Calculate Transformer Full Load Current

Full Load Current Formula:

\[ I_{full} = \frac{kVA \times 1000}{V} \]

Full Load Current:

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1. What is Full Load Current?

Full load current 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 transformer sizing and protection.

2. How Does the Calculator Work?

The calculator uses the full load current formula:

\[ I_{full} = \frac{kVA \times 1000}{V} \]

Where:

\( I_{full} \) — Full load current (amperes)
\( kVA \) — Transformer rating in kilovolt-amperes
\( V \) — Voltage (volts)

Explanation: The formula converts kVA to VA (by multiplying by 1000) then divides by voltage to get current.

3. Importance of Full Load Current Calculation

Details: Knowing the full load current is essential for proper conductor sizing, circuit breaker selection, and overload protection of transformers.

4. Using the Calculator

Tips: Enter transformer kVA rating and voltage in volts. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Is this formula for single-phase or three-phase transformers?
A: This is the basic formula for single-phase transformers. Three-phase calculations require additional factors.

Q2: What's the difference between kVA and kW?
A: kVA is apparent power (volts × amps), while kW is real power (volts × amps × power factor).

Q3: Why multiply kVA by 1000?
A: To convert kilovolt-amperes to volt-amperes (1 kVA = 1000 VA).

Q4: How does voltage affect full load current?
A: Current is inversely proportional to voltage - higher voltage means lower current for the same power.

Q5: What safety margin should I add?
A: Typically 25% margin is added for continuous loads per electrical codes.