1. What is 3-Phase Current Calculation?

The 3-phase current calculation determines the electrical current flowing in a three-phase power system based on power, voltage, and power factor. This is essential for proper sizing of electrical components and circuit protection.

2. How Does the Calculator Work?

The calculator uses the 3-phase current formula:

Where:

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

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

3. Importance of Current Calculation

Details: Accurate current calculation is crucial for selecting proper wire sizes, circuit breakers, overload protection devices, and ensuring electrical system safety and efficiency.

4. Using the Calculator

Tips: Enter power in watts, line-to-line voltage in volts, and power factor (typically 0.8-0.95 for most industrial loads). 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 and phase voltage?
A: In 3-phase systems, line voltage is between any two lines, while phase voltage is between any line and neutral. For star connections, line voltage = √3 × phase voltage.

Q2: What is a typical power factor value?
A: Power factor ranges from 0 to 1. Resistive loads have PF=1, inductive loads (motors) typically 0.8-0.9, and poor power factors are below 0.7.

Q3: Can I use this for single-phase calculations?
A: No, single-phase uses a different formula: I = P / (V × PF). This calculator is specifically for balanced three-phase systems.

Q4: 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.

Q5: How does power factor affect current?
A: Lower power factor means higher current for the same real power. Improving power factor reduces current and system losses.