1. What is 3-Phase Power Calculation?

The 3-phase power calculation is used to determine the real power (in watts) in a balanced three-phase electrical system. It's essential for sizing motors, determining electrical loads, and ensuring proper operation of industrial equipment.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

• \( P \) — Real power in watts
• \( V \) — Line-to-line voltage in volts
• \( I \) — Current in amps
• \( PF \) — 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 three-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 equipment overload.

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 positive (voltage > 0, current > 0, 0 < PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What is power factor and why is it important?
A: Power factor measures how effectively electrical power is converted to useful work. Low PF increases current for the same real power, causing energy losses.

Q2: Should I use line-to-line or line-to-neutral voltage?
A: Always use line-to-line (phase-to-phase) voltage for this calculation in standard 3-phase systems.

Q3: What's typical power factor for induction motors?
A: Typically 0.85 at full load, but varies with load. It's lower at partial loads and highest near full load.

Q4: How does this differ from single-phase power calculation?
A: Single-phase uses P = V × I × PF without the √3 factor. 3-phase is more efficient for the same power.

Q5: Can I calculate current if I know power?
A: Yes, rearrange the formula: \( I = \frac{P}{\sqrt{3} \times V \times PF} \)