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Single-Phase Power Formula:
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Single-phase power is an electrical system where the voltage varies simultaneously. It is commonly used in residential and light commercial applications for lighting, heating, and small motor loads.
The calculator uses the single-phase power formula:
Where:
Explanation: This formula calculates the real power in a single-phase AC circuit, accounting for the phase difference between voltage and current through the power factor.
Details: Power factor represents the ratio of real power to apparent power. A power factor of 1 indicates perfect efficiency, while lower values indicate reactive power losses. Improving power factor can reduce energy costs and increase system capacity.
Tips: Enter voltage in volts, current in amps, and power factor as a decimal between 0 and 1. For purely resistive loads, use power factor of 1.0. All values must be positive numbers.
Q1: What is the difference between single-phase and three-phase power?
A: Single-phase uses one alternating voltage, while three-phase uses three voltages phase-shifted by 120 degrees. Three-phase is more efficient for large industrial loads.
Q2: When should I use power factor less than 1?
A: Use power factor less than 1 for inductive loads like motors, transformers, or fluorescent lighting where current lags voltage.
Q3: What are typical power factor values?
A: Resistive loads: 1.0, Induction motors: 0.8-0.9, Fluorescent lighting: 0.5-0.9. Power factor correction can improve values to near 1.0.
Q4: Can this calculator be used for DC circuits?
A: For DC circuits, omit the power factor (use 1.0) since there is no phase difference in DC systems.
Q5: How does power factor affect electrical bills?
A: Many commercial and industrial customers pay penalties for low power factor, as it requires utilities to supply more current for the same real power.