Applicable Systems
AC500
AC590
ACS580
ACS880
Symptoms
Brake unit fault detected.
Possible Causes
- Brake resistor open circuit
- Brake chopper failure
- Brake resistor overheated
Troubleshooting Steps
- Step 1: Check brake resistor continuity
Resistor within rated resistance - Step 2: Inspect brake chopper operation
Chopper switching correctly - Step 3: Verify brake resistor sizing
Resistor properly sized for load
How to Reset
Reset via control panel after brake repair.
Source: ABB ACS510/550 User Manual, ABB Drives
Category: PLC & VFD