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a few comments (i was the one who destubed this article btw although i wasn't logged in at the time)
seems someone has done a style edit on this page and in doing so added at least one definate error and one possible error
firstly when i said british isles i meant british isles. maybe it is more correct to say united kinddom and republic of ireland but editing it to just united kindom was wrong
secondly while i haven't heard mention of the ring mains use outside of the brish isles that doesn't mean it is only used in the british isles i think i will need to rephrase that bit
Ring circles use more wiring material than radial circuit !
ISTR installing lighting rings with my father may years ago. Perhaps he's just a perfectionist? Rich Farmbrough 21:17, 11 Dec 2004 (UTC)
A LOT of laypeople in the uk refer to all cuircuits as "rings" and it is not unheared of to find a lighting cuircuit wired in a ring by a diyer but this is certainly not normal practice. Plugwash 21:53, 11 Dec 2004 (UTC)
You can only form a ring from the fuse to the switch. You have a branch from the switch to the lamp.
Or if the terminal is above the lamp: then the switch cable is a branch and also the cable in the lamp itself.
I have been a working electrician for a long time and only met a 3 phase ring circuit once - in a (very) poorly installed workshop. Modern 3 phase installations are invariably radial. (unsigned comment by Alastairrr)
mmm yes when i wrote the first section i didn't mean to imply the ring itself would be three phase just that it was part of a three phase electrical installation. I can see how it could be misread though and will try and make it clearer. Plugwash
I have certainly never heared of anyone using three phase rings though i have never seen it explicitly prohibited anywhere either. I can't think of many situations in which it would be usefull though (maybe if you wanted a LOT of 13A sockets with high total load it might be an idea but the 415V warning stickers everywhere would be a pita).Plugwash 01:55, 2 Apr 2005 (UTC)
I found a diagram of a ring circuit in an old British book ( J. W. Sims The Boy Electician, Eighth Edition - couldn't have that title today!) which explained very concisely what was meant by a "ring circuit". DOes anyone feel up to getting us a similar diagram for this article? It would save much explanation. --Wtshymanski15:51, 24 May 2005 (UTC)[reply]
good but you should actually show that there is some kind of junction box we don't wan't to encourage people joining cables in mid air with no enclosure ;) also needs to be shown a bit bigger than default thumb size to be clear imo
i've also made some tweaks to the imo rather washed out looking colors and re-done some of the green/yellow lines in a uniform patten (i got bored before i did them all). Plugwash23:53, 20 October 2005 (UTC)[reply]
The wiring colours used in the diagram are incorrect - the colours shown are those for the conductors in flexible cables connected via plugs TO the ring! The ring cable conductors are usually black, red and copper(bared ground/earth).
Here in the USA, electrical circuits like these are strictly verboten. ;) The wires run from the breaker, with all sockets in parallel, terminating at the end of each line. Sockets and switches usually have two sets of terminals to make extending a circuit easy. Heavy enough wire is specified so that in a typical house, there is no practical problem with the length of a circuit.
Wire with a 1.5mm cross sectional area, running 250 volts? That makes me want to run screaming into the night! Most audio speaker wire is heavier than that.
can't see the problem with it - the insulation is quite able to withstand the voltage, and the CSA is only relevant for the current carrying capacity (and possibly mechanical strength). It is permissible to use 1.0 mm² cable for lighting circuits which are fused at 5A - the current carrying capacity of the cable is about 13 A so there is plenty of margin there. Flexible cable of 0.5 mm² can be used for light duty appliances flexes. --Ali@gwc.org.uk11:09, 20 October 2005 (UTC)[reply]
Don't they have terrible problems with EMI ring circuits? After reading the article, I seems to me like regulation mandated ground loops from hell.
ring cuircuits are NOT mandated thier just more flexible in use than 20A radials and easier/cheaper to install than 32A radials. it doesn't seem to cause noticable interference problems in normal domestic and commercial installation though i belive its not generally reccomended to use them for studio installations for this reason.
btw we use 1.0mm cable in our lighting cuircuits still at 240V ofc Also let me assure you that pyro isn't exactly a weak cable type ;) Plugwash20:34, 20 October 2005 (UTC)[reply]
Ring circuits are a way of installing a circuit using a cable size smaller than an equivelent radial circuit could safely manage as the loadings on the cables are reduced by 50%. These are common in the UK, and a small number of other countries. American readers of this should remember that as the UK uses 240V supplies for single phase services, compared to their circuits, the loading on the cables is reduced by half for a given supply.
Three phase (400V) rings are common in the UK. Some heavy loading buildings, such as older schools, have 400V rings installed in undercrofts in order to supply the various buildings when they are not resticted to a single building. This installation is similar to the types of ring circuits that are installed by supply authorities in towns etc and forming part of the local supply network.
