1. What is the Electric Motor Horsepower Formula?

The electric motor horsepower formula calculates the mechanical power output of an electric motor based on its electrical input characteristics. It accounts for voltage, current, power factor, and efficiency to determine the actual horsepower delivered to the load.

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 formula converts electrical power (adjusted for power factor and efficiency) to mechanical horsepower. One horsepower equals 746 watts.

3. Importance of Horsepower Calculation

Details: Accurate horsepower calculation is essential for motor selection, sizing mechanical loads, determining energy consumption, and ensuring proper system design.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, power factor (typically 0.8-0.95 for motors), and efficiency (usually 0.8-0.95 for good 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 0.80-0.95 when fully loaded. It decreases at lighter loads.

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 in the formula?
A: 746 watts equals 1 horsepower, so this converts the wattage calculation to horsepower units.

Q4: Can I use this for DC motors?
A: Yes, but set power factor to 1 (DC has no power factor) and use the actual efficiency of the DC motor.

Q5: What's the difference between input and output horsepower?
A: Input HP is electrical power divided by 746. Output HP (what this calculates) is input HP multiplied by efficiency.