On Tue, Jul 19, 2016 at 12:53 PM, Mouse <mouse at rodents-montreal.org> wrote:
[...],
especially since most electrical installations (even domestic)
are 3-phase.
This, I believe, must be location-specific. In North America, it is
usual for domestic electrical feeds to be only two-phase (that is, they
are the two sides of a centre-tapped secondary - the two hot wires are
180 degrees out of phase with one another).
Right... and in my area (hardly unique, I'd wager), you cannot get
3-phase in residential areas. The shared transformers on the poles
don't provide it and you can't pay them to add/change a transformer.
You have to be in a commercial area to get that. Fortunately for me,
my tastes in minicomputers runs "small", so my largest machines have a
30A 110V single-phase plug (frequently to an H-861, but not always).
Code in my area allows for homeowners to do some of their own wiring,
but for projects larger than, essentially, outlet and toggle-switch
replacement, permits are required (but enforcement is, of course,
negligible unless something goes horribly wrong). They did just amend
code locally to _prohibit_ landlords from self-repair of electrical
(and I think gas and plumbing) in rental properties, because of
several high-profile fires caused by inexpert work. So you can work
on your own domicile, but not your tenants'.
-ethan