EL
ErrorLib
Brands
||
  1. Home
  2. Vacon
  3. NXP/C
  4. 12
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

12

Brake chopper supervision

Vacon · NXP/C

What does 12 mean?

This fault indicates a problem with the braking system, specifically that no brake resistor is installed, the installed brake resistor is broken (open circuit), or there is an internal failure within the brake chopper itself. The drive cannot dissipate regenerative energy during deceleration without a functioning brake resistor and chopper.

Common Causes

  • Brake resistor circuit fault or short circuit.
  • Brake chopper module failure.
  • Overheating of the brake resistor.
  • Brake control signal malfunction.
  • DC bus voltage exceeding brake capacity.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify that a brake resistor is correctly installed and securely connected to the frequency converter's brake terminals.

  2. 2

    Measure the resistance of the brake resistor to ensure it is within specified limits and not open-circuited.

  3. 3

    Inspect the cabling between the frequency converter and the brake resistor for any damage or loose connections.

  4. 4

    If the brake resistor and cabling are confirmed functional, the internal brake chopper may be faulty. Contact your local distributor.

Browse all codes in this manual (11)
Verified technical data. Last updated: April 2026

Related Faults

10Input line supervision11Output phase supervision13Frequency converter undertemperature
Source: Vacon NXP/C
Open Manual (Page 107)Search more codes in this manual