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Power Formula:
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The AC power calculation determines the real power (in watts) in an alternating current circuit by accounting for voltage, current, and the power factor. Unlike DC circuits, AC power calculations must consider the phase difference between voltage and current.
The calculator uses the power formula:
Where:
Explanation: The formula calculates the actual power consumed by the load, accounting for the phase difference between voltage and current in AC circuits.
Details: Power factor represents the ratio of real power to apparent power. A PF of 1 means all power is real power (resistive loads), while lower values indicate reactive components (inductive or capacitive loads).
Tips: Enter voltage in volts, current in amps, and power factor (between 0 and 1). For purely resistive loads (like incandescent lights), use PF=1. For motors, typical PF ranges from 0.7 to 0.9.
Q1: What's the difference between real power and apparent power?
A: Real power (watts) is the actual power consumed, while apparent power (VA) is the product of voltage and current. The ratio is the power factor.
Q2: Why is power factor important?
A: Low power factor means more current is needed to deliver the same real power, increasing energy losses in distribution systems.
Q3: How can I improve power factor?
A: For inductive loads (motors), adding capacitors can improve power factor by offsetting the lagging current.
Q4: Does this calculation work for three-phase systems?
A: No, three-phase power requires multiplying by √3 (1.732) for balanced systems: \( P = \sqrt{3} \times V \times I \times PF \).
Q5: What's typical power factor for household appliances?
A: Resistive loads (heaters, incandescent lights) have PF=1. Motors (refrigerators, AC units) typically 0.7-0.9. Electronics with power supplies often 0.6-0.8.