HP Formula for Motor

Motor Horsepower Formula:

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

Voltage (V):

volts

Current (I):

amps

Efficiency (η):

Power Factor (PF):

Horsepower (HP):

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1. What is the Motor Horsepower Formula?

Definition: This calculator estimates the horsepower of an electric motor based on voltage, current, efficiency, and power factor.

Purpose: It helps engineers and technicians determine the power output of electric motors for various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

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

Where:

\( HP \) — Horsepower output
\( V \) — Voltage (volts)
\( I \) — Current (amps)
\( \eta \) — Motor efficiency (0-1)
\( PF \) — Power factor (0-1)

Explanation: The product of voltage and current gives apparent power, which is adjusted by efficiency and power factor to get real power, then converted to horsepower (1 HP = 746 watts).

3. Importance of Motor Horsepower Calculation

Details: Accurate horsepower calculation ensures proper motor sizing, energy efficiency, and system compatibility.

4. Using the Calculator

Tips: Enter the voltage in volts, current in amps, efficiency (default 0.85), and power factor (default 0.9). Efficiency and power factor must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: Why divide by 746?
A: 746 watts equals 1 horsepower, so we convert from watts to HP.

Q2: What's a typical motor efficiency?
A: Standard motors are typically 85-95% efficient (0.85-0.95).

Q3: What affects power factor?
A: Load conditions and motor design affect PF, typically 0.8-0.95 for motors.

Q4: Can I use this for three-phase motors?
A: For three-phase, you need to multiply by √3 (1.732) for line-to-line voltage.

Q5: How accurate is this calculation?
A: It provides theoretical HP; actual output may vary due to operating conditions.