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Single-phase AC Power Formula:
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Single-phase AC power refers to the electrical power in a system that uses a single alternating current waveform. It is commonly used in residential and light commercial applications for powering household appliances, lighting, and small motors.
The calculator uses the single-phase AC power formula:
Where:
Explanation: The formula calculates the real power consumed in a single-phase AC circuit, taking into account the phase difference between voltage and current through the power factor.
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 consumption that doesn't perform useful work but still requires infrastructure capacity.
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, while apparent power (S) is the product of voltage and current measured in volt-amperes (VA). Real power = apparent power × 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 displacement between voltage and current.
Q3: How can power factor be improved?
A: Power factor can be improved by adding power factor correction capacitors, using synchronous motors, or optimizing motor loads to reduce reactive power consumption.
Q4: What are typical power factor values?
A: Residential power factors typically range from 0.8 to 0.95, while industrial facilities aim for 0.9 to 0.95. Pure resistive loads have a power factor of 1.
Q5: Why is power factor important for utility billing?
A: Many commercial and industrial customers pay power factor penalties because low power factor requires utilities to provide more current for the same real power, increasing infrastructure costs.