Three-Phase Transformer Connections:

Then far, our discussion has dealt along with the operation of single-phase transformers.  The Three-phase transformer operation is identical except in which three single-phase windings are used. These windings might be linked in wye, delta, or any combination of the two.

Delta Connection

Within the delta connection, all three phases are linked in series to form a closed loop display in the figure.

Figure: Delta Connection

Wye Connection

Within the wye connection, three general ends of every phase are connected together at a general terminal (marked "N" for neutral), and the other three ends are connected to a three-phase line was show in the below figure.

Figure: Wye Connection