1. What is 3-Phase Power Calculation?

The 3-phase power calculation converts kilowatts to amperes for balanced three-phase systems. This is essential for electrical system design, circuit protection, and equipment selection in industrial and commercial applications.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

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

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

3. Importance of 3-Phase Current Calculation

Details: Accurate current calculation is crucial for proper wire sizing, circuit breaker selection, motor protection, and ensuring electrical system safety and efficiency.

4. Using the Calculator

Tips: Enter power in kW, 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 < 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 √3 times line-to-neutral voltage. This calculator uses line-to-line voltage.

Q2: What is a typical power factor value?
A: Induction motors typically have 0.8-0.9 PF, resistive loads have 1.0 PF, and fluorescent lighting has 0.5-0.9 PF.

Q3: Can I use this for single-phase systems?
A: No, for single-phase use I = (kW × 1000)/(V × PF) instead (without the √3 factor).

Q4: Why does power factor affect current?
A: Lower power factor means more current is needed to deliver the same real power due to reactive power components.

Q5: How accurate is this calculation?
A: It's accurate for balanced three-phase systems. For unbalanced loads, each phase must be calculated separately.