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Full Load Current: Three Phase AC Motors

by Brandy McNeil
in Electrical Tables
February 16, 2017
Motor Horsepower Motor Ampere Size Breaker Size Starter Heater Ampere Size Wire Size Conduit
1 230V
460 V 		4.2
2.1 		15
15 		00
00 		4.830
2.415 		12
12 		3/4″
3/4″
1-1/2 230V
460V 		6.0
3.0 		15
15 		00
00 		6.900
3.450 		12
12 		3/4″
3/4″
2 230V
460V 		6.8
3.4 		15
15 		0
00 		7.820
3.910 		12
12 		3/4″
3/4″
3 230V
460V 		9.6
4.8 		15
15 		0
0 		11.040
5.520 		12
12 		3/4″
3/4″
5 230V
460V 		15.2
7.6 		15
15 		1
0 		17.480
8.740 		12
12 		3/4″
3/4″
7-1/2 230V
460V 		22
11 		40
30 		1
1 		25.300
12.650 		10
12 		3/4″
3/4″
10 230V
460V 		28
14 		50
30 		2
1 		32.200
16.100 		10
12 		3/4″
3/4″
15 230V
460V 		42
21 		70
40 		2
2 		48.300
24.150 		6
10 		1″
3/4″
20 230V
460V 		54
27 		100
50 		3
2 		62.100
31.050 		6
10 		1″
3/4″
25 230V
460V 		68
34 		100
50 		3
2 		78.200
39.100 		4
8 		1-1/2″
1″
  1. 1. Overcurrent device may have to be increased due to starting current and
    load conditions. See NEC 430-52, Table 430-152. Wire based on 75°C
    terminations and insulation.
  2. 2. Overload heater must be based on motor nameplate and sized per NEC
    430-32.
  3. 3. Conduit size based on Rigid metal conduit with some spare capacity. For
    minimum size and other conduit types, see NEC Appendix C, or UGLY’S pages
    102-122.