Interference on ring circuits is reduced, if there is any at all, for the same reason the loadings on each leg of the ring are reduced. Properly installed services (Ring or Radial)have little or not EMI as the Phase/Neutral conductors effectively cancel each others magnetic field, and in 400V rings, the Earthed Armouring of the sheath grounds the cable so that any EMI produced is very effectively removed from the cable.
Lastly, lighting circuits should never be installed as a ring inside a building. This is not normal practise and would be extremely dangerous to do so. However some street lighting is installed as a ring in towns, usually on a 400V ring specifically installed for this purpose, with alternating posts on each phase of the service. [SparksJim]: 05:35, 27 October 2005 (UTC)
what do you belive would be dangerous about installing lighting as a ring? just the fact that someone may not expect it and hurt themselves when working on the system or some issue that would actually affect the normal users of the system? Plugwash04:01, 20 November 2005 (UTC)[reply]
Support, I think if there isn't any disagreement by this point, it should be done now since there's been nearly 2 months to discuss this and no one has chimed in against it. I don't have much knowledge in this subject (and since neither is a stub) I don't quite know how to integrate the two, so have at it. Radagast8304:39, 12 November 2006 (UTC)[reply]
Disagree: The use of different forms of electrical installation is a practical, not a political issue. Naming the region of use the British Isles (a geographic , not political area) by the contributor was perfectly correct in this instance. Although the ring main system may be a British phenomenon, it is a recognised technology and should not be relegated to specific electrical installation practices in the UK or any other politically delimited territory..CCS 00:35, 14 December 2006 (UTC)
I disagree - I foound this article because I was looking for specific information on this type of circuit. Merging this article into a more general one would reduce its usefulness.
Disagree the reason you give is both flawed (in suggesting that this is not a generic concept) and only grounds for merging the UK centric details. UK electical wiring is a location specific page, whilst ring circuit is a generic electrical concept. Moreso, I am appauled by the apparent absence of a compainion article on radial curcuits. To propose this move is very much an aspect of systematic bias ('not used in the US so must not be real or important'). Where information specific to the UK is listed, it should be detailed within electrical wiring (UK), but there is still grounds to explain the international concept of a ring circuit (by LinaMishima, not logged in) 147.188.27.318:17, 13 January 2007 (UTC)[reply]
Disagree as per LinaMishima, and also the fact ring circuits are equally as common in Ireland. Also, I think there is a significant amount of information here for the concept to have its own article. --Zilog Jones02:01, 28 January 2007 (UTC)[reply]
Disagree Ring Circuits are a separate concept and probably best dealt with separately. I see no mention was made of the the other advantage of this topology, that of fault tolerance. MarcSinclair00:37, 27 February 2007 (UTC)[reply]
Disagree Ring mains are part of the Scottish Standard Grade Physics curriculum (similar to GCSE in England & Wales). Pupils do not find them intuitive. They deserve their own article. Incidentally, Hong Kong uses UK-style, 13A, 3-pin, 240 Vac, 50Hz sockets, so I suspect they use ring mains as well.StuFifeScotland11:28, 3 April 2007 (UTC)[reply]
Disagree Despite Wtshymanski's suggestion, neither of these articles is a stub. A ring main is a type of circuit and not specific to the UK, it is totally appropriate that it should have it's own article. Trewornan08:16, 28 April 2007 (UTC)[reply]
Disagree If this article is incorporated into the general entry it is likely to be edited down and lose its value. I agree with StuFifeScotland, ring main is a non-intuitive topic and it is not only students who will be looking for an explanation of this.
Disagree UK style ring mains are also found in the middle east, countries such as Qatar and Iraq, and can be found in Cyprus, Malta, Gibraltar, Singapore and other countires that use British Standard methods Refer to the wiki article on BS 1363 socket outlets. I agree with others who feel this topic is worthy of standing on its own. As an American who has worked with ring mains in other countries for years, I still found parts of this article illuminating and provided me with a better understanding of the point of it all and some downsides I hadn't previously considered.--Pgarrity (talk) 16:25, 15 January 2008 (UTC)[reply]
Disagree for various reasons already stated. Plus bear in mind there is a good deal more theory to the subject than is present in the article now, it will get bigger and more complex in time. Tabby (talk) 12:39, 4 March 2008 (UTC)[reply]
Considering the above arguments, the growth that this article has seen since I proposed a merger, and considering the substantial scope for additional discussion and references of this topic, I'm withdrawing my proposal for a merger.Markus Kuhn (talk) 18:03, 19 March 2008 (UTC)[reply]
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
I've removed a para about reduced resistive heating being an advantage, allowing the use of lower spec wire; whilst this may be an advantage if the ring is unbroken, it's a positive disadvantage if the ring is broken: designing too near the margin is actively unsafe in this case, and -- even worse -- the fault condition is undetectable in practice (unless you're in the habit of checking your mains sockets with a time-domain reflectometer...) -- The Anome (talk) 12:50, 9 February 2008 (UTC)[reply]
"A ‘ring’ accidentally wired as a figure-of-eight risks overloading one leg"
Would someone like to explain this? I dont see what 'wired as a figure of 8' means, nor how any layout variation would result in one leg overload.
