Hoist Brake Control
Overview
Hoist Brake Control verifies that the motor has developed sufficient torque before releasing the mechanical brake. This ensures the brake only releases when sufficient motor torque is available to support the load, helping to prevent unwanted movement.
The function also eliminates the need for the drive to unnecessarily hold zero speed while waiting for the brake to release, resulting in smoother operation.
Before Starting
Before configuring Hoist Brake Control, ensure that:
The motor has been fully commissioned.
All control and power wiring has been completed correctly.
Relay 1 is wired in series with the electromechanical brake coil.
A valid Run command is available to start the drive.
All relevant safety procedures have been followed before operating the system.
Configuration
Caution
Final values should be verified during commissioning to ensure smooth brake operation and secure load control under all operating conditions.
Final parameter values should always be verified during commissioning to ensure smooth brake operation and secure load control under all operating conditions.
Set Relay 1 Function Select (P-18) to 18: Motor Brake.
Set P9-06 Brake Release Speed Threshold to the minimum speed required before the brake is released.
Tip
As a starting point, use the motor slip speed. and verify operation at maximum application load.
Set P9-07 Brake Release Torque Threshold to the minimum torque required before the brake is released.
Set P9-08 Brake Apply Speed Threshold to the speed at which the brake will be applied during stopping.
Tip
This value is typically lower than the Brake Release Speed Threshold. Setting the value too high may cause unnecessary brake wear or mechanical shock during stopping.
Set P9-09 Brake Apply delay
Tip
A typical setting is 200-500 ms. This defines how long the drive maintains motor torque after commanding the brake to close, allowing the brake time to fully engage before torque is removed.
Operation
Starting
If P9-06 is configured, the brake will remain engaged until the programmed speed threshold is reached.
If P9-07 is configured, the brake will remain engaged until the programmed torque threshold is reached.
If both P9-06 and P9-07 are configured with non-zero values, both conditions must be satisfied before the brake is released.
Stopping
When the motor speed falls below P9-08 Brake Apply Speed Threshold, the brake is commanded to close.
The drive continues to provide motor torque for the duration of P9-09 Brake Apply Delay.
After the delay has elapsed, torque is removed and the motor is allowed to stop.
Troubleshooting & FAQs
Problem | Cause | Solution |
|---|---|---|
Brake does not release | The drive has not reached the release thresholds set in P9-06 or P9-07. | Reduce the value of P9-06 and/or P9-07 and retest. Ensure the motor can achieve the configured speed and torque before current or torque limits are reached. |
Relay 1 is not configured for brake control. | Verify that P-18 is set to 18: Motor Brake. | |
Load drops when the brake releases | Insufficient motor torque is available when the brake opens. | Increase P9-06 and/or P9-07 in small increments until the motor can support and accelerate the load without movement. |
Load drops when stopping | Brake Apply Delay is too short. | Increase P9-09 to allow the brake sufficient time to engage before torque is removed. |
Excessive mechanical shock during stopping | Brake Apply Speed Threshold is set too high. | Reduce P9-08 and verify smooth stopping operation. |