What is power factor angle?

In a purely resistive circuit, the voltage and current are in phase, so the power factor angle is 0 degrees. In circuits with inductive or capacitive components, the voltage and current are out of phase, resulting in a non-zero power factor angle. For inductive loads, the current lags the voltage, leading to a positive phase angle, while for capacitive loads, the current leads the voltage, resulting in a negative phase angle.

The power factor angle is related to the power factor (PF), which is a measure of how effectively the current is being converted into useful work. Power factor is calculated as the cosine of the power factor angle:

\[ \text{PF} = \cos(\text{Power Factor Angle}) \]

A power factor close to 1 (or 100%) indicates that most of the power is being used effectively, whereas a lower power factor indicates that more power is wasted, often as reactive power.