4
Breakdown in Braking Unit and/or Braking Resistors
Kone · Frequency Inverter
What does 4 mean?
This error signifies a fault within the regenerative braking unit or its associated braking resistors. This system is crucial for dissipating excess energy generated by the motor during deceleration, and a breakdown can cause DC bus overvoltage.
Common Causes
- Open circuit or short circuit condition in the braking resistor(s).
- Malfunction or failure of the braking transistor (chopper) circuit.
- Overheating of the braking resistors due to continuous or excessive regenerative energy.
- Faulty wiring or loose connections within the braking circuit.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Visually inspect the braking resistors for any signs of burning, cracking, or physical damage.
- 2
Measure the resistance of the braking resistors; compare the measured value with the specified nominal resistance.
- 3
Verify all electrical connections between the drive, the braking unit, and the braking resistors for security and integrity.
- 4
If possible, check the operation of the braking transistor (chopper) for proper switching.
Verified technical data. Last updated: March 2026
Related Faults
Source: Kone Frequency Inverter