# Inductive and capacitive loads

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#### jitesh lulla

##### Newbie level 3 power factor of inductive and capacitive loads

please can anyone share his or her knowledge about power factor in inductive and capacitive loads?

#### Kral

##### Advanced Member level 4 inductive and capacitive loads impact on source

jitesh lulla,
For a purely capacitive or purely inductive load, the power factor is zero. For a purely resistive load, the power factor is 1. For complex loads, and sinusoidal source voltage, calculate the phase shift using Theta = |Tan-1(X/R)| where X is the reactance (capacitive or inductive) and R is the resistance, Tan-1 is the arctangent function. Power factor = Cos(Theta).
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For non-sinusoidal waveforms, the calculation is much more complicated. One way is to do a Fourier analysis of the voltage and current waveforms. Calculate the power contribution for each frequency by using the above formulas. Then the total power P is equal to SQRT{[I1V1cos(Theta1)]^2 +....[InVncos(Thetan)]^2 (Square root of the sum of the squares of the powers at each frequency. The total volt amperes is the IrmsVrms. Power factor = P/(Volt Amperes).
Regards,
Kral

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