The National Electrical Manufacturers Association (NEMA) recently published a new standard designed to reduce carbon emissions and improve system energy savings. NEMA MG 10011-2022 Power Index Calculation Procedure—Standard Rating Methodology for Power Drive Systems and Complete Drive Modules discusses the power index (PI) for power drive systems (PDS). The PDS, which is defined as a motor coupled with an electronic adjustable speed drive, provides an opportunity to save energy.
MG 10011 introduces a PI metric, which allows PDS and drives to be compared for optimal energy savings for end users. The PI rating balances engineering rigor and broad, data-driven assumptions that can be applied over a variety of motor types. This provides an easy-to-use metric similar to an automobile city/highway rating of miles per gallon.
“The power index provides an easy-to-understand, public-facing description that highlights the energy savings potential of common PDS applications,” says Sarah Widder, principal for the Emerging Technology Team at Cadeo, a clean energy consulting firm.
NEMA and the Northwest Energy Efficiency Alliance worked together to develop the PI rating system, providing a streamlined method to evaluate the reduction in power and associated energy savings by controlling equipment speed with a PDS.
Dan Hounsell is senior editor, facility group.
