Or that I am thinking things through very logically. The confusion stemsThey ARE NOT in phase. The fact that you have to ask this question
indicates that you are in out of your depth. There is no blame for not
knowing, but there IS for dealing with things that you don't know about.
from page 23, of Wiring Simplified 39th edition based on NEC 1999 by Richter
and Schwan. It implies that supplies in USA are in single phase whereas I
would have expected a 180deg phase differential which has indeed been
confirmed by a few posters.
Also just to underline, when dealing with any such DIY projects I do get a
qualified electrician in to validate the work before switching on. As far
as I am aware I have not broken any Swiss regs.