1. What is Transformer VA?

VA (Volt-Ampere) is a unit of apparent power in an electrical circuit. For transformers, VA rating represents the maximum power the transformer can deliver to the load.

2. How Does the Calculator Work?

The calculator uses the basic power formula:

Where:

• \( V \) — Voltage (volts)
• \( I \) — Current (amps)

Explanation: The VA rating is simply the product of the transformer's output voltage and maximum output current.

3. Importance of VA Calculation

Details: Knowing a transformer's VA rating is essential for proper sizing in electrical systems to ensure it can handle the load without overheating or failing.

4. Using the Calculator

Tips: Enter the transformer's output voltage in volts and maximum output current in amps. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between VA and watts?
A: VA is apparent power (volts × amps), while watts is real power. They're equal in purely resistive loads but differ in reactive loads.

Q2: Why is VA rating important for transformers?
A: It determines the maximum load the transformer can safely handle without overheating or voltage drop.

Q3: Can I exceed the VA rating temporarily?
A: Brief overloads may be possible, but sustained operation above VA rating can damage the transformer.

Q4: How does temperature affect VA rating?
A: Higher ambient temperatures typically require derating (using a transformer with higher VA than calculated).

Q5: What about three-phase transformers?
A: For three-phase, use \( VA = \sqrt{3} \times V_{line} \times I_{line} \).