Marine Service Guide - ISES

OHMS LAW
ELECTRICAL FORMULAE
● Ohms = Volts/Amperes (R = E/1)
● Amperes = Volts/Ohms (1 = E/R)
● Volts = Amperes x Ohms (E = 1R)
POWER - A-C CIRCUITS
● Efficiency = 746 x Output Horsepower
Input Watts
● Three-Phase Kilowatts = Volts x Amperes x Power Factor x 1.732
1000
● Three-Phase Volt-Amperes = Volts x Amperes x 1.732
● Three-Phase Amperes = 746 x Horsepower
1.732 x Volts x Efficiency x Power Factor
● Three-Phase Efficiency = 746 x Horsepower
Volts x Amperes x Power Factor x 1.732
● Three-Phase Power Factor = Input Watts
Volts x Amperes x 1.732
● Single-Phase Kilowatts = Volts x Amperes x Power Factor
1000
● Single-Phase Amperes = 746 x Horsepower
Volts x Efficiency x Power Factor
● Single-Phase Efficiency = 746 x Horsepower
Volts x Amperes x Power Factor
● Single-Phase Power Factor = Input Watts
Volts x Amperes
● Horsepower (3 Phase) = Volts x Amperes x 1.732 x Efficiency x Power Factor
746
● Horsepower (1 Phase) = Volts x Amperes x Efficiency x Power Factor
746
POWER - D-C CIRCUITS
● Watts = Volts x Amperes (W = E1)
● Amperes = Watts
Volts
(1 = W/E)
● Horsepower = Volts x Amperes x Efficiency
746
26