1. What is 3-Phase kVA Calculation?

Definition: This calculator determines the apparent power (kVA) in a three-phase electrical system based on voltage and current.

Purpose: It helps electrical engineers, technicians, and electricians properly size electrical equipment and assess power requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( kVA \) — Apparent power (kilovolt-amperes)
• \( V \) — Line-to-line voltage (volts)
• \( I \) — Line current (amps)
• \( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

Explanation: The formula accounts for the phase relationship in three-phase systems, where power is √3 times higher than in single-phase at the same voltage and current.

3. Importance of kVA Calculation

Details: Proper kVA calculation ensures correct sizing of transformers, generators, circuit breakers, and other electrical components to handle the load safely and efficiently.

4. Using the Calculator

Tips: Enter the line-to-line voltage in volts and line current in amps. Both values must be > 0. The calculator automatically applies the √3 factor for three-phase systems.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between kVA and kW?
A: kVA is apparent power (volts × amps), while kW is real power. They differ by the power factor (kW = kVA × PF).

Q2: Why √3 in the formula?
A: In 3-phase systems, the voltage between phases is √3 times the voltage from phase to neutral, hence the multiplier.

Q3: Is this for line-to-line or line-to-neutral voltage?
A: The formula uses line-to-line voltage (typically 208V, 400V, 480V in industrial systems).

Q4: How does this differ from single-phase calculation?
A: Single-phase uses V×I/1000 without the √3 factor.

Q5: When would I need this calculation?
A: When sizing transformers, generators, UPS systems, or determining circuit loads in 3-phase installations.