Power factor of motor with VSD?

[Martinz]

TL;DR Summary

Power factor at the motor with VSD

If I have a motor with a full load power factor of 0.8 and starting power factor of 0.3 and I install a VSD to run it with a datasheet power factor of 0.95, will the power factor during starting be 0.3 or 0.95? And at full load?

Cheers!

 

[Baluncore]

Welcome to PF.

The power input to the VSD should be maintained at 0.95 by a PF correction circuit that controls the switching input rectifier.

The DC reservoir capacitors isolate the PF of the motor load, from the PF of the main supply.

The motor PF will not change, but the VSD must be rated to handle the reactive VAR of the motor load.