3 Phase AC Motors: Full Load Current, Breaker Size, AWG Wire Size, Conduit Size, and Other Data

For 3 phase electric motors, use this table to calculate full load current (amps), breaker size, NEMA size starter, heater amps, AWG wire size and conduit size, given the motor horsepower (hp) and volts(v).

3 Phase Motor Data Chart

To jump to the data for your motor, select a motor horsepower:

1 hp motor↓

1.5 hp motor↓

2 hp motor↓

3 hp motor↓

5 hp motor↓

7.5 hp motor↓

10 hp motor↓

15 hp motor↓

20 hp motor↓

25 hp motor↓

Motor
Horsepower		 1
Motor
Volts		 230V 460V
Motor
Amps		 4.2 2.1
Size
Breaker		 15 15
NEMA Size
Starter		 00 00
Heater
Amps		 4.830 2.415
Size Wire
AWG		 12 12
Size
Conduit		 3/4″ 3/4″
Motor
Horsepower		 1 1/2
Motor
Volts		 230V 460V
Motor
Amps		 6.0 3.0
Size
Breaker		 15 15
NEMA Size
Starter		 00 00
Heater
Amps		 6.900 3.450
Size Wire
AWG		 12 12
Size
Conduit		 3/4″ 3/4″
Motor
Horsepower		 2
Motor
Volts		 230V 460V
Motor
Amps		 6.8 3.4
Size
Breaker		 15 15
NEMA Size
Starter		 0 00
Heater
Amps		 7.820 3.910
Size Wire
AWG		 12 12
Size
Conduit		 3/4″ 3/4″
Motor
Horsepower		 3
Motor
Volts		 230V 460V
Motor
Amps		 9.6 4.8
Size
Breaker		 15 15
NEMA Size
Starter		 0 0
Heater
Amps		 11.040 5.520
Size WireAWG 12 12
Size
Conduit		 3/4″ 3/4″
Motor
Horsepower		 5
Motor
Volts		 230V 460V
Motor
Amps		 15.2 7.6
Size
Breaker		 15 15
NEMA Size
Starter		 1 0
Heater
Amps		 17.480 8.740
Size
Wire		 12 12
Size
Conduit		 3/4″ 3/4″
Motor
Horsepower		 7 1/2
Motor
Volts		 230V 460V
Motor
Amps		 22.0 11.0
Size
Breaker		 45 20
NEMA Size
Starter		 1 1
Heater
Amps		 25.300 12.650
Size Wire
AWG		 10 12
Size
Conduit		 3/4″ 3/4″
Motor
Horsepower		 10
Motor
Volts		 230V 460V
Motor
Amps		 28.0 14.0
Size
Breaker		 60 30
NEMA Size
Starter		 2 1
Heater
Amps		 32.200 16.100
Size Wire
AWG		 10 12
Size
Conduit		 3/4″ 3/4″
Motor
Horsepower		 15
Motor
Volts		 230V 460V
Motor
Amps		 42.0 21.0
Size
Breaker		 70 40
NEMA Size
Starter		 2 2
Heater
Amps		 48.300 24.150
Size Wire
AWG		 6 10
Size
Conduit		 1″ 3/4″
Motor
Horsepower		 20
Motor
Volts		 230V 460V
Motor
Amps		 54.0 27.0
Size
Breaker		 100 50
NEMA Size
Starter		 3 2
Heater
Amps		 62.100 31.050
Size Wire
AWG		 4 10
Size
Conduit		 1″ 3/4″
Motor
Horsepower		 25
Motor
Volts		 230V 460V
Motor
Amps		 68.0 34.0
Size
Breaker		 100 50
NEMA Size
Starter		 3 2
Heater
Amps		 78.200 39.100
Size Wire
AWG		 4 8
Size
Conduit		 1 1/2″ 1″

1. Overcurrent device may have to be increased due to starting current and load conditions. See NEC® Table 430-250. 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.

See Our Other Related Guides:

Warning: For safety, call a licensed electrician and consult the NEC®. All licensed electricians have passed examinations covering the National Electric Code®, know state and local building codes, and may carry insurance to cover damages.