MbF Brake Release Failure fault in delta drive

MbF Brake Release Failure fault in delta drive troubleshooting

Description

MbF is used in hoist/elevator applications. The drive commands the mechanical brake to open (via a relay) and expects a confirmation signal (limit switch) back into a digital input. If the drive outputs "Open Brake" but doesn't get the "Brake is Open" signal within a second, it trips MbF to prevent driving against a locked brake.

Causes

1. Switch Failure: The micro-switch on the physical brake is broken or misadjusted.
2. Contactor Fail: The brake contactor didn't fire.
3. Broken Wire: The feedback wire to the VFD input is cut.

Solution

Check brake logic:
1. Inspect Brake: Does the brake physically open? If yes, the switch is bad.
2. Check Wiring: Verify the feedback signal at the digital input terminal.
3. Time Delay: Slightly increase the "Brake Verification Time" parameter if the mechanical brake is sluggish.