Three Phase Power Calculator
Calculate Three-Phase Power
P = √3 × VL × IL × PF
Calculate Three-Phase Current
IL = P / (√3 × VL × PF)
Star (Y) / Delta (Δ) Conversion
Convert between star and delta voltage/current relationships
Formula
P = √3 × VL × IL × PF | S = √3 × VL × IL | Q = √(S² - P²) | Star: VL = √3 × Vφ | Delta: IL = √3 × Iφ
Frequently Asked Questions
What is three-phase power?
Three-phase power uses three AC voltage waveforms, each 120° apart. It is the standard for industrial and commercial power distribution because it provides constant power delivery (no zero-crossing), is more efficient for transmission, and can directly power three-phase motors.
What is the difference between line and phase voltage?
Line voltage (VL) is measured between any two of the three power lines. Phase voltage (Vφ) is measured between a line and neutral. In star (Y) connection: VL = √3 × Vφ. In delta (Δ) connection: VL = Vφ. Common US systems: 480V line = 277V phase, 208V line = 120V phase.
What is the difference between star (Y) and delta (Δ) connections?
Star (Y): All three phase windings share a common neutral point. VL = √3 × Vφ, IL = Iφ. Provides both line and phase voltage. Delta (Δ): Windings connected in a triangle. VL = Vφ, IL = √3 × Iφ. No neutral point. Delta is common for motors; star is common for distribution.
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