UK Ring Circuits (previously Ring Mains) for Socket Outlets 

Hello from the weird year 2020. I just watched Technology Connections explaining the U.S. electrical system. He casually explained that it's not nearly as weird as the U.K. ring mains. So that's why I am here. Great explanation. Yes, I now understand why it should be removed from the current standard.

Technology Connections brought me here!

I don't know anything about electrics and to be honest i'm not sure how i ended up here, but i find this guy strangely captivating. I'm now considering installing a new consumer unit and ring main for no reason other than John Ward showed me how.

I was taught the virtues of the ring mains when I left school in the 80's and did my apprenticeship, just before moving into IT, and thought it was a great idea. Now in my 50's and having moved into various old properties (and always checking for signs of heat/loose connections in electrical outlets) this video has explained so much. Well worth 16 minutes of my life to totally change my mind as to the safety of electrical circuits.

By far and away the most lucid explanation I have ever seen. Something I've always thought should be fairly simple has always had an air of complex, don't touch, experts only etc. and John's explanation is so easy to absorb. Your a genius JW.

Who else came here after Technology Connections (06/20) drove you to a search?

I am a retired electronics tech who actually did some rewiring in my father's house in the UK. The old, lead-covered cable under the floorboards was beautifully layed out and neatly dressed, but as soon as it was disturbed the old rubber insulation disintegrated. I am guilty of incorporating "a borrowed neutral" into a three-way stair lighting circuit, but I am sure that the house has been completely rewired since my father sold it in the late 1980s. I could not understand the need for a ring circuit, primarily because I understood the risk of overloading in the event of ring discontinuity. This is the first video I have encountered that explains why I was correct about ring circuits.

Fantastic Explanation, 6 years later your video was recommended to me. All praise the algorithm.

You described how to wire a ring main up perfectly clear,I understood it perfect! Thank you !

The Canadian Electrical code still allows ring circuits in 2015. Never used one, never seen one and didn't even know what it was until I watched this video. Great video.

The ring main was introduced after a long and hard war (WW2) and materials were in short supply, previously houses with electricity had few 15A sockets each wired as a spur from a fuse box. With the advent of 13a fused plugs and ring mains (as then called) with the limited and perhaps rationed cable could be used for more houses than the same amount of copper used as single socket radial circuits. Whether a ring circuit NOW represents the best practice doesn't matter because there are probably 20 million ring circuits in existance and most electricians will meet them on a daily basis.

Great video. Clear explanation. Currently studying this on my Level 1 Diploma course. Makes so much more sense to install separate radial circuits throughout a domestic dwelling. Cheers!

Thanks JW you brought me back up to speed, having done house wiring back at college as part of my apprenticeship I went into electronics and only ever used household electrics when needing to do my own, I will keep this video as a reminder. Thanks again. Ray.

Now that i moved to london i found your videos very helpfull understanting uk domestic instalations. Thank you very very much.

Crystal clear and very much appreciated , why can’t all d I Y videos be made like this . Great job

Excellent teacher, excellent channel. Thanks JW. I had a 32A ring circuit in an old outbuilding, and rodents had gotten into the walls, chewed on the wires and the RCD kept tripping. I expected the worst, that the circuit had been destroyed, but the electrician isolated and removed the chewed section and I was delighted to end up with two 16A radial circuits that tested fine and with roughly the same number of sockets on each. Could have been worse.

Singapore, and a few other Commonwealth countries, use Ring Whatevers. Here in VietNam Singapore invested highfises are equipped wigh clunky UK Plugs although not Ring Mains. We also use US-style flat in plugs, as well as Chinese plugs. When travelling i prefer the universal connector that comprises 2 wires wiith bared ends and fit almost anything!

Very interesting as always but twice as amusing 👍😃 love your commentary on this video!

Thanks again for a very important subject

When I first heard about these, I thought they were relics of the past. I was _shocked_ (lol) to find out that they're still in use today, and you've explained very clearly to me how they work. I wouldn't want one in my house; good thing everything here in the States is what you refer to as radial.

Thanks John. Simple explanation. Much appreciated. Keith

Clear explanation John, thanks very much

Very comprehensive thank you, I thought it was a great point about a wire in the ring losing connection and creating a scenario where the circuit is able to draw more than the rated 26 amp. Even worse if they are double sockets which is way more likely. Anyone is able to test this with a simple continuity check.

Thank you John for the nice video.

Fairly strong opinions being expressed at the beginning. You certainly aren't shy !

Old ways die hard. Ring circuits usually reliable enough.Great variety of wiring globally.Protection way better now than it used to be. A neighbour called in about faulty socket years ago. Upon investigation at the fusebox, there in place of a fuse was a 6 inch nail glowing red hot. Necessity is the mother of house fires.

