Motor Selection Made Easy: Choosing the Right Motor for Centrifugal Pump Applications

The renewed interest in energy has increased the popularity of electrical variable-frequency drives (EVFDs) to power pumps, resulting in significant energy savings versus mechanical means for adjusting the flow of the pumping system. Because of the characteristics of pumps, it is easy to misapply motors in EVFD pump applications. This article will present some of the characteristics of frequently used pumps and how these characteristics affect the motor selection (speed, torque, and power ratings). Real-life examples will be included of some often made mistakes in selecting the correct motors for these pumps. Primarily, this discussion will be in regard to centrifugal pumps.