1. What is 3-Phase Current?

Three-phase current is the electrical current flowing in a three-phase power system, commonly used in industrial and commercial applications. It's more efficient than single-phase power for high-power applications.

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 (unitless, 0-1)
• \( \eta \) — Efficiency (unitless, 0-1)

Explanation: The formula accounts for the three-phase power system characteristics and includes power factor and efficiency corrections.

3. Importance of Current Calculation

Details: Accurate current calculation is essential for proper sizing of circuit breakers, wires, and other electrical components to ensure safe and efficient operation of three-phase equipment.

4. Using the Calculator

Tips: Enter power in watts, voltage in volts, power factor (typically 0.8-0.95 for motors), and efficiency (typically 0.85-0.95 for motors). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical power factor for motors?
A: Induction motors typically have power factors between 0.8 and 0.9 at full load, lower at partial loads.

Q2: How does voltage affect current?
A: Current is inversely proportional to voltage - higher voltage systems require less current for the same power.

Q3: Why include efficiency in the calculation?
A: Efficiency accounts for power losses in the motor, giving the actual input current needed to produce the rated output power.

Q4: 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 a line and neutral (line voltage = √3 × phase voltage in star configuration).

Q5: Can I use this for single-phase calculations?
A: No, single-phase current is calculated differently (I = P / (V × PF × η)).