Full Load Current in Amperes:

Three Phase AC Motors

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. 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. Overload heater must be based on motor nameplate and sized per NEC 430-32.
  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.