1. What is a Motor Horsepower Calculator?

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

Purpose: It helps engineers, electricians, and technicians evaluate motor performance and select appropriate motors for applications.

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)
• 746 — Conversion factor (watts to HP)

Explanation: The formula converts electrical power (adjusted for efficiency and power factor) to mechanical horsepower.

3. Importance of Horsepower Calculation

Details: Accurate horsepower calculation ensures proper motor sizing, prevents overload conditions, and optimizes energy efficiency.

4. Using the Calculator

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

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 0.8-0.95 for industrial motors.

Q2: What is power factor?
A: Power factor (PF) is the ratio of real power to apparent power, usually 0.8-0.95 for AC motors at full load.

Q3: Why divide by 746?
A: 746 watts equals 1 horsepower, so this converts electrical watts to mechanical horsepower.

Q4: Can I use this for three-phase motors?
A: For three-phase, multiply the result by √3 (≈1.732) to account for phase relationships.

Q5: How do I find motor efficiency?
A: Check motor nameplate or manufacturer specifications; typical values are 85-95% for efficient motors.