Electrical Motors - Full Load Currents

Full load currents for 460 volts, 230 volts and 115 volts motors - single and 3-phase

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

  • 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 the protective devices, wiring and switch gear.

Single-Phase Motors - HP and Full-Load Currents

Motor Size 

(hp)

Full Load Current (amps)
115 V208 V230 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 V230 V460 V575 V2300 V230 V460 V575 V2300 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

Related Topics

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

Related Documents

Tag Search

Search the Engineering ToolBox

- "Search is the most efficient way to navigate the Engineering ToolBox!"

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your SketchUp model with the Engineering ToolBox - SketchUp Extension/Plugin - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Translate the Engineering ToolBox!
About the Engineering ToolBox!

close