Efficiency Standards History: The Energy Policy and Conservation Act (EPCA) established the energy conservation program for consumer products other than automobiles. Motors one horsepower and larger[1] have been subject to minimum energy efficiency standards since 1999. The Energy Policy Act of 1992 (EPACT 1992) amended EPCA to authorize DOE to prescribe energy conservation standards for small electric motors. The amendment requires DOE to prescribe test procedures, and then standards, for those small motors for which DOE has determined that standards would be technologically feasible and economically justified and would result in significant energy savings. On July 10, 2006, the Secretary of Energy issued a positive determination, and DOE initiated the development of energy efficiency test procedures and standards for certain small electric motors.

To support DOE's determination process, the Energy Efficiency Standards (EES) group at LBNL analyzed the potential energy savings, price increases, and other impacts that could potentially occur if energy-efficiency improvements were made to small electric motors. The analysis investigated the small motors market, with special focus on how small motors are used. EES also assessed design options for improving the energy efficiency of small motors, and the potential impacts on motor manufacturers and users.

For the determination, DOE published a Technical Support Document in June 2006. DOE also published an earlier report, Analysis of Energy Conservation Standards for Small Electric Motors, in June 2003.

Product Description and Usage: The Energy Policy and Conservation Act (EPCA) defines ‘small electric motor’ as a NEMA (National Electrical Manufacturers Association) general purpose alternating current single-speed induction motor, built in a two-digit frame number series in accordance with NEMA Standards Publication MG1-1987—i.e., motors with NEMA frame sizes 42, 48, and 56, and motors with horsepower ratings ranging from 1/4 to 3 horsepower. These motors operate at 60 hertz (Hz) and have either a single-phase or a polyphase electrical design. EPCA also specifies that standards for small electric motors shall not apply to motors that are components of other covered products or equipment subject to energy efficiency standards.

Single-phase small electric motors are commonly found in products and appliances including pumps, fans, and power tools. Small motors range in capacity from 1/4 horsepower to one horsepower and are available in two-, four-, or six-pole configurations, with the four-pole configuration being the most common.

Polyphase motors are used to drive such equipment as pumps, fan blades, and compressor cylinders. Those motors in a two-digit NEMA frame size range from 1/4 horsepower to three horsepower, although the majority are one horsepower or less. Such motors are available in two-pole, four-pole, or six-pole configurations, with the four-pole configuration being the most common.

Efficiency Rating: As of June 2008, DOE has not yet proposed a test procedure for small electric motors.

Equipment Classes: For the determination analysis, DOE separately analyzed the following products as separate classes:

(i) single-phase, capacitor-start, induction-run motors;

(ii) single-phase, capacitor-start, capacitor-run motors; and

(iii) polyphase motors.

Current Analyses: Under contract to DOE, LBNL's Energy Efficiency Standards (EES) group is conducting analyses for the advance notice of proposed rulemaking (ANOPR) for small electric motors.

[1] The standards referenced regulate motors with a “three-digit frame size” up to 200 horsepower. Frame size determines the dimensions of the physical housing in which the motor is mounted and is defined in NEMA industry standard MG-1. Small motors have two-digit frame sizes and some motors with a power rating of 1 horsepower or larger have a two-digit frame size.