3 Phase AC Power Formula

3-Phase Power Formula:

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

3-Phase Power (P):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is 3-Phase Power?

Three-phase power is a common method of alternating-current electric power generation, transmission, and distribution. It is more efficient than single-phase power for large industrial motors and other heavy loads.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

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

Where:

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

Explanation: The formula accounts for the phase difference in three-phase systems and the power factor which represents the ratio of real power to apparent power.

3. Importance of Power Factor

Details: Power factor is crucial in AC circuits as it indicates how effectively electrical power is being converted into useful work. A low power factor (below 0.8) indicates poor utilization of electrical power and may result in additional charges from utility companies.

4. Using the Calculator

Tips: Enter line-to-line voltage in volts, current in amperes, and power factor (between 0 and 1). Typical power factors are 0.8 for industrial loads and 0.95 or higher for power-corrected systems.

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 between any two phases, while line-to-neutral is between one phase and neutral. Line-to-line is √3 times line-to-neutral.

Q2: Why is √3 used in the formula?
A: The √3 factor accounts for the 120° phase difference between the three phases in a balanced system.

Q3: What's a typical power factor value?
A: Induction motors typically have 0.8-0.9 PF, resistive loads have 1.0 PF, and heavily inductive loads can have PF as low as 0.5.

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

Q5: How does power factor affect energy consumption?
A: Low power factor means higher current is needed for the same real power, increasing energy losses in distribution systems.