1. What is the 3-Phase Motor Power Formula?

The 3-phase motor power formula calculates the real power (in kilowatts) delivered to a 3-phase motor based on line-to-line voltage, current, and power factor. This is essential for determining motor performance and energy consumption.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

• \( V \) — Line-to-line voltage (volts)
• \( I \) — Current (amperes)
• \( PF \) — Power factor (unitless, 0 to 1)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula accounts for the phase relationship in 3-phase systems and converts the result to kilowatts by dividing by 1000.

3. Importance of Power Calculation

Details: Accurate power calculation is crucial for motor sizing, energy efficiency assessment, electrical system design, and determining operating costs.

4. Using the Calculator

Tips: Enter line-to-line voltage in volts, current in amperes, and power factor (typically 0.8-0.95 for motors). All values must be positive, with power factor between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor in motors?
A: Power factor represents the ratio of real power to apparent power, indicating how effectively current is being converted into useful work.

Q2: What's the difference between kW and kVA?
A: kW is real power (what does work), while kVA is apparent power (volts × amps). The ratio is the power factor (PF = kW/kVA).

Q3: Why is √3 used in 3-phase calculations?
A: It accounts for the 120° phase shift between the three phases in a balanced system.

Q4: What's a typical power factor for motors?
A: Induction motors typically have PF of 0.85 at full load, lower at partial loads. Synchronous motors can achieve unity (1.0) PF.

Q5: How does voltage affect motor power?
A: Power is directly proportional to voltage. A 10% voltage drop results in about 10% power reduction (assuming current stays constant).