•  


Electric Motors

Sign up for e-mail updates on regulations for this and other products

The Department of Energy (DOE) has regulated the energy efficiency level of electric motors since 1997. Electric motors convert electrical energy to rotating mechanical energy. When operating, the electrical energy is transferred as useful mechanical energy to some driven device such as a fan, pump, blower, compressor, or conveyor.

The Energy Policy and Conservation Act (EPCA), as amended by the Energy Independence and Security Act of 2007 (EISA 2007), covers three broad categories of electric motors: general purpose, definite purpose and special purpose.

These broad categories include a variety of motors including single-speed, continuous-duty polyphase motors with voltages not greater than 600 volts; motors with or without mounting feet; motors built in a T- or U-frame; motors built with synchronous speeds of 3600, 1800, 1200, or 900 rpm (two, four, six, or eight poles, respectively); National Electrical Manufacturers Association (NEMA) Design B motors from 1 to 500 horsepower, NEMA Design A and C motors from 1 to 200 horsepower; and motors that are close-coupled pump or vertical solid-shaft normal thrust motors.

The standard covering NEMA Design A and C motors from 1 to 200 horsepower will save approximately 2 quads of energy and result in approximately $18.7 billion in energy bill savings for products shipped from 1997-2016. The standard will avoid about 109 million metric tons of carbon dioxide emissions, equivalent to the annual greenhouse gas emissions of about 21.4 million automobiles.


Recent Updates | Standards | Test Procedures | Waiver, Exception, and Exemption Information | Statutory Authority | Historical Information | Contact Information


Recent Updates

DOE published a notice of proposed rulemaking regarding energy conservation standards for certain commercial and industrial electric motors, under subpart B of Title 10 of the Code of Federal Regulations, Part 431, including a number of different groups of electric motors that DOE has not previously regulated. 78 FR 73590 (December 6, 2013). For more information, please see the rulemaking page.

DOE published a final rule regarding test procedures for electric motors. 78 FR 75962 (December 13, 2013). For more information, please see the rulemaking page.


Standards for Electric Motors

The following content summarizes the energy conservation standards for medium electric motors. The text is not an official reproduction of the Code of Federal Regulations and should not be used for legal research or citation.

Current Standard

This standard addresses two subtypes of electric motors, as indicated below:

General purpose electric motor (subtype I) means any motor which is designed in standard ratings with either:

  1. Standard operating characteristics and standard mechanical construction for use under usual service conditions, such as those specified in NEMA Standards Publication MG1–1993, paragraph 14.02, "Usual Service Conditions," and without restriction to a particular application or type of application; or
  2. Standard operating characteristics or standard mechanical construction for use under unusual service conditions, such as those specified in NEMA Standards Publication MG1–1993, paragraph 14.03, "Unusual Service Conditions," or for a particular type of application, and which can be used in most general purpose applications.

General purpose electric motor (subtype II) means any motor incorporating the design elements of a general purpose electric motor (subtype I) that are configured as one of the following:

  1. A U-frame motor;
  2. A NEMA Design C motor;
  3. A close-coupled pump motor;
  4. footless motor;
  5. A vertical solid shaft normal thrust motor (as tested in a horizontal configuration);
  6. An 8-pole motor (900 rpm); or
  7. A poly-phase motor with voltage of not more than 600 volts (other than 230 or 460 volts).

Electric motors manufactured (alone or as a component of another piece of equipment), on or after December 19, 2010, and distributed in commerce, as defined by 42 U.S.C. 6291 (16), must meet the energy conservation standards specified in the Code of Federal Regulations, 10 CFR 431.25. This information is also available in the Electronic Code of Federal Regulations.

