1. What is 3-Phase Motor Power Calculation?

Definition: This calculator estimates the power consumption of a 3-phase electric motor based on voltage, current, efficiency, and power factor.

Purpose: It helps electrical engineers and technicians determine the actual power requirements of 3-phase motors.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_w \) — Power in watts
• \( V \) — Line voltage (volts)
• \( I \) — Line current (amps)
• \( \eta \) — Motor efficiency (0-1)
• \( PF \) — Power factor (0-1)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula accounts for all electrical characteristics of a 3-phase motor to calculate real power consumption.

3. Importance of Motor Power Calculation

Details: Accurate power calculation ensures proper sizing of electrical components, energy efficiency analysis, and cost estimation.

4. Using the Calculator

Tips: Enter line voltage, line current, motor efficiency (default 0.9), and power factor (default 0.85). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why do we multiply by √3?
A: The √3 factor accounts for the phase difference in 3-phase systems, converting line-to-line measurements to phase values.

Q2: What's a typical power factor for motors?
A: Induction motors typically have power factors between 0.8-0.9 at full load, lower at partial loads.

Q3: How do I find motor efficiency?
A: Check motor nameplate or manufacturer specifications. Standard efficiency motors are typically 85-95% efficient.

Q4: Does this calculate real or apparent power?
A: This calculates real power (watts). For apparent power (VA), omit the power factor term.

Q5: Can I use this for single-phase motors?
A: No, for single-phase use P = V × I × PF (omit the √3 factor).