1. What is the 3-Phase Power Formula?

The 3-phase power formula calculates current (amperes) from power (kilowatts), voltage, and power factor. It's essential for electrical system design and load calculations in three-phase AC systems.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

• \( I \) — Current in amperes (A)
• \( 30 \) — 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 converts 30kW to watts (30,000W), then divides by the product of voltage, power factor, and √3 to get current.

3. Importance of Power Factor

Details: Power factor represents the ratio of real power to apparent power. Lower PF means more current is required to deliver the same real power, increasing system losses.

4. Using the Calculator

Tips: Enter line-to-line voltage (typically 400V, 480V, or 208V in different regions) and power factor (typically 0.8-0.95 for industrial loads). All values must be valid (voltage > 0, 0 < PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: Why multiply by 1000 in the formula?
A: We multiply by 1000 to convert kilowatts (30kW) to watts (30,000W) since voltage is in volts and we want current in amperes.

Q2: 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 the line-to-neutral voltage. This formula uses line-to-line voltage.

Q3: What are typical power factor values?
A: Resistive loads have PF=1, motors typically 0.8-0.9, and heavily inductive loads can be 0.5 or lower.

Q4: How does voltage affect the current?
A: Current is inversely proportional to voltage - higher voltage means lower current for the same power.

Q5: Can I use this for single-phase calculations?
A: No, for single-phase use I = P/(V×PF) without the √3 factor.