What causes this motor sound to appear after a few minutes - running on VFD?

[Rata222]

Hi all. I would appreciate any insight you may have in correcting my VFD/Motor problem. Newbie here.

I hooked up my 1-1/2 HP motor to a Delta VFD and set parameters per Delta setup guide I found online. The motor runs with the expected squeal four about 4 minutes, then will develop a higher pitched/louder squeal after about four minutes. Carrier frequency is set at maximum, which is default, at 15. The squeal is coming from the motor at all RPM. It happens at about 30 sec into the video. If I stop and restart the motor the sound goes away for another 4 minutes.

Can anyone give me an idea of what causes this and possible solutions?

Thank you, Jim

 

[markba633csi]

I would try different carrier frequencies, maybe 8KHz and 10KHz
Are the bearings ok on that motor? Seems like I hear a bearing noise also
It's possible there is a loose winding or pole piece in the motor which vibrates