3 Phase Line Current Calculator

3-Phase Line Current Equation:

\[ I_{line} = \frac{P}{\sqrt{3} \times V_{line}} \]

Line Current (I_line):

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1. What is 3-Phase Line Current?

Three-phase line current refers to the current flowing through each conductor in a three-phase electrical power system. It's a critical parameter in electrical engineering for designing, analyzing, and maintaining three-phase power systems commonly used in industrial and commercial applications.

2. How Does the Calculator Work?

The calculator uses the 3-phase line current equation:

\[ I_{line} = \frac{P}{\sqrt{3} \times V_{line}} \]

Where:

\( I_{line} \) — Line current (amperes)
\( P \) — Total power (watts)
\( V_{line} \) — Line-to-line voltage (volts)
\( \sqrt{3} \) — Mathematical constant (approximately 1.732)

Explanation: This formula calculates the current in each phase of a balanced three-phase system when the total power and line voltage are known.

3. Importance of Line Current Calculation

Details: Accurate line current calculation is essential for proper sizing of circuit breakers, conductors, transformers, and other electrical components to ensure system safety, efficiency, and compliance with electrical codes.

4. Using the Calculator

Tips: Enter the total power in watts and line-to-line voltage in volts. Both values must be positive numbers. The calculator will compute the line current in amperes.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line current and phase current?
A: In a balanced three-phase system, line current is the current in each supply line, while phase current is the current through each load element. For star connections, they're equal; for delta connections, line current is √3 times phase current.

Q2: Does this formula work for both star and delta connections?
A: Yes, this formula works for both balanced star and delta connections when using line-to-line voltage and total three-phase power.

Q3: What if the power factor is not unity?
A: This formula assumes a purely resistive load (power factor = 1). For reactive loads, the formula becomes \( I_{line} = \frac{P}{\sqrt{3} \times V_{line} \times PF} \) where PF is the power factor.

Q4: Can I use this for single-phase calculations?
A: No, this formula is specifically for three-phase systems. For single-phase systems, use \( I = \frac{P}{V} \).

Q5: What are typical voltage values for three-phase systems?
A: Common three-phase voltages include 208V, 240V, 380V, 400V, 415V, 480V, and 600V, depending on the country and application.