1. What is the 3-Phase Current Formula?

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

Purpose: It helps electrical engineers, technicians, and electricians determine the current flow in three-phase power systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Current (amperes)
• \( P_{kW} \) — Power (kilowatts)
• \( V \) — Voltage (volts)
• \( PF \) — Power factor (unitless, between 0 and 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 configuration.

3. Importance of 3-Phase Current Calculation

Details: Accurate current calculation is essential for proper sizing of circuit breakers, wires, transformers, and other electrical components to ensure safety and efficiency.

4. Using the Calculator

Tips: Enter the power in kW, line voltage in volts, and power factor (default 0.8). Power factor must be between 0.01 and 1. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor and why is it important?
A: Power factor represents the ratio of real power to apparent power. It affects system efficiency and current calculations.

Q2: Is this formula for line or phase current?
A: This calculates line current in a balanced three-phase system.

Q3: What's a typical power factor value?
A: Industrial systems often have PF between 0.8-0.95. Motors might have lower PF (0.7-0.9) depending on load.

Q4: How does voltage affect the current?
A: Higher voltage results in lower current for the same power, which is why transmission systems use high voltages.

Q5: Can I use this for single-phase calculations?
A: No, for single-phase use \( I = \frac{P_{kW} \times 1000}{V \times PF} \) (without the √3 factor).