1. What is Motor Horsepower Calculation?

Definition: This calculator determines the mechanical horsepower output of an electric motor based on its electrical input parameters.

Purpose: It helps engineers, technicians, and maintenance personnel evaluate motor performance and sizing requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Horsepower output
• \( V \) — Voltage input (volts)
• \( I \) — Current draw (amps)
• \( \eta \) — Motor efficiency (0-1)
• \( PF \) — Power factor (0-1)

Explanation: The electrical power (V×I) is adjusted by efficiency and power factor to get mechanical power, then converted to horsepower (1 HP = 746 watts).

3. Importance of Horsepower Calculation

Details: Proper horsepower determination ensures motors are correctly sized for their loads, preventing underperformance or energy waste.

4. Using the Calculator

Tips: Enter the motor's voltage, current draw, efficiency (default 0.85), and power factor (default 0.9). Efficiency and power factor must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is motor efficiency?
A: Efficiency (η) is the ratio of mechanical power output to electrical power input, typically 0.7-0.95 for electric motors.

Q2: What is power factor?
A: Power factor (PF) is the ratio of real power to apparent power, representing phase difference between voltage and current (typically 0.8-0.95).

Q3: Why divide by 746?
A: 746 watts equals 1 mechanical horsepower, the conversion factor between electrical and mechanical power units.

Q4: Can I use this for three-phase motors?
A: For three-phase, multiply voltage by √3 (1.732) first, or use our Three-Phase Motor HP Calculator.

Q5: Where do I find motor efficiency?
A: Check motor nameplate or manufacturer specifications. Older motors typically have lower efficiency (0.7-0.85).