In a 1000 KVA three-phase transformer with a secondary voltage of 206/120, what is the secondary full load amperage?

In a 1000 KVA three-phase transformer with a secondary voltage of 206/120, what is the secondary full load amperage?

• A. 12.5
• B. 8.33
• C. 15.8
• D. 10.0

Answer: (B)

To determine the secondary full load amperage of a three-phase transformer, you can use the formula for calculating the full load current (I) in a three-phase system. The formula is: \[ I = \frac{KVA \times 1000}{\sqrt{3} \times V} \] where KVA is the transformer capacity, and V is the secondary voltage line-to-line. In this case, the transformer has a capacity of 1000 KVA and a secondary voltage of 206 volts (line-to-line). Plugging these values into the formula, we perform the following calculation: 1. Convert KVA to watts: \( 1000 KVA = 1000 \times 1000 = 1,000,000 \, \text{watts} \). 2. Calculate the full load current: \[ I = \frac{1000 \times 1000}{\sqrt{3} \times 206} \] 3. The value of \(\sqrt{3}\) is approximately 1.732. Now substituting that value: \[ I = \frac{1,000,000}{1.732 \times 206} \] 4. Calculating the denominator

To determine the secondary full load amperage of a three-phase transformer, you can use the formula for calculating the full load current (I) in a three-phase system. The formula is:

[ I = \frac{KVA \times 1000}{\sqrt{3} \times V} ]

where KVA is the transformer capacity, and V is the secondary voltage line-to-line.

In this case, the transformer has a capacity of 1000 KVA and a secondary voltage of 206 volts (line-to-line). Plugging these values into the formula, we perform the following calculation:

1. Convert KVA to watts: ( 1000 KVA = 1000 \times 1000 = 1,000,000 , \text{watts} ).

2. Calculate the full load current:

[ I = \frac{1000 \times 1000}{\sqrt{3} \times 206} ]

3. The value of (\sqrt{3}) is approximately 1.732. Now substituting that value:

[ I = \frac{1,000,000}{1.732 \times 206} ]

4. Calculating the denominator