1. What is the 3 Phase Power Formula?

The 3-phase power formula calculates the real power (in watts) in a balanced three-phase system. It accounts for the line-to-line voltage, current, and power factor of the system.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

• \( P \) — Real power in watts (W)
• \( V \) — Line-to-line voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, between 0 and 1)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula calculates the actual power being used in the system, accounting for the phase difference between voltage and current.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for sizing electrical equipment, determining energy consumption, calculating efficiency, and ensuring proper circuit protection.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is line-to-line voltage?
A: It's the voltage measured between any two phase conductors in a 3-phase system, also called phase-to-phase voltage.

Q2: What is a typical power factor for motors?
A: Induction motors typically have power factors between 0.85 (small motors) to 0.95 (large motors) at full load.

Q3: How does power factor affect the calculation?
A: Lower power factor means more current is required to deliver the same real power, increasing losses in the system.

Q4: Is this formula for balanced systems only?
A: Yes, this simplified formula assumes a perfectly balanced 3-phase system. Unbalanced systems require more complex calculations.

Q5: What's the difference between real power and apparent power?
A: Real power (P) does actual work, while apparent power (S = V×I) includes reactive power. The ratio P/S is the power factor.