Electrical Motor - Full Load Current

Full load current - 460 Volts, 230 Volts and 115 Volts motors - single and 3-phase

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As a "rules of thumb" amps horsepower rating can be estimated as

  • 115 Volts motor - single-phase : 14 amps/hp
  • 230 Volts motor - single-phase : 7 amps/hp
  • 230 Volts motor - 3-phase : 2.5 amps/hp
  • 460 Volts motor - 3-phase : 1.25 amps/hp

Always check nameplate information before designing protective devices, wiring and switchgear.

Single-Phase Motors - HP and Full-Load Currents

Motor Size 

(hp)

 Full Load Current (Amps)
115 V 208 V 230 V
1/6 4.4 2.4 2.2
1/4 5.8 3.2 2.9
1/3 7.2 4.0 3.6
1/2 9.8 5.4 4.9
3/4 13.8 7.6 6.9
1 16 8.8 8
1 1/2 20 11 10
2 24 13.2 12
3 34 18.7 17
5 56 30.8 28

Three-Phase Motors - HP and Full-Load Currents

Motor Size

(hp)

 Full-Load Current (Amps)

Induction Type

Squirrel-Cage and Wound Motor

Synchronous Type

Unity Power Factor
115 V 230 V 460 V 575 V 2300 V 230 V 460 V 575 V 2300 V
1/2 4 2 1 0.8
3/4 5.6 2.8 1.4 1.1
1 7.2 3.6 1.8 1.4
1 1/2 10.4 5.2 2.6 2.1
2 13.6 6.8 3.4 2.7
3 9.6 4.8 3.9
5 15.2 7.6 6.1
7 1/2 22 11 9
10 28 14 11
15 42 21 17
20 54 27 22
25 68 34 27 53 26 21
30
80 40 32 63 32 26
40 104 52 41 83 41 33
50 130 65 52 104 52 42
60 154 77 62 16 123 61 49 12
75 192 96 77 20 155 78 62 15
100 248 124 99 26 202 101 81 20
  • 1 hp (English horse power) = 745.7 W = 0.746 kW = 550 ft lb/s = 2,545 Btu/h = 33.000 ft lb/m = 1.0139 metric horse power ~= 1.0 KVA

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Related Topics

  • Electrical - Amps and electrical wiring, AWG - wire gauge, electrical formulas, motors and units

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