Motor Efficiency Formula Calculator

Motor Efficiency Formula:

\[ \eta = \left( \frac{\text{Output Power}}{\text{Input Power}} \right) \times 100 \]

Motor Efficiency (η):

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1. What is Motor Efficiency?

Motor efficiency (η) is the ratio of mechanical power output to electrical power input, expressed as a percentage. It measures how effectively a motor converts electrical energy into mechanical energy.

2. How Does the Calculator Work?

The calculator uses the motor efficiency formula:

\[ \eta = \left( \frac{\text{Output Power}}{\text{Input Power}} \right) \times 100 \]

Where:

\( \eta \) — Motor efficiency (%)
Output Power — Mechanical power output (W)
Input Power — Electrical power input (W)

Explanation: The formula compares the useful power output to the total power consumed, with 100% representing perfect efficiency (unattainable in practice).

3. Importance of Efficiency Calculation

Details: Calculating motor efficiency helps in energy conservation, cost analysis, performance evaluation, and identifying maintenance needs.

4. Using the Calculator

Tips: Enter both output and input power in watts. Values must be positive numbers. For best results, measure power under typical operating conditions.

5. Frequently Asked Questions (FAQ)

Q1: What is a good efficiency for electric motors?
A: Standard motors typically range from 70-96% efficiency, with premium efficiency motors reaching up to 97%.

Q2: Why can't efficiency be 100%?
A: Energy is lost to heat, friction, windage, and other factors due to fundamental physics laws.

Q3: How does load affect motor efficiency?
A: Motors are most efficient at 75-100% of rated load. Efficiency drops significantly below 50% load.

Q4: What improves motor efficiency?
A: Proper sizing, high-quality materials, precision manufacturing, and regular maintenance.

Q5: How is output power measured?
A: Typically calculated from torque and speed: Output Power = Torque × Angular Velocity.