How do you calculate the current draw of an AC induction motor?

Calculating the current consumption of an AC induction motor involves multiple parameters. Below are the detailed steps and formulas to help you calculate the current consumption of an AC induction motor.

Basic Parameters

Rated Power P (Unit: Watts, W or Kilowatts, kW)

Rated Voltage V (Unit: Volts, V)

Power Factor PF (Dimensionless, usually between 0 and 1)

Efficiency η (Dimensionless, usually between 0 and 1)

Number of Phases n (Single-phase or three-phase, typically 1 or 3)

Calculation Formulas

1. Single-Phase AC Motor

For a single-phase AC motor, the current I can be calculated using the following formula:

Where:

P is the rated power of the motor (Watts or Kilowatts).

V is the rated voltage of the motor (Volts).

PF is the power factor.

η is the efficiency of the motor.

2. Three-Phase AC Motor

For a three-phase AC motor, the current I can be calculated using the following formula:

Where:

P is the rated power of the motor (Watts or Kilowatts).

V is the line voltage of the motor (Volts).

PF is the power factor.

η is the efficiency of the motor.

Square root of 3  is the coefficient for a three-phase system.