Brake chopper overcurrent

What does F4.1 mean?

An overcurrent condition has been detected in the brake chopper circuit. This is typically caused by excessive regenerative power during deceleration, a short circuit in the braking resistor circuit, or an incorrectly sized braking resistor. Failure to resolve risks damage to the brake chopper or resistor.

• Short circuit in the braking resistor wiring or internal fault within the braking resistor unit.
• Braking resistor resistance value too low for the application, leading to excessive current during regeneration.
• Excessive regenerative energy generated by the motor during rapid deceleration or dynamic braking.
• Incorrectly configured braking parameters (e.g., Parameter P5-01, P5-02) or brake chopper activation thresholds.
• Internal failure of the brake chopper IGBT or its gate driver circuit, causing uncontrolled conduction.

Click steps to track your progress.

1. 1

   Disconnect the braking resistor from the drive's terminals (e.g., X20/X21). Measure the resistance of the braking resistor using a multimeter and compare to the specified value.

2. 2

   Inspect the braking resistor wiring for any short circuits between conductors or to ground, and for proper insulation.

3. 3

   Increase the deceleration time (e.g., Parameter P3-05) to reduce the rate of regenerative energy return to the DC bus.

4. 4

   Verify the braking resistor's power rating (watts) and resistance value (ohms) are correctly specified for the application and drive model.

5. 5

   Check drive parameters P5-01 (Brake chopper activation voltage) and P5-02 (Brake chopper duty cycle limit) to ensure proper configuration.