1. What is 3-Phase Current Calculation?

The 3-phase current calculation determines the current flowing in a three-phase electrical system given the power, voltage, and power factor. It's 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 (unitless, between 0 and 1)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula accounts for the phase relationship in 3-phase systems and the power factor which represents the phase difference between voltage and current.

3. Importance of Current Calculation

Details: Accurate current calculation is crucial for selecting proper wire sizes, circuit breakers, and other electrical components to ensure safety and prevent overheating or equipment damage.

4. Using the Calculator

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

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. The calculator uses line-to-line voltage.

Q2: What is power factor and why does it matter?
A: Power factor represents the phase difference between voltage and current. Lower PF means more current is needed for the same power, increasing system losses.

Q3: How does this differ from single-phase current calculation?
A: Single-phase uses I = P/(V×PF) without the √3 factor. 3-phase is more efficient for the same power transfer.

Q4: What's a typical power factor value?
A: Motors typically have PF of 0.8-0.9. Resistive loads have PF=1. Capacitive or inductive loads have lower PF.

Q5: Can I use this for DC systems?
A: No, DC systems use simply I = P/V as there's no phase angle or √3 factor involved.