What is the current output of a 75 kVA, 480 V, three-phase transformer?

What is the current output of a 75 kVA, 480 V, three-phase transformer?

• A. 75 amps
• B. 90.37 amps
• C. 60 amps
• D. 100 amps

Answer: (B)

To determine the current output of a 75 kVA, 480 V, three-phase transformer, you start by using the formula for three-phase power, which is given by:

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

Here, ( P ) is the power in kVA, ( V ) is the voltage in volts, and ( I ) is the current in amps.

First, convert the kVA to VA:

75 kVA = 75,000 VA

Next, use the voltage in the formula. For a three-phase system with a voltage of 480 V, apply the formula:

[ I = \frac{75,000}{\sqrt{3} \times 480} ]

Calculating ( \sqrt{3} ), which is approximately 1.732:

[ I = \frac{75,000}{1.732 \times 480} ]

[ I = \frac{75,000}{829.44} ]

[ I \approx 90.37 \text{ amps} ]

Thus, the correct answer of 90.37 amps reflects the precise calculation for the current output of the transformer based on the