Tabby (talk) 03:11, 5 March 2008 (UTC)[reply]
I've decided to move the comment to here for discussion, since:
its a subject I'm qualified in
I don't see what description could possibly mean
and I don't see any way that rearrangement of the ring layout could cause the problem claimed
removed:
A ‘ring’ accidentally wired as a figure-of-eight risks overloading one leg
The ring is based on the assumption that load will be reasonablly spread out arround the center of the ring such that neither leg will be overloaded. If this assumption does not hold then it is quite possible for one of the legs to be overloaded on a regular basis. This is one reason it is frowned upon to put the kitchen on the same ring as the rest of a floor.
If a ring becomes a figure-eight then you essentially have two rings one feeding the other. This means that all the load from the second ring will appear at the same point (or two close points) on the first ring and if that point is not central it can easily overload one leg of the first ring. It also means that testing for ring continuity will only test part of the circuit allowing faults to remain undiscovered for longer. Plugwash (talk) 23:29, 24 October 2009 (UTC)[reply]
Forgive me if I'm stating the obvious, but for some reason it does seem to get overlooked a lot when discussing ring circuits.
The only way to see the pros and cons of rings is to look at what happens with any given situation with both ring and radial circuits, and see which is better/worse. To point out an issue with rings, neglect to mention that radials fare far worse, and then call this a downside of rings is sadly all too common, depsite being senseless. That this simple illogic is often repeated in articles presenting themselves as scholarly is disappointing.
Tabby (talk) 03:08, 5 March 2008 (UTC)[reply]
Much of the material in this discussion is a summary of points made by various established experts at an IET event on the subject, with downloadable references given. Could you please clarify your criticism and provide alternative references that back up what you would like to see described? Considering that ring final circuits are considered at least bad (if not illegal) practice in parts of the world, there will no doubt some controversy remain in this discussion, but I agree that the pros and cons could be listed much better than they are at present. Markus Kuhn (talk) 17:55, 19 March 2008 (UTC)[reply]
CENELEC has been working to harmoize e;ectrical standards across the EU. When a term is proceeded with harmoized it means it is to one of those harmonized standards rather than an old national one. Plugwash (talk) 23:16, 24 October 2009 (UTC)[reply]
The gratuitous use of this non-word is odd. The word is, as far as I can tell, propagated by handymen and the like who like to think that it has some better technical validity. I do not think that the word will appear in any technical standard, and its use should be deprecated. What is wrong with the word 'plug'? — Preceding unsigned comment added by 86.155.127.195 (talk) 21:50, 29 June 2011 (UTC)[reply]
Indeed, it's a ridiculous term which seems to have appeared out of nowhere. A "plug top" is the cover which goes on top of the plug to cover up the terminals and make it a complete unit. So next time somebody asks for a "plug top," unscrew a cover and hand him JUST the top! 87.113.45.147 (talk) 20:46, 19 August 2012 (UTC)[reply]
Nope. A 'plug top' is a colloquial term used by many British non techie folk to describe what we all know as a 'plug'. These same folk often call the socket that goes with it a 'wall plug' or even just a 'plug'. I believe that in may be a regional dialect thing as these terms are more common in the north of England than elsewhere. 86.166.70.84 (talk) 15:31, 27 September 2012 (UTC)[reply]
While sympathizing with the view that "plug top" is an odd expression, it is an established expression whose use can be traced back to the earliest appearances of plugs and sockets around the end of the nineteenth century. It was not uncommon to refer to the combination of a plug and socket as a "plug" or "wall plug", and the term "plug top" specified the actual plug as opposed to the plug and socket. There are many uses to be found over the intervening years, one example of which can be found at the bottom of page 14 of D.W.M. Latimer's "History of the 13 amp plug and the ring circuit." (as referenced in the main article) where Mr Latimer quotes a passage from a committee memorandum (from 1943) which includes the phrase "Two standard plug tops for the up rated 10-ampere B.S..S. three-pin socket". Deucharman (talk) 14:30, 19 July 2013 (UTC)[reply]
This article mentions it, along with many others on the subject on the web, but does not explain the science behind not having more spurs than sockets on a ring. If someone who does understand it could add it tot he article, it would be good. Talltim (talk) 12:54, 18 May 2015 (UTC)[reply]
In the first row, it says "Radials with a broken connection will not function (if L or N broken) ...". Is this true? I think the opposite is the case. Because a socket is fed from two sides, it will continue to function even if L or N are severed on one side (I assume by "radials" it means the remaining circuit after a ring is broken at some point). Noggo (talk) 12:40, 18 May 2018 (UTC)[reply]
But radials are only fed from one side (not both), so if you have a break then it is non-functional. I have reverted your edit on this and a number of other mistaken changes. However, you were right that the paragraph on poor joints had become detached. FF-UK (talk) 14:20, 18 May 2018 (UTC)[reply]
Ok, but then I wonder what the part "Radials with a broken connection will not function (if L or N broken) ..." is supposed to tell me. I would expect something that opposes (or is at least related to) the corresponding statement in the left column. The way it is now, the two statements are not really connected - or am I missing something here?. But regarding the rest I changed: I'd appreciate if not everthing were reverted as a whole, including links I added, which in my opinion didn't harm anything. Noggo (talk) 19:47, 18 May 2018 (UTC)[reply]
To be honest, I am not sure why it is written like that, but it is true. "Radial circuits" are linked the first time the phrase appears (in the lead), repetitive linking is unnecessary and discouraged see MOS:REPEATLINKFF-UK (talk) 20:15, 18 May 2018 (UTC)[reply]
Article currently reads in part (often incorrectly called a ring main or informally a ring).
