Calculateur d'Ampacité de Câble
Calculez l'ampacité maximale d'un câble électrique.
Real Power
14.13 kW
Real Power vs Line-to-Line Voltage
Formule
## Three-Phase Power Calculations Three-phase systems are the standard for industrial and commercial power distribution. ### Formulas (Balanced Load) **Apparent Power = sqrt(3) x V_line x I_line** **Real Power = Apparent x Power Factor** **Reactive Power = sqrt(Apparent^2 - Real^2)** **Phase Voltage = Line Voltage / sqrt(3)** The sqrt(3) factor (approximately 1.732) arises from the 120-degree phase separation between the three phases.
Exemple Résolu
480 V three-phase, 20 A line current, 0.85 power factor.
- 01Apparent: sqrt(3) x 480 x 20 = 16,627 VA = 16.63 kVA
- 02Real: 16,627 x 0.85 = 14,133 W = 14.13 kW
- 03Reactive: sqrt(16627^2 - 14133^2) = 8,744 VAR = 8.74 kVAR
- 04Phase voltage: 480 / 1.732 = 277.1 V
Questions Fréquentes
When is three-phase power used?
For loads above about 5 kW, large motors, industrial equipment, and commercial buildings. It provides constant power delivery and efficient motor operation.
What is the difference between line and phase values?
Line values are measured between phases (L-L). Phase values are measured from one phase to neutral. V_line = sqrt(3) x V_phase for wye connections.
What if the load is unbalanced?
These formulas assume balanced loads. For unbalanced loads, calculate each phase separately and sum the results.
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