1. What is Volt-Ampere (VA)?

Volt-Ampere (VA) is a unit of measurement for apparent power in an electrical circuit. It represents the product of the root-mean-square (RMS) voltage and RMS current in the circuit.

2. How Does the Calculator Work?

The calculator uses the basic power equation:

Where:

• \( V \) — Voltage in volts
• \( A \) — Current in amperes
• \( VA \) — Apparent power in volt-amperes

Explanation: This simple multiplication gives the apparent power in a circuit, which is important for sizing electrical equipment.

3. Importance of VA Calculation

Details: Calculating VA is essential for determining the power requirements of electrical devices, sizing circuit breakers, transformers, and uninterruptible power supplies (UPS).

4. Using the Calculator

Tips: Enter voltage in volts and current in amperes. Both values must be positive numbers. The calculator will compute the apparent power in VA.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between VA and Watts?
A: VA measures apparent power (voltage × current), while Watts measure real power. They're equal in purely resistive loads but differ in reactive loads.

Q2: Why is VA important for UPS sizing?
A: UPS systems are rated in VA because they must handle the total apparent power, not just the real power (Watts).

Q3: Can VA be less than Watts?
A: No, VA is always equal to or greater than Watts in any AC circuit (Watts = VA × power factor).

Q4: How does VA relate to three-phase power?
A: For three-phase systems, VA = √3 × V × A (line-to-line voltage × line current).

Q5: When should I use VA instead of Watts?
A: Use VA when sizing wiring, circuit breakers, transformers, and UPS systems. Use Watts for energy consumption calculations.