1. What is 3 Phase Power Calculation?

The 3-phase power calculation determines the real power (in kilowatts) delivered to a 3-phase motor or load. It accounts for the phase relationship between voltage and current in a balanced 3-phase system.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

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

Explanation: The formula calculates real power by accounting for the phase difference between voltage and current in AC systems.

3. Importance of Power Factor

Details: Power factor represents the ratio of real power to apparent power. A higher PF (closer to 1) indicates more efficient power usage. Motors typically have PFs between 0.8-0.95 when fully loaded.

4. Using the Calculator

Tips: Enter line-to-line voltage in volts, current in amperes, and power factor (0 to 1). Typical power factor for motors is 0.85 if unknown.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between kW and kVA?
A: kW is real power (what does work), while kVA is apparent power (voltage × current). kW = kVA × PF.

Q2: Why use line-to-line voltage?
A: 3-phase power calculations typically use line-to-line voltage as it's the measurable voltage between any two phases.

Q3: What's a typical power factor for motors?
A: Induction motors typically have 0.85 PF at full load, dropping to about 0.2 at no load.

Q4: Does this work for single-phase systems?
A: No, for single-phase use: kW = (V × I × PF)/1000 (without the √3 factor).

Q5: How accurate is this calculation?
A: It's accurate for balanced 3-phase systems. Unbalanced loads require more complex calculations.