1. What is Motor Input Power?

Motor input power (Pin) is the electrical power required by a motor to produce a certain mechanical output power (Pout). The relationship between input and output power depends on the motor's efficiency (η).

2. How Does the Calculator Work?

The calculator uses the motor power equation:

Where:

• \( P_{in} \) — Input power (watts)
• \( P_{out} \) — Output power (watts)
• \( \eta \) — Motor efficiency (0 to 1)

Explanation: The equation shows that input power equals output power divided by efficiency. Higher efficiency means less input power is needed for the same output.

3. Importance of Power Calculation

Details: Calculating input power is essential for proper motor selection, electrical system design, and energy consumption estimation.

4. Using the Calculator

Tips: Enter output power in watts and efficiency as a decimal between 0 and 1 (e.g., 0.85 for 85% efficiency). All values must be valid (Pout > 0, 0 < η ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What is typical motor efficiency?
A: Small motors may have 50-70% efficiency, while large industrial motors can reach 90-95% efficiency.

Q2: How does efficiency affect energy costs?
A: Higher efficiency motors use less input power for the same output, reducing electricity costs over time.

Q3: Can I use this for other power converters?
A: Yes, the same principle applies to any power conversion system where output = input × efficiency.

Q4: What if my efficiency is given as a percentage?
A: Divide the percentage by 100 to get the decimal value (e.g., 85% → 0.85).

Q5: Why is my calculated input power higher than output?
A: This is normal - input power is always greater than output power due to efficiency losses (heat, friction, etc.).