On Tue, 27 Oct 2009 15:38:12 -0400, Existential Angst wrote:
Seems so. Although it is more hassle to set up, and I'm never quite
convinced of the loading benefits given that the ring could fail yet still
appear to work; at least with a radial system if a connection goes bad
it's pretty obvious that it's done so.

(http://en.wikipedia.org/wiki/Ring_circuit for the curious)

That was VERY inneresting!!!
Am I correct in observing that the diagram shows two "radial" connections to
the ring?

Yes, such spur connections seem reasonably common for things like attics,
garages, and where rooms are later added on to buildings - and in that
respect they're not really much different to US wiring layouts, I suppose
(apart from they feed back to the ring, not always back to the service
panel).

It took me a while to grok the "point" of the schematic, and when I did,
it left me with a very big Q:

How does a ring circuit SAVE copper? ?

As Bud says, you have multiple loads on the ring, and the ring's quite
large, so from any given outlet the run length of the two routes back to
the consumer unit (service panel) is never quite equal.

The article pointed out some potent disadvantages, as well -- somewhat
dicey, eh?

Certainly can be. Hazards with any system, I suppose.

Aside: I can never quite decide whether I prefer UK-style outlets/plugs or
US ones. Remember that all plugs for UK appliances have their own fuse,
rather than relying on tripping a breaker back in the service panel, and
all outlets there have a live/neutral/earth connection - as a result the
plugs are quite large (although not as chunky as US 240V plugs,
thankfully), but the built-in fuse is nice to have.

OTOH I like how compact US plugs are - particularly on things like wall
warts where the pins fold away for storage.

OTOH (again) US plugs can be knocked such that they expose the pins, which
seems like a major safety hazard...

Interestingly, NYC still has DC running to some older commercial
buildings!

Yeah, so I've heard. I really like big old DC stuff - shame just about all
of it's gone to the junkyard these days. It appeals to the mad scientist
in me ;-)

But, I thought Europe was all 220, ie, two hot legs, residentially??

Yeah, I think it's all technically 230V these days actually - the UK
lowered theirs slightly (as did others) whilst some other countries on
220V upped theirs a little. It's just too ingrained in my mind such that
I'll always call the UK system 240V...

I'm curious how much 120V is used outside of the US, actually - I'm not
sure what other places in the world are using.

g-dAmerica never quite gets it right, unless it comes to fleecing their
public. Who needs a junta or a dictatorship when you have a Congress
blowing Wall Street, using the Media as a condom??

:-) I think the US system just evolved slowly over time, and with such a
high population it's hard to put the brakes on and simply change over to
something else; the European picture was a bit different because it was
all such a mess after WWII that there was a far more opportunity to start
over with different systems and standards. Not that they always got it
right, of course!

(I still find black wires as being 'hot' kind of weird in the US -
after doing a lot of electronics work over the years it was
surprising to me when I found that the wire that makes you go ouch is
the black one, not the white one ;-)

Altho amazingly our vitamins are a lot more available, fwiu. Whazzup
wit dat, over there???

No comment, really. Never been one to buy vitamins - although I've heard
that medicine's generally a lot cheaper over there (or free, given the
NHS) than it is in the US.

cheers!

Jules