Table 1. Full-Load Efficiencies for General Purpose Electric Motors [Subtype I]
Motor Horsepower Nominal Full Load Efficiency
Open Motors
(Number of Poles)
Enclosed Motors
(Number of Poles)
6 4 2 6 4 2
1 82.5 85.5 77.0 82.5 85.5 77.0
1.5 86.5 86.5 84.0 87.5 86.5 84.0
2 87.5 86.5 85.5 88.5 86.5 85.5
3 88.5 89.5 85.5 89.5 89.5 86.5
5 89.5 89.5 86.5 89.5 89.5 88.5
7.5 90.2 91.0 88.5 91.0 91.7 89.5
10 91.7 91.7 89.5 91.0 91.7 90.2
15 91.7 93.0 90.2 91.7 92.4 91.0
20 92.4 93.0 91.0 91.7 93.0 91.0
25 93.0 93.6 91.7 93.0 93.6 91.7
30 93.6 94.1 91.7 93.0 93.6 91.7
40 94.1 94.1 92.4 94.1 94.1 92.4
50 94.1 94.5 93.0 94.1 94.5 93.0
60 94.5 95.0 93.6 94.5 95.0 93.6
75 94.5 95.0 93.6 94.5 95.4 93.6
100 95.0 95.4 93.6 95.0 95.4 94.1
125 95.0 95.4 94.1 95.0 95.4 95.0
150 95.4 95.8 94.1 95.8 95.8 95.0
200 95.4 95.8 95.0 95.8 96.2 95.4
Table 2: Full-Load Efficiencies for General Purpose Electric Motors [Subtype II]
Motor Horsepower
Open Motors
(Number of Poles)
Enclosed Motors
(Number of Poles)
8 6 4 2 8 6 4 2
1 74.0 80.0 82.5 - 74.0 80.0 82.5 75.5
1.5 75.5 84.0 84.0 82.5 77.0 85.5 84.0 82.5
2 85.5 85.5 84.0 84.0 82.5 86.5 84.0 84.0
3 86.5 86.5 86.5 84.0 84.0 87.5 87.5 85.5
5 87.5 87.5 87.5 85.5 85.5 87.5 87.5 87.5
7.5 88.5 88.5 88.5 87.5 85.5 89.5 89.5 88.5
10 89.5 90.2 89.5 88.5 88.5 89.5 89.5 89.5
15 89.5 90.2 91.0 89.5 88.5 90.2 91.0 90.2
20 90.2 91.0 91.0 90.2 89.5 90.2 91.0 90.2
25 90.2 91.7 91.7 91.0 89.5 91.7 92.4 91.0
30 91.0 92.4 92.4 91.0 91.0 91.7 92.4 91.0
40 91.0 93.0 93.0 91.7 91.0 93.0 93.0 91.7
50 91.7 93.0 93.0 92.4 91.7 93.0 93.0 92.4
60 92.4 93.6 93.6 93.0 91.7 93.6 93.6 93.0
75 93.6 93.6 94.1 93.0 93.0 93.6 94.1 93.0
100 93.6 94.1 94.1 93.0 93.0 94.1 94.5 93.6
125 93.6 94.1 94.5 93.6 93.6 94.1 94.5 94.5
150 93.6 94.5 95.0 93.6 93.6 95.0 95.0 94.5
200 93.6 94.5 95.0 94.5 94.1 95.0 95.0 95.0
Table 3: Full-Load Efficiencies of NEMA Design B General Purpose Electric Motors
Motor Horsepower
Open Motors
(Number of Poles)
Enclosed Motors
(Number of Poles)
8 6 4 2 8 6 4 2
250 94.5 95.4 95.4 94.5 94.5 95.0 95.0 95.4
300 - 95.4 95.0 - 95.0 95.4 95.4
350 - 95.4 95.4 95.0 - 95.0 95.4 95.4
400 - - 95.4 95.4 - - 95.4 95.4
450 - - 95.8 95.8 - - 95.4 95.4
500 - - 95.8 95.8 - - 95.8 95.4
Table 4: Full-Load Efficiencies of Fire Pump Motors
Motor Horsepower
Open Motors
(Number of Poles)
Enclosed Motors
(Number of Poles)
8 6 4 2 8 6 4 2
1 74.0 80.0 82.5 - 74.0 80.0 82.5 75.5
1.5 75.5 84.0 84.0 82.5 77.0 85.5 84.0 82.5
2 85.5 85.5 84.0 84.0 82.5 86.5 84.0 84.0
3 86.5 86.5 86.5 84.0 84.0 87.5 87.5 85.5
5 87.5 87.5 87.5 85.5 85.5 87.5 87.5 87.5
7.5 88.5 88.5 88.5 87.5 85.5 89.5 89.5 88.5
10 89.5 90.2 89.5 88.5 88.5 89.5 89.5 89.5
15 89.5 90.2 91.0 89.5 88.5 90.2 91.0 90.2
20 90.2 91.0 91.0 90.2 89.5 90.2 91.0 90.2
25 90.2 91.7 91.7 91.0 89.5 91.7 92.4 91.0
30 91.0 92.4 92.4 91.0 91.0 91.7 92.4 91.0
40 91.0 93.0 93.0 91.7 91.0 93.0 93.0 91.7
50 91.7 93.0 93.0 92.4 91.7 93.0 93.0 92.4
60 92.4 93.6 93.6 93.0 91.7 93.6 93.6 93.0
75 93.6 93.6 94.1 93.0 93.0 93.6 94.1 93.0
100 93.6 94.1 94.1 93.0 93.0 94.1 94.5 93.6
125 93.6 94.1 94.5 93.6 93.6 94.1 94.5 94.5
150 93.6 94.5 95.0 93.6 93.6 95.0 95.0 94.5
200 93.6 94.5 95.0 94.5 94.1 95.0 95.0 95.0
250 94.5 95.4 95.4 94.5 94.5 95.0 95.0 95.4
300 - 95.4 95.4 95.0 - 95.0 95.4 95.4
350 - 95.4 95.4 95.0 - 95.0 95.4 95.4
400 - - 95.4 95.4 - - 95.4 95.4
450 - - 95.8 95.8 - - 95.4 95.4
500 - - 95.8 95.8 - - 95.8 95.4

