1. What is a Motor Horsepower Calculator?

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

Purpose: It helps electrical engineers, technicians, and maintenance professionals determine motor power output for proper equipment sizing and selection.

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 output.

3. Importance of Motor HP Calculation

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

4. Using the Calculator

Tips: Enter the voltage in volts, current in amps, 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: Why divide by 746 in the formula?
A: 746 watts equals 1 horsepower, so this converts electrical power (watts) to mechanical power (HP).

Q2: What's a typical motor efficiency value?
A: Standard motors range from 0.85-0.95 efficiency, with premium motors reaching 0.96.

Q3: How do I find the power factor?
A: Check motor specifications or use a power meter. Most induction motors have 0.8-0.9 PF at full load.

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: What if my motor is overloaded?
A: The calculator shows theoretical output. Actual output may be lower if the motor exceeds its rated current.