Zero Servo Fault

What does SVE mean?

The motor position moved more than 10,000 revolutions during zero servo operation, indicating a loss of position control. This can be caused by an excessively small torque limit, an overly large load torque, or a fault within the control circuit, possibly due to electrical noise interfering with position feedback.

• Insufficient torque limit (L7-01) set, preventing the Drive from holding the motor position against the load.
• Excessive mechanical load or external forces acting on the motor shaft, overpowering the zero servo hold.
• Encoder feedback signal loss or noise, causing the Drive to misinterpret motor position.
• Incorrect tuning of the position control loop (e.g., PID gains for position) leading to instability.
• Motor brake not engaging properly or slipping, allowing unintended movement.

Click steps to track your progress.

1. 1

   1. Increase parameter L7-01 (Torque Limit) to allow the Drive to apply sufficient holding torque in zero servo mode (ensure not to exceed motor rating).

2. 2

   2. Verify that the mechanical load on the motor shaft is within the motor's holding torque capabilities for zero servo operation.

3. 3

   3. Inspect the encoder cabling for proper shielding, secure connections, and any signs of damage that could introduce signal noise or loss.

4. 4

   4. Monitor the encoder feedback signal at the Drive's input terminals to confirm consistent and accurate position data.

5. 5

   5. Review and re-tune the position control loop gains (e.g., P, I, D parameters for position control) to improve stability and responsiveness during zero servo.