1. What is 3-Phase Amperage from kW Calculator?

Definition: This calculator determines the current (amperage) in a three-phase electrical system based on power in kilowatts, line voltage, and power factor.

Purpose: It helps electricians, engineers, and technicians properly size electrical components and verify system loads.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Current (amperes)
• \( P_{kW} \) — Power (kilowatts)
• \( V \) — Line-to-line voltage (volts)
• \( PF \) — Power factor (0 to 1)

Explanation: The kW value is converted to watts (×1000), then divided by the product of voltage, power factor, and √3 (1.732) for three-phase systems.

3. Importance of 3-Phase Current Calculation

Details: Accurate current calculation ensures proper wire sizing, circuit breaker selection, and prevents equipment overload in three-phase systems common in industrial and commercial applications.

4. Using the Calculator

Tips: Enter power in kW, line-to-line voltage (default 480V), and power factor (default 0.85). Power factor must be between 0.01 and 1.

5. Frequently Asked Questions (FAQ)

Q1: Why is √3 used in the formula?
A: √3 (1.732) accounts for the phase difference in three-phase systems when converting between line and phase quantities.

Q2: What's a typical power factor value?
A: Motors typically have 0.8-0.9 PF, while resistive loads have 1.0. The default 0.85 is common for mixed loads.

Q3: What voltage should I use?
A: Use line-to-line voltage: 208V, 240V, 480V, or 600V are common in North America; 380V, 400V, 415V in Europe.

Q4: Can I use this for single-phase systems?
A: No, use \( I = P_{kW} \times 1000 / (V \times PF) \) for single-phase (omit the √3 factor).

Q5: How does power factor affect current?
A: Lower power factor increases current for the same real power (kW). Improving PF reduces current and system losses.