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. 1

    Check the brake resistor for continuity and proper resistance value.

  2. 2

    Verify the cabling between the frequency converter and the brake resistor for proper connection and integrity.

  3. 3

    If the resistor and cabling are confirmed good, the chopper unit is faulty.

Browse all codes in this manual (73)
Verified technical data. Last updated: March 2026

Related Faults

Source: Vacon 100 FLOW Application Guide