1. What is Electric Motor Horsepower?

Horsepower (HP) is a unit of power that measures the rate at which work is done. For electric motors, it represents the mechanical output power based on electrical input power, accounting for efficiency and power factor.

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, 0-1)
• \( \eta \) — Efficiency (decimal, 0-1)
• 746 — Conversion factor from watts to horsepower

Explanation: The equation converts electrical power (adjusted for power factor and efficiency) to mechanical horsepower.

3. Importance of Horsepower Calculation

Details: Calculating motor horsepower helps in selecting the right motor for an application, determining electrical requirements, and assessing performance.

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.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical power factor for electric motors?
A: Most AC induction motors have power factors between 0.80-0.95 when fully loaded. It decreases at lighter loads.

Q2: How does efficiency affect horsepower?
A: Efficiency accounts for energy losses (heat, friction). A motor with 90% efficiency converts 90% of electrical input to mechanical output.

Q3: Why divide by 746?
A: 746 watts equals 1 horsepower. The division converts 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. Efficiency is still needed.

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