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

The 3-phase motor power formula calculates the real power consumed by a three-phase AC motor, accounting for voltage, current, power factor, and motor efficiency. It's essential for sizing hydraulic systems and electrical components.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

• \( P \) — Power (kW)
• \( V \) — Line voltage (Volts)
• \( I \) — Line current (Amps)
• \( PF \) — Power factor (0-1)
• \( \eta \) — Motor efficiency (0-1)

Explanation: The √3 factor accounts for the phase difference in three-phase systems. The formula converts apparent power to real power by considering power factor and efficiency.

3. Importance of Motor Power Calculation

Details: Accurate power calculation is crucial for proper motor selection, circuit protection sizing, energy efficiency analysis, and hydraulic system design.

4. Using the Calculator

Tips:

• Measure line-to-line voltage for 3-phase systems
• Use current measurements from all three phases if possible
• Typical power factor for motors: 0.8-0.95
• Motor efficiency typically ranges 0.85-0.95

5. Frequently Asked Questions (FAQ)

Q1: Why divide by 1000 in the formula?
A: The division converts watts to kilowatts (kW) for more practical power unit in industrial applications.

Q2: What's the difference between real and apparent power?
A: Real power (kW) does actual work, while apparent power (kVA) includes reactive power. The power factor is their ratio.

Q3: How does motor load affect power calculation?
A: Underloaded motors operate at lower power factor and efficiency. Always calculate at expected operating load.

Q4: Can I use this for single-phase motors?
A: No, single-phase motors use P = V × I × PF × η without the √3 factor.

Q5: How accurate are typical power factor values?
A: For precise calculations, measure actual power factor with a meter, especially for variable speed drives.