VFD Selection for Variable and Fixed Speed Pumping Applications
This white paper discusses the following selection criteria for VFD’s in pumping applications.
- Sizing VFD’s and motors for different pump applications.
- Variable Torque (Normal Duty) VFD rating for centrifugal pumps compared to Constant Torque (Heavy Duty) VFD rating for positive displacement pumps.
- Comparing the common NEMA Enclosure ratings for VFD’s and considerations for heat dissipation
- Optional and auxiliary hardware for VFD’s and where they should be applied.
- VFD control Inputs and Outputs (I/O) and their uses for pump applications.
- Different VFD control modes for pumping application and where they should be applied.
BY ADRIAN VAN DER VLIET, P.ENG
ENGINEERING SYSTEMS GROUP