Ring mains

the usual ill considered arguments

Reply to
NT
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Do you know the year of that booklet?

NT

Reply to
NT

Why would a manufacturer want a system which is *more* economical on cable than the previous one?

Reply to
Dave Plowman (News)

Committee members do not have to declare their commercial interests :-)

A downside with ring final circuits is where a house is multiple occupancy renters. It can be better to have 32A ring/radial for kitchen, then 16/20A radials for each room. Likewise for disabled re any important equipment.

The 32A ring final is much maligned, but does have many benefits.

- We have plug top fuses, but unfortunately lost arguably better round pins

- It can serve a larger area, offers two paths to balance loads although I suspect many unbalanced, two routes for CPC re lower EFLI (& hence larger area served), more conductor CSA (5mm) than a 32A radial (4mm) would afford, length not restricted re EFLI (4mm has oddly 1.5mm CPC, ring has twin 1.5mm CPC).

The cost benefit was in fuseboard ways incidentally, not just ease of new build installation. It made it cheaper for builders, put simply.

Reply to
js.b1

Only by foreigners who don't know what the f**k they're talking about. Not by anyone using it for the purposes intended.

Reply to
Dave Plowman (News)

That might have been the government's theory but my parents' typical

1950's spec built 3 bedroom semi had 5 sockets on the ring - and 3 of those were on a couple of spurs.
Reply to
Mike Clarke

Part of this?

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Reply to
ARWadsworth

Because dennis was in charge of the sales department.

Reply to
ARWadsworth

r topology. =A0You could have as many sockets as you like on a single line = of 30A cable. =A0Yes I know it would cost a bit more, but if something gets= disconnected, you have no connection, instead of half a connection.

It would probably cost about the same due to UK housing layout.

The 30A star hub could go under the hall floor (upstairs), with a run to each room and drop to rooms below. Unfortunately it would require a newly developed junction box using L-N-E bus-bars to handle 8-9x 4mm sized cables. It would be useful for central inspection and testing, but buried under a floorboard it could well end up forgotten and screws can work loose.

Such "star spiders" are sometimes used for complex lighting circuits, built up using modern enclosures and DIN rail terminals. Easy central inspection and testing, neutral at every light switch etc.

Reply to
js.b1

1957 according to:

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I would have thought earlier, BS1363 plugs date from 1947 AIUI.

Owain

Reply to
Owain

But the link in the footnote to the Wiki page

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no longer takes one to that paper and I cannot now find them (or the minutes of the meeting) on the IET site or elsewhere. Can you or others work some magic to make them appear again pl?

Reply to
Robin
8<

Every connection in a ring is safety critical. There wouldn't be any point in making them a ring if the joints weren't safety critical. Why bother testing them if they work properly and safely with faulty joints?

Why do rings need rules to prevent users putting large loads at one end of the ring if they are more tolerant of large loads

Protects it from what? Sure they will blow if you short the circuit but they don't stop the thing from passing over current for long periods.

The problem with rings is they appear to work fine even when there are bad connections. The bad connections can exist for years without a user noticing. Then they are less safe than a radial because the conductor is sized smaller than the fuse. Of course if you used a 20A breaker, as 2.5 mm radials do. the rings would be somewhat safer as in a connection fault condition they revert to being a

2.5 mm radial. Unlike present rings that become a 2.5 mm radials with a 30A fuse, which is not allowed as its unsafe.

Being as rings are seldom tested and as you say faults are a fairly common occurrence I don't see how you can claim they are safe.

Reply to
dennis

If you want to wire up your house with a rats' nest of radials fed from a 100-way consumer unit, go ahead, there's nothing stopping you, and the IEEE regs even tell you how to do it safely. Me, I'll stick to feeding a single cable from the CU around the house and back to the same CU outlet.

JGH

Reply to
jgharston

Do you know what a modern radial is?

Reply to
dennis

Well, that was a way around it at the time to fix existing installations, but 2.5mm T&E was changed to have a 1.5mm CPC, verses the original 1mm CPC.

Yes.

Reply to
Andrew Gabriel

Voilà:

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history paper (David Latimer) is far and away the most interesting (IMHO).

Reply to
Andy Wade

Yes; and I am reminded how much I enjoyed the author's style (including in the last paragraph (para. 12.1) where it seems to me he gently injects the thought that if imitation is the sincerest form of flattery then ......).

Reply to
Robin

My study has (mumble, mutter) 76 sockets in it.

Needless to say, not all of them have something plugged into them.

Reply to
Huge

That must cut-down on the wallpapering ...

Reply to
Andy Burns

talk to me about it when you understand the subject

NT

Reply to
NT

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