1. What is Transformer Full Load Current?

Transformer Full Load Current (FLC) is the maximum current that a transformer can supply at its rated voltage without exceeding its temperature rise limits. It's a critical parameter for proper transformer sizing and protection.

2. How Does the Calculator Work?

The calculator uses the FLC formula:

Where:

• \( kVA \) — Transformer rating in kilovolt-amps
• \( V \) — Voltage in volts

Explanation: The formula converts kVA to VA (by multiplying by 1000) and divides by voltage to calculate the full load current in amperes.

3. Importance of FLC Calculation

Details: Accurate FLC calculation is essential for proper circuit breaker sizing, cable selection, overload protection, and ensuring the transformer operates within its designed capacity.

4. Using the Calculator

Tips: Enter transformer kVA rating and operating voltage. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between kVA and kW?
A: kVA represents apparent power (including reactive power), while kW represents real power. For resistive loads, they are equal, but for inductive or capacitive loads, kVA is larger than kW.

Q2: Why multiply kVA by 1000 in the formula?
A: kVA is in thousands of volt-amps, so multiplying by 1000 converts it to volt-amps for current calculation.

Q3: Does this formula work for both single-phase and three-phase transformers?
A: This basic formula works for single-phase transformers. For three-phase transformers, additional factors (like √3) need to be considered.

Q4: What safety margin should be added to FLC?
A: Typically, a 25% safety margin is added for circuit protection devices to account for inrush currents and temporary overloads.

Q5: How does transformer efficiency affect FLC?
A: The FLC formula gives the output current. Input current will be slightly higher due to transformer losses and efficiency factors.