1. What is a 3-Phase Watts Calculator?

Definition: This calculator computes the real power (in watts) in a three-phase electrical system using voltage, current, and power factor.

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_w \) — Real power (watts)
• \( V \) — Line-to-line voltage (volts)
• \( I \) — Current (amps)
• \( PF \) — Power factor (0 to 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 ratio of real power to apparent power.

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, 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-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 vs 120V).

Q2: What is a typical power factor value?
A: Industrial loads typically range from 0.8 to 0.95. Resistive loads have PF=1, while inductive loads have lower PF.

Q3: Why multiply by √3 in the formula?
A: This accounts for the 120° phase shift between the three phases in a balanced system.

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

Q5: Can I use this for DC systems?
A: No, for DC simply use P = V × I (no power factor or √3 needed).