Crystal clear and comprehensive as always. Thanks.

Hello John, I'm finding your videos to be an excellent learning resource, thank you! Could you, at some time, please do one on adding a garage consumer unit?

Very clear concise explanation of ring circuit.

Very interesting thanks John. I often wondered why the ring circuit concept was introduced.

I shoud not say this, or even go there, but the holy grail of all audipophile nutters is their own spur and somehow the magic electricity is different and everything is better with a dedicated spur. Loved the video, learnt lots please ignore previous comment 8) .

I watched this when it was new. I installed a garden building on my own land for my office, it was all wired using advice from this vid without ring circuits, but higher rated cable (6mm). 5 years later, it all still works perfectly. even with a 2.7Kw heater running off it at one point, as well as a computer and LED lighting. BTW, I also have a spur direct from the consumer unit for my Ring doorbell. All common sense stuff.

Thumb up for the first 15 sec! I'm an electrician from abroad and I was so scared when I opened my UK house consumer unit

I heard, and believe story that, those 2* single sockets as spurs, were often changed to double-sockets (e.g. those conversion sockets)), thereby overloading the protection requirements for unfused spurs. So, regulations changed to disallow that configuration.

Thank you for the video, it was really helpful!

My employer loves a Ring circuit, they'd put one in for any socket circuit consisting of 2 or more double sockets. I personally fail to see the point most of the time. It does make sense to have a 32A circuit for a kitchen/utility and I guess the little bit of extra testing involved still beats fitting a load of sockets with two 4mm cables in them. I remember one of my college teachers saying about how he'd converted a lighting circuit wired in 1mm into a ring because it was on a 10A MCB and the cables were all buried in insulation, bet that was a head scratcher for the next guy to work on it 😂

below comment is not good john but i appreciate you about your work because i know that what hard work are required for sharing some knowledge for others thanks john

Makes sense to me ,often thought about doing it that way using rcbos

Good video, learned a lot. Thanks.

Great video. Answers most DIY questions!

thanks so much for the info..perfectly explained, per usual.

I will never get over how differently you Electricians in the U.K. Do things differently than us Electricians in the States. Though I know you are professional tradesmen and take great skill in your craft , and know what you are doing, something like that would never be allowed over here. Always enjoy watching the way things are done over there. Wasn't intending to be disrespectful if I was, anyways cheers from the States.

Nice video John well explained very well done

I could have done with a ring circuit to power my twin 2400W boiler elements for my still. I actually like the concept. Cheaper than having 20 amp circuitry installed.

Thanks for an excellent factual presentation 👍

Excellent explanation thanks, needed a refresher.

Thanks for these videos

Wow... I can almost admire this in concept. Wow.

Thanks for your time.

Come to think of it, I use a similar "circuit design" on my electrical fence (that adds extra incentive for my dogs to not try to go through the yard fence). If a wire gets broken, both sections of the fence still have power. I can see a reason why the ring circuit could have an advantage from a fault tolerance standpoint, but I would still size the wire so that even if the ring was broken, it could still handle as much current as the circuit breaker for the circuit. I never rely on a house that I buy to be wired *correctly* since a previous owner might have thought he was competent to do DIY electrical work (and he wasn't) or the builder was using somewhat unskilled workers who didn't particularly care whether they did it right for the wiring installation. I've seen cases where 110VAC was on the *ground* at an outlet because some wires were touching in an outlet box. To be fair though, this was an old house which was originally built without electricity and there were still remnants of previous electrical wiring designs. There were places in the attic where some of the old asbestos and tar wiring insulation was still around (although it wasn't being used). There were also some remnants of the old "knob-and-tube" style where wires didn't have insulation on them and bare wires were run while being separated from contact with the materials of the house (or each other) by porcelain knob and tube insulations.

The most compelling reason for ring mains/circuits as compared with separate cabling to each socket (as in the forties) is that they give the user maximum choice in where to plug in portable appliances, without increasing the amount of wiring in proportion to the number of outlets. The intention is that in a room with plentiful sockets there will not be any need for long leads on portable equipment (trip hazards) or multi way adaptors (which can be a fire hazard). Why not use a radial? The advantage of the ring over the radial is that you can test for loop resistance. This detects whether there are any poor connections at any point in the ring, which could lead to a fire risk. You can test this at any point in the ring, without visiting all the sockets. This test is the reason for most of the rules about spurs. Secondly, if a poor connection does develop, it's less likely to cause a fire unless a second poor connection arises. This is because most of the power will flow to the socket that's in use by the line of least resistance. The dodgy socket gets hot when it is used, and hopefully the consumer will notice. That socket does not get hot when other sockets are in use (unless there are TWO dodgy connections) In contrast, in a radial, if there is a poor connection at an unused socket, that socket will get hot whenever sockets are used that are further from the CU. If that socket is rarely used, or is a permanently plugged in appliance, the consumer is unlikely to notice the hot socket till it bursts into flame. So the extra cabling back to the CU is for testing and safety. There is a coherent case to support this You clearly feel the the disadvantages outweigh those advantages, but it's only fair to mention that there is some sense to the design. It's not totally daft, as you seen to imply

