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3-Phase Current Formula:
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The 3-phase current calculation determines the current flowing in each phase of a three-phase electrical system based on the power (kW), voltage, and power factor. This is essential for electrical system design, circuit protection, and equipment selection.
The calculator uses the 3-phase current formula:
Where:
Explanation: The formula converts kW to watts (×1000), accounts for the 3-phase system configuration (√3), and adjusts for the power factor which represents the phase difference between voltage and current.
Details: Accurate current calculation is crucial for selecting proper wire sizes, circuit breakers, and other protective devices to ensure safe and efficient operation of electrical systems.
Tips: Enter power in kW, line-to-line voltage in volts, and power factor (typically 0.8-0.95 for most industrial loads). All values must be positive (power factor between 0 and 1).
Q1: What's the difference between line-to-line and line-to-neutral voltage?
A: In 3-phase systems, line-to-line voltage is between two phases, while line-to-neutral is between one phase and neutral. For balanced systems, line-to-line = √3 × line-to-neutral.
Q2: Why is power factor important?
A: Power factor affects the actual current needed to deliver a certain amount of power. Lower PF means higher current for the same real power.
Q3: What's a typical power factor value?
A: Motors typically have 0.8-0.9 PF, fluorescent lights 0.5-0.9, and resistive loads 1.0. Industrial plants often aim for ≥0.95.
Q4: How does voltage affect current?
A: For the same power, higher voltage means lower current, which reduces conductor size requirements and power losses.
Q5: Can this be used for single-phase systems?
A: No, for single-phase use \( I = \frac{kW \times 1000}{V \times PF} \) (without the √3 factor).