Section 431.446 - Small electric motors energy conservation standards and their effective dates(a) Each small electric motor manufactured (alone or as a component of another piece of non-covered equipment) after March 9, 2015, or in the case of a small electric motor which requires listing or certification by a nationally recognized safety testing laboratory, after March 9, 2017, shall have an average full load efficiency of not less than the following: | Motor horsepower/standard kilowatt equivalent | Average full load efficiency |
| Polyphase |
| Open motors (number of poles) |
| 6 | 4 | 2 |
| 0.25/0.18 | 67.5 | 69.5 | 65.6 |
| 0.33/0.25 | 71.4 | 73.4 | 69.5 |
| 0.5/0.37 | 75.3 | 78.2 | 73.4 |
| 0.75/0.55 | 81.7 | 81.1 | 76.8 |
| 1/0.75 | 82.5 | 83.5 | 77.0 |
| 1.5/1.1 | 83.8 | 86.5 | 84.0 |
| 2/1.5 | N/A | 86.5 | 85.5 |
| 3/2.2 | N/A | 86.9 | 85.5 |
| Motor horsepower/standard kilowatt equivalent | Average full load efficiency |
| Capacitor-start capacitor-run and capacitor-start induction-run |
| Open motors (number of poles) |
| 6 | 4 | 2 |
| 0.25/0.18 | 62.2 | 68.5 | 66.6 |
| 0.33/0.25 | 66.6 | 72.4 | 70.5 |
| 0.5/0.37 | 76.2 | 76.2 | 72.4 |
| 0.75/0.55 | 80.2 | 81.8 | 76.2 |
| 1/0.75 | 81.1 | 82.6 | 80.4 |
| 1.5/1.1 | N/A | 83.8 | 81.5 |
| 2/1.5 | N/A | 84.5 | 82.9 |
| 3/2.2 | N/A | N/A | 84.1 |
(b) For purposes of determining the required minimum average full load efficiency of an electric motor that has a horsepower or kilowatt rating between two horsepower or two kilowatt ratings listed in any table of efficiency standards in paragraph (a) of this section, each such motor shall be deemed to have a listed horsepower or kilowatt rating, determined as follows:(1) A horsepower at or above the midpoint between the two consecutive horsepower ratings shall be rounded up to the higher of the two horsepower ratings;(2) A horsepower below the midpoint between the two consecutive horsepower ratings shall be rounded down to the lower of the two horsepower ratings; or(3) A kilowatt rating shall be directly converted from kilowatts to horsepower using the formula 1 kilowatt = (1/0.746) hp, without calculating beyond three significant decimal places, and the resulting horsepower shall be rounded in accordance with paragraphs (b)(1) or (b)(2) of this section, whichever applies. 75 FR 10947 , Mar. 9, 2010; 75 FR 17036 , Apr. 5, 2010