ASHRAE-90.1-2022- - Page 180

Extracted Content

Table 10.8-2 Minimum Nominal Full-Load Efficiency for NEMA Design C and IEC Design H Motors at 60 Hz [ a,b]

Motor Horsepower, hp	Nominal Full-Load Efficiency, %	Col3	Col4	Col5	Col6	Col7
Motor Horsepower, hp	4-Pole	4-Pole	6-Pole	6-Pole	8-Pole	8-Pole
Motor Horsepower, hp	Enclosed	Open	Enclosed	Open	Enclosed	Open
1	85.5	85.5	82.5	82.5	75.5	75.5
1.5	86.5	86.5	87.5	86.5	78.5	77.0
2	86.5	86.5	88.5	87.5	84.0	86.5
3	89.5	89.5	89.5	88.5	85.5	87.5
5	89.5	89.5	89.5	89.5	86.5	88.5
7.5	91.7	91.0	91.0	90.2	86.5	89.5
10	91.7	91.7	91.0	91.7	89.5	90.2
15	92.4	93.0	91.7	91.7	89.5	90.2
20	93.0	93.0	91.7	92.4	90.2	91.0
25	93.6	93.6	93.0	93.0	90.2	91.0
30	93.6	94.1	93.0	93.6	91.7	91.7
40	94.1	94.1	94.1	94.1	91.7	91.7
50	94.5	94.5	94.1	94.1	92.4	92.4
60	95.0	95.0	94.5	94.5	92.4	93.0
75	95.4	95.0	94.5	94.5	93.6	94.1
100	95.4	95.4	95.0	95.0	93.6	94.1
125	95.4	95.4	95.0	95.0	94.1	94.1
150	95.8	95.8	95.8	95.4	94.1	94.1
200	96.2	95.8	95.8	95.4	94.5	94.1

a. Nominal efficiencies shall be established in accordance with DOE 10 CFR 431. b. 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 kilo-

watt ratings listed in this table, 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. 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 (1) or (2), whichever applies.

Table 10.8-3 Minimum Average Full-Load Efficiency for Polyphase Small Electric Motors [ a]

Number of Poles 	Full-Load Efficiency, %	Col3	Col4
Number of Poles	Open Motors	Open Motors	Open Motors
Number of Poles	2	4	6
**Synchronous Speed (RPM)**	3600	1800	1200

Motor Size, hp	Col2	Col3	Col4
0.25	65.6	69.5	67.5
0.33	69.5	73.4	71.4
0.50	73.4	78.2	75.3
0.75	76.8	81.1	81.7
1	77.0	83.5	82.5
1.5	84.0	86.5	83.8
2	85.5	86.5	N/A
3	85.5	86.9	N/A

a. Average full-load efficiencies shall be established in accordance with 10 CFR 431.

178 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)