Power in 3 Phase Formula

3-Phase Power Formula:

\[ P_{kW} = \frac{V \times I \times PF \times \sqrt{3}}{1000} \]

Power (P_kW): kW

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1. What is 3-Phase Power Calculation?

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

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

2. How Does the Calculator Work?

The calculator uses the formula:

\[ P_{kW} = \frac{V \times I \times PF \times \sqrt{3}}{1000} \]

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 three-phase systems (≈1.732)

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

3. Importance of 3-Phase Power Calculation

Details: Accurate power calculation is essential for sizing equipment, determining energy consumption, and ensuring electrical system safety.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line and phase voltage?
A: In 3-phase systems, line voltage is between any two lines, while phase voltage is between any line and neutral.

Q2: What's a typical power factor value?
A: Motors typically have 0.8-0.9 PF, resistive loads have 1.0 PF, and poor power factors are below 0.7.

Q3: Why do we divide by 1000?
A: To convert watts to kilowatts (1 kW = 1000 W).

Q4: Can I use this for single-phase systems?
A: No, use P = V × I × PF / 1000 for single-phase systems (without the √3 factor).

Q5: What if I don't know the power factor?
A: For estimation, use 0.8 for motors or 1.0 for purely resistive loads like heaters.