1. What is an Electric Motor Horsepower Calculator?

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

Purpose: It helps engineers, technicians, and electricians determine motor performance and verify specifications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Horsepower output
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( \eta \) — Motor efficiency (0-1)
• \( PF \) — Power factor (0-1)
• 746 — Conversion factor (watts to HP)

Explanation: The electrical power (V×I) is adjusted by efficiency and power factor to get actual mechanical power output, then converted to horsepower.

3. Importance of Horsepower Calculation

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

4. Using the Calculator

Tips: Enter the motor voltage, current draw, efficiency (default 0.9), and power factor (default 0.85). 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 0.8-0.95 for good 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 0.8-1.0).

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

Q4: Can I use this for three-phase motors?
A: This formula works for single-phase. For three-phase, multiply by √3 (1.732) for line-to-line voltage.

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