Delta-Wye Conversions

These equations are used to transform a delta-connected set of resistances to a wye-connected (Y-connected) set of resistances.

Delta transformer winding drawing<===>Wye Y transformer winding drawing

Δ - Y  Conversion
R1 =

Rb·Rc
Ra + Rb + Rc

R2 =

Ra·Rc
Ra + Rb + Rc

R3 =

Ra·Rb
Ra + Rb + Rc

Y - Δ  Conversion
Ra =

R1·R2 + R2·R3 + R3·R1

R1

Rb =

R1·R2 + R2·R3 + R3·R1

R2

Rc =

R1·R2 + R2·R3 + R3·R1

R3