powering electric motors

Fairchild Toolworks - Machine Shop Motor Power & Current Calculator

Motor Parameters

HP
Common Sizes:
%
Determines inrush starting current. Most standard industrial induction motors are Class B.
% of FLA

Electrical Sizing Recommendations

FLA: 17.48 A
Min Wire Size (Copper)
10 AWG
Based on 125% of FLA (75°C terminals)
Circuit Breaker Size
25 Amps
Next standard breaker size (125% min)
Starting Current Spike
5.5x FLA
Locked Rotor Amps (LRA) multiplier
Locked-Rotor Power
23.6 - 26.6 kVA
Starting electrical load range

Motor Current Profile Comparison

Idling Current
7.0 A
Full Load (FLA)
17.5 A
Startup Spike (LRA Max)
64.1 A
Spike occurs briefly (1-3 seconds) during motor startup acceleration.

Three-Phase Amps Output

Voltage Full Load (FLA) Idling Amps Startup Spike (LRA Range)

Single-Phase Amps Output

Voltage Full Load (FLA) Idling Amps Startup Spike (LRA Range)
Disclaimer: Electrical guidelines are estimates based on standard National Electrical Code (NEC) tables. Actual motor nameplate ratings can vary. Always consult a licensed electrician and check your specific motor manufacturer specifications before designing branch circuits, selecting wire sizes, or installing phase converters.
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