Calculators
Electrical Load & Motor Sizing
Full-load amps, input kW, and kVA for a 3-phase induction motor from nameplate horsepower and voltage. NEC Article 430 reference.
Method: 3-phase full-load current FLA = HP · 746 / (V · √3 · η · pf). Input electrical kW = HP · 0.746 / η. Apparent power kVA = kW / pf. Running load = input kW · LF. Compare calculated FLA against NEC Table 430.250 for standard motor sizes — code values are used for feeder sizing regardless of nameplate. Source: NEC Article 430 (2023), NEC Table 430.250; IEEE 141 (Red Book); NEMA MG-1.
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