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AC Power Formula:
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AC Power Calculation determines the real power consumed in an alternating current circuit. Unlike DC power, 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:
Example: For a circuit with 120V, 10A current, and 0.8 power factor:
\( P = 120 \times 10 \times 0.8 = 960 \) W
Details: Power factor represents the efficiency of power usage in AC circuits. A power factor of 1 indicates perfect efficiency, while lower values indicate reactive power losses. Utilities often charge penalties for low power factor in industrial settings.
Tips: Enter voltage in volts, current in amperes, and power factor as a decimal between 0 and 1. All values must be positive, with power factor ranging from 0 to 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) is the product of voltage and current (V×I) measured in VA. The ratio P/S is the power factor.
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 shift 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.
Q4: What is a typical power factor value?
A: Residential power factors are usually 0.95-1.0. Industrial facilities may have 0.7-0.9 without correction. Utilities often require 0.9 or higher.
Q5: Does this formula work for three-phase systems?
A: For three-phase systems, multiply by √3: \( P = \sqrt{3} \times V \times I \times PF \), where V is line-to-line voltage.