1. What is Three-Phase Line Current?

Three-phase line current refers to the current flowing through each conductor in a three-phase electrical system. It is a fundamental parameter in electrical engineering used for system design, protection, and analysis of three-phase power systems.

2. How Does the Calculator Work?

The calculator uses the three-phase line current formula:

Where:

• \( I \) — Line current (amperes)
• \( P \) — Total power (watts)
• \( V \) — Line voltage (volts)
• \( \sqrt{3} \) — Approximately 1.732 (constant for three-phase systems)

Explanation: This formula calculates the current per phase in a balanced three-phase system where the power is evenly distributed across all three phases.

3. Importance of Line Current Calculation

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

4. Using the Calculator

Tips: Enter total power in watts and 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 is the difference between line current and phase current?
A: Line current is the current through each line conductor, while phase current is the current through each phase winding. In star connection, they are equal; in delta connection, 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 star and delta connections in balanced three-phase systems, as it uses line voltage which is the same for both configurations.

Q3: What is line voltage in three-phase systems?
A: Line voltage is the voltage between any two line conductors. In star connection, line voltage is √3 times phase voltage; in delta connection, line voltage equals phase voltage.

Q4: When should I use this calculation?
A: Use this calculation for designing three-phase electrical systems, selecting appropriate cable sizes, determining circuit breaker ratings, and analyzing power distribution networks.

Q5: What assumptions does this formula make?
A: This formula assumes a balanced three-phase system with equal loads on all phases, sinusoidal waveforms, and unity power factor (for apparent power calculations).