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Single Phase AC Current Formula:
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Single-phase AC current is the alternating current that flows through a two-wire AC power circuit (one phase wire and one neutral wire). It's commonly used in residential applications for lighting, heating, and small appliances.
The calculator uses the single-phase AC current formula:
Where:
Explanation: The formula calculates the current needed to deliver a certain amount of real power at a given voltage, accounting for the power factor which represents the phase difference between voltage and current.
Details: Power factor is crucial in AC circuits as it represents the ratio of real power (that does work) to apparent power (that is supplied). A low power factor means higher currents are needed to deliver the same amount of real power, leading to increased energy losses.
Tips: Enter power in watts, voltage in volts, and power factor (typically between 0.8 and 1.0 for most equipment). All values must be positive numbers with power factor between 0.01 and 1.0.
Q1: What's the difference between single-phase and three-phase current?
A: Single-phase uses one alternating voltage, while three-phase uses three voltages phase-shifted by 120°. Three-phase is more efficient for large loads.
Q2: What is a typical power factor value?
A: Resistive loads (heaters, incandescent lights) have PF=1.0. Motors typically have PF=0.8-0.9. Electronic power supplies often have PF=0.6-0.7.
Q3: Why does power factor affect current?
A: With lower power factor, more current is needed to deliver the same real power because some current is out of phase with voltage (reactive power).
Q4: How can I improve power factor?
A: Power factor correction capacitors can be added to counteract inductive loads (motors, transformers) that cause lagging power factor.
Q5: Is this calculation valid for DC circuits?
A: No, for DC circuits the formula simplifies to I = P/V since there's no power factor in DC systems.