PFC & Small load

[ptonsparky]

Started a 50 HP 480v motor that had very little load on it today. It is a hammermill and had no product in it. Amps before PFC was 21, with 4. FLA on label is close to 58. I can't say that I have ever had that much change but I don't remember ever checking a motor with no load. A similar motor connected to a fully loaded fan was .84 of FLA.

Sound typical? Correction is somewhat bigger than needed for the individual motor.

 

[beanland]

Pfc

Pfc

Sounds about right. An idling motor consumes few watts but a lot of VARs (magnetizing current.) The PFC supplies VARs. That means the only thing on the branch circuit would be watts and those VARs not provided by the PFC.