1. What is 3 Phase Current Calculation?

Definition: This calculator determines the current (in amps) in a 3-phase electrical system based on power, voltage, and power factor.

Purpose: It helps electricians, engineers, and technicians properly size electrical components and ensure safe system operation.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Current (amps)
• \( P_{kW} \) — Power (kilowatts)
• \( V \) — Voltage (volts)
• \( PF \) — Power factor (unitless, 0-1)

Explanation: The formula converts kW to watts (×1000), then divides by the product of voltage, power factor, and √3 (approximately 1.732) which accounts for the three-phase system.

3. Importance of 3-Phase Current Calculation

Details: Accurate current calculation is essential for proper wire sizing, circuit breaker selection, and preventing equipment damage or safety hazards.

4. Using the Calculator

Tips: Enter the power in kW, line-to-line voltage (default 480V), and power factor (default 0.85). All values must be > 0, with PF between 0.01 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing how effectively current is being converted into useful work (typically 0.8-0.95 for motors).

Q2: Why √3 in the formula?
A: The √3 accounts for the phase difference in three-phase systems when calculating line current from phase-to-phase voltage.

Q3: What voltage should I use?
A: Use the line-to-line (phase-to-phase) voltage, common values being 208V, 240V, 480V, or 600V depending on the system.

Q4: Can I use this for single-phase systems?
A: No, for single-phase use \( I = P_{kW} \times 1000 / (V \times PF) \) (without the √3 factor).

Q5: What if my power is in HP instead of kW?
A: First convert HP to kW (1 HP ≈ 0.746 kW) before using this calculator.