1. What is 3-Phase Power Formula?

Definition: This calculator computes the real power in watts for a balanced three-phase electrical system.

Purpose: It helps electrical engineers, technicians, and electricians determine the actual power consumption in three-phase circuits.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_w \) — Real power (watts)
• \( V \) — Line-to-line voltage (volts)
• \( I \) — Line current (amps)
• \( PF \) — Power factor (unitless, 0 to 1)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula accounts for all three phases in the system and the phase relationship between voltage and current.

3. Importance of 3-Phase Power Calculation

Details: Accurate power calculation is essential for proper equipment sizing, energy efficiency analysis, and electrical system design.

4. Using the Calculator

Tips: Enter the line-to-line voltage in volts, line current in amps, and power factor (default 0.8). All values must be > 0, with PF between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line and phase voltage?
A: Line voltage is between two lines, while phase voltage is between a line and neutral. In star systems, line voltage is √3 times phase voltage.

Q2: What is power factor?
A: Power factor represents the ratio of real power to apparent power, indicating how effectively current is being converted into useful work.

Q3: Why is √3 used in the formula?
A: The √3 factor accounts for the 120° phase difference between the three phases in a balanced system.

Q4: What's a typical power factor value?
A: Motors typically have 0.8-0.9 PF, lighting 0.95-1.0, and heavily inductive loads may be as low as 0.5.

Q5: Does this formula work for unbalanced systems?
A: No, this formula is for balanced systems. Unbalanced systems require calculating each phase separately.