Brake resistor overtemperature

What does 42 mean?

Overtemperature has been detected in the brake resistor. Subcodes S1-S5 (BCU related) specify the issue: S1 (Internal brake chopper overtemp), S2 (Brake resistance too high), S3 (Brake resistance too low), S4 (Brake resistance not detected), or S5 (Brake resistance leakage/earth fault).

• Brake resistor temperature exceeding its limit.
• Brake resistor failure or short circuit.
• Excessive regenerative braking causing resistor overheat.
• Resistor temperature sensor fault (P1-21).

Click steps to track your progress.

1. 1

   Reset the unit to clear the fault.

2. 2

   Increase the deceleration time setting to a longer duration to reduce the amount of braking energy dissipated.

3. 3

   Verify the dimensioning of the brake chopper and external brake resistor for the application's braking requirements.

4. 4

   If an internal brake chopper overtemperature (S1) is the cause, consider implementing or replacing with an external brake resistor system.