Motor Power Calculation: Understanding Reactive Power
What is the reactive power drawn by a motor if the 20 hp motor draws an apparent power of 20 kva?
Reactive power is a component of electrical power that represents the energy exchange between reactive elements, such as inductors and capacitors, in an alternating current (AC) circuit. It is measured in units called volt-ampere reactive (VAR).
How can we calculate the reactive power drawn by the motor based on the given data?
Calculation of Reactive Power for the Motor:
Given data: Apparent Power (S) = 20 kVA
Since the power factor is not provided, we will assume a common power factor of 0.85 for motors.
Reactive Power (Q) = Apparent Power (S) x sine(arccos(power factor))
For power factor 0.85:
Reactive Power (Q) = 20 kVA x sine(arccos(0.85))Calculating the reactive power:
Reactive Power (Q) = 20 kVA x sine(30.58 degrees)This calculation will give us the estimated reactive power drawn by the motor.
Reactive power is crucial in understanding the full power consumption in electrical systems and ensuring efficient operation.