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

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

3. Importance of Horsepower Calculation

Details: Knowing a motor's horsepower is essential for proper motor selection, ensuring the motor can handle the required mechanical load without being oversized or undersized.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between input and output horsepower?
A: Input HP is the electrical power consumed, while output HP is the mechanical power delivered. This calculator determines output HP after accounting for efficiency losses.

Q2: Why is power factor important?
A: Power factor represents the phase difference between voltage and current in AC systems. A lower PF means more current is required for the same real power.

Q3: What are typical efficiency values?
A: Standard motors are about 85-90% efficient, while premium efficiency motors can reach 93-96%. Efficiency decreases with motor size and age.

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

Q5: How does this relate to motor torque?
A: HP = (Torque × RPM)/5252. You can calculate torque if you know the motor's speed.