1. What is Apparent Power (VA)?

Apparent power (VA) is the product of the RMS voltage and RMS current in an AC circuit. It represents the total power in the circuit, combining both real power (watts) and reactive power (VAR).

2. How Does the Calculator Work?

The calculator uses these equations:

Where:

• \( VA \) — Apparent power in volt-amperes
• \( V \) — Voltage in volts
• \( I \) — Current in amperes
• \( W \) — Real power in watts
• \( PF \) — Power factor (unitless, 0 to 1)

Explanation: First calculates voltage from watts, current and power factor, then calculates apparent power from voltage and current.

3. Importance of VA Calculation

Details: VA is important for sizing electrical equipment like transformers, UPS systems, and wiring, as it represents the total current-carrying capacity required.

4. Using the Calculator

Tips: Enter watts in W, current in A, and power factor (0 to 1). All values must be valid (watts > 0, amps > 0, 0 < PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between watts and VA?
A: Watts represent real power that does work, while VA represents total power (real + reactive). They're equal only when power factor is 1.

Q2: Why is power factor important?
A: Power factor indicates efficiency of power usage. Lower PF means more current is needed for the same real power.

Q3: What's a typical power factor value?
A: For computers: 0.6-0.7, for motors: 0.8-0.9, for resistive loads: 1.0.

Q4: When should I use VA instead of watts?
A: Use VA for sizing electrical infrastructure (wires, breakers, transformers), and watts for actual energy consumption.

Q5: Can VA be less than watts?
A: No, VA is always equal to or greater than watts (when PF ≤ 1).