1. What is a 3 Phase AC Current Calculator?

Definition: This calculator computes the electrical current in a three-phase alternating current system based on power, voltage, and power factor.

Purpose: It helps electricians, engineers, and technicians determine the current flow in three-phase power systems for proper equipment sizing and safety.

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, between 0 and 1)

Explanation: The power in kilowatts is converted to watts (×1000), then divided by the product of voltage, power factor, and the square root of 3 (approximately 1.732).

3. Importance of Current Calculation

Details: Accurate current calculation ensures proper wire sizing, circuit breaker selection, and prevents equipment damage from overcurrent conditions.

4. Using the Calculator

Tips: Enter the power in kW, system 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.

Q2: Why is √3 used in the formula?
A: The square root of 3 (≈1.732) accounts for the phase difference in three-phase systems.

Q3: What's a typical power factor value?
A: Industrial loads typically range from 0.75 to 0.95. The default 0.85 is common for motors.

Q4: Can I use this for single-phase systems?
A: No, use the formula I = P × 1000 / (V × PF) for single-phase systems (without the √3 factor).

Q5: How do I find the power factor?
A: Use a power meter or check equipment specifications. Many motors list PF on their nameplate.