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AC Power Formula:
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AC Power calculation determines the actual power consumed in an alternating current circuit. Unlike DC circuits, AC power calculation must account for the phase difference between voltage and current, represented by the power factor.
The calculator uses the AC Power formula:
Where:
Explanation: This formula calculates real power in single-phase AC circuits, accounting for the phase relationship between voltage and current through the power factor.
Details: Power factor represents the efficiency of power usage in AC systems. A power factor of 1 indicates perfect efficiency, while lower values indicate reactive power consumption that doesn't perform useful work but still requires infrastructure capacity.
Tips: Enter voltage in volts, current in amps, and power factor as a decimal between 0 and 1. All values must be positive, with power factor specifically between 0 and 1 inclusive.
Q1: What is the difference between real power and apparent power?
A: Real power (P) is the actual power consumed and measured in watts. Apparent power (S = V × I) is the product of voltage and current, measured in volt-amps (VA).
Q2: What causes low power factor?
A: Low power factor is typically caused by inductive loads like motors, transformers, and fluorescent lighting that create phase displacement between voltage and current.
Q3: How can power factor be improved?
A: Power factor correction involves adding capacitors to counteract inductive reactance, bringing the power factor closer to 1 and reducing reactive power.
Q4: Is this formula for single-phase or three-phase systems?
A: This calculator uses the formula for single-phase AC circuits. Three-phase systems require different calculations involving the square root of 3.
Q5: What are typical power factor values?
A: Residential: 0.85-0.95, Industrial: 0.70-0.90, Commercial: 0.75-0.85. Utilities often charge penalties for power factors below 0.90.