Title 10

SECTION 431.25

431.25 Energy conservation standards and effective dates.

§ 431.25 Energy conservation standards and effective dates.

(a) Except as provided for fire pump electric motors in paragraph (b) of this section, each general purpose electric motor (subtype I) with a power rating of 1 horsepower or greater, but not greater than 200 horsepower, including a NEMA Design B or an equivalent IEC Design N motor that is a general purpose electric motor (subtype I), manufactured (alone or as a component of another piece of equipment) on or after December 19, 2010, but before June 1, 2016, shall have a nominal full-load efficiency that is not less than the following:

Table 1 - Nominal Full-Load Efficiencies of General Purpose Electric Motors (Subtype I), Except Fire Pump Electric Motors

Motor horsepower/Standard kilowatt equivalent Nominal full-load efficiency
Open motors
(number of poles)
Enclosed motors
(number of poles)
6 4 2 6 4 2
1/.75 82.5 85.5 77.0 82.5 85.5 77.0
1.5/1.1 86.5 86.5 84.0 87.5 86.5 84.0
2/1.5 87.5 86.5 85.5 88.5 86.5 85.5
3/2.2 88.5 89.5 85.5 89.5 89.5 86.5
5/3.7 89.5 89.5 86.5 89.5 89.5 88.5
7.5/5.5 90.2 91.0 88.5 91.0 91.7 89.5
10/7.5 91.7 91.7 89.5 91.0 91.7 90.2
15/11 91.7 93.0 90.2 91.7 92.4 91.0
20/15 92.4 93.0 91.0 91.7 93.0 91.0
25/18.5 93.0 93.6 91.7 93.0 93.6 91.7
30/22 93.6 94.1 91.7 93.0 93.6 91.7
40/30 94.1 94.1 92.4 94.1 94.1 92.4
50/37 94.1 94.5 93.0 94.1 94.5 93.0
60/45 94.5 95.0 93.6 94.5 95.0 93.6
75/55 94.5 95.0 93.6 94.5 95.4 93.6
100/75 95.0 95.4 93.6 95.0 95.4 94.1
125/90 95.0 95.4 94.1 95.0 95.4 95.0
150/110 95.4 95.8 94.1 95.8 95.8 95.0
200/150 95.4 95.8 95.0 95.8 96.2 95.4

(b) Each fire pump electric motor that is a general purpose electric motor (subtype I) or general purpose electric motor (subtype II) manufactured (alone or as a component of another piece of equipment) on or after December 19, 2010, but before June 1, 2016, shall have a nominal full-load efficiency that is not less than the following:

Table 2 - Nominal Full-Load Efficiencies of Fire Pump Electric Motors

Motor horsepower/standard kilowatt equivalent Nominal full-load efficiency
Open motors
(number of poles)
Enclosed motors
(number of poles)
8 6 4 2 8 6 4 2
1/.75 74.0 80.0 82.5 74.0 80.0 82.5 75.5
1.5/1.1 75.5 84.0 84.0 82.5 77.0 85.5 84.0 82.5
2/1.5 85.5 85.5 84.0 84.0 82.5 86.5 84.0 84.0
3/2.2 86.5 86.5 86.5 84.0 84.0 87.5 87.5 85.5
5/3.7 87.5 87.5 87.5 85.5 85.5 87.5 87.5 87.5
7.5/5.5 88.5 88.5 88.5 87.5 85.5 89.5 89.5 88.5
10/7.5 89.5 90.2 89.5 88.5 88.5 89.5 89.5 89.5
15/11 89.5 90.2 91.0 89.5 88.5 90.2 91.0 90.2
20/15 90.2 91.0 91.0 90.2 89.5 90.2 91.0 90.2
25/18.5 90.2 91.7 91.7 91.0 89.5 91.7 92.4 91.0
30/22 91.0 92.4 92.4 91.0 91.0 91.7 92.4 91.0
40/30 91.0 93.0 93.0 91.7 91.0 93.0 93.0 91.7
50/37 91.7 93.0 93.0 92.4 91.7 93.0 93.0 92.4
60/45 92.4 93.6 93.6 93.0 91.7 93.6 93.6 93.0
75/55 93.6 93.6 94.1 93.0 93.0 93.6 94.1 93.0
100/75 93.6 94.1 94.1 93.0 93.0 94.1 94.5 93.6
125/90 93.6 94.1 94.5 93.6 93.6 94.1 94.5 94.5
150/110 93.6 94.5 95.0 93.6 93.6 95.0 95.0 94.5
200/150 93.6 94.5 95.0 94.5 94.1 95.0 95.0 95.0
250/186 94.5 95.4 95.4 94.5 94.5 95.0 95.0 95.4
300/224 95.4 95.4 95.0 95.0 95.4 95.4
350/261 95.4 95.4 95.0 95.0 95.4 95.4
400/298 95.4 95.4 95.4 95.4
450/336 95.8 95.8 95.4 95.4
500/373 95.8 95.8 95.8 95.4

