1. What is a 3-Phase kW to Amps Calculator?

Definition: This calculator converts electrical power in kilowatts (kW) to current in amperes (A) for three-phase AC systems.

Purpose: It helps electricians, engineers, and technicians determine the current draw of three-phase electrical equipment.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Current in amperes (A)
• \( P_{kW} \) — Power in kilowatts (kW)
• \( V \) — Line-to-line voltage (V)
• \( PF \) — Power factor (0-1)
• \( \sqrt{3} \) — Constant for three-phase systems (≈1.732)

Explanation: The formula accounts for all three phases in the system and the power factor which represents the phase difference between voltage and current.

3. Typical Values

Common Voltages: 208V, 400V, 480V (industrial), 230V, 415V (commercial)

Power Factors: 0.8 (standard motors), 0.95 (high efficiency), 1.0 (resistive loads)

4. Using the Calculator

Tips: Enter the power in kW, line voltage (default 400V), and power factor (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is the power factor important?
A: It accounts for the phase difference between voltage and current in AC systems. Lower PF means higher current for the same power.

Q2: What's the difference between line and phase voltage?
A: In 3-phase systems, line voltage is between any two lines, while phase voltage is between any line and neutral (line voltage = phase voltage × √3).

Q3: How does this differ from single-phase calculation?
A: Single-phase uses I = P/(V×PF) without the √3 factor.

Q4: When would I use this calculation?
A: When sizing circuit breakers, cables, or transformers for three-phase equipment like motors, HVAC systems, or industrial machinery.

Q5: What if I know the current and want to find power?
A: Rearrange the formula: P = (I × V × PF × √3)/1000