Taking a step toward the expansion of the Premium-Efficiency Motors Initiative, CEE's Motors and Motor Systems Committee has drafted the Guidance Specification for Large (250-500 hp), Low-Voltage, General Purpose Motors.
The Guidance Specification provides general performance and application information for program administrators to consider when developing incentive programs for motors in this category.
The current initiative covers motors addressed by the Energy Policy Act of 1992, i.e., 1-200 hp, low-voltage, general-purpose motors, and aligns with the NEMA Premium® efficiency levels for this range of product. As proposed, and if approved by the Board, the revised initiative would recommend a custom approach to addressing motors in the 250-500 hp range rather than the prescriptive approach recommended for the 1-200 hp size class.
“Because of their size, large motors are more expensive, consume more energy, and have a greater potential for energy savings than their smaller counterparts,” explained CEE Industrial Program Manager Ilene Mason.
“Correspondingly, duty cycle, loading factor, operating hours and other application parameters have a greater impact on overall efficiency and energy savings than for smaller motors. Given this greater variability in savings, it is prudent to consider large motors on a case-by-case basis.”
Another consideration in developing the recommendation was the difficulty of establishing a nationally applicable baseline for motors above 200 hp. Unlike motors in the 1-200 hp range, there is no federal minimum efficiency standard for these motors.
The Guidance Specification provides information about member approaches for establishing baseline efficiency as well as information on some common data sources on efficiency for motors in this size range.
“In addition to providing information about operating and application parameters that may affect motor performance and energy consumption, the Guidance Specification recommends that efficiency program administrators consider integrating NEMA Premium terminology into their programs,” Mason said.
“Using the NEMA Premium brand name helps reduce confusion and ensure that products purchased will meet the NEMA Premium efficiency levels.”
While it is true that large motors make up a small portion of the overall motor market and of motor incentive applications, there are ample reasons for program administrators to consider providing incentives for large motors. According to a 1998 Department of Energy study …
- Motors 250 hp and above account for only 1 percent of all motors used in the manufacturing industry but consume 45 percent of the electricity in this sector.
- More than 80 percent of the motors in the 250-500 hp range are pre-EPAct 1992 models.
- Harmonization of the CEE specification with NEMA Premium would provide greater consistency of terminology in the market.
In accordance with CEE's customary process for revising product specifications, the proposed Guidance Specification is currently being circulated among motor industry stakeholders with final comments due by March 14.
Following that, the committee will consider all comments received and develop a final recommendation for consideration by CEE's Board of Directors.
In the second quarter of 2007, the committee is scheduled to begin exploring the inclusion of other motor categories, such as medium-voltage motors and special and definite-purpose motors, to the initiative.
For additional information or if would like to participate in this project, please contact Ilene Mason at 617-589-3949, ext. 225.
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