Current Per Phase Calculator

3-Phase Current Equation:

\[ I = \frac{P}{\sqrt{3} \times V \times PF} \]

Current Per Phase:

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1. What is 3-Phase Current Calculation?

The 3-phase current calculation determines the current flowing through each phase in a balanced three-phase electrical system. It's essential for proper sizing of electrical components and circuit protection.

2. How Does the Calculator Work?

The calculator uses the 3-phase current equation:

\[ I = \frac{P}{\sqrt{3} \times V \times PF} \]

Where:

\( I \) — Current per phase (Amperes)
\( P \) — Total power (Watts)
\( V \) — Line voltage (Volts)
\( PF \) — Power factor (unitless, 0-1)
\( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The equation accounts for the balanced distribution of power across three phases in an AC system, with power factor correcting for phase difference between voltage and current.

3. Importance of Current Calculation

Details: Accurate current calculation is crucial for selecting proper wire sizes, circuit breakers, overload protection devices, and ensuring safe operation of electrical equipment.

4. Using the Calculator

Tips: Enter total power in watts, line-to-line voltage in volts, and power factor (typically 0.8-1.0 for most systems). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line and phase voltage?
A: In 3-phase systems, line voltage is between any two phases, while phase voltage is between a phase and neutral. For delta connections, they're equal; for wye, line voltage is √3 times phase voltage.

Q2: Why is power factor important?
A: Power factor represents the ratio of real power to apparent power. Lower PF means more current is needed for the same real power, increasing losses.

Q3: Is this calculation valid for unbalanced loads?
A: No, this calculator assumes a balanced 3-phase system. Unbalanced loads require individual phase calculations.

Q4: What's typical power factor for motors?
A: Induction motors typically have 0.8-0.9 PF at full load, lower at partial loads. Synchronous motors can achieve unity or leading PF.

Q5: How does voltage variation affect current?
A: Current is inversely proportional to voltage for constant power. 10% voltage drop means ~11% current increase for the same power.