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 heavy industrial loads.

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.

3. Importance of Power Factor

Details: Power factor represents the ratio of real power to apparent power. A PF of 1 means all power is real (useful) power, while lower values indicate reactive power that doesn't do useful work but still loads the system.

4. Using the Calculator

Tips: Enter line-to-line voltage (typically 208V, 230V, 400V, 480V, etc.), current in amps, and power factor (0 to 1). For purely resistive loads, use PF=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 (e.g., 208V line-to-line = 120V line-to-neutral).

Q2: Can I use this for single-phase calculations?
A: No, for single-phase use P = V × I × PF (without the √3 factor).

Q3: What's a typical power factor value?
A: Motors typically have PF 0.8-0.9, resistive loads 1.0, and fluorescent lights 0.5-0.9.

Q4: Why is three-phase power more efficient?
A: It provides constant power transfer (no zero crossings) and uses less conductor material for the same power.

Q5: How do I measure line-to-line voltage?
A: Use a multimeter between any two phase conductors (not phase to neutral).