In comp.sys.ibm.pc.hardware.misc Scott Dorsey wrote:
Arfa Daily wrote:

I'd love to have 3 phase, I've never seen it in a residence though, and
residential equipment is all single phase anyway, it works.

I kinda like above ground power, at least for the big stuff. Most of the
houses around here from the late 70s on have underground power, but some
of the old lines are starting to deteriorate so they've had to dig up
streets and flower beds to replace them.


Isn't the 'high' voltage that you have in the US for powering washing
machines and the like, phase to phase ? Seems like it wouldn't be that hard
for the power company to put in the third phase as well ? (I might be
totally adrift on this one - I'm not a power engineer ;-) )

In the US, the high voltage distribution is done with three phases, shifted
120' from one another. You can also in many places order low voltage lines
with three-phase power, but it's not common in residential areas.

In most residential areas, they will send one leg of that three
phase 3KV out to a distribution transformer near your house. The
secondary of that transformer has a center-tap tied to the neutral,
and then two hot wires that are 180' out of phase. So neutral to
one leg is 120V, but leg to leg is 240V.

That would be 210V leg-to leg, because of the phase shift.

But this does not help you if you want to run a 25-foot turret lathe
in your garage, which requires three phases with a 120' shift
between them. For that, you either have to move to an industrial
neighborhood, or call the power company to pull three-phase 3KV in
and then drop it down to a low voltage with your own set of
transformers. They will charge for this.

Hmm. The typical approch in Europe is 15kV to large transformers
and then 3 phase distribution to the houses. Above ground is for
is moslty for rural areas, you do not see above ground lines in
cities, at least not in Germany or Switzerland. So getting three
phase is trivial. Typically flats have 3-phase times 16A (at 240V)
for electric stoves. Getting 3x25A at 240V is just some in-house
wiring. If you want 3x40A, you may need to have your feed checked,
since it is typically rated at 3x63A or 3x100A for larger houses.

Arno