What is wattless current?

Wattless current is the current that does not produce any net power or energy consumption. It occurs when current and voltage are 90° out of phase, usually in pure inductive or capacitive circuits.

• Power equation: P = VIcosφ. When φ = 90°, cosφ = 0, so power = 0.
• Although current flows, no actual work or heat is produced.
• Energy is stored temporarily in the magnetic or electric field and returned each cycle.

Examples

• Pure inductor or capacitor circuits in AC systems.
• Reactive components in transmission lines.

Significance

• Wattless current causes voltage drops and losses without useful work.
• Power factor correction reduces wattless current using capacitors or inductors.