Question

Three single$-$phase transformers, each rated at $12$ kVA, $120/240$ V$,60$ Hz $,$ are connected to form a three$-$phase, step$-$up$,\frac{Y}{}$ connection. The parameters of each transformer are $,,,,,$ and $.$ What are the nominal voltage, current, and power ratings of the three$-$phase transformer? When it delivers the rated load at the rated voltage and $0\mathrm{.}8$ pf lagging, determine the line voltages, the line currents, and the efficiency of the transformer.

RH $133\mathrm{.}5$ mOhm

XH $201$mOhm

RL $39\mathrm{.}5$ mOhm

XL $61\mathrm{.}5$mOhm

RcL$=240$ Ohm

Xml$=290$ Ohm