1. What is Motor Horsepower Calculation?

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 personnel determine motor power output from electrical measurements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Horsepower output
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( \eta \) — Motor efficiency (0.85–0.95 typical)
• \( PF \) — Power factor (0.8–0.95 for AC, 1 for DC)

Explanation: The formula converts electrical power (adjusted for efficiency and power factor) to mechanical horsepower (1 HP = 746 watts).

3. Importance of Motor HP Calculation

Details: Proper horsepower estimation ensures motor sizing matches load requirements, prevents overload conditions, and optimizes energy efficiency.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, efficiency (default 0.9), and power factor (default 0.85). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical motor efficiency value?
A: Most electric motors have efficiencies between 85-95% (0.85-0.95). Higher for premium efficiency motors.

Q2: How does power factor affect the calculation?
A: Power factor accounts for phase difference in AC circuits. Lower PF means more current is needed for same power output.

Q3: Is this formula for AC or DC motors?
A: Works for both, but DC motors always have PF = 1 (no phase difference).

Q4: Why divide by 746?
A: 1 horsepower equals 746 watts - this converts electrical watts to mechanical HP.

Q5: Can I use this for three-phase motors?
A: Yes, but you'll need to multiply by √3 (1.732) for three-phase power calculations.