1. What is 3-Phase Current?

Three-phase current is the current flowing in a three-phase electrical system, which is commonly used for power distribution and large motors. The current in each phase can be calculated when power, voltage, and power factor are known.

2. How Does the Calculator Work?

The calculator uses the 3-phase current formula:

Where:

• \( I \) — Current in amperes (A)
• \( P \) — Power in watts (W)
• \( V \) — Line-to-line voltage in volts (V)
• \( PF \) — Power factor (unitless, between 0 and 1)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula accounts for the phase relationship in three-phase systems and the power factor which represents the phase difference between voltage and current.

3. Importance of Current Calculation

Details: Accurate current calculation is essential for proper sizing of circuit breakers, wires, and other electrical components to ensure safety and efficiency in electrical systems.

4. Using the Calculator

Tips: Enter power in watts, line-to-line voltage in volts, and power factor (typically between 0.8 and 1.0). All values must be positive numbers with power factor between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing how effectively electrical power is being used. It ranges from 0 to 1.

Q2: Is this for line or phase current?
A: This calculates line current in a balanced three-phase system.

Q3: What voltage should I use?
A: Use the line-to-line (phase-to-phase) voltage, not the line-to-neutral voltage.

Q4: Can I use this for single-phase systems?
A: No, for single-phase use I = P / (V × PF) without the √3 factor.

Q5: What's a typical power factor value?
A: For motors, typically 0.8-0.95. Resistive loads have PF=1. Always check specifications.