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Three Phase Transformer Amps Formula:
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The three phase transformer amps calculation determines the current (in amps) flowing through a three phase transformer based on its power rating in kilovolt-amps (kVA) and the system voltage. This is essential for proper electrical system design and transformer sizing.
The calculator uses the three phase transformer formula:
Where:
Explanation: The formula converts kVA to volt-amps (by multiplying by 1000), then divides by the product of voltage and the square root of 3 to account for the three phase power distribution.
Details: Accurate current calculation is crucial for selecting proper conductor sizes, circuit protection devices, and ensuring the transformer operates within its rated capacity without overheating or damage.
Tips: Enter the transformer kVA rating and system voltage in volts. Both values must be positive numbers greater than zero for accurate calculation.
Q1: Why is the square root of 3 used in three phase calculations?
A: The square root of 3 (approximately 1.732) accounts for the 120-degree phase difference between the three phases in a balanced three phase system.
Q2: What's the difference between line voltage and phase voltage?
A: Line voltage is the voltage between any two lines, while phase voltage is between any line and neutral. In three phase systems, line voltage equals phase voltage times √3.
Q3: Can this formula be used for single phase transformers?
A: No, for single phase transformers use: I = (kVA × 1000) / V (without the √3 factor).
Q4: What are typical kVA ratings for three phase transformers?
A: Three phase transformers commonly range from 15 kVA to over 10,000 kVA, depending on application requirements.
Q5: How does power factor affect this calculation?
A: This formula assumes unity power factor (1.0). For non-unity power factor, the actual current would be higher: I = (kVA × 1000) / (V × √3 × PF).