1. What is 3-Phase Power?

Three-phase power is a common method of alternating-current electric power generation, transmission, and distribution. It is more efficient than single-phase power for motors and high-power applications because the power transfer is constant.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

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

Explanation: The formula calculates the real power in a balanced three-phase system, accounting for the phase difference between voltage and current through the power factor.

3. Importance of Power Factor

Details: Power factor represents the ratio of real power to apparent power. A higher power factor (closer to 1) indicates more efficient power usage, while lower power factors result in higher currents for the same real power.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line-to-line and line-to-neutral voltage?
A: In 3-phase systems, line-to-line voltage is √3 times the line-to-neutral voltage. This calculator uses line-to-line voltage.

Q2: What is a typical power factor value?
A: For resistive loads it's 1.0, for motors typically 0.8-0.95, and for heavily inductive loads it can be much lower (0.5 or less).

Q3: Can this be used for single-phase calculations?
A: No, for single-phase use P = V × I × PF (without the √3 factor).

Q4: What if my system is unbalanced?
A: This calculator assumes a balanced 3-phase system. For unbalanced systems, calculate each phase separately and sum the results.

Q5: How does this relate to apparent power (kVA)?
A: Apparent power = √3 × V × I (without PF). Real power (kW) = apparent power × PF.