I’ve put a few new sockets on existing 32amp 4mm wire radial no problems love it.

Thank you John. That was very clear and well explained :-)

Hello John. Thanks for all the videos. Have you though about a short intro on the organ at the start Monty Pythonesque styleeeeee. Good Luck lad

Brilliant ! Many thanks.

Great explanation John , genuinely you can have the same number of spurs as you have sockets on the ring , in theory you can have as many sockets as you like as long as you don’t exceed a certain floor area of a 100 square metre. But as you rightly say it comes down to common sense. Till recently a domestic property ie a two story house had three ring mains , and two lighting circuits,one for the ground floor one for the upper floor and the kitchen had its own ring main because there would be quite a few high power appliances such as fridge freezer washing machines tumbler dryers microwave , electric toaster kettle food mixer and if you could afford it a dishwasher. Personally I think ringmains still have their place . In houses . Because if you have a fault on say the ground floor ring you still have the upstairs ring as well with the lights .

Cheers JW love your videos.

Hello John, love the videos, crystal clear and based in reality. I'm a basic DIY'er but want to do things safely and in accordance with the standards/guidance where possible. I live in a victorian terraced house in Wales. It has a modern CU but what I'm not sure about is whether it has a ring or radial circuit. Is there an easy way to find out? I've had a look at a couple of other videos but am left confused... Many thanks, Craydon

As an American with an electrical background, I've always been interested in what a UK "ring circuit" actually is, and how it works. This is the first guy I've encountered who explained it clearly in a way I understood. Thanks for that. It does seem like a simple enough concept, but I can also see why it was probably never adopted over here, because of extra wire, expense, etc.

4mm cable is harder to pull through, more expensive to buy and the wires are more difficult to screw 2 into the back of the terminals on socket oulets. Just a few disadvantages of radial to balance things a bit.

I agree with John ring mains can be potentially dangerous I had a situation where I did some work on a property I tested the ring a couple of weeks before when I changed the distribution board and then I went back to add a socket to find the ring now wasn't continuous luckily there was a freshly decorated wall where a socket looked as if it was tampered with as it was put back on wonky so I pulled the socket off to my surprise there was a loose connection to get to the point I filled out a cert on that property a couple of weeks before now if I never went back that ring circuit could still be a potential danger

A great learning channel...thanks

Very interesting!

20A radials for the win. Chances are most houses now have some sort of radial circuit from a spur...off a spur off a spur. Swap the MCB for a 20A to be on the safe side.

Thank you John.

I only did a short course as part of a mechanical engineering day release course many years ago, so my knowledge is limited as since then I've only done DIY electrical work, appliance repairs adding the odd spur, wiring up sheds, or simple light circuits. I'm old enough to remember the days when the previous wiring circuits were still used in many older houses, before these came in; if I remember right, sockets were on the same type of circuit as lights are now (can't remember what they're called), and people would often run half a dozen things, radio, lamp, iron etc, off the light socket on the ceiling. Overload became a serious problem back then, and we had warnings about it on the tv. Now, on a circuit such as your diagram, a person could have a 12 way tower, plus half a dozen USBs on each socket, and from those towers, further extension leads. There are no warnings about overload! I know my example is at the extreme end but, even though many things draw much less power than they used to, surely we're heading towards some serious problems. Circuit breakers are so good these days, that I've almost forgotten how to change a fuse in a plug, but are they really good enough, that we can safely keep on plugging things in the way we do? Isn't it time we had warnings on the tv again? Or am I worried about nothing?

Let's see what kind of shamble this are , brilliant the way you mentioned 😀

Very well described!

I guess it made sense to the committee in the '40s. It does not make sense today. At least you use an efficient voltage. 120V requires way too much copper.

