AC Motor Horsepower Calculator

Three-Phase AC Motor Horsepower Formula:

\[ HP = \frac{V \times I \times \sqrt{3} \times PF \times Eff}{746} \]

Voltage (V):

volts

Current (I):

amps

Power Factor (PF):

unitless

Efficiency (Eff):

decimal

Output Horsepower (HP):

Unit Converter ▲

Unit Converter ▼

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1. What Is AC Motor Horsepower Calculation?

AC Motor Horsepower Calculation determines the mechanical power output of a three-phase AC motor based on electrical input parameters. It converts electrical power to mechanical horsepower, accounting for motor efficiency and power factor.

2. How Does The Calculator Work?

The calculator uses the three-phase AC motor horsepower formula:

\[ HP = \frac{V \times I \times \sqrt{3} \times PF \times Eff}{746} \]

Where:

\( V \) — Voltage in volts
\( I \) — Current in amps
\( \sqrt{3} \) — Three-phase power factor (approximately 1.732)
\( PF \) — Power factor (unitless, 0 to 1)
\( Eff \) — Motor efficiency (decimal, 0 to 1)
\( 746 \) — Conversion factor from watts to horsepower

Explanation: This formula calculates the actual mechanical power output by considering both the electrical input power and the motor's efficiency in converting electrical energy to mechanical work.

3. Importance Of Horsepower Calculation

Details: Accurate horsepower calculation is essential for motor selection, sizing mechanical loads, energy efficiency analysis, and ensuring proper motor operation within its design specifications.

4. Using The Calculator

Tips: Enter voltage in volts, current in amps, power factor as a decimal (e.g., 0.85 for 85%), and efficiency as a decimal (e.g., 0.92 for 92%). All values must be positive and within valid ranges.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor and why is it important?
A: Power factor represents the ratio of real power to apparent power. Low power factor indicates poor electrical efficiency and may require power factor correction.

Q2: How does motor efficiency affect horsepower output?
A: Higher efficiency means more electrical power is converted to mechanical work. Typical motor efficiencies range from 85% to 95% for modern motors.

Q3: What are typical power factor values for AC motors?
A: Power factor typically ranges from 0.8 to 0.95 for AC induction motors under full load, decreasing at lighter loads.

Q4: Can this calculator be used for single-phase motors?
A: No, this calculator is specifically for three-phase motors. Single-phase motors use a different calculation formula.

Q5: Why is the √3 factor used in three-phase calculations?
A: The √3 factor accounts for the phase relationship in three-phase power systems, where power is the sum of power in all three phases.