Answer to Question #275122 in Electrical Engineering for Queue

Question

A 20 kVA closet transformer located inside a building is used to step down the voltage for the building. It is connected to a primary 4800 V AC power source. The ratio of the number of primary windings to the number of secondary windings on the transformer is 20 to 1 and 40 to 1.

a. Approximate the secondary voltage provided.

b. Approximate the current available, in amps

Answer 1

a. Approximate the secondary voltage provided:

$$V_{21}=4800/20=240\text{ V},\\ V_{22}=4800/40=120\text{ V}.$$

b. Approximate the current available:

$$I_{21}=20000/240=83.3\text{ A},\\ I_{22}=20000/120=167\text{ A}.$$