Power Calculation for 3 Phase Voltage

3-Phase Power Formula:

\[ P = \sqrt{3} \times V \times I \times PF \]

Voltage (V):

volts (V, line-to-line)

Current (I):

amperes (A)

Power Factor (PF):

(unitless, 0 to 1)

Power (P):

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1. What is 3-Phase Power Calculation?

The 3-phase power calculation determines the real power in a three-phase electrical system. It accounts for the voltage, current, and power factor to calculate the actual power being consumed or delivered in watts.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

\[ P = \sqrt{3} \times V \times I \times PF \]

Where:

\( P \) — Real power in watts (W)
\( V \) — Line-to-line voltage in volts (V)
\( I \) — Current in amperes (A)
\( PF \) — Power factor (unitless, between 0 and 1)
\( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula calculates real power by accounting for the phase relationship between voltage and current in a balanced 3-phase system.

3. Importance of Power Factor

Details: Power factor represents the ratio of real power to apparent power. A PF of 1 means all power is real (useful) power, while lower PF indicates reactive power is present, which doesn't do useful work but still requires current flow.

4. Using the Calculator

Tips: Enter line-to-line voltage in volts, current in amperes, and power factor (between 0 and 1). All values must be positive numbers with power factor 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. This calculator uses line-to-line voltage.

Q2: What is a typical power factor value?
A: For resistive loads it's 1.0, for motors typically 0.8-0.95, and for heavily inductive loads it can be 0.5 or lower.

Q3: Why use √3 in the calculation?
A: The √3 factor accounts for the 120° phase difference between the three phases in a balanced system.

Q4: Does this work for unbalanced loads?
A: This formula assumes balanced loads. For unbalanced systems, you need to calculate power for each phase separately.

Q5: How does this differ from single-phase power calculation?
A: Single-phase uses P = V × I × PF without the √3 factor, and typically uses line-to-neutral voltage.