Electric Motor Horsepower Calculator

Horsepower Formula:

\[ HP = \frac{V \times I \times PF \times \eta}{746} \]

Voltage (V):

volts

Current (I):

amps

Power Factor (PF):

(0-1)

Efficiency (η):

(0-1)

Horsepower (HP):

Unit Converter ▲

Unit Converter ▼

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1. What is Electric Motor Horsepower?

Horsepower (HP) is a unit of measurement for power that quantifies the rate at which work is done. For electric motors, it represents the mechanical output power based on electrical input parameters.

2. How Does the Calculator Work?

The calculator uses the electric motor horsepower formula:

\[ HP = \frac{V \times I \times PF \times \eta}{746} \]

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 accounts for both the electrical power input (V × I) and the motor's performance characteristics (PF and η) to determine mechanical power output.

3. Importance of Horsepower Calculation

Details: Calculating motor horsepower is essential for proper motor sizing, energy efficiency analysis, and mechanical system design. It helps ensure the motor can handle the required load without being oversized.

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 0.85-0.95 for most motors). 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 produced. 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 for electric motors?
A: Standard efficiency motors range from 85-93%, while premium efficiency motors can reach 94-97%. Efficiency decreases as motors age.

Q4: Can this be used for both AC and DC motors?
A: Yes, but for DC motors, set PF = 1 since there's no reactive power component.

Q5: How does this relate to motor torque?
A: HP = (Torque × RPM)/5252. This calculator provides HP which can be converted to torque if RPM is known.