(c) Except as provided for fire pump electric motors in paragraph (b) of this section, each general purpose electric motor (subtype II) with a power rating of 1 horsepower or greater, but not greater than 200 horsepower, including a NEMA Design B or an equivalent IEC Design N motor that is a general purpose electric motor (subtype II), manufactured (alone or as a component of another piece of equipment) on or after December 19, 2010, but before June 1, 2016, shall have a nominal full-load efficiency that is not less than the following:

Table 3 - Nominal Full-Load Efficiencies of General Purpose Electric Motors (Subtype II), Except Fire Pump Electric Motors

Motor horsepower/
Standard kilowatt equivalent
Nominal full-load efficiency
Open motors
(number of poles)
Enclosed motors
(number of poles)
8 6 4 2 8 6 4 2
1/.75 74.0 80.0 82.5 74.0 80.0 82.5 75.5
1.5/1.1 75.5 84.0 84.0 82.5 77.0 85.5 84.0 82.5
2/1.5 85.5 85.5 84.0 84.0 82.5 86.5 84.0 84.0
3/2.2 86.5 86.5 86.5 84.0 84.0 87.5 87.5 85.5
5/3.7 87.5 87.5 87.5 85.5 85.5 87.5 87.5 87.5
7.5/5.5 88.5 88.5 88.5 87.5 85.5 89.5 89.5 88.5
10/7.5 89.5 90.2 89.5 88.5 88.5 89.5 89.5 89.5
15/11 89.5 90.2 91.0 89.5 88.5 90.2 91.0 90.2
20/15 90.2 91.0 91.0 90.2 89.5 90.2 91.0 90.2
25/18.5 90.2 91.7 91.7 91.0 89.5 91.7 92.4 91.0
30/22 91.0 92.4 92.4 91.0 91.0 91.7 92.4 91.0
40/30 91.0 93.0 93.0 91.7 91.0 93.0 93.0 91.7
50/37 91.7 93.0 93.0 92.4 91.7 93.0 93.0 92.4
60/45 92.4 93.6 93.6 93.0 91.7 93.6 93.6 93.0
75/55 93.6 93.6 94.1 93.0 93.0 93.6 94.1 93.0
100/75 93.6 94.1 94.1 93.0 93.0 94.1 94.5 93.6
125/90 93.6 94.1 94.5 93.6 93.6 94.1 94.5 94.5
150/110 93.6 94.5 95.0 93.6 93.6 95.0 95.0 94.5
200/150 93.6 94.5 95.0 94.5 94.1 95.0 95.0 95.0

(d) Each NEMA Design B or an equivalent IEC Design N motor that is a general purpose electric motor (subtype I) or general purpose electric motor (subtype II), excluding fire pump electric motors, with a power rating of more than 200 horsepower, but not greater than 500 horsepower, manufactured (alone or as a component of another piece of equipment) on or after December 19, 2010, but before June 1, 2016 shall have a nominal full-load efficiency that is not less than the following:

Table 4 - Nominal Full-Load Efficiencies of NEMA Design B General Purpose Electric Motors (Subtype I and II), Except Fire Pump Electric Motors

Motor horsepower/
standard kilowatt equivalent
Nominal full-load efficiency
Open motors
(number of poles)
Enclosed motors
(number of poles)
8 6 4 2 8 6 4 2
250/186 94.5 95.4 95.4 94.5 94.5 95.0 95.0 95.4
300/224 95.4 95.4 95.0 95.0 95.4 95.4
350/261 95.4 95.4 95.0 95.0 95.4 95.4
400/298 95.4 95.4 95.4 95.4
450/336 95.8 95.8 95.4 95.4
500/373 95.8 95.8 95.8 95.4

(e) For purposes of determining the required minimum nominal 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 energy conservation standards in paragraphs (a) through (d) 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 horsepowers shall be rounded up to the higher of the two horsepowers;

(2) A horsepower below the midpoint between the two consecutive horsepowers shall be rounded down to the lower of the two horsepowers; or

(3) A kilowatt rating shall be directly converted from kilowatts to horsepower using the formula 1 kilowatt = ( 1/0.746) horsepower. The conversion should be calculated to three significant decimal places, and the resulting horsepower shall be rounded in accordance with paragraph (e)(1) or (e)(2) of this section, whichever applies.

(f) The standards in Table 1 through Table 4 of this section do not apply to definite purpose electric motors, special purpose electric motors, or those motors exempted by the Secretary.

