Washington Administrative Code › Title 51 - Enterprise Services, Department of (Building Code Council) › Chapter 51-11C - State Building Code adoption and amendment of the 2021 edition of the International Energy Conservation Code, Commercial › Section 51-11C-40508 - Section C405.8-Electric motors

Current through Register Vol. 24-14, July 15, 2024
C405.8
Electric
			 motor efficiency.
All electric motors, fractional or otherwise, shall
			 meet the minimum efficiency requirements of Tables C405.8(1) through C405.8(4)
			 when tested and rated in accordance with DOE
			  10 C.F.R.
			 431 . The efficiency shall be verified through
			 certification under an approved certification program or, where no
			 certification program exists, the equipment efficiency ratings shall be
			 supported by data furnished by the motor manufacturer.
EXCEPTION:
The standards in this section shall not apply to the
						  following exempt electric motors.
1. Air-over electric motors.
2. Components sets of an electric motor.
3. Liquid-cooled electric motors.
4. Submersible electric motors.
5. Inverter-only electric motors.
Fractional hp fan motors that are 1/12 hp or greater and less
				than 1 hp (based on output power) which are not covered by Tables C405.8(3) and
				C405.8(4) shall be electronically commutated motors or shall have a minimum
				motor efficiency of 70 percent when rated in accordance with DOE
				 10 C.F.R.
				431 . These motors shall also have the means
				to adjust motor speed for either balancing or remote control. Belt-driven fans
				may use sheave adjustments for airflow balancing in lieu of a varying motor
				speed.
EXCEPTIONS:
1. Motors that are an integral part of specialized
						  process equipment.
2. Where the motor is integral to a listed piece of
						  equipment for which no complying motor has been approved.
3. Motors used as a component of the equipment meeting
						  the minimum efficiency requirements of Section C403.3.2 and Tables C403.3.2(1)
						  through C403.3.2 (16) provided that the motor input is included when
						  determining the equipment efficiency.
4. Motors in the airstream within fan-cand terminal
						  units that operate only when providing heating to the space served.
5. Fan motors that are not covered by Tables C405.8(1)
						  through C405.8(4) and are used to power heat recovery ventilators, energy
						  recovery ventilators, or local exhaust fans in Group R subject to the efficacy
						  requirements of Section C403.8.4.
6. Domestic clothes dryer booster fans, range hood
						  exhaust fans, and domestic range booster fans that operate
						  intermittently.
7. Radon and contaminated soil exhaust fans.
8. Group R heat recovery ventilator and energy recovery
						  ventilator fans that are less than 400 cfm.
Table C405.8(1)
Minimum Nominal Full-load Efficiency for NEMA Design A,
				NEMA Design B and IEC Design N Motors (Excluding Fire Pump) Electric Motors at
				60 Hza,b
Motor horsepower (Standard kilowatt
						  equivalent)
Nominal full-load efficiency (%) as of
						  June 1, 2016
2 pole
4 pole
6 pole
8 pole
Enclosed
Open
Enclosed
Open
Enclosed
Open
Enclosed
Open
1 (0.75)
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
77.5
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
a Nominal efficiencies shall be
				established in accordance with DOE
				 10 C.F.R.
				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 kilowatt 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 kW = (1/0.746) horsepower. The conversion
				should be calculated to three significant decimal places, and the resulting
				horsepower shall be rounded in accordance with 1 or 2, whichever
				applies.
Table C405.8(2)
Minimum Nominal Full-load Efficiency for NEMA Design C
				and IEC Design
H Motors at 60
				Hza,b
Motor horsepower (Standard kilowatt
						  equivalent)
Nominal full-load efficiency (%) as of
						  June 1, 2016
4 pole
6 pole
8 pole
Enclosed
Open
Enclosed
Open
Enclosed
Open
1 (0.75)
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
77.5
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
NR - No requirement.
a Nominal efficiencies shall be
				established in accordance with DOE
				 10 C.F.R.
				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 kilowatt 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 kW = (1/0.746) horsepower. The conversion
				should be calculated to three significant decimal places, and the resulting
				horsepower shall be rounded in accordance with 1 or 2, whichever applies.
Table C405.8(3)
Minimum Average Full Load Efficiency for Polyphase Small
				Electric Motorsa
OPEN MOTORS
NUMBER OF POLES
						  ==>
2
4
6
SYNCHRONOUS SPEED (RPM)
						  ==>
3600
1800
1200
MOTOR HORSEPOWER *
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 C.F.R.
				431.
Table C405.8(4)
Minimum Average Full Load Efficiency
For Capacitor-start Capacitor-run and Capacitor-start
				Induction-run Small Electric Motorsa
OPEN MOTORS
NUMBER OF POLES
						  ==>
2
4
6
SYNCHRONOUS SPEED (RPM)
						  ==>
3600
1800
1200
MOTOR HORSEPOWER *
0.25
66.6
68.5
62.2
0.33
70.5
72.4
66.6
0.50
72.4
76.2
76.2
0.75
76.2
81.8
80.2
1
80.4
82.6
81.1
1.5
81.5
83.8
N/A
2
82.9
84.5
N/A
3
84.1
N/A
N/A
a Average full load efficiencies
				shall be established in accordance with
				 10 C.F.R.
				431.
Statutory Authority:
				  RCW
				    19.27A.020,
				  19.27A.025 and
				  chapters
				  19.27 and
				  34.05 RCW. 13-04-056, §
				  51-11C-40508, filed 2/1/13, effective
				  7/1/13.