> On 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).
Yes, and time dependent as well. I grew up in Holland; in the 1970s, we had 3 phase in our house because we had an electric cooking range. But ours was the only house in the block with 3 phase service; all our neighbors cooked with gas. In the USA, if you're a home owner with a need for 3 phase power, you probably have to get a phase converter. Fortunately those are not hard to get, and solid state ones (variable frequency motor controllers) can be rather inexpensive. I have one for the 3-phase motor on the lathe in the barn. $100 for a 3 hp model, as I recall, though that may have been on sale. VFCs should even work for 3 phase 400 Hz power, just the thing if you have a CDC Cyber tucked away in the basement. paul