NEMA Premium Efficiency Motors
A motor can be marketed as a NEMA Premium motor if it meets or exceeds a set of minimum full-load efficiency levels. These premium efficiency motor standards cover the 1 horsepower (hp) to 500 hp three-phase low-voltage NEMA Design A and B general, special, and definite purpose induction motors that are in widespread use in U.S. industrial facilities.
The energy savings from replacing in-service standard and energy efficient motors with premium efficiency motor models can be substantial.
This Premium Efficiency Motor Selection and Application Guide is intended to help guide new motor purchase decisions, and identify and determine the energy and cost savings for those motors that should be replaced with premium efficiency units.
This guide begins by examining the in-service motor population and motor uses in the industrial sector. The guide then discusses the evolution of voluntary and mandatory motor efficiency standards and summarizes the current mandatory minimum full-load efficiency requirements and the classes of motors covered by the standards.
!!! The guide indicates how to evaluate motor efficiency opportunities, address application considerations, and determine cost-effectiveness. Potential adverse motor interactions with electronic adjustable speed drives are illustrated and actions that can be taken to protect the motor are given.
The guide also provides an overview of currently available and emerging advanced “Super Premium” efficiency motor technologies. It also provides tips on “tuning” your in-plant distribution system to ensure efficiency gains are not lost due to Undervoltage operation or excessive voltage unbalance.
Finally, this guide discusses the preventive and predictive maintenance activities necessary to keep premium efficiency motors operating at peak efficiency.
