I was pondering how difficult it would be to retrofit & install a european 230V outlet (Schuko or UK plug) into a US kitchen so that high-powered/quick-brewing european tea kettles, coffee makers, etc, could be used. Would be trivial & straightforward to pull a dedicated circuit for new construction, but could be very difficult to pull in a new dedicated circuit in an existing home.
Question: I know it would work electrically, but would it be legal to place the two 20A GFCI kitchen circuits on a 20A 2-pole breaker, and tap both hots on the line sides of the GFCIs to power a 230V euro outlet? If the romex are run together from the panel (no reason they wouldn't be), would that be considered to be run in the same raceway? 210.52(B)(3) does not seem to prohibit this, either.