Excellent Video

I have split many ring mains into two radials on 25 amp RCBOs,usually due to cumulative earth leakage,the bane of all RCD protected circuits with today’s ever increasing electronic supplies

Always wired 30 or 32A with 4mm2, you are on the safe side in any scenario. For bedrooms you could use 2.5mm2 with 20A MCB which is more than enough for average house

I come from a industrial/commercial installation background 15yrs+ , but for the last 5yrs I have been working in Domestic. I was recently instructed by my boss to add a F.C.U. in a garage for a new Electric Door. When I arrived I found the existing Socket within the Garage that I was to spur off of, was itself a spurred off of a Socket Outlet on the adjoining Kitchen Ring. I called my Boss and expressed that I felt it would be better practice to either add a leg to the existing spurred socket to make it a part of the ring main, or to add a F.C.U. to the Ring within the Kitchen, which could then feed this existing spurred Garage Socket Outlet, and then spur off of it to feed the new F.C.U. for the Garage Door. My Boss said it was fine because it was an F.C.U. I disagreed, and expressed that it was about protecting the cable leaving the Kitchen Ring, and that the F.C.U. was only protecting anything it gave power to. I’m sure I was right, am I?

The one big saftey advantage I can see with a ring circuit would be in the case of a connection going resistive or resistive break. Connections going resistive is where fires start. The connection becomes very hot due to the voltage drop across the unintentional resistance. In the case of a ring circuit though since power is still supplied from the other end the resistive connection will see no voltage drop and no power dissipation.

I defo use ring mains for kitchen appliances with a few isolators in a cupboard so that it becomes a balanced load on cables and hidden away from worktops make a neater job, I would use it to feed for example, cooker hood, hob ignitor, dishwasher, waste disposal, hot tap, bolier. Fridge will be on its own RCBO circuit for obvious reasons such as going on holiday you don't want some thing to trip the RCD and affect the fridge if it wasn't wired in separately.

Please make a video explaining kitchen ring. Thanks

Fantastic tutorial thank you

good tutorial thankyou

Knew nothing of the circuits in our first house. Second had a ring circuit on each floor. Third, one for front four rooms, one for back three (a bedroom plus the kitchen and utility). All three bedrooms had one socket on the ring and one on a spur. There was, bizarrely, a 2A socket attached in one of them as well. This ring was later properly extended as more sockets were needed. My own places, single ring in first flat, two likely rings in second - one covered only the kitchen, the other all the rest. Third and fourth flats had single rings, current bungalow has two probable rings - once again one is just for the kitchen.

You are the best Thanks

I'd like to suggest that a ring main does have an advantage in that it halves the resistance to the furthest socket, while using easier to handle cable. Also in most situations it begins down one side of a house or room and returns along the other, enabling sockets on both sides. The alternative of two radials would double the resistance by comparison unless 5mm cable were used. Resistance can matter especially when using things like grills and halogen ovens where a small drop in voltage results in a large drop in radiant heat (I experienced this problem). It's true that electronic devices are generally neither large current devices, nor very sensitive to voltage, but if you are feeding two radials down each side of a room, why not just join the ends and complete a ring, halving the resistance. I agree that the potential to overload the ring cable with loads near the consumer unit makes a nonsense of the ring in principal when it comes to pushing 26A cable to 32A, but again, in practice, the ring will often begin some distance from the area it feeds, such that the feed to every socket has a reasonably balanced feed, the initial long feeds serving to balance the current sharing. One thing that surprises me is that you, like others, work on the assumption that the cable is required to carry only 32A worst case, when in reality MCBs will sustain around 1.5 times their rating for a long time without tripping (depending on the type of MCB), so the cable has to take 48A in fact. I think the sensible answer is to simply require that all circuits using 2.5mm cable have a 20A MCB while all circuits or spurs using 4mm cable can have a 32A MCB. With the cables thus protected at source no further rules are needed regarding spurs or number of sockets. In a bungalow my preferred method is to take spurs in 4mm cable down to each socket from junction boxes, from a 2.5mm ring in the loft that has no sockets directly on it, leaving the ring uncut where possible as it runs through the boxes. This makes life easier in many ways - no threading of two cables down inside plastic conduit (which I always use), no need to put two wires into each socket terminal, and easy access to junction boxes for adding sockets. Plus less opportunity for arcing with less joins. Of course this works well in a floored loft with easy access to the edges, but not perhaps in one piled high with glass fibre insulation. One reason that the ring worked better in the past was that it served fewer sockets, whereas today a lot of extra cable is wasted looping down the wall and back up (wiring across walls from socket to socket is not encouraged because of the increased risk of drilling into cables when fixing to walls.) My solution of using 4mm cable down from the ring shortens the cable length in the ring and is ideal in every respect.

Thanks John

Thanks for sharing.

Came here from Delroy. As an Aussie sparky I found ring circuits weird but probably only still in the standard because it exists in old homes. A lot like engineers still having to deal with imperial machine threads and sizes.

