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Ramifications of December 19, 2010: Motor efficiency

Sept. 1, 2009
Does this date mean anything to you? Motors manufactured after this date must comply with the Energy Independence & Security Act of 2007 (EISA).

The Energy Independence and Security Act of 2007 (EISA) was passed by Congress and signed into law December 19, 2007. EISA builds on the previous Energy Policy Act of 1992 (EPAct), updating mandated efficiency standards for general-purpose, three-phase ac industrial motors from 1 to 500 hp that are manufactured for sale in the United States. The U.S. Department of Energy is responsible for establishing rules to implement and enforce EPAct. EISA will apply to motors manufactured after December 19, 2010. As the deadline approaches, we present answers to some pressing concerns surrounding the upcoming requirements and rule changes.

What are the efficiency standards under EISA?

For each general-purpose rating (Subtype I) from 1 to 200 hp that was previously covered by EPAct, the new law specifies a nominal full-load efficiency level based on NEMA Premium efficiency as stated in NEMA MG 1, Table 12-12. All motors now under EPAct, and manufactured after December 19, 2010, must meet or exceed this efficiency level.

General Purpose Electric Motors (Subtype II) not previously covered by EPAct will be required to comply with efficiencies as defined by NEMA MG 1, Table 12-11. The term “general purpose electric motor (Subtype II)” refers to motors incorporating design elements of a general purpose electric motor (Subtype I) that are configured as one of the following: U-Frame motor; Design C motor; close-coupled pump motor; footless motor; vertical solid shaft normal thrust motor (as tested in a horizontal configuration); 8-pole motor (900 rpm); and poly-phase motor with voltage of not more than 600 V (other than 230 or 460 V).

Motors ranging from 201 to 500 hp not previously covered by EPAct are required to comply with energy efficiency standards as defined by NEMA MG 1, Table 12-11.

Are fractional hp and 48 or 56 frame motors included in EISA?

Only 1 to 500 hp motors with three-digit frame NEMA numbers (143T and up) are included in EISA. This also includes equivalent IEC frame designations, 90 and up.

What motors are not covered by EISA?

  • Design D with high slip

  • Adjustable speed with optimized windings

  • Customized OEM mounting

  • Intermittent duty

  • Integral with gearing or brake, where motor cannot be used separately

  • Submersible motors

  • Single phase motors

  • DC motors

Does EISA apply to every three-phase electric motor from 1 to 500 hp?

No, but almost. The only exceptions are some special OEM designs with proprietary configurations. The following are exempt from EISA compliance: Integral gearmotors; integral brake motors; inverter-duty motors with windings optimized for adjustable speed drive use that cannot be line-started; and design D high-slip motors.

What about motors included in OEM equipment that require listing or certification?

EISA will require that any custom motors falling within the guidelines of the Act comply with the efficiency levels for that type of motor. OEMs are urged to prepare for the changes well before December 2010 and develop designs immediately, particularly when UL or CSA approvals are required.

What about duty-cycle rated motors?

EISA makes no distinction for duty cycle rating. One needs to look at the EPAct definition of “electric motors” and “general purpose” to determine if a particular design falls under the requirements.

Does EISA include IEC frame motors?

Yes. The DOE considers motors built to IEC metric frame dimensions equivalent to NEMA T-frame dimensions to fall under EISA.

Does EISA apply to both stock and custom motors?

Yes. EISA makes no distinction between stock and custom motors. The determining factor under EISA is whether a particular motor meets the law's definition of “electric motor.”

Does EISA apply to motors manufactured outside of the U.S. and imported for use?

Yes. The requirements of EISA include imported electric motors. This also includes electric motors used “as a component of another piece of equipment.”

What about electric motors for export outside of the U.S.?

EISA does not apply to motors exported outside the U.S., including motors mounted on equipment. The DOE will require these motors or their boxes to be marked “Intended for Export.” Countries outside of the U.S. are enacting their own Minimum Efficiency Performance Requirements (MEPS) that may also require compliance. For example, NRCan (Natural Resources Canada) enacted regulations similar to EISA that took effect January 1, 2011.

What about equipment (containing motors) that is manufactured outside of the U.S., but sold within the U.S.?

All motors on equipment sold within the U.S. must comply with EISA rules.

Does EISA require any motors in use to be replaced?

No. EISA does not contain any requirement to replace electric motors already in use.

How about electric motors in inventory?

EISA does not affect inventories of electric motors. The law only applies to motors manufactured after December 19, 2010. Motors in inventory on that date can be sold or used just as before the law went into effect.

Does EISA apply to rebuilt, repaired, or rewound motors?

No. EISA only applies to new motors manufactured after the effective date.

How is full-load nominal efficiency determined?

Like EPAct, EISA specifies that the test procedures for determining a motor's efficiency shall be as specified in NEMA MG1-2006 and IEEE Standard 112, Test Method B or CSA 390.

What are the labeling requirements under EISA?

Like EPAct, EISA requires that an electric motor's nameplate include the nominal full-load efficiency for that motor rating. EPAct and EISA also require product catalogs and literature to include motor efficiency information.

Information courtesy of Baldor Electric Co. For more information, visit or

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