Current In 3 Phase Formula

Three-Phase Current Formula:

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

Current (I):

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1. What Is Three-Phase Current Formula?

The three-phase current formula calculates the line current in a three-phase electrical system based on power, voltage, and power factor. It is essential for electrical engineering applications and power system design.

2. How Does The Calculator Work?

The calculator uses the three-phase current formula:

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

Where:

\( I \) — Line current in amperes (A)
\( P \) — Power in watts (W)
\( V \) — Line-to-line voltage in volts (V)
\( PF \) — Power factor (dimensionless, 0-1)
\( \sqrt{3} \) — Mathematical constant ≈ 1.732

Explanation: The formula accounts for the three-phase power distribution system where power is distributed across three conductors with 120-degree phase separation.

3. Importance Of Three-Phase Current Calculation

Details: Accurate current calculation is crucial for proper sizing of electrical components, circuit protection devices, conductors, and transformers in three-phase systems.

4. Using The Calculator

Tips: Enter power in watts, voltage in volts (line-to-line), and power factor as a decimal between 0 and 1. All values must be positive with power factor between 0 and 1 inclusive.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between line current and phase current?
A: Line current is the current in each line conductor, while phase current is the current in each phase winding. In star connection, they are equal; in delta connection, line current is √3 times phase current.

Q2: Why is power factor important in this calculation?
A: Power factor represents the ratio of real power to apparent power. Lower power factor means higher current for the same real power, requiring larger conductors and equipment.

Q3: What is the typical power factor range?
A: Power factor typically ranges from 0.7 to 1.0. Industrial loads often have 0.8-0.9, while purely resistive loads have 1.0.

Q4: Can this formula be used for both star and delta connections?
A: Yes, the formula applies to both configurations when using line-to-line voltage and total three-phase power.

Q5: What are common applications of three-phase current calculation?
A: Motor sizing, transformer selection, circuit breaker rating, cable sizing, and overall electrical system design in industrial and commercial facilities.