Recent content by drmayer

thanks for the reply. I see this peak with the motor loaded or unloaded (it is larger when loaded). They are 4 pole motors however.

electricpete, when you say that most problems occur due to a 2x excitation frequency, what do you mean by that? I'm trying to figure it out and haven't gotten anywhere. thanks.

I am doing vibration analysis on some of the fans our company produces. I am finding a large contributor occurs at 7200 cpm or 120Hz. The motors are less than 1hp, single phase, 60Hz, 115V induction motors. Could someone explain this peak at 120 Hz? I know it's a 2nd harmonic of 60Hz, but...