1. What is Motor Power Calculation?

The motor power calculation determines the input power required by a motor to deliver a specified amount of mechanical power (shaft power) at a given efficiency. It accounts for energy losses in the motor.

2. How Does the Calculator Work?

The calculator uses the motor power formula:

Where:

• \( Motor\ P \) — Input power to motor (watts)
• \( Shaft\ P \) — Mechanical power output at shaft (watts)
• \( Efficiency \) — Motor efficiency (decimal between 0 and 1)

Explanation: The formula accounts for energy losses in the motor by dividing the required output power by the motor's efficiency.

3. Importance of Motor Power Calculation

Details: Accurate motor power calculation is crucial for selecting properly sized motors, ensuring efficient operation, and preventing overloading or underutilization of equipment.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is typical motor efficiency?
A: Typical AC motor efficiency ranges from about 70% for small motors to over 95% for large, high-efficiency motors.

Q2: How does this relate to horsepower?
A: 1 horsepower ≈ 746 watts. You can convert the result to HP by dividing watts by 746.

Q3: Why is efficiency less than 1?
A: Motors lose energy through heat, friction, and other factors, so not all input power becomes mechanical output.

Q4: Should I add a safety factor?
A: For practical applications, it's common to add 10-20% to the calculated power to account for startup loads and variations.

Q5: Does this work for all motor types?
A: The basic principle applies to all motors, but specific motor types may have additional considerations for power calculation.