(g) The standards in Table 5 through Table 7 of this section apply only to electric motors, including partial electric motors, that satisfy the following criteria:

(1) Are single-speed, induction motors;

(2) Are rated for continuous duty (MG 1) operation or for duty type S1 (IEC);

(3) Contain a squirrel-cage (MG 1) or cage (IEC) rotor;

(4) Operate on polyphase alternating current 60-hertz sinusoidal line power;

(5) Are rated 600 volts or less;

(6) Have a 2-, 4-, 6-, or 8-pole configuration,

(7) Are built in a three-digit or four-digit NEMA frame size (or IEC metric equivalent), including those designs between two consecutive NEMA frame sizes (or IEC metric equivalent), or an enclosed 56 NEMA frame size (or IEC metric equivalent),

(8) Produce at least one horsepower (0.746 kW) but not greater than 500 horsepower (373 kW), and

(9) Meet all of the performance requirements of one of the following motor types: A NEMA Design A, B, or C motor or an IEC Design N or H motor.

(h) Starting on June 1, 2016, each NEMA Design A motor, NEMA Design B motor, and IEC Design N motor that is an electric motor meeting the criteria in paragraph (g) of this section and with a power rating from 1 horsepower through 500 horsepower, but excluding fire pump electric motors, manufactured (alone or as a component of another piece of equipment) shall have a nominal full-load efficiency of not less than the following:

Table 5 - Nominal Full-Load Efficiencies of NEMA Design A, NEMA Design B and IEC Design N Motors (Excluding Fire Pump Electric Motors) at 60 Hz

Motor horsepower/
standard kilowatt equivalent
Nominal full-load efficiency (%)
2 Pole 4 Pole 6 Pole 8 Pole
Enclosed Open Enclosed Open Enclosed Open Enclosed Open
1/.75 77.0 77.0 85.5 85.5 82.5 82.5 75.5 75.5
1.5/1.1 84.0 84.0 86.5 86.5 87.5 86.5 78.5 77.0
2/1.5 85.5 85.5 86.5 86.5 88.5 87.5 84.0 86.5
3/2.2 86.5 85.5 89.5 89.5 89.5 88.5 85.5 87.5
5/3.7 88.5 86.5 89.5 89.5 89.5 89.5 86.5 88.5
7.5/5.5 89.5 88.5 91.7 91.0 91.0 90.2 86.5 89.5
10/7.5 90.2 89.5 91.7 91.7 91.0 91.7 89.5 90.2
15/11 91.0 90.2 92.4 93.0 91.7 91.7 89.5 90.2
20/15 91.0 91.0 93.0 93.0 91.7 92.4 90.2 91.0
25/18.5 91.7 91.7 93.6 93.6 93.0 93.0 90.2 91.0
30/22 91.7 91.7 93.6 94.1 93.0 93.6 91.7 91.7
40/30 92.4 92.4 94.1 94.1 94.1 94.1 91.7 91.7
50/37 93.0 93.0 94.5 94.5 94.1 94.1 92.4 92.4
60/45 93.6 93.6 95.0 95.0 94.5 94.5 92.4 93.0
75/55 93.6 93.6 95.4 95.0 94.5 94.5 93.6 94.1
100/75 94.1 93.6 95.4 95.4 95.0 95.0 93.6 94.1
125/90 95.0 94.1 95.4 95.4 95.0 95.0 94.1 94.1
150/110 95.0 94.1 95.8 95.8 95.8 95.4 94.1 94.1
200/150 95.4 95.0 96.2 95.8 95.8 95.4 94.5 94.1
250/186 95.8 95.0 96.2 95.8 95.8 95.8 95.0 95.0
300/224 95.8 95.4 96.2 95.8 95.8 95.8
350/261 95.8 95.4 96.2 95.8 95.8 95.8
400/298 95.8 95.8 96.2 95.8
450/336 95.8 96.2 96.2 96.2
500/373 95.8 96.2 96.2 96.2

(i) Starting on June 1, 2016, each NEMA Design C motor and IEC Design H motor that is an electric motor meeting the criteria in paragraph (g) of this section and with a power rating from 1 horsepower through 200 horsepower manufactured (alone or as a component of another piece of equipment) shall have a nominal full-load efficiency that is not less than the following:

Table 6 - Nominal Full-Load Efficiencies of NEMA Design C and IEC Design H Motors at 60 Hz

