What is the maximum line current a 500 KVA 480-volt three-phase delta secondary transformer can deliver without exceeding its rating?

To determine the maximum line current that a 500 KVA, 480-volt three-phase delta secondary transformer can deliver, we need to use the formula for calculating current in a three-phase system. The formula to find the current (I) for a three-phase transformer is:

[

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

]

Where:

• ( P ) is the power in watts (in this case, 500 KVA, which is equal to 500,000 VA),

• ( V ) is the line-to-line voltage (480 volts),

• ( \sqrt{3} ) is approximately 1.732, representing the conversion in a three-phase system.

Substituting the values into the formula:

[

I = \frac{500,000}{\sqrt{3} \times 480}

]

Calculating it step by step:

1. Calculate ( \sqrt{3} \times 480 ):

[

\sqrt{3} \approx 1.732 \quad \text{thus,} \quad 1.732 \times 480 \approx 829.44

]

2. Now, divide