How to calculate 3 phase electrical power?
GeneralClass 12AllAnswered 27 Mar 2026
Answer
For three-phase power calculations, use these formulas:
For balanced loads:
- P = √3 × V × I × PF (where PF is power factor)
- P = 3 × V(phase) × I(phase) × PF
Where:
- P = Power in watts
- V = Line-to-line voltage
- I = Line current
- √3 ≈ 1.732
- PF = Power factor (typically 0.8 to 1.0)
Example: For 400V line voltage, 10A current, and 0.9 power factor: P = 1.732 × 400 × 10 × 0.9 = 6,235 watts or 6.235 kW
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