3 Phase Induction Motor Current Calculator

3 Phase Induction Motor current calculator is used to calculate the rated and full load amperes of the motor. Enter the rated volts, amps, power, and efficiency to find the current flowing through the motor.


The 3 phase Induction motor is popular for its efficiency and is widely employed in the electric systems for doing mechanical work. The current flowing through motor depends on various factors including its voltage, power factor, efficiency and rated power. Mathematically, rated load amperes and full load amperes are defined as:
3-phase-induction-motor-current-formula-calculatorWhere

HP = Horsepower

kW = kilowatts

E = V = voltage

SF = Service factor

PF = Power factor

kW and HP are used to represent the power. Whereas 1 HP = 745.6 kW

%Efficiency of the motor is defined as its rated efficiency and it is ration between output input.

Service factor is the ratio of actual maximum power to the rated power mentioned on the plate of the motor.

Example # 1: A 230 volt three phase, 1/2 HP induction motor has an efficiency rating of 88% and a power factor of 85%. Find the amp-load of the motor.

Solution: I = (0.5 * 745.7)/(√3 *230 * 0.85 * 0.88) = 1.25

Example # 2: A 2 kW, 3 phase motor at 400 V has an efficiency rating of 85% and the power factor of 80%. Find the amps. Find the FLA when the service factor is 1.25.

Solution: I = (2,000)/(√3 * 400 * 0.85 * 0.8) = 4.25 A -> RLA

Whereas the For FLA multiply RLA with 1.25.

FLA = 1.25 * 4.25 = 5.31 A

Electrical Calculators © 2018