1. What is Electric Motor Horsepower?

Horsepower (HP) is a unit of measurement for power, representing the rate at which work is done. For electric motors, it indicates the mechanical output power the motor can deliver.

2. How Does the Calculator Work?

The calculator uses the electric motor horsepower formula:

Where:

• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( PF \) — Power factor (unitless, 0 to 1)
• \( \eta \) — Efficiency (decimal, 0 to 1)
• 746 — Conversion factor from watts to horsepower

Explanation: The formula calculates the actual mechanical power output by accounting for electrical input power (V×I), power factor (PF), and motor efficiency (η).

3. Importance of Horsepower Calculation

Details: Accurate horsepower calculation is essential for proper motor selection, ensuring the motor can handle the required load without overheating or inefficiency.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, power factor (typically 0.8-0.95), and efficiency (typically 0.8-0.95 for most motors). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical power factor for electric motors?
A: Most AC induction motors have power factors between 0.80 and 0.95 at full load. Smaller motors tend to have lower power factors.

Q2: How does efficiency affect horsepower?
A: Efficiency accounts for energy lost as heat. A motor with 90% efficiency converts 90% of electrical input to mechanical output.

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

Q4: Can I use this for DC motors?
A: Yes, but set PF=1 since DC motors don't have power factor considerations.

Q5: What's the difference between input and output horsepower?
A: Input HP is electrical power (V×I/746), while output HP is mechanical power after accounting for PF and efficiency.