At the risk of quibbling, this is itself incorrect. It may be incorrect to use the term ring main in this sense in a technical bulletin, but in laymen's conversation this is quite normal.
He tore up all the skirting boards to try and find the main
And I had to get a carpenter to put them back again
- Flanders and Swann, The Gasman Cometh, a song of unending domestic upheaval
OK, that's about a gas "main" rather than an electrical one, and the term was chosen to make the rhyme. But the point is, mains power is what laymen call the stuff that comes out of power points, and the mains is the wiring behind them, and a ring main is what they commonly call the technique described in this article when it's in their home. And many sources support this... I think I first saw the term in the Knowledge magazines I used to get as a primary school child.
I'm sure that's true, and I'd guess that the Australian Wiring Rules would say the same (I no longer have a copy to check it, but I seem to recall that we are not allowed to use it to reduce cable gauge in domestic wiring... I'd regard that as very false economy in any case, but reducing voltage drop might be a better reason in commercial wiring... even then I saw someone killed by not checking a ring circuit in a commercial installation, thinking it was disconnected, years ago, the shock didn't actually kill him but the thirty-foot fall that followed it did, multiple SWM violations but that was no consolation).
But that's not the point anyway. We're a general encyclopedia. Certainly, point out that it's not the official terminology. But I think it's a bit strong to call it incorrect in the introduction when it's common English and readily understood by our readers.
I only have the UK regs (and a lingering sense of eldritch horror from doing some wiring in the US once). We don't "reduce the gauge" (I wire rings in the same stuff I wire radials with) but we are allowed far more useful load over them. My radials and spurs would be very limited in the number of socket outlets they're allowed, but my rings are just limited to floor area and more commonly by a discretionary convenience factor, so that I don't have to do topological nightmares to link up awkward buildings, or to have all floors etc. trip out together. Andy Dingley (talk) 19:43, 14 September 2019 (UTC)[reply]
Question and Comment on Ring vs Radial Final Circuits
Electrical Engineer here who is familiar with US and a few other Radial-wired countries, looking to understand the advantages of UK Ring-wired final circuits.
Let's look at the example diagram showing 5 sockets on a ring, and add the information from the article that the wiring for phase and neutral in the ring are rates to 67% of the mains OCPD (Over Current Protective Device e.g. a fuse). e.g. let's assume a 30A ring that has wiring rated to carry 20A.
Let's assume the total length of the ring, from the consumer unit, going in a loop through all the sockets, and back to the consumer unit, is 2L.
This Ring wiring will cost: 2L * cost-per-unit-length(20A wiring) [for line/neutral/earth]
We could break the Ring into two Radials at the midpoint of the Ring and feed half the sockets from one half of the broken Ring and the other half of the sockets from the other half of the broken Ring. This would not be safe because the OCPD is 30A while each of the two Radials is wired with 20A wiring. So the 30A OCPD must be replicated into two 20A OCPDs, one each to protect the two Radials. That would result in a safe and legal Radial wiring in the UK, US or any other Radial-wired country.
As can be seen, this means that no additional copper wiring is needed compared to the original Ring circuit. It would now cost:
L * cost-per-unit-length(20A wiring) * 2 [for line/neutral/earth]
which is identical to the above.
So isn't the claim that Ring circuits reduce copper wiring requirements by 25% demonstrably false?
On the other hand, proponents of Ring circuits frequently claim that it reduces OCPD costs. As can be seen from the above thought-experiment, that is true -- one 30A OCPD likely costs much less than two 20A OCPDs. Yet, this obvious (and common) benefit of Ring circuits is not mentioned in the article. It should be.
