Three-Phase Voltage Calculator

Apparent power is the total power in a three-phase circuit, measured in volt-amperes (VA) or kilovolt-amperes (kVA). It represents the combination of active power (which does useful work) and reactive power (which is stored and released by reactive components).

For three-phase systems, apparent power (S) is calculated using the formula: S = √3 × VL × IL, where VL is the line-to-line voltage and IL is the line current. The √3 factor (approximately 1.732) accounts for the three-phase relationship.

Active power (kW) is the actual power consumed to do useful work, while apparent power (kVA) is the total power supplied to the circuit. Active power equals apparent power multiplied by the power factor: P = S × cos(φ).

Reactive power (kVAR) is the power that oscillates between the source and reactive components like inductors and capacitors. It doesn't do useful work but is necessary for maintaining voltage levels and magnetic fields in motors and transformers.

In star (Y) connection, phase voltage equals line voltage divided by √3, while phase current equals line current. In delta (Δ) connection, phase voltage equals line voltage, while phase current equals line current divided by √3.

Three-phase current depends on the known parameters. If you know apparent power and voltage: I = S/(√3 × V). If you know active power: I = P/(√3 × V × cos(φ)). The √3 factor accounts for the three-phase system.

Power factor (cos φ) indicates how efficiently electrical power is being used. A power factor of 1.0 means all power is being used for useful work, while lower values indicate reactive power is present, requiring higher current for the same active power.

Three-phase power calculations are very accurate for balanced systems where all three phases have equal voltage magnitudes and are 120° apart. In unbalanced systems, individual phase calculations may be needed for precise results.