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Wednesday, October 23, 2019
The Motion Control Community Forum, sponsored by Control Technology Corporation.
Variable Frequency Drive
Altivar variator drive does not work correctly when frequency increases after passing 10 HZ.

Good afternoon,

I hope you can help me with the problem that comes my way.

I have an ATV38HC33N4X altivar variator that presents the following fault. The inverter is put into normal operation. When the frequency increases after passing 10 HZ, the motor does not work correctly, and the output frequency is distorted, that is, it does not have a constant value. It goes up and down quickly, and the drive indicates the SCF fault which tells me that the motor is short. However, I disconnect the motor that was connected and perform tests with another motor, but the fault continues.

Has anyone ever presented this fault? If you can help, I would appreciate it.

The inverter was working perfectly, then they did a maintenance to the motor and from there the fault appeared. I uncovered the inverter and found the sensors of disconnected currents. Would it be that the sensors suffered some damage when being disconnected and this would be the reason of the failure?