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 for efficiency and power factor, then converted 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 voltage, current, 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: The ratio of mechanical power output to electrical power input, typically 80-95% for good motors.

Q2: What affects power factor?
A: Motor design, load conditions, and power quality. Most motors range from 0.8-0.95 PF.

Q3: Why divide by 746?
A: 1 horsepower equals 746 watts, converting electrical watts to mechanical HP.

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

Q5: How do I measure motor current?
A: Use a clamp meter on one power lead under normal operating load.