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 efficiency formula:

Where:

• \( \eta \) — Efficiency in percentage (%)
• \( P_{out} \) — Mechanical output power in watts (W)
• \( P_{in} \) — Electrical input power in watts (W)

Explanation: The formula calculates what percentage of input electrical energy is converted to useful mechanical work.

3. Importance of Efficiency Calculation

Details: Motor efficiency is crucial for energy conservation, cost savings, and environmental impact. Higher efficiency motors reduce energy waste and operating costs.

4. Using the Calculator

Tips: Enter both output and input power in watts. Output power must be less than or equal to input power. Typical motor efficiencies range from 70% to 96%.

5. Frequently Asked Questions (FAQ)

Q1: What is a good efficiency for an electric motor?
A: Premium efficiency motors typically have η ≥ 90%. Small motors may be 70-85% efficient, while large industrial motors can reach 95-96%.

Q2: Why can't efficiency be 100%?
A: Due to inherent energy losses like heat from resistance, friction, and magnetic losses in the motor components.

Q3: How can I improve motor efficiency?
A: Use properly sized motors, maintain them well, ensure good power quality, and consider high-efficiency motor designs.

Q4: Does efficiency change with load?
A: Yes, motors are typically most efficient at 75-100% of rated load. Efficiency drops significantly below 50% load.

Q5: What's the difference between nominal and actual efficiency?
A: Nominal is manufacturer's tested value under specific conditions. Actual efficiency depends on operating conditions and load.