Originally Posted by
Don Baer
Frank and others
"EVS" stand for Eltronic Variable Speed, this can be either a DC drive or a "Variable Frequency Drive". In order to use a VFD you must have a 3 phase motor so if one wants to do this as a retrofit they'll have too change out the motor. Many VFD's will operate on 1 phase, they create there own 3 phase. These can be had up to 2 HP for under $400 depending on the size and feature. I did a tutorial on how to do this sometime back if anyone wants to look it up.