1. What is 3-Phase AC Power?

Definition: This calculator computes the real power in kilowatts (kW) for a balanced three-phase AC electrical system.

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Real power in kilowatts
• \( V \) — 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.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing how effectively current is being converted into useful work.

Q2: What's a typical power factor value?
A: Industrial motors typically have 0.8-0.9 PF, while purely resistive loads have PF=1. The default 0.8 is common for many applications.

Q3: Is this formula for line or phase values?
A: This formula uses line-to-line voltage and line current (not phase voltage/current).

Q4: How does this differ from single-phase power?
A: Single-phase uses P=VI×PF, while three-phase includes the √3 factor to account for all three phases.

Q5: What if I have unbalanced phases?
A: This calculator assumes balanced three-phase. For unbalanced systems, calculate each phase separately and sum the results.