Talk:Ring circuit

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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

Contents

[edit] Lighting Rings

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)

[edit] 415V ring circuits?

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)
3-phase ring mains (as distinct from ring circuits) are commonly used for the final supply distribution to consumers. 81.187.162.107 18:24, 11 February 2007 (UTC)

[edit] How about a diagram?

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. --Wtshymanski 15:51, 24 May 2005 (UTC)

how's this for a first stab? Please let me have any comments --Ali@gwc.org.uk 23:03, 20 October 2005 (UTC)
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). Plugwash 23:53, 20 October 2005 (UTC)

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).

The diagram shows correctly the international standard (IEC 60446) colours that have been recommended in the UK for fixed installations by the IEE wiring "regs" since 2004 (see electrical wiring (UK)), and in most other countries long before that. Markus Kuhn 12:35, 19 September 2006 (UTC)

An SVG version would be nice. Markus Kuhn (talk) 13:44, 9 February 2008 (UTC)

[edit] Electrical noise?

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.uk 11:09, 20 October 2005 (UTC)

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 ;) Plugwash 20:34, 20 October 2005 (UTC)


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? Plugwash 04:01, 20 November 2005 (UTC)

[edit] Merge

The following discussion is archived. Please do not modify it. Subsequent comments should be made in a new section.


The result was not to merge into electrical wiring (UK). – Markus Kuhn (talk) 18:03, 19 March 2008 (UTC)

Given that the topic of ring circuit is just one particular aspect of the topic of electrical wiring (UK), I propose to merge the former article into the latter. This will avoid overlap and duplication. Markus Kuhn 12:47, 19 September 2006 (UTC)

  • Support, for the reasons stated. Atlant 13:24, 19 September 2006 (UTC)
  • Support - better one comprehensive article than a flurry of stubs. --Wtshymanski 17:43, 19 September 2006 (UTC)
  • 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. Radagast83 04:39, 12 November 2006 (UTC)
  • 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) 147.188.27.3 18:17, 13 January 2007 (UTC)
  • 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 Jones 02:01, 28 January 2007 (UTC)
  • 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. MarcSinclair 00:37, 27 February 2007 (UTC)
  • 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.StuFifeScotland 11:28, 3 April 2007 (UTC)
  • 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. Trewornan 08:16, 28 April 2007 (UTC)
  • 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)
  • 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)

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)

The above discussion is preserved as an archive. Please do not modify it. Subsequent comments should be made in a new section.


[edit] Material removed

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)


[edit] Fig of 8

"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)

I've decided to move the comment to here for discussion, since:

  1. its a subject I'm qualified in
  2. I don't see what description could possibly mean
  3. 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

Tabby (talk) 03:27, 5 March 2008 (UTC)

You have read the quoted references (Lovegrove), which is available online? Markus Kuhn (talk) 17:48, 19 March 2008 (UTC)

[edit] Disadvantage or illogic?

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)

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)