1. What is Electric Motor Horsepower?

Horsepower (HP) is a unit of power that measures the rate at which work is done. For electric motors, it indicates the mechanical output power the motor can deliver. The calculation considers voltage, current, and motor efficiency.

2. How Does the Calculator Work?

The calculator uses the electric motor horsepower formula:

Where:

• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( EFF \) — Motor efficiency (decimal, 0-1)
• 746 — Conversion factor from watts to horsepower

Explanation: The formula converts electrical power (volts × amps) to mechanical power (horsepower) by accounting for motor efficiency.

3. Importance of Horsepower Calculation

Details: Accurate horsepower calculation is essential for selecting the right motor for an application, ensuring proper performance, and preventing overload conditions.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, and efficiency as a decimal between 0 and 1 (e.g., 0.85 for 85% efficiency). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is efficiency important in the calculation?
A: Not all electrical energy converts to mechanical energy. Efficiency accounts for energy lost as heat, noise, and vibration.

Q2: What's the difference between input and output horsepower?
A: Input HP is electrical power (watts), output HP is mechanical power delivered. This calculator determines output HP.

Q3: What's a typical efficiency for electric motors?
A: Standard motors range from 70-96% efficiency, with higher efficiency in larger, premium motors.

Q4: Can I use this for three-phase motors?
A: Yes, but you'll need to include the power factor (PF) in the calculation: HP = (V × I × EFF × PF × √3)/746.

Q5: Why 746 watts per horsepower?
A: This is the conversion factor established by James Watt when comparing steam engine output to draft horses.