Power factor-Basics

 In AC circuits, the power factor is the ratio of the Real/true power that is used to do work and the apparent power that is supplied to the circuit.

• The power factor can get values in the range from 0 to 1.
• When all the power is reactive power with no real power (usually inductive load) - the power factor is 0.
• When all the power is real power with no reactive power (resistive load) - the power factor is 1.

Power factor=True power/Apparent power

=watts/volts-amps

=KW/KVA

Real power is the actual power consumed or dissipated due to the resistance load and is 

• Measured in Watts
• Symbolized by the capital letter P, as always

Apparent power is a phantom power combination of reactive power and true power and it is the product of a circuit’s voltage and current, without reference to phase angle,

• Measured in the unit of Volt-Amps (VA) 
• Symbolized by the capital letter

Why should I improve the power factor

Improving the power factor can improve the current-carrying capacities

• Improve voltage drop in equipment or even cancel completely the (inductive) reactive current in upstream conductors
• Reduce power loss/heat generated

Losses in cables are proportional to the current squared. The reduction of the total current in a conductor by 10% for example, will reduce the losses by almost 20%.

• Reduction in cable size
• Lower electric bill and save money