How to Identify a Spur from a Ring Final Socket Circuit | Electrical Testing
Testing a ring main socket circuit, or to use the correct term ring final circuit, is a bit more involved than a regular electrical circuit. In this electricians Q&A, we run through the test procedure to identify spurs and incorrectly wired sockets.
This electricians Q&A was raised in our previous video which explored ring final circuit testing using the new Metrel automated ring final circuit tester.
📺 👉 • The FAST Way to Test R...
================================
🔦 More electrical Q&A videos from eFIXX
👉 www.efixx.co.uk/electricians-...
================================
🆕 FREE CPD Learn about new applications, regulations and best practices with our FREE CPD modules. - New modules are released every month, covering everything from surge protection to lighting.
👉hub.efixx.co.uk/CPD
================================
📍SUBSCRIBE TO THE CHANNEL
eFIXX helps electricians, electrical contractors, building services engineers, and electrical apprentices. So if you've been on the tools for years or just starting your electrical journey, we'll help you stay up to date with the latest regulations and developments in the electrical industry.
👉hub.efixx.co.uk/youtube-subscribe
========================================
📺 NEW TO THE CHANNEL?
Watch our essential videos playlist
👉 hub.efixx.co.uk/essentials
=========================================
#efixx #electricians #electrical
This is really useful info and helps with my learning
Thank you very much - pleased we've helped!
Well, I've learnt something... I'm 63, can sell coals to Newcastle, drive a Routemaster London bus, play the piano to a reasonable standard, given a bit of classical music to sight-read but I could definitely never have been an electrician. Too many sums! 😂 Really clearly and beautifully explained and I really enjoyed it but number blindness kicked in and I ended up baffled, still love to watch your vids though! 😁👍
That was an easy one there are more difficult ones 😀
@@carlrobson5745 yes I know! 😂 Started watching these chaps and Artisan Electrics because I was having a board change and thought it would be interesting to see what that entailed.. and also what a 'good' electrician looked like. Found a good company, all done, but still watch the channels to have my mind blown at just how educated and skilled electricians are. Not to mention imaginative and clever... and in Cory's case downright funny, how is that guy so young?! 😄
Nicely explained , clear easy to understand. Fantastic video Joe as always 👍👍👍👍❤️
always makes me smile when people say ring final circuit and never radial final circuit, its just ring or radial in plain speak, great vid
That's because rings are a final circuit within that DB/CU, where's radials for example, can start at the main 3 phase DB, then you may come out of there to a single phase CU, say from a 63amp MCB into the main switch of the CU, thus having a radial from the main DB to the CU and you can then have multiple radials off that CU and if you have a shed at the bottom of a garden, you again come out of the CU with a radial circuit. Hope that helps you?
@@craigemmott4976 a domestic lighting circuit is a radial final circuit, a cooker supply is a radial final circuit, ect ect, hope that helps you understanding a final circuit
Great visualisation of the calculation!
Simply brilliant this is real life Electrics and such a common scenario
very helpful. many thanks ! GOD bless you 1
As copper prices are at a peak, I think you should stick to your rings a while longer. Just a tip from "ringless" Austria as we struggle to even get the cables for any price😉
Muy bien compañero 👏 👍 aquí en España tenemos circuitos Radiales, pero tu explicación sobre el circuito de Anillo(Ring) ha sido muy gráfico para los compañeros del Reino Unido. 2 resistencias en paralelo. 🍺👍
Hi, I find that unless working on new or fairly new ring final circuits the results when tested at the socket outlets can vary considerably which makes confirming multiple spurs or interconnections difficult. Where doubt exists this usually means removing the face plate and actually testing at the conductors,making a simple test time consuming along with the other problems associated with removing old sockets ( stripped back box lugs, decoration damage) when carrying out EICRs ring final circuits are often the most likely to be unsatisfactory.
I agree. You're effectively trying to reverse engineer and create a circuit diagram by measuring resistances. Not ideal, and not easy.
Nice 👍 please make video on dielectric strength of insulators
Seeing it like that pulled open let's me see a circle of wire so at any point to point at opposing sides. Yes should be the same. I do still like ring circuits but yes a danger if open some were. In the work shop I have 4mm to my radial sockets. An some that are red sockets no earthing on them this is for some test gear. The equipment is on rubber mats my thinking is also I should really have isolation transformer. Or round pin plugs so no one can use them. Or lock off key. But as I only work in there on that side no one should touch anything but we all know every one messes about with stuff.
