1. What is Three Phase Motor Power Calculation?

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

Purpose: It helps electrical engineers and technicians determine the actual power consumption of three-phase motors.

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 to 1)
• \( \sqrt{3} \) — Constant for three-phase systems

Explanation: The formula accounts for all three phases in the system and converts the result to kilowatts.

3. Importance of Motor Power Calculation

Details: Accurate power calculation ensures proper motor sizing, energy efficiency assessment, and electrical system design.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

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

Q2: What's a typical power factor for motors?
A: Induction motors typically have power factors between 0.8 and 0.9 when fully loaded.

Q3: Should I use line or phase voltage?
A: Use line-to-line voltage (typically what you'd measure between any two phases).

Q4: How does this differ from single-phase calculation?
A: Single-phase uses P = V×I×PF, without the √3 factor needed for three-phase systems.

Q5: Can I calculate current if I know power?
A: Yes, rearrange the formula: \( I = \frac{P_{kW} \times 1000}{V \times PF \times \sqrt{3}} \)