Brake control detected fault
Schneider Electric · ATV32HD11N4 Variable Speed Drive
What does bLF mean?
A fault indicating that the brake release current was not reached, or the brake engage frequency threshold was not set while brake control was assigned. This points to an issue within the motor's braking system or its configuration, potentially preventing the brake from operating correctly.
Common Causes
- Brake release current threshold (P2-08) not reached during motor startup.
- Brake engage frequency threshold (P2-09) not set correctly while brake control is active.
- High resistance or open circuit in the motor brake coil winding.
- Internal brake control relay failure within the drive.
- Wiring fault between drive brake terminals and motor brake (e.g., TB1-1 and TB1-2).
Repair Steps & Checklist
Click steps to track your progress.
- 1
1. Measure the resistance of the motor brake coil directly at the motor terminals (ensure power is off).
- 2
2. Verify the brake release current parameter (P2-08) is set above the actual motor brake current.
- 3
3. Confirm the brake engage frequency parameter (P2-09) is appropriately set for the application (e.g., 0.5 Hz).
- 4
4. Check for proper voltage output from the drive's brake control terminals (e.g., +24VDC to brake coil) during a run command.
- 5
5. Inspect the wiring connections from the drive's brake output terminals to the motor brake for continuity and secure connection.