On June 15, the CEE Board of Directors approved a Guidance Specification for Large (250-500 hp), Low-Voltage, General Purpose Motors recommended by CEE’s Motors and Motor Systems Committee. Effective immediately, this Guidance Specification provides performance, operating, and application information for members to consider when developing incentive programs for motors in this category.

CEE launched its Premium-Efficiency Motors Initiative in 1996 to address general-purpose, low-voltage motors from 1-200 hp. In 2001, CEE and the National Electrical Manufacturers Association (NEMA) agreed to promote a common set of specifications for these motors under the NEMA PremiumTM brand. NEMA Premium also addresses motors that are not covered by the CEE Initiative, such as medium-voltage motors, special and definite purpose motors, and larger motors from 200-500 hp. The Guidance Specification expands the scope of motors covered by CEE’s Premium-Efficiency Motors Initiative to more fully align with NEMA Premium. It provides a national platform for program administrators to consider NEMA Premium-efficiency levels in projects with larger motors.

While motors over 200 hp represent only one percent of all the motors in the industrial sector, they consume approximately 45 percent of the energy. One DOE study estimates potential energy savings of approximately 2.6 billion kWh annually through the installation of energy-efficient motors in the 250-500 hp range.

By expanding the scope of motors covered under the CEE’s Premium-Efficiency Motors Initiative, the newly approved Guidance Specification will help efficiency program administrators maximize large motor energy savings. While both the original Initiative and the new Guidance Specification align with the NEMA Premium efficiency levels for motors 1-500 hp, the CEE Motors Committee determined that additional considerations for large motors (250-500hp) were appropriate.

“Large motors are expensive and parameters such as duty cycle, loading factor, and operating hours can have a greater impact on overall efficiency than for smaller motors,” explained CEE Industrial Program Manager Ilene Mason. “Given this greater variability in savings, it is prudent to consider large motors on a case-by-case basis.”

Rather than simply recommending NEMA Premium, the most appropriate, high-efficiency motor is recommended based on engineering analysis. Any program incentives are then derived from the projected energy savings. The Guidance Specification highlights the opportunity for program administrators to acheive additional savings in applications where NEMA Premium motors are appropriate both technically and economically. It is intended to support consideration of NEMA Premium efficiency levels for large motor projects on a routine basis.

The Guidance Specification recommends incorporating “NEMA Premium” terminology in relevant program descriptions; educating in-house project development and evaluation teams about motor efficiency definitions and terminology, life-cycle costing of motors, and other relevant information; and extending the educational effort to others outside the organization who routinely submit custom projects. The Guidance Specification also provides reference information to help members establish appropriate efficiency baselines for motors in this size range. For additional information, please contact Ilene Mason.

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