How to Calculate Horsepower of Motor

Horsepower Formula for 3-Phase Induction Motor:

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

Voltage (V):

volts

Current (I):

amps

Efficiency (Eff):

decimal

Power Factor (PF):

unitless

Horsepower (HP):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Horsepower Calculation?

Horsepower calculation for 3-phase induction motors determines the mechanical power output based on electrical input parameters. It helps in motor selection, performance evaluation, and energy efficiency analysis.

2. How Does the Calculator Work?

The calculator uses the horsepower formula for 3-phase induction motors:

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

Where:

\( V \) — Voltage in volts
\( I \) — Current in amps
\( Eff \) — Efficiency as decimal (e.g., 0.85 for 85%)
\( PF \) — Power Factor (unitless)
\( \sqrt{3} \) — Constant for 3-phase systems
\( 746 \) — Conversion factor (watts to horsepower)

Explanation: This formula calculates the actual mechanical power output by considering electrical input power and motor efficiency.

3. Importance of Horsepower Calculation

Details: Accurate horsepower calculation is essential for proper motor sizing, energy consumption analysis, system design, and ensuring optimal performance in industrial applications.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, efficiency as decimal (0-1), and power factor (0-1). All values must be positive and within valid ranges.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between input and output horsepower?
A: Input horsepower refers to electrical power input, while output horsepower is the actual mechanical power delivered by the motor shaft.

Q2: Why is power factor important in horsepower calculation?
A: Power factor accounts for the phase difference between voltage and current, affecting the actual power delivered to the motor.

Q3: What are typical efficiency values for motors?
A: Standard efficiency motors range from 85-90%, while high-efficiency motors can achieve 92-96% efficiency.

Q4: Can this formula be used for single-phase motors?
A: No, this formula is specifically for 3-phase motors. Single-phase motors use a different calculation method.

Q5: What is the significance of the √3 factor?
A: The √3 factor accounts for the three-phase power calculation in balanced three-phase systems.