Ignoramus27812 wrote:

What I was working on lately is a contactor system that switches my
three phase transformer (six secondaries, two paralleled on each
phase), from low voltage "parallel delta" at 65 VAC, to "series Wye"
at 240V.


I gave this a quick glance. What protection do you have if something
unplanned happens and one contactor switches and the other one does
not? Generally when I see a delta / wye changer it has both
contactors physically interlocked.

Wes S