1. What is 3 Phase AC Motor Power Calculation?

Definition: This calculator computes the real power (in kilowatts) consumed by a three-phase AC motor based on voltage, current, and power factor.

Purpose: It helps electrical engineers, technicians, and maintenance personnel determine motor power consumption for energy management and system design.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Real power (kilowatts)
• \( V \) — Line-to-line voltage (volts)
• \( I \) — Line current (amps)
• \( PF \) — Power factor (unitless, 0-1)
• \( \sqrt{3} \) — Constant for three-phase systems

Explanation: The formula calculates the actual power being used (real power) as opposed to the apparent power (VA) in a three-phase system.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for proper motor sizing, energy efficiency analysis, electrical system design, and cost estimation.

4. Using the Calculator

Tips: Enter the line-to-line voltage in volts, line current in amps, and power factor (default 0.85). Power factor must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor and why is it important?
A: Power factor is the ratio of real power to apparent power. It indicates how effectively electrical power is being used (1 = most efficient).

Q2: What's a typical power factor for AC motors?
A: Most AC motors operate between 0.8-0.9 PF when fully loaded, but this drops significantly at partial loads.

Q3: Should I use line-to-line or line-to-neutral voltage?
A: Always use line-to-line (phase-to-phase) voltage for this calculation.

Q4: How does this differ from single-phase power calculation?
A: Single-phase uses P=VI×PF, while three-phase adds the √3 factor to account for phase relationships.

Q5: Can I calculate horsepower from this result?
A: Yes, 1 HP ≈ 0.746 kW, so divide kW result by 0.746 to get horsepower.