For further guidance or to submit questions related to the implementation of this standard, visit the Guidance and Frequently Asked Questions page.

Test Procedure for Electric Motors

Current Test Procedure

For purposes of Title 10 of the Code of Federal Regulations, Part 431, (10 CFR part 431) and the Energy Policy and Conservation Act, as amended, (EPCA) the test procedures for measuring the energy efficiency of an electric motor shall be the test procedures specified in 10 CFR 431.16 and appendix B to subpart B. The test procedures are also under subpart B of 10 CFR Part 431 in the Electronic Code of Federal Regulations.

Amended Test Procedures

After June 11, 2014, any representations made with respect to the energy use or efficiency of electric motors for which energy conservation standards are currently provided at 10 CFR 431.25 shall be in accordance with the results of testing pursuant to appendix B to subpart B of 10 CFR Part 431 ? Uniform Test Method for Measuring Nominal Full-load Efficiency of Electric Motors.

For further guidance or to submit questions related to the implementation of this test procedure, visit the Guidance and Frequently Asked Questions page.

Waivers, Exceptions, and Exemptions

Waivers

Test procedure waivers have not been issued for electric motors.

For information about obtaining test procedure waivers, see 10 CFR 431, subpart V.

Exceptions

The DOE Office of Hearings and Appeals has not authorized exception relief for electric motors.

For information about obtaining exception relief, see 10 CFR part 1003.

State Exemptions to Federal Pre-emption

DOE has not exempted any states from this energy conservation standard. States may petition DOE to exempt a state regulation from preemption by the Federal energy conservation standard. States may also petition DOE to withdraw such exemptions. For details, see 10 CFR 431, subpart W.

Statutory Authority

The current energy conservation standards for medium electric motors are mandated by Part A–1, the "Certain Industrial Equipment" of Title III of the Energy Policy and Conservation Act (EPCA), as amended. (42 U.S.C. 6311–6317). This equipment is treated as covered equipment under Part A-1. (42 U.S.C. § 6311(1)(A))

Historical Information

EPCA directs DOE to determine no later than 24 months after the effective date of the final rule whether to amend the standards in effect for electric motors. EISA 2007 constitutes the most recent amendment to EPCA and energy conservation standards for electric motors. Because these amendments went into effect on December 19, 2010, DOE is required by statute to publish by December 19, 2012, a final rule determining whether to amend the EISA 2007 energy conservation standards for electric motors. Any such amended standards that DOE establishes would go into effect December 19, 2015. DOE is currently conducting this rulemaking.

Previous Test Procedures

Final Rule: Test Procedures, Federal Register, 64 FR 54114 (Oct. 5, 1999)

Helpful Links and Contact Information

Helpful Links

Find tips and guidance for making your home, workplace, or vehicle more energy efficient visit EnergySavers.gov.

Contact information

For more information related to the regulation of this product, please email:


medium_electric_motors@ee.doe.gov