The US Department of Energy (DOE) has issued rulemaking on test procedures for small electric motors for more than a decade. The present “final rule,” effective February 3, 2021, is the culmination of those efforts. The final rule will be mandatory for product testing beginning July 6, 2021. If you want to view the complete detail of the final rule that was published in the Federal Register on January 4, 2021, it can be found at https://beta.regulations.gov/. For further reading about the final rule, see this DOE site.
A question you may ask is how the rule defines a small motor. The Energy Policy and Conservation Act (EPCA) defines “small electric motor” as “a NEMA general purpose alternating current single-speed induction motor, built in a two-digit frame number series in accordance with NEMA Standards Publication MG 1–1987.” In another rule, DOE determined that CSIR (capacitor-start, induction run [often termed “capacitor-start”]), CSCR (capacitor-start, capacitor-run) and certain polyphase motors are the only motor categories that satisfy the relevant criteria set by EPCA to be regulated as small electric motors.
In the final rule, DOE further harmonized its test procedures with industry practice and harmonized certain test conditions with current industry standards to improve the comparability of test results for small electric motors. None of these changes affected the measured average full-load efficiency of small electric motors or the measured nominal full-load efficiency of electric motors when compared to current test procedures. These changes are summarized in the table below.
| Current |
Proposed |
Final New |
Reason |
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Incorporated by reference IEEE 112–2004 to measure full-load efficiency of polyphase small electric motors.
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Adding IEEE 112–2017 as an alternative to IEEE 112–2004.
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Replaced IEEE 112–2004 with IEEE 112–2017 (considered equivalent)
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Achieves consistency with industry update to IEEE 112–2017.
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Did not incorporate by reference IEC 60034–2–1:2014.
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Adding Method 2–1–1B of IEC 60034–2–1:2014 as an alternative to IEEE 112–2004 Test Method B, IEEE 112–2017 Test Method B and CSA C390–10.
Adding Method 2–1–1A of IEC 60034–2–1:2014 as an alternative to IEEE 114–2010, IEEE 112–2004, IEEE 112–2017 Test Method A and CSA C747–09.
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Identical to proposed.
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Addresses suggestions offered in industry petition from NEMA and UL.
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For Small Electric Motors: specified testing at rated load but did not define that term.
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Defined ‘‘rated load’’ (and ‘‘rated output power’’ and ‘‘breakdown torque’’ to support the definition of ‘‘rated load’’) of small electric motors based on NEMA MG 1–2016.
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Similar to proposed. Clarified that DOE will not require additional testing and measurement of breakdown torque. Also clarified the definition of breakdown torque.
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Reflects industry practice and improves the representativeness of the test procedure.
Addresses comments about the proposed regarding testing and reporting.
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For Small Electric Motors: Specified testing at rated voltage and rated frequency but did not define those terms.
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Defined “rated voltage,” which provides that manufacturers select the voltage that is used for testing, and “rated frequency.”
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Similar to proposed. Also clarified that the rated voltage must be one of the voltages used by the manufacturer for representation of the small electric motor performance.
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Improves repeatability of the test procedure.
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