1. What is 3-Phase Power Calculation?

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 systems.

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

Explanation: The formula accounts for all three phases in the system and the phase difference 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, current in amps, and power factor (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (watts) does actual work, while apparent power (VA) is the product of voltage and current. The ratio is the power factor.

Q2: What's a typical power factor value?
A: For motors, 0.8-0.9 is common. Resistive loads have PF=1, while inductive loads have lower power factors.

Q3: Is this formula for line-to-line or line-to-neutral voltage?
A: This uses line-to-line voltage (typically 208V, 380V, 480V in three-phase systems).

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

Q5: Why is the power factor important?
A: Lower power factors mean more current is needed for the same real power, increasing system losses and costs.