VFD's and Total Harmonic Distortion. 3

[Chuk1t]

I have a client who wants to keep the Total Harmonic Distortion for current less than 5% at the VFD breaker. What is a reasonable value of % current THD that would be expected for a 12 pulse drive? Supply voltage is 480 Volts.

Motor sizes range from 10 to 50 HP

 

[ozmosis]

gonso
Sure, an AFE will certainly reduce your THID to very low levels but if you thought a 12-pulse drive was expensive at 10-50Hp, then an AFE will certainly be even more.