On Tue, Jul 19, 2016 at 12:53 PM, Mouse <mo...@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
