the specified value (e.g., 50 Ohms).

2. 2

   Inspect the wiring connections between the drive's R+/RB terminals and the braking resistor for loose terminals, corrosion, or damage.

3. 3

   Check the brake chopper parameters (e.g., P6-11, P6-12) to ensure the brake resistor connection and values are correctly configured.

4. 4

   Perform a diode test on the internal brake chopper IGBT (between DC+ and RB terminal) using a multimeter in diode mode, comparing readings against specifications.

5. 5

   Verify that the braking resistor is properly mounted and has adequate ventilation to prevent overheating and premature failure.