πŸ› οΈ FreeToolsHub
⚑

3 Phase to Single Phase Calculator

Calculate power conversion between three-phase and single-phase electrical systems. Find the right phase converter size for your equipment. Free calculator with sizing guide.

πŸ’‘

Key Formulas

3-Phase Power: P = √3 Γ— V Γ— I Γ— PF Β |Β 1-Phase Current: I₁ = (√3 Γ— I₃ Γ— V₃) Γ· V₁ Β | √3 β‰ˆ 1.732

⚑ 3-Phase Input

πŸ“Š Results

3-Phase Power

7.07
kW (Real)
8.31
kVA (Apparent)

Single-Phase Equivalent @ 240V

34.6
Amps Required
8.31
kVA

Motor Equivalent

9.5 HP
β‰ˆ 7.07 kW

P = √3 Γ— 480V Γ— 10A Γ— 0.85 = 7.07 kW

⚑ Understanding Phase Conversion

Three-phase power is commonly used in industrial and commercial settings because it's more efficient for running large motors and equipment. However, most residential areas only have single-phase power available.

Why Convert Single-Phase to Three-Phase?

  • Run industrial equipment: CNC machines, lathes, mills, and compressors
  • Home workshops: Use professional-grade tools at home
  • Cost savings: Cheaper than installing utility 3-phase service
  • Remote locations: Where 3-phase isn't available

The √3 Factor Explained

The √3 (approximately 1.732) factor appears in three-phase calculations because of the 120° phase relationship between the three voltage waveforms. This geometric relationship means three-phase systems can deliver more power with the same wire size compared to single-phase.

⚑ Quick Reference

√3 = 1.732

1 HP = 0.746 kW

1 kW = 1.341 HP

Typical PF = 0.85

πŸ“ Sizing Rule of Thumb

Motors: Converter = 1.5Γ— HP

Compressors: Converter = 2Γ— HP

Welders: Converter = 2.5Γ— HP

Multiple loads: Add 50% of secondary loads

Frequently Asked Questions

Yes, but it's rarely needed. Three-phase to single-phase conversion typically involves using only one phase of the three-phase supply, which provides about 1/3 of the total power. For balanced loads, you'd need a transformer. Most conversions go the other wayβ€”single-phase to three-phaseβ€”to run industrial equipment from residential power.

Yes, they work well when properly sized. Phase converters (static, rotary, or digital) can effectively convert single-phase power to three-phase for running motors and equipment. The key is choosing the right type and size for your application. Rotary converters provide the best balance, while VFDs offer precise control.

Phase converters are worth it when: 1) You need to run 3-phase equipment but only have single-phase power, 2) The cost of installing 3-phase service exceeds the converter cost, 3) You're in a location where 3-phase isn't available. For occasional use, a static converter may suffice. For workshops with multiple machines, a rotary converter is a better investment.

Yes. If you have 208V three-phase, you can get 208V single-phase between any two legs. For 480V three-phase, a step-down transformer can provide 240V single-phase. The single-phase voltage from a three-phase system depends on whether it's wye or delta configuration and which terminals you use.

General rule: Converter HP rating should be 1.5Γ— to 2Γ— your largest motor's HP rating. For hard-starting loads (compressors, pumps), use 2Γ— or more. For multiple motors, size for the largest motor plus 50% of other running loads. Always consult manufacturer guidelines for specific applications.

For power: P(3Ο†) = √3 Γ— V Γ— I Γ— PF. For equivalent single-phase current: I(1Ο†) = (√3 Γ— I(3Ο†) Γ— V(3Ο†)) / V(1Ο†). The √3 factor (approximately 1.732) accounts for the phase relationship in three-phase systems.

⚑ Disclaimer: This calculator provides estimates for educational and planning purposes. Always consult a licensed electrician before making electrical installations. Follow local electrical codes and safety standards.