Can you compare us and British wiring I’m an American electrician apprentice and I don’t understand whats happening
Thats easy!Look at the drawing,when the wires goes up thats the spur!!😆
Why don’t you use the X-1 calculation? It’s more accurate than dividing by 4.
Ring Final Circuits are only bad when the DIY’ers get their hands on them. If installed correctly, left alone and not bodged, they are perfect. Plus if there’s a fault you can still leave the customer with working radials. A problem with those readings not being consistent are cheap socket outlets, terminals catching insulation (DIY’ers), and limp wrists.
Man, when diy'ers get their hands on electricity it's shit period.
Ring circuits are bad because when a break in the circuit appears, no one without a measuring device can tell it’s happened. At which point your protective device is oversized for the wire. They’re an inherent fire hazard. Of course an electrician can detect and fix such a thing - but tends to forget about the years or possibly decades in between electricians’ visits, where such a break can appear, whether a DIYer ever opens up the accessories or not. I’ll grant the risk is fairly low in practice, but “perfect” is very definitely not it. (There is a secondary point to be made about things that are “great as long as everybody who touches it knows what they are doing” being inherently bad because it’s pretty much guaranteed that there will be people around who don’t know what they are doing *somewhere*, and those customers - whether they did it to themselves, or their Handy Uncle did it, or someone who claimed to be a fully certified electrician and got paid as a fully certified electrician but wasn’t - are not an acceptable sacrifice to make for some exceedingly minor advantages, but I’ll leave that to others.)
No they are not perfect. They suffer from an inherent design flaw where too much current can flow down one side of the ring exceeding the cable rating and fuses and breakers do not trip. That potentially can lead to a house fire. They are intrinsically less safe than a radial circuits.
Not forgetting shoddy 'professionals'.
@@JasperJanssen A break in the CPC on a radial is also not evident without a test (on a ring, it would need two breaks for the CPC to fail).
My house has been a nightmare for rings There were only two plugs in the original upstairs and downstairs rings Until the previous owner spured several additional sockets of the upstairs ring And then he spured in the middle of those spurs to add more sockets downstairs Where he used 1.5 wire to link to the additional junction box Before going back to 2.5 🤦 And at one point he used a 6mm cable to go to a single socket Did I mention the spur to the lights? So unless you turned off the breakers for both sets of lights AND sockets, there was always a live feed to everything I'm not even going to start on the disaster that was the kitchen wiring 🤦 He should have had his head tested 🤣
in many countries, ring final is still the standard. what's the modern equivalent to ring final in the uk?
Radials.
Don't think that's right. Yes, there are several countries which use the British Standards as their wiring regs (or base their own wiring regs on the BS), and as such use rings for final circuit wiring (UAE, Singapore etc). That being said, the vast majority of countries don't follow BS, and don't use rings for final circuit wiring (radial circuits are used).
No such thing as an equivalent. A ring’s a ring
The video description asks the simple question how to identify a spur from a ring final socket circuit. Yet you went way beyond that question. The answer to that question is simple remove the socket or sockets and see how many conductors there are if there three wow it’s a spur . 😊
And how would you know if you opened up a socket which was a spur of a spur. Say thanks to the man and move on. Great video 👍
Quick question, how many sockets are permitted on a single ring? Being in the US this is not used here. I have seen some that seem to wire all sockets in the house to the same ring there, for some older installations. Great job sir. 👍
Unlimited within 100m²
There is no limit to the number of socket outlets on a ring main, but the circuit can only cover an area of 100 square metres.
@@MrJustbrowsing12345 was about to type that myself
We don't go in for limiting the number of sockets on a socket circuit in the UK (I think some mainland European countries do). IMO this is a sensible policy, the number of sockets generally bears little relationship to the ammount of load. If there are less sockets people will just use more power strips/extension leads. There is a guideline to limit floor area to 100 square meters, I don't think this is an actual regulation though just a guideline but in practice it would be pretty rare to see a ring serve a floor area that large. You do see some smaller and/or older installations with only one ring, but in a modern installation it would be normal to at least split out the kitchen onto it's own ring, and generally in a house to split upstairs from downstairs.
The number of sockets isn't really the problem..if you plug in too many appliances then you will exceed the current rating of the breaker and that's a safe condition because the power is removed. The issue is around plugging in too much load on one side of the ring which results in the current rating for the cable being exceeded but the current is less than the breaker rating and the breaker doesn't trip. And this is an unsafe condition because the cable will overheat.
