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Integral Motor Horsepower Rule - New DOE Efficiency Requirements - Effective June 1, 2016


efficienciescomparisons.pngBeginning June 1, 2016, the US Department of Energy (DOE) has implemented an Integral Horsepower Motor Rule into the regulation of electric motor's efficiencies.

History of Motor Efficiency Regulations:

  • Energy Policy Act of 1992 (EPAct)
    • Effective October 1997
    • General Purpose 1-200HP at MG 1, table 12-11 Energy Efficient
  • Energy Policy Act of 2005
    • Raised purchases for government to table 12-12 Premium Efficient (via executive order from the President)
  • Energy Independence & Security Act of 2007 (EISA)
    • Effective December 2010
    • General Purpose 1-200HP EPAct motors to table 12-12 Premium Efficient
    • Other 1-200HP motors at table 12-11 Energy Efficient
    • 201-500HP motors at 12-11 Energy Efficient


So... How does the new rule compare to EISA?



So... Whats included under the expanded scope?

The motors regulated under expanded scope meet the following nine characteristics:

  1. Single speed induction motor
  2. Rated for continuous duty (MG 1) operation or for duty type S1 (IEC)
  3. Contains a squirrel-cage (MG 1) or cage (IEC) rotor
  4. Operated on polyphase alternating current (AC) 60 hertz sinusoidal line power
  5. Has 2, 4, 6, or 8 pole configuration
  6. Is rated 600 volts or less
  7. Have a three or four digit NEMA frame size (or IEC metric equivalent), including those designs between two consecutive NEMA frame sized (or IEC equivalent) or an enclosed 56 NEMA Frame size (or IEC equivalent)
  8. Has no more than 500 horsepower, but greater than or equal to 1 horsepower (or kilowatt equivalent)
  9. Meets all the performance requirements of a NEMA design A, B, or C electric motor or an IEC design N or H electric motor


What specific motors are being added, that were previously not covered?

  • NEMA Design A motors from 201-500HP
  • Electric motors with moisture-resistant windings, sealed or encapsulated windings
  • Partial electric motors (including gearmotors)
  • Totally enclosed non ventilated (TENV) electric motors
  • Immersible electric motors
  • Integral or non-integral brake electric motors
  • U-frame motors
  • Design C motors
  • IEC 100 frame, NEMA 66 frame motors
  • Electric motors with non-standard endplates or flanges
  • Electric motors with non-standard base or mounting feet
  • Footless motors (C-face or D-flange motors)
  • Electric motors with special shafts
  • Close-coupled pump motors
  • 56J Jet pump motors (enclosed)
  • Vertical hollow shaft electric motors
  • Vertical medium and high thrust solid shaft electric motors
  • Electric motors with sleeve bearings
  • Electric motors with thrust bearings
  • Pre-NEMA frame motors
  • Arbor saw motors


So what does all this mean to me?

Essentially what this means to you, as a motor end user, is that some of the motors that have not been regulated under efficiency laws will not be covered. The motor manufacturers, like Siemens, have to do some re-designs on certain designs of motors to meet these new requirements.

This is a two-fold result to you. Re-designs and increased active materials mean a higher initial purchase cost of the motor. On the flip side you receive a more energy efficient motor, saving on energy costs.

The end result is that the DOE is just filling in some holes that were in EISA in 2007.

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To learn more about what our “All Systems Go” approach, please contact:

Justin Hatfield

HECO - All Systems Go



About the author:

Justin Hatfield is Vice President of Operations of HECO, Inc. He is responsible for Electric Motor & Drive Sales, Electric Motor & Generator Repairs, and Predictive Services. Justin was instrumental in developing HECO MAPPS (Motor And Powertrain Performance Systems) which focuses on “why” you have a motor problem instead of simply “What” product or service should be recommended. HECO is EASA Accredited.

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