Download wye-delta and solid state starter application guide

Wye-Delta and Solid State Starter Application Guide
Figure 1. Simple System Line Diagram
Traditional
Design Theory
By definition, wye-delta is a traditional electro-mechanical method of reducing the voltage
applied to the motor during starting. While this method has significant advantages over
conventional full voltage starting, the disadvantage is that it requires more panel space, more
components, and most importantly a motor that has all its winding terminations available to the
outside so the wye connection can be created.
While the term “reduced voltage starter” is used for the wye-delta starting method, in actuality
the full line voltage is still being applied to the motor leads. The reduced voltage occurs simply
because of the electrical characteristic of the Wye vs. Delta relationship.
33