20 Mar
2011
20 Mar
'11
1:43 a.m.
Jochen Kunz wrote:
In Germany, well, most if not all of Europe, the
entire power grid is
three phase. The power that gets distributed to a house is always three
phase 230 / 400 V in Y configuration. Single phase loads like ordinary
power outlets are wired from one phase to neutral. The single phase
circuits in a house (apartment, flat, ...) are spreed across all phases
to spreed load. Biger loads like electric stoves, water heaters, big
motors, ... are allways three phase. So we have three phase in every
household.
That seems far more sensible than the 120/240V "split-phase" wiring used
in residential and light business here in the US. I assume that we use
split-phase because putting a single-phase transformer on the power pole
is less expensive than a three-phase transformer. It's also stupid that
we use such a low voltage; it means that only a few outlets in a US
house are wired for 240V, generally just the stove/range, clothes dryer,
central water heater, and furnace. (Where available, people use natural
gas for those instead, as it costs less.) Electric kettles, room
heaters, etc. have to run on 120V at 15A or less, so they are very slow.
Eric