3 Phase AC Power Calculation RMS

3-Phase Power Formula:

\[ P = \sqrt{3} \times V_{rms} \times I_{rms} \times PF \]

3-Phase Power (P):

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1. What is 3-Phase AC Power?

Three-phase AC power is a common method of electric power transmission, generation, and distribution. It's more efficient than single-phase power for heavy industrial loads. The power in a balanced three-phase system can be calculated using the RMS values of voltage and current.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

\[ P = \sqrt{3} \times V_{rms} \times I_{rms} \times PF \]

Where:

\( P \) — Real power in watts (W)
\( V_{rms} \) — Line-to-line RMS voltage in volts (V)
\( I_{rms} \) — RMS current in amperes (A)
\( PF \) — Power factor (unitless, between 0 and 1)
\( \sqrt{3} \) — Constant for balanced three-phase systems

Explanation: The formula calculates the real power in a balanced three-phase AC system, accounting for the phase difference between voltage and current through the power factor.

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 values indicate reactive power that doesn't do useful work but still requires current flow.

4. Using the Calculator

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

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 much lower (0.5 or less).

Q3: Can this be used for single-phase power calculation?
A: No, for single-phase use P = V × I × PF (without the √3 factor).

Q4: What if my system is unbalanced?
A: This calculator assumes a balanced system. For unbalanced systems, you would need to calculate power for each phase separately and sum them.

Q5: How does this relate to apparent power (kVA)?
A: Apparent power (S) = √3 × V × I (without PF). Real power (P) = S × PF.