Brake sequence fault

What does E.MB4 mean?

This brake sequence fault stops the inverter output due to a sequence error occurring during the operation of the brake sequence function (configured by Pr. 278 to Pr. 283). This protective feature is not active in the initial inverter status. It indicates a timing or logical error in the controlled braking process.

• External mechanical brake not releasing within the programmed time (Pr. 279 Brake Open Timing) during start sequence.
• External mechanical brake not engaging within the programmed time (Pr. 280 Brake Close Timing) during stop sequence.
• Feedback signal from the external brake (e.g., brake open/close limit switch) not registering correctly.
• Incorrect parameter settings for brake sequence control (Pr. 278 to Pr. 283) not matching the brake's operating characteristics.
• Faulty wiring or damaged limit switch for the external mechanical brake feedback.

Click steps to track your progress.

1. 1

   Verify that brake sequence parameters Pr. 278 (Brake Operation Selection), Pr. 279 (Brake Open Timing), and Pr. 280 (Brake Close Timing) are set correctly for the installed mechanical brake.

2. 2

   Visually inspect the external mechanical brake's operation, ensuring it fully opens and closes without mechanical obstruction.

3. 3

   Using a multimeter, verify the operation of the brake open/close limit switches or proximity sensors, checking their state changes.

4. 4

   Confirm that the brake feedback wiring to the inverter's input terminals (e.g., STF, STR, RL) is correct and free from damage.

5. 5

   Adjust Pr. 279 and Pr. 280 with slightly longer times if the brake's mechanical response is slow.

6. 6

   Measure the voltage supplied to the brake coil during activation and deactivation to confirm it is within specification.