1. What is a 3 Phase HP to Amps Calculator?

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

Purpose: It helps electricians and engineers properly size electrical components like wires, breakers, and starters for motor applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Current in amps
• \( HP \) — Horsepower rating
• \( V \) — Line voltage (volts)
• \( PF \) — Power factor (0-1)
• 746 — Conversion factor (watts per HP)
• √3 — Constant for 3-phase systems (≈1.732)

Explanation: The formula converts mechanical power (HP) to electrical power (watts), then calculates current based on voltage and power factor.

3. Importance of Accurate Current Calculation

Details: Proper current calculation prevents equipment damage, ensures safety, and helps meet electrical code requirements.

4. Using the Calculator

Tips: Enter the motor HP rating, system voltage (default 480V), and power factor (default 0.85). All values must be > 0.

5. Frequently Asked Questions (FAQ)

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

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, use a different formula (I = (HP × 746)/(V × PF) for single-phase.

Q4: Should I use nameplate or actual voltage?
A: Use the actual measured voltage at the motor terminals for most accuracy.

Q5: How does efficiency affect the calculation?
A: This formula assumes 100% efficiency. For precise results, divide by efficiency (η) if known.