At last! Ring circuit made easy

Very interesting wiring structure

Hi, thanks for your videos. Could you please make a tutorial about how to connect/wire a 3 gang switch so it controls 3 devices for example? In my kitchen, I have a ventilator, ceiling light and led light under the cabinets and I have 4 set of cables (each having a Ground, L, N) coming out from the wall ready to be connected to a switch.

I never knew the UK did this, its a good idea in theory but the fact that its so easy to end up putting too many amps through the conductor from a single point failure is scary.

16:00 i Loved your hint of frustration there, rings have no place in this day and age and if the next edition or regulation want to do something sensible and worthwhile then they should ban these massively outdated ridiculous circuits.

Thanks for explaining this peculiar arrangement. Around here you are not allowed to rely on a fuse at the end to protect a wire, ever. It has to be at the beginning. The only exception is short proof wire (with thicker insulation), for example the spur feeding a fuse or circuit breaker from a bus bar.

Best program 👌

Hi John, we have been getting defects from fixed wire testing for the additional wire at the fuse for a spur. I thought it was ok. Thanks for confirming it. I wish people who do the testing knew this too

I'm not big fan of ring circuits, but there is the benefit that the overall resistance of the circuit is reduced considerably when you have that last leg back. I mean, it does effectively nearly double the effective CSA of the conductor, and thus capacity of the circuit, by just having that (often short) return leg. I could see there being a lot more burnt-up sockets/cables if radials with many sockets on them where more common, as connections inevitably loosen over time, resistance (impedance?) increases, and then folk go and plug electric heaters and the like into them. I know regular testing should defeat this possibility, but really, how often do people actually get their installations tested? In my experience, the answer is: much, much less than they should.

Hi John, thanks for the useful video. I have recently bought a static caravan in which the ring main for the sockets is protected by a 20A breaker. The wiring is 2.5mm T&E. Is there any reason why I may not be able to increase the breaker to 32A? Would the incoming supply from the park affect this - although there are much bigger vans on the park than mine which must have higher loads?

Great video! You’d make a fantastic news “READER” the last word of each of your sentences are very “PRONOUNCED” non the less, you really seem to know your “SUBJECT”

thanks great 👍🏼 video

Nice video thanks

I always used to argue with my lecturer at uni about ring circuits. He explained that if you create a ring circuit, there will be NO current within the cable. His point was that because it was acting like a massive battery terminal. So, he decided to show this with an ammeter. As you can imagine, even with a load, the ammeter displayed zero load. Now, i wasnt convinced. i argued with this lecturer for over 2 years and ended up giving up. He always took the stand that there is NO load on the ring. The point i was trying to make to him was that yes, even though the meter displayed a zero load. It was simply because the meter could NOT measure it due to it being a ring (In theory, the meter was never going to be in series as im sure you know when measuring current it has to be in series (Voltage is measured across)) as the ring was always attached at either end. Just wanted to rant a little there :)

Major newsreader vibes but I learnt a lot, thanks!

Ring vs. Radial Which you should specify depends on many factors. What are the expected loads (does the building have central heating, so will plug in electric heaters be used or not, what appliances are expected to be used, etc. etc.). How many socket outlets do you want, both NOW and in the future (when someone decides to rearrange the furniture in the rooms). Now draw up a plan on paper to work out the details. I always recommend that you specify more socket outlets than your immediate current requirements, as providing them now is far easier than making alterations later. In a rooms where there are plenty of socket outlets, the distance between the sockets will not be that far, so the difference in cable cost between two radials and a single ring circuit will be insignificant if buying drums of cable. Properly designed and installed ring circuits are just as safe as radial circuits. Ring circuits are more flexible for the end user, as they can plug any normal appliance in to any socket outlet they like. Whereas if 20A radial circuits are used, too many high powered appliances connected and switched on at the same time on one circuit will trip the MCB. Worse if the protective device is a fuse... Fuses have the disadvantage that people can put in higher rated fuses, higher rated fuse-wire, or normal wire or other conductive material. And don’t think that a MCB protected consumer unit can save the day, as I have come across radial circuits run in 2.5mm squared cable protected by 32A MCBs... Properly designed and installed radial circuit circuits have the advantage that no fixed wiring cables should overheat. But a poor conductor connection in a socket outlet could cause overheating and may result in a fire. So the argument that a fault will always show up in a radial circuit does not wash with me. With a ring circuit, a disconnection or a poor connection could result in a cable being overloaded if multiple high power appliances are in use. But as there are two current paths, it does depend on where the fault is in relation to the circuit wiring.