1. What is 3-Phase Power Calculation?

The 3-phase power calculation determines the real power (in watts or kilowatts) consumed by a three-phase electrical system. It's essential for sizing motors, determining electrical loads, and ensuring proper system operation.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

• \( P \) — Power (W)
• \( V \) — Line-to-line voltage (V)
• \( I \) — Current (A)
• \( PF \) — Power factor (0-1)
• \( \sqrt{3} \) — 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 ratio of real power to apparent power.

3. Importance of Power Calculation

Details: Accurate power calculation is crucial for proper motor sizing, electrical system design, energy efficiency analysis, and preventing circuit overloads.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power (kW) to apparent power (kVA). It represents how effectively electrical power is converted to useful work.

Q2: What's the difference between line and phase voltage?
A: Line voltage is between any two phases, while phase voltage is between a phase and neutral. In balanced systems, line voltage = phase voltage × √3.

Q3: Why is √3 used in the formula?
A: The √3 factor accounts for the 120° phase difference between the three phases in a balanced system.

Q4: What's a typical power factor for motors?
A: Induction motors typically have PF of 0.8-0.9 at full load, lower at partial loads. Synchronous motors can achieve unity (1.0) PF.

Q5: How does this differ from single-phase power calculation?
A: Single-phase power is P = V × I × PF, without the √3 factor. Three-phase can deliver more power with less conductor material.