1. What is the Electric Motor Horsepower Formula?

Definition: This calculator computes the horsepower of an electric motor based on voltage, current, efficiency, and power factor.

Purpose: It helps electrical engineers, technicians, and hobbyists determine motor power output from electrical characteristics.

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 product of voltage and current gives apparent power, which is then adjusted by efficiency and power factor to get real mechanical power.

3. Importance of Horsepower Calculation

Details: Accurate HP calculation ensures proper motor sizing, efficient energy use, and prevents overloading electrical systems.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, efficiency (default 0.85), and power factor (default 0.9). Efficiency and PF must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: Why divide by 746?
A: 746 watts equals 1 horsepower, so we convert electrical watts to mechanical horsepower.

Q2: What's a typical motor efficiency?
A: Standard motors range from 0.8-0.95, with premium motors reaching 0.95+ efficiency.

Q3: How do I find the power factor?
A: Check motor specifications or use a power meter. Most motors range from 0.85-0.95 PF.

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

Q5: Why is the result sometimes lower than nameplate HP?
A: Nameplate shows maximum capability; actual HP depends on operating conditions and load.