Understanding the Integral Horsepower Motor Rule

It’s official. On June 1st the DOE’s amendment and final ruling of the Energy Policy and Conservation Act of 1975 (EPCA) went into effect. Known as the Integral Horsepower Motor Rule, this policy maintains current energy conservation standards for some electric motor (EC Motors) types and amends the energy conservation standards for other electric motor types. If you work with electric motors for consumer products, commercial and industrial equipment – including commercial and industrial electric motors – then read on, my friend. Here’s what you need to know in a nutshell:

What are the new standards?

• Efficiency levels should be maintained at Premium (NEMA Standard MG 1-2011, Table 12-12, 20A and 20B) for 1- to 500-horsepower (HP) motors.
• This 12-12 level is equivalent to IE3 (Premium efficiency) as defined in International Electro-technical Commission (IEC) Standard 60034-30
• The Integral Horsepower Motor Rule also covers a number of different groups of electrical motors not previously regulated.
• This new law supersedes the existing Energy Independence and Security Act of 2007.

What equipment is covered?

• 1-HP to 500-HP (0.75 – 370 kW) electric motors
• All three-phase, 60-hertz (Hz) designs, 600V & less
• Motors with special shafts & mountings
• 56-frame enclosed motors
• Partial motors built without a drive endplate
• Both NEMA & IEC motor designs, plus motors mounted to equipment imported to and used in the U.S.

Why the changes?

• According to the DOE, these new and amended energy conservation standards bring significant conservation of energy, and are technologically feasible and economically justified.
• Furthermore, most definite-purpose and special-purpose motors are included, along with options that previously exempted motors from coverage.
• This closes some loopholes from the previous Energy Policy Act of 2005 and Extended Industry Standard Architecture (EISA).

What’s the impact on engineers & end users?

Form, Fit, Function:

• Previously unregulated motors may be a larger size
• Premium motors have less slip; higher speed
• Some designs may be Design A; higher inrush current
• Some designs in larger NEMA frame

Lifecycle Value:

• More material; additional cost for Premium efficiency
• Motor cost 2% to 97% for electricity
• Can continue to buy & use motors built before June 1, 2016

Remember, the regulation is point of manufacture, not the end user. In addition, the Integral Horsepower Motor Rule significantly adds embedded motors as covered products.

Learn more about electronically commutated (EC) motors in this whitepaper: Why Electronically Commutated (EC) Motors?

Or get help from an ENERVEX energy efficiency expert. Other resource: DOE’s electric motors final rule, presentation: U.S. Motor Efficiency Regulation Update (NEMA via EASA)