Contents

Troubleshooting
If There is Mechanical Oscillation
Use the following information when there is mechanical vibration:
•Oscillation and hunting occur with V/f control
The torque compensation parameter settings may be incorrect for the machine. Adjust parameters C4-01
(Torque Compensation Gain) and C4-02 (Torque Compensation Delay Time). Decrease C4-01 carefully in
steps of 0.05 and/or increase C4-02.
Furthermore the Slip Compensation Delay Time (C3-02) can be decreased.
•Oscillation and hunting occur with Open Loop Vector control.
The torque compensation parameter settings may be incorrect for the machine. Adjust parameters C4-01
(Torque Compensation Gain), C4-02 (Torque Compensation Delay Time Parameter) and C3-02 (Slip Compensation
Delay Time) in order. Lower the gain parameters and raise the delay time parameters.
If auto-tuning has not been performed, proper performance may not be achieved for Vector Control. Perform
auto-tuning or set the motor parameters through hand calculations.
•Oscillation and hunting occur with Closed Loop Vector control
The gain adjustment may be insufficient. Adjust the speed control loop (Automatic Speed Regulator, ASR) by
changing C5- gain parameters. If the oscillation points overlap with those of the machine and cannot be
eliminated, increase the ASR Delay Time, and then readjust the ASR gains.
If auto-tuning has not been performed, proper performance may not be achieved for Closed Loop Vector Control.
Perform auto-tuning or set the motor parameters through hand calculations.
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