Electrical Formulas

Electrical formulas for computing alternator amperage

Desired dataSingle-phaseThree-phaseDirect current
Kilovolt-Amps (kVA)Volts x Amps / 1,000Volts x Amps x 1.732 / 1,000
Kilowatts (kW)kVA x Power Factor (PF)kVA x Power Factor (PF)Volts x Amps / 1,000
AMPS – When kW are knownkW x 1,000 / Volts x PFkW x 1,000 / 1.732 x Volts x PFkW x 1,000 / Volts
AMPS – When kVA is knownkVA x 1,000 / VoltskVA x 1,000 / 1.732 x Volt