A 1500 KVA three-phase transformer has a secondary voltage of 480/277. What is its secondary full load amperage?

To calculate the secondary full load amperage of a three-phase transformer, you can use the following formula:

[ I = \frac{P}{\sqrt{3} \times V}

]

Where:

• ( I ) is the full load amperage,
• ( P ) is the power in kilovolt-amperes (KVA),
• ( V ) is the voltage in volts.

Given that the transformer has a power rating of 1500 KVA and a secondary voltage of 480 volts (line-to-line voltage for a three-phase system), you would substitute these values into the formula.

First, calculate the full load amperage using the 480 V:

1. Convert KVA to VA: [ P = 1500 \times 1000 = 1,500,000 \text{ VA} ]

2. Apply the values in the formula: [ I = \frac{1,500,000}{\sqrt{3} \times 480} ]

3. Calculate ( \sqrt{3} ) which is approximately 1.732. [ I = \frac{1,