1. What is 3 Phase AC Power?

Three-phase AC power is a common method of electric power transmission that uses three alternating currents which are offset in time by one-third of the period. It is widely used in industrial and commercial applications due to its efficiency and power delivery capabilities.

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, between 0 and 1)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula calculates 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 Calculation

Details: Accurate power calculation is essential for sizing electrical equipment, determining energy consumption, calculating efficiency, and ensuring proper circuit protection in three-phase systems.

4. Using the Calculator

Tips:

• Enter line-to-line voltage (typically 208V, 380V, 400V, 415V, 480V, etc.)
• Enter current in amperes (measured or nameplate value)
• Power factor should be between 0 and 1 (0.8 is typical for motors)
• All values must be positive numbers

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 between any two phases, while line-to-neutral is between one phase and neutral. Line-to-line is √3 times line-to-neutral.

Q2: Why is power factor important?
A: Power factor indicates how effectively current is being converted into useful work. Low PF means more current is needed for the same real power.

Q3: What's typical power factor for different loads?
A: Motors: 0.8-0.9, Incandescent lights: 1.0, Fluorescent lights: 0.7-0.9, Induction furnaces: 0.1-0.3.

Q4: How does this differ from single-phase power calculation?
A: Single-phase uses P = V × I × PF without the √3 factor. Three-phase delivers more power with less conductor material.

Q5: What if my system is unbalanced?
A: This calculator assumes balanced loads. For unbalanced systems, calculate each phase separately and sum the results.