HP to Amps 3 Phase Formula

3 Phase Current Formula:

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

Current (I): amps

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1. What is HP to Amps 3 Phase Calculator?

Definition: This calculator converts horsepower (HP) to electrical current (amps) for three-phase systems.

Purpose: It helps electricians and engineers determine the current draw of three-phase motors based on their horsepower rating.

2. How Does the Calculator Work?

The calculator uses the formula:

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

Where:

\( I \) — Current in amps
\( HP \) — Horsepower rating
\( V \) — Line voltage (volts)
\( PF \) — Power factor (0-1)

Explanation: The formula converts mechanical power (HP) to electrical power (watts) using the 746 watts/HP conversion factor, then calculates current based on three-phase power equation.

3. Importance of Current Calculation

Details: Proper current calculation ensures correct wire sizing, circuit breaker selection, and prevents electrical system overloads.

4. Using the Calculator

Tips: Enter the motor horsepower, system voltage (default 480V), and power factor (default 0.85). All values must be > 0, with PF between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: Why 746 in the formula?
A: 746 watts equals 1 horsepower, converting mechanical power to electrical power.

Q2: What's a typical power factor?
A: Most motors have PF between 0.8-0.95. 0.85 is a common default value.

Q3: Does this work for single-phase systems?
A: No, this is specifically for three-phase. Single-phase has a different formula.

Q4: What voltage should I use?
A: Use the line-to-line voltage of your three-phase system (common values: 208V, 240V, 480V).

Q5: Does this include efficiency?
A: No, this is theoretical current. For actual current, divide result by motor efficiency.