1. What is 3-Phase Power Calculation?

The three-phase power calculation determines the real power (in watts) consumed by a three-phase electrical system. It accounts for the voltage, current, and power factor in a balanced three-phase system.

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 three-phase systems (≈1.732)

Explanation: The formula calculates the actual power being used (real power) as opposed to the apparent power (VA). The power factor accounts 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 (typically 208V, 230V, 400V, 480V, etc.)
• Enter current measured in one phase
• Power factor is typically between 0.8-0.95 for motors (default is 0.85)
• All values must be positive numbers

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (watts) is the actual power consumed, while apparent power (VA) is the product of voltage and current. The ratio is the power factor.

Q2: Why is the power factor important?
A: Lower power factor means more current is required to deliver the same real power, increasing losses and requiring larger conductors.

Q3: What's typical power factor for motors?
A: Induction motors typically have power factors between 0.8-0.9 at full load, lower at partial loads.

Q4: Is this formula for balanced 3-phase systems only?
A: Yes, this formula assumes all three phases are balanced (equal voltage, current, and phase angles).

Q5: How does this differ from single-phase power calculation?
A: Single-phase uses P = V × I × PF, without the √3 factor which accounts for phase relationships in 3-phase systems.