Originally Posted by
Malcolm McLeod
Newer VFDs with Sensorless Vector Control (SVC) or Flux Vector Control will allow a motor to produce at or near both rated torque and Hp, even at lower than 100% speed.
Simple (older) VFDs used just V/hz control, and if a motor was run at less than its synchronous speed, it would produce proportionally less than rated Hp. So if you plan to run slow with a old VFD, Jeff is correct.
However, I can't imagine why you would want a jointer or planer to be running at less than its rated speed. If running at 100% speed, even using a old technology VFD, this power loss should be a non-issue. ....You would basically be using the VFD as a soft start only, and presumably for phase conversion in this case.