Calculating 3 Phase Power

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 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 (kilowatts)
\( V \) — 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 all three phases and the phase difference between voltage and current.

3. Importance of 3-Phase Power Calculation

Details: Accurate power calculation ensures proper equipment sizing, energy efficiency, and electrical system safety.

4. Using the Calculator

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

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: For motors, it's typically 0.8-0.9. Resistive loads have PF=1, while inductive loads have lower PF.

Q3: Is this formula for line or phase values?
A: This uses line-to-line voltage and line current (most common measurement scenario).

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

Q5: When would I need this calculation?
A: When sizing generators, transformers, circuit breakers, or calculating energy consumption in 3-phase systems.