Brake sequence fault

What does E.MB6 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.

• Mismatch between the actual brake response time and the configured sequence timing (Pr. 278-Pr. 283) during deceleration or stopping phases.
• Failure of the brake control output (e.g., digital output terminal DO1, DO2) from the inverter to energize/de-energize the brake within the expected window.
• Mechanical brake solenoid or hydraulic actuator sticking, preventing the brake from engaging or disengaging fully.
• High inertia load causing the motor to continue rotating beyond the allowed speed for brake engagement during the braking sequence.
• Feedback signal debounce time (if adjustable) not correctly configured for the brake feedback switch, leading to transient false states.

Click steps to track your progress.

1. 1

   1. Review and fine-tune parameters Pr. 278 through Pr. 283, specifically checking the delays and confirmation speeds to ensure they accommodate the mechanical brake's operational characteristics.

2. 2

   2. Confirm that the inverter's digital output (e.g., relay output R-A, R-B, R-C) assigned to brake control is switching correctly by measuring voltage across its contacts (e.g., 24VDC, 120VAC) when commanded.

3. 3

   3. Inspect the mechanical brake for signs of wear, foreign material, or damage that could impede its operation. Lubricate or clean if necessary, referring to the brake manufacturer's manual.

4. 4

   4. Verify the brake coil's current draw against its specification using a clamp meter while the brake is commanded ON. High current may indicate a short, low current an open circuit or high resistance.

5. 5

   5. Check the brake feedback switch's operation by manually actuating it and verifying the corresponding input status (e.g., DI1, DI2) on the inverter's display or I/O status screen.