1. What is Motor Power Calculation?

The motor power calculation determines the actual power consumption of a three-phase electric motor in kilowatts (kW). It accounts for voltage, current, and power factor to estimate the real power being used.

2. How Does the Calculator Work?

The calculator uses the three-phase power formula:

Where:

• \( P \) — Power in kilowatts (kW)
• \( V \) — Line-to-line voltage (volts)
• \( I \) — Current (amps)
• \( PF \) — Power factor (unitless, 0-1)

Explanation: The √3 factor accounts for the phase difference in three-phase systems. The power factor represents the ratio of real power to apparent power.

3. Importance of Motor Power Calculation

Details: Accurate power calculation helps in sizing motors correctly, determining energy consumption, calculating efficiency, and proper electrical system design.

4. Using the Calculator

Tips: Enter line-to-line voltage in volts, current in amps, and power factor (typically 0.8-0.95 for motors). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical power factor for motors?
A: Induction motors typically have power factors between 0.8-0.9 at full load, dropping at lighter loads.

Q2: Is this formula for single-phase or three-phase?
A: This is for three-phase motors. For single-phase, use P = V × I × PF / 1000 (without the √3 factor).

Q3: Why divide by 1000?
A: The division converts watts to kilowatts (1 kW = 1000 watts).

Q4: Should I use line or phase voltage?
A: Use line-to-line voltage (the voltage between any two phases in a three-phase system).

Q5: How accurate is this calculation?
A: It provides a good estimate but actual power may vary due to motor efficiency, voltage fluctuations, and measurement accuracy.