1. What is 3-Phase Current Calculation?

The 3-phase current calculation determines the current flowing in each phase of a balanced three-phase AC system. It's essential for proper sizing of circuit breakers, wires, and other electrical components in motor applications.

2. How Does the Calculator Work?

The calculator uses the 3-phase current formula:

Where:

• \( I \) — Phase current (Amps)
• \( P \) — Power (Watts)
• \( V \) — Line voltage (Volts)
• \( PF \) — Power factor (unitless, 0-1)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula accounts for the balanced three-phase power distribution and the phase difference between voltage and current (power factor).

3. Importance of Current Calculation

Details: Accurate current calculation is crucial for electrical system design, ensuring proper wire sizing, circuit protection, and preventing equipment damage from overload.

4. Using the Calculator

Tips: Enter power in watts, line-to-line voltage in volts, and power factor (typically 0.8-0.95 for motors). All values must be positive (power > 0, voltage > 0, 0 < power factor ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What is power factor in motors?
A: Power factor represents the ratio of real power to apparent power, affected by motor inductance. Typical values range from 0.8 for small motors to 0.95 for large, efficient motors.

Q2: Is this calculation for line or phase current?
A: This calculates the current in each phase (phase current) for a balanced 3-phase system.

Q3: What voltage should I use?
A: Use the line-to-line (phase-to-phase) voltage, not the phase-to-neutral voltage.

Q4: Does this work for both delta and wye connections?
A: Yes, as long as you use the correct line-to-line voltage and the system is balanced.

Q5: How accurate is this calculation?
A: It provides theoretical current under balanced conditions. Actual current may vary due to efficiency losses, voltage fluctuations, and load variations.