Rings are still king when it comes to general purpose socket circuits, and with good reason. A 32A ring will permit greater diversity when compared to a 20A radial, while allowing much more flexibility in terms of installation methods than a 4mm 32A radial (which can only be installed method C). Rings also allow a WAY longer circuit length in terms of voltage drop than either radial, nearly 2.5 times as long! Rings are less prone to arcing in the event of a loose live conductor (there will only be a few volts difference between the 2 separated legs), and will still have a CPC to most, if not all points, in the event of a loose CPC. It's true that rings involve slightly more testing, but it's not THAT difficult is it. It's only really something that lesser sparks seem to struggle with. Radials have their place for sure, but with so many advantages to rings, they won't be axed any time soon.
“Greater diversity”? That’s an odd way of phrasing it. Having a single circuit cover so many sockets makes diversity worse, surely? If something is nuisance tripping I’d like that to cover as few devices as possible. But then again the UK also still allows dual-RCD CUs, so clearly you all just enjoy candle light trips to the fuse box.
@@JasperJanssen I think you think nuisance RCD trips are more of a problem than they actually are. That aside, new board installs and changes all have RCBOs with SPDs and AFDDs.
Greater diversity? Not sure what you mean with that phrase in the way you have used it. The example you give isn't good because you have different current figures specified, so of course one is going to be able to handle more load.
@@deang5622 I'll try to explain it as best I can. 2 identical houses: House A has a single 32A ring for all of its sockets. Total load permitted is 32A. House B has two 20A radials, 1 for the sockets in the kitchen, 1 for the sockets in the rest of the house. Total permitted load is 40A. House B has a greater total permitted load, yet is more likely to overload any one circuit. I should also mention that BS7671 doesn't have diversity in its definitions, but this is how I understand it.
@@andrewcadby ok. Diversity is about having appliances connected to the circuit which total up a higher power (or current) than that permitted for the circuit. So if you have a 20 amp circuit - I will work in watts here - the maximum load that can be used before the breaker trips is 20*240 =4800 watts. However, the principle of diversity says you can have appliances on the 20 amp circuit which in total exceed 4800 watts, say 7000 watts as an example. The risk is, that if you turn all the appliances on that 20 amp circuit, the breaker trips, because 7kW of load exceeds the 20 amp limit for the breaker. Underlying the principle then is the idea that you will almost never have all the appliances turned on at the same time. So total connected load for the circuit exceeds the total the circuit can handle. Is that what you are referring to?
Haven't watched the video yet but surely if its a double socket then there will only be 3 cables inside. Unless it's a fused spur upon an fused spur and your looking at the first spur 🤔
Clue is in the title - identifying by electrical testing.
What a fucking nightmare to handle though, i'm just happy we only install our sockets paralell.
Ring mains are probably the most dangerous circuits in a domestic installation or elsewhere. Besides the addition of spurs etc a ring can easily become not a ring if the wires at the socket or at the mcb become loose and then the first thing that will happen is the Zs value will not be correct and the 32amp mcb is now protecting a 2.5mm wire that can't take 32amps. Besides that they are difficult to test and the wires have to be disconnected from the Neutral busbar and the mcb to carry out the test which means when the circuit has been reinstalled it isn't guaranteed to be as per the test. All rings should be downgraded to 20amp and declared to be radial in old installations and not allowed in new installations.
I get.where you are.coming from but feel if they were that dangerous they would be banned but they won't be, for now. Now that said, it doesn't mean you have to install ring final circuits. 😊
The first part of your statement is a bit over the top, there is nothing wrong with a correctly installed ring final circuit, and thats the punch line. where I have concerns is in the quality of the intrusive testing and the tester, all the above increases the mean time between failure. I can understand some people not liking them because of the testing requirements but that is not the fault of the design. Certainly radials installed in kitchens and utilities where overloads that whilst may not be continious are certainly a possibillity are also a concern. Please dont tell me this is covered by good design, it certainly should be but is it? we have all seen horror stories some being installed as we speak. A badly installed and maintained radial is still a problem.
Where in a domestic dwelling will anyone use 32amps off their sockets. The 32amp breaker serves only to provide protection to the circuit and not protection for the user. I see lots of talk about DIYers and have walked into many premises where spurs are common. Unless a law is made to stop DIYers then my initial argument still stands.
@@craigemmott4976 you don’t have to start by banning them, because *in practice* they don’t cause that many fires or electrocutions. But I am still very surprised you guys haven’t at least started deprecating them for new builds.