Brake Control Fault

What does bLF mean?

This fault indicates an issue with the motor's brake control, either because the brake release current was not reached or the brake engage frequency threshold was not properly set while brake control was assigned. This can prevent the motor from starting or stopping correctly, leading to potential mechanical damage or uncontrolled movement.

• Brake release current (e.g., Parameter P3-10) not reached due to insufficient voltage or current.
• Brake engage frequency threshold (e.g., Parameter P3-11) improperly set for application dynamics.
• Brake feedback switch wiring fault (open circuit) or physical malfunction preventing status confirmation.
• Mechanical binding or excessive wear in the motor brake mechanism, preventing full release or engagement.
• External brake contactor coil fault or wiring break preventing brake power application.

Click steps to track your progress.

1. 1

   1. Measure voltage across brake terminals (e.g., T1, T2) during a brake release command; verify it matches specified brake voltage (e.g., 207VAC).

2. 2

   2. Verify Parameter P3-10 (Brake release current) is set correctly for the installed motor brake's specifications.

3. 3

   3. Confirm Parameter P3-11 (Brake engage frequency) is configured appropriately for the application's deceleration profile.

4. 4

   4. Inspect brake feedback switch wiring (if used) for continuity and proper closure when the brake is released.

5. 5

   5. Manually cycle the brake mechanism (if safe) to check for free mechanical movement and absence of binding.

6. 6

   6. Check for continuity on the external brake contactor coil and verify its control circuit supply voltage.