1. What is 3-Phase Power?

Three-phase power is a common method of alternating-current electric power generation, transmission, and distribution. It's more efficient than single-phase power for motors and heavy loads because the power transfer is constant.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

• \( P \) — 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 calculates real power in a balanced 3-phase system, accounting for the phase difference between voltage and current.

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, current, and power factor. Typical power factors for motors range from 0.8-0.95. All values must be positive (PF between 0-1).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line and phase voltage?
A: In 3-phase systems, line voltage is between any two lines, while phase voltage is between any line and neutral. For wye connections, line voltage = √3 × phase voltage.

Q2: How does power factor affect motor performance?
A: Lower PF means more current is needed for the same real power, increasing losses. Motors should operate near rated load for best PF.

Q3: Can I use this for single-phase calculations?
A: No, single-phase power is P = V × I × PF (without the √3 factor).

Q4: What's typical current for a 10HP motor?
A: At 480V and PF=0.85, about 10.6A (1HP ≈ 746W). Exact current depends on efficiency and load.

Q5: How can I improve power factor?
A: Use power factor correction capacitors, avoid motor underloading, and use high-efficiency motors.