On Tue 30 Jul 2019 at 14:30:50 (+0200), Matthew Crews wrote: > On 7/29/19 12:57 PM, David Wright wrote: > > On Mon 29 Jul 2019 at 20:43:04 (+0100), Joe wrote: > >> On Mon, 29 Jul 2019 10:26:14 -0500 John Hasler <jhas...@newsguy.com> wrote: > >> > >>> They don't have to be on the same branch circuit: just on the same > >>> "phase"[1]. There is probably a gadget available that bridges the > >>> signal between phases. > >>> > >>> [1] They aren't really phases but everyone calls them that. > >> > >> They are in my country. 3-phase, 240V RMS each phase to neutral, 415V > >> RMS between phases. > > > > Irrelevant in a domestic setting: it's illegal to have more than one > > phase in an ordinary house. Houses will have one phase each, so you'll > > share your phase with various neighbours scattered along the street. > > How do you figure?
As I pointed out elsewhere, "my country" is the UK where domestiv voltages are twice those in the US. There are people who run small workshops where they have managed to install 3 phase supplies. If you read up their accounts, most of them are operating very much at the edge of legality with respect to building regs, planning laws (US zoning) and running businesses in domestic premises. I never got the impression that enforcement in this area was thorough. In large residential blocks, you get 3 phase supplied to the block, but they're typically split so that individual floors in a block of flats will all be on one phase. But you're bound to get exceptions: for example, our house was temporarily (over a year) connected to supplies from two different streets so running a vacuum cleaner across the bridge could be mixing phases. However, that was at US voltages, not UK ones. > In the US most 240V outlets are 3 phase, and they are > relatively common. You need them for most ovens, washing machines, and > electric cars. I'm not sure where you get that impression, but I suspect it's from counting pins on the appliance plugs. But look at the plate on the back of the appliance or the installation leaflet and you'll see they're 240v and they just take both 110v hot lines from both sides of the breaker box. That's two pins; the third is neutral and the fourth is earth. Obsolete 3-pin appliances have earth and neutral combined on a single pin. For cars, that makes them charge at level 2 (level 1 is through a normal 110v outlet, so slow). As for washing machines, in my experience, most here are hot and cold fill, whereas the UK has gazillions of cold fill. I would hate to pay for heating up a top-loading cold fill washing machine with electricity. That's not to say there are no 3-phase supplies in the US, but I've never come across them. As they're still 110v, you wouldn't see any difference as a visitor, of course. But you have a problem with 240v items like those above, because the voltage between any two hot lines is only just over 200v. As I say, I've not knowingly encountered it; perhaps the woman in Austin TX has. People who've spent all their lives here might know more. Cheers, David.
