@ renosteinke:
Thanks for the answer. I have already seen those schemes with transformers tapped in the midst of one leg. So I have no problem with the details given for the small installation in this thread, assuming the 2 hot wires are at 180° of a single phase transformer (or single leg):
" 1 phase, 60 Hz., 230 volt, 2 hot wires plus a neutral and a ground wire
but I wondered how does one provide 460V, 230 V and 115 V at the same time out of one transformer in three phases:
3 phase, 230/460 volt, 60 Hz., 3 hot wires plus a neutral and a ground.
The timer, alarm and control system on all units are always 115 volts single phase powered.
As all voltages are linked here by factor 2 and not 1.73, what is three phase here? Or is a second transformer involved?
Thnaks for your patience.