12
Brake chopper supervision
Vacon · 100 FLOW Application Guide
What does 12 mean?
This fault indicates that either no brake resistor is installed, the installed brake resistor is broken, or there is a failure within the brake chopper unit itself. This prevents proper dissipation of regenerative energy.
Common Causes
- The brake chopper circuit is not functioning as expected.
- Excessive voltage detected across the brake chopper resistor.
- Failure of the brake chopper semiconductor switch.
- Brake resistor is open or shorted.
- Brake chopper duty cycle exceeded.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Check the brake resistor for continuity and proper resistance value.
- 2
Verify the cabling between the frequency converter and the brake resistor for proper connection and integrity.
- 3
If the resistor and cabling are confirmed good, the chopper unit is faulty.
Verified technical data. Last updated: March 2026
Related Faults
Source: Vacon 100 FLOW Application Guide