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Single-phase AC Power Formula:
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AC Power calculation determines the real power consumed in an electrical circuit. For single-phase AC systems, power depends on voltage, current, and the power factor which represents the phase difference between voltage and current waveforms.
The calculator uses the single-phase AC power formula:
Where:
Explanation: The formula calculates the actual power consumed, accounting for the phase relationship between voltage and current in AC circuits.
Details: Power factor indicates how effectively electrical power is being used. A power factor of 1 means all power is real power (useful work), while lower values indicate reactive power (stored energy that does no useful work).
Tips: Enter voltage in volts, current in amps, and power factor (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 = V × I) is measured in VA and represents the total power in the circuit.
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 shifts between voltage and current.
Q3: How can power factor be improved?
A: Power factor can be improved by adding capacitors to counteract inductive reactance, using synchronous motors, or employing power factor correction equipment.
Q4: What are typical power factor values?
A: Residential: 0.85-0.95, Commercial: 0.75-0.85, Industrial: 0.70-0.80. Utilities often charge penalties for power factors below 0.90.
Q5: Does this formula work for three-phase systems?
A: No, for three-phase systems use: P = √3 × V × I × PF, where V is line-to-line voltage and I is line current.