Often times it is necessary to convert impedance connected in a delta fashion to its equivalent wye/star values. The calculator provided below can be used to perform this conversion.

Referring to the figure above, Rd1, Rd2, Rd3 are the delta impedances while Ry1, Ry2, Ry3 are the Wye impedances.

The equations for delta wye conversions are provided below.

The equations for wye delta conversions are provided below.

If all the delta impedances are found to be the same (Z_d), the delta wye conversion simplifies as follows:

If all the wye impedances are found to be the same (Z_y), the wye delta conversion simplifies as follows:

The angles of the delta and equivalent wye impedances will remain the same.

Additional Reading:

Wye and Delta Connection Vector Diagram