Should you specify an “inverter duty,” “inverter ready,” “inverter rated,” or a “VFD compatible” motor for your fans and pumps in HVAC applications? Is there a difference in these terms? Don’t answer too quickly without doing a little research.
Now, without taking time to research any industry definitions of these terms, go look at your company fan, pump, and motor specifications and see if there is any clarification on specifically what type of motor would be acceptable to you if you were reviewing a submittal for a motor for a fan or pump on a VFD. Would you need a specific type of insulation? Would you need a premium efficiency motor, and, if so, what level of efficiency would make the motor acceptable for a VFD drive, or does motor efficiency matter when a VFD is used? Would either an ODP or TEFC motor be acceptable with a VFD? Can you use a brand “B” motor with a brand “M” VFD? How would you enforce this compatibility based on your specification criteria?