1. What is Transformer Rating?

Transformer rating in kVA (kilovolt-amperes) represents the maximum apparent power that a transformer can deliver continuously without exceeding its temperature limits.

2. How Does the Calculator Work?

The calculator uses the transformer rating formula:

Where:

• \( V \) — Voltage in volts
• \( I \) — Current in amps
• 1000 — Conversion factor to kVA

Explanation: The formula calculates apparent power by multiplying voltage and current, then converts to kVA by dividing by 1000.

3. Importance of Transformer Rating

Details: Proper transformer sizing is crucial for electrical system design, ensuring safe operation and preventing overheating or premature failure.

4. Using the Calculator

Tips: Enter voltage in volts and current in amps. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between kVA and kW?
A: kVA measures apparent power (voltage × current), while kW measures real power. They differ by power factor (kW = kVA × power factor).

Q2: Why use kVA instead of kW for transformers?
A: Transformers must be sized based on apparent power (kVA) because their capacity is limited by current and voltage, not just real power.

Q3: How does three-phase calculation differ?
A: For three-phase: kVA = (V × I × √3)/1000. This calculator is for single-phase systems.

Q4: What are typical transformer ratings?
A: Common ratings range from small 0.5 kVA transformers to utility-scale units of 1000+ kVA.

Q5: How much overload can transformers handle?
A: Most can handle 10-20% overload for short periods, but continuous operation should be at or below rated kVA.