Re: "Repeaters", etc.
On Tue, May 28, 2024 at 06:37:35PM +0100, debian-user@howorth.org.uk wrote:
> Michael Grant <mgrant@grant.org> wrote:
> > On Tue, May 28, 2024 at 06:11:48PM +0100, debian-user@howorth.org.uk
> > wrote:
> > > Most houses in the UK are wired to a single phase, so everything is
> > > connected together at the consumer unit and powerline works just
> > > fine. If you have a specific problem, then there are DIN rail
> > > powerline units designed specifically to be mounted in the CU to
> > > spread the signal better over ALL the circuits.
> > >
> > > If your house has 3-phase wiring, which is unusual in the UK, then
> > > you may have a problem because powerline signals do need to be on
> > > the same phase.
> >
> > In the US, most houses are wired with 240V split-phase giving 120V to
> > a mains outlet. It's a 50/50 crapshot if you are on the same leg in a
> > different part of the house. I don't know if some electricians like
> > to put all the mains outlets on the same leg or not. I don't know if
> > these ethernet over power things will work over different legs. The
> > legs share a neutral and ground, so maybe! I'd be interested to know!
> >
> > Similarrly, over 3-phase, I would suspect the same is true, 3
> > different legs around the property with a common neutral and common
> > ground.
>
> Yes, I was talking specifically about the UK in response to Brad, who
> you elided. Powerline works between 'live' and 'neutral'. Earth is
> strictly a safety earth, not involved in any circuitry. The distribution
> of phases in a 3-phase installation varies quite a lot depending on the
> peculiarities of the particular site. The main concern is to make it
> impossible to easily mix phases (i.e. don't have sockets on one phase
> near sockets on another phase). I gather the rules are somewhat
> different in the US with split phase systems.
>
In the U.S. (as mentioned before), the voltage between "hots" is 240V, and
between "hot" and "neutral" on any phase is 120V. I'm not sure why our
systems were designed this way. But I do know that it is possible to have
circuits on both phases share a neutral. Thus, if the load on each phase is
the same, the neutral will carry no current. In any given room in a house,
it is entirely possible to have to receptacles which are on different
phases, and possibly sharing a neutral (though this isn't required).
Paul
--
Paul M. Foster
Personal Blog: http://noferblatz.com
Company Site: http://quillandmouse.com
Software Projects: https://gitlab.com/paulmfoster
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