Motor horsepower/standard kilowatt equivalent Nominal full-load efficiency (%)
4 Pole 6 Pole 8 Pole
Enclosed Open Enclosed Open Enclosed Open
1/.75 85.5 85.5 82.5 82.5 75.5 75.5
1.5/1.1 86.5 86.5 87.5 86.5 78.5 77.0
2/1.5 86.5 86.5 88.5 87.5 84.0 86.5
3/2.2 89.5 89.5 89.5 88.5 85.5 87.5
5/3.7 89.5 89.5 89.5 89.5 86.5 88.5
7.5/5.5 91.7 91.0 91.0 90.2 86.5 89.5
10/7.5 91.7 91.7 91.0 91.7 89.5 90.2
15/11 92.4 93.0 91.7 91.7 89.5 90.2
20/15 93.0 93.0 91.7 92.4 90.2 91.0
25/18.5 93.6 93.6 93.0 93.0 90.2 91.0
30/22 93.6 94.1 93.0 93.6 91.7 91.7
40/30 94.1 94.1 94.1 94.1 91.7 91.7
50/37 94.5 94.5 94.1 94.1 92.4 92.4
60/45 95.0 95.0 94.5 94.5 92.4 93.0
75/55 95.4 95.0 94.5 94.5 93.6 94.1
100/75 95.4 95.4 95.0 95.0 93.6 94.1
125/90 95.4 95.4 95.0 95.0 94.1 94.1
150/110 95.8 95.8 95.8 95.4 94.1 94.1
200/150 96.2 95.8 95.8 95.4 94.5 94.1

(j) Starting on June 1, 2016, each fire pump electric motor meeting the criteria in paragraph (g) of this section and with a power rating of 1 horsepower through 500 horsepower, manufactured (alone or as a component of another piece of equipment) shall have a nominal full-load efficiency that is not less than the following:

Table 7 - Nominal Full-Load Efficiencies of Fire Pump Electric Motors at 60 Hz

Motor horsepower/
standard kilowatt
equivalent
Nominal full-load efficiency (%)
2 Pole 4 Pole 6 Pole 8 Pole
Enclosed Open Enclosed Open Enclosed Open Enclosed Open
1/.75 75.5 82.5 82.5 80.0 80.0 74.0 74.0
1.5/1.1 82.5 82.5 84.0 84.0 85.5 84.0 77.0 75.5
2/1.5 84.0 84.0 84.0 84.0 86.5 85.5 82.5 85.5
3/2.2 85.5 84.0 87.5 86.5 87.5 86.5 84.0 86.5
5/3.7 87.5 85.5 87.5 87.5 87.5 87.5 85.5 87.5
7.5/5.5 88.5 87.5 89.5 88.5 89.5 88.5 85.5 88.5
10/7.5 89.5 88.5 89.5 89.5 89.5 90.2 88.5 89.5
15/11 90.2 89.5 91.0 91.0 90.2 90.2 88.5 89.5
20/15 90.2 90.2 91.0 91.0 90.2 91.0 89.5 90.2
25/18.5 91.0 91.0 92.4 91.7 91.7 91.7 89.5 90.2
30/22 91.0 91.0 92.4 92.4 91.7 92.4 91.0 91.0
40/30 91.7 91.7 93.0 93.0 93.0 93.0 91.0 91.0
50/37 92.4 92.4 93.0 93.0 93.0 93.0 91.7 91.7
60/45 93.0 93.0 93.6 93.6 93.6 93.6 91.7 92.4
75/55 93.0 93.0 94.1 94.1 93.6 93.6 93.0 93.6
100/75 93.6 93.0 94.5 94.1 94.1 94.1 93.0 93.6
125/90 94.5 93.6 94.5 94.5 94.1 94.1 93.6 93.6
150/110 94.5 93.6 95.0 95.0 95.0 94.5 93.6 93.6
200/150 95.0 94.5 95.0 95.0 95.0 94.5 94.1 93.6
250/186 95.4 94.5 95.0 95.4 95.0 95.4 94.5 94.5
300/224 95.4 95.0 95.4 95.4 95.0 95.4
350/261 95.4 95.0 95.4 95.4 95.0 95.4
400/298 95.4 95.4 95.4 95.4
450/336 95.4 95.8 95.4 95.8
500/373 95.4 95.8 95.8 95.8

(k) For purposes of determining the required minimum nominal 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 energy conservation standards in paragraphs (h) through (l) 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 horsepowers shall be rounded up to the higher of the two horsepowers;

(2) A horsepower below the midpoint between the two consecutive horsepowers shall be rounded down to the lower of the two horsepowers; or

(3) A kilowatt rating shall be directly converted from kilowatts to horsepower using the formula 1 kilowatt = ( 1/ 0.746) horsepower. The conversion should be calculated to three significant decimal places, and the resulting horsepower shall be rounded in accordance with paragraph (k)(1) or (k)(2) of this section, whichever applies.

(l) The standards in Table 5 through Table 7 of this section do not apply to the following electric motors exempted by the Secretary, or any additional electric motors that the Secretary may exempt:

(1) Air-over electric motors;

(2) Component sets of an electric motor;

(3) Liquid-cooled electric motors;

(4) Submersible electric motors; and

(5) Inverter-only electric motors.

[79 FR 31010, May 29, 2014]