ring main in concrete or wall?

[paulfromswindon]

I am I going to say it's in the regs so it must be right, buit apart from what I'm about to say, I'm not going to justify it either. As a professional I think it makes sense, and encourages best practice.

The big thing is this; As I have said, on a ring, because of the ring, there each ringed socket has two earth routes back to mains so if an earth got cut out somewhere or snapped of behind a socket it would not remove the earth from all other sockets, or perhaps even the faulty one . Spurs have no redundancy. Therefore many spurs are not as safe as ringed sockets. On a ring you also have a doubled earth-wire capacity which might, just might, be very useful in a fault (though I accept this is unlikely to be called on to save your skin)

As for junction boxes, every one that is installed makes it more of a headache for fault-finding, and introduces another weak-link in the system. Any sparks who has spent hours looking for junction boxes to resolve faults will agree with me, I'm sure.

I would discourage the use of spurs for this reason, and perhaps the regs are just trying to discourage spurs. Perhaps they are being considerate to people by not banning spurs, as that would be the safest thing in my view. A spur is just not as intrinsically safe as a ring. They are clearly sometimes appropriate when adding sockets, cos of the work involved in splitting a ring, but not justifiable, in my view, in rewires or new installs.

I'm sorry if people take issue with what I say. I am simply passing my knowledge on to those who request it, it's not for me to defend (or justify)the regs. I can only say that as a pro with 19 years experience, I don't have an issue with the regs. No sparky i've known would ever rewire a house with 50% ringed sockets and 50% spurs, many would consider it bad form to even put one or two spurs in a rewire.

If you really want to put loads of spurs in , why not wire some 20A radial circuits? you can go spur-crazy then, and it'll meet the regs.n It's designed that way. A ring should be a ring. That's what the name means.

Sorry if this sounds stroppy - it's not meant to be, but we can strip anything down to 'logic' if we want to because we can find easier ways to do it. Easiest is not always best or safest though. I'm sure there are many other reasons why the regs for rings say what they do. I may look into it next time i'm bored, but I won't be bored for a while.

Paul

 

[ban-all-sheds]

I am I going to say it's in the regs so it must be right, buit apart from what I'm about to say, I'm not going to justify it either. As a professional I think it makes sense, and encourages best practice.

The big thing is this; As I have said, on a ring, because of the ring, there each ringed socket has two earth routes back to mains so if an earth got cut out somewhere or snapped of behind a socket it would not remove the earth from all other sockets, or perhaps even the faulty one . Spurs have no redundancy.)

That is indeed true, but if it were a genuine safety concern then radial circuits would not be permitted, and they are, so clearly the regulations consider the risk is sufficiently low for radials to be an acceptable practice. A spur is no less intrinsically safe than a radial - in fact by your argument it is safer because a broken CPC would create just one socket with no earth, whereas on a radial it could be all of the sockets.

Therefore many spurs are not as safe as ringed sockets.

That is also true, but the regulations do not concern themselves with the number of spurs that are installed, just the number in relation to the number of sockets on the ring. If I have a ring with 10 sockets and 15 spurs, not one of those spurs becomes any safer if I add another 5 sockets into the ring. It just becomes compliant without providing me any benefit.

On a ring you also have a doubled earth-wire capacity which might, just might, be very useful in a fault (though I accept this is unlikely to be called on to save your skin

Yo - hard to see how it would.

As for junction boxes, every one that is installed makes it more of a headache for fault-finding, and introduces another weak-link in the system. Any sparks who has spent hours looking for junction boxes to resolve faults will agree with me, I'm sure.

Agreed, but inconvenience and best practice are reasons to deprecate and prefer, they are reasons to say "you may only do this if...", they are not justifiable reasons to say "you must not..."

I would discourage the use of spurs for this reason, and perhaps the regs are just trying to discourage spurs. Perhaps they are being considerate to people by not banning spurs, as that would be the safest thing in my view. A spur is just not as intrinsically safe as a ring.

Then why do the regulations permit, and why do you suggest, the use of radials? They aren't as intrinsically safe as rings either. I would agree, absolutely, that a ring is to be preferred, but what the regulations mean to me is not a choice between multiple spurs and a ring, they mean a choice between multiple spurs and no sockets on the ground floor of my house.
It's a bit like whacking someone on the back of the head with a lump of 4x2 to get them to pay attention

They are clearly sometimes appropriate when adding sockets, cos of the work involved in splitting a ring, but not justifiable, in my view, in rewires or new installs.

Ah - well lets talk about "appropriate", and "work involved" shall we?
If you were rewiring my house, you would have the following very interesting choices to make when it came to rewiring all the sockets on the ground floor.

OPTION 1 Removing all the parquet flooring in the hall and the through lounge/diner, removing all the quarry tiles in the kitchen; cutting channels into the concrete slab on which my house sits, laying in the cables (possibly in conduit - don't know what the rules are); making good the concrete; replacing the dpm and screed and relaying the parquet and quarry tiles.

OPTION 2 Chasing out several 2.5m long channels in all of the walls, including the kitchen where there are tiles so that you can run cables down from under the floorboards on the first floor; making good; repapering and repainting the walls (everywhere of course, not just the bits where the chasing was done); retiling the kitchen.

OPTION 3 Pulling single spur cables through the existing conduits in the walls to each socket.

I hope you'll forgive me when I say that as the man paying the bill I'm much keener on Option 3 than #1 or #2

I'm sorry if people take issue with what I say. I am simply passing my knowledge on to those who request it, it's not for me to defend (or justify)the regs.

Well, I'm sorry too - I do take issue with what you say, but not on a personal level - I take issue with what the regs say.
But I will not let you get away with that cop-out. You are a professional. You are the final implementation point of the regulations. The law says (or will soon say) that only people like you can do installation work because only people like you have the skills to implement the regulations. I can assure you that if you were sitting in my living room having just told me that if I want the convenience of my sockets downstairs being on a different circuit to those upstairs then I need to add several thousand pounds and huge mess and disruption to your price, you going all slopy-shouldered and jobsworth about it not being your job to justify the regulations would not impress me. Sorry, but your whole industry and your personal income stems from the regulations, of course it is your job to defend and justify them.

I can only say that as a pro with 19 years experience, I don't have an issue with the regs. No sparky i've known would ever rewire a house with 50% ringed sockets and 50% spurs, many would consider it bad form to even put one or two spurs in a rewire.

And I consider it bad form to have my house half destroyed to implement a regulation that is at best on very shaky safety grounds, and at worst impossible to justify. Unless "it's not as elegant" counts as a justification.

If you really want to put loads of spurs in , why not wire some 20A radial circuits? you can go spur-crazy then, and it'll meet the regs.n It's designed that way.

Now it's getting really weird. After all you said about the value of rings, now you say I can have radials each feeding as many spurs as I like? I don't want to put lots of spurs in, I have no choice, or at least no viable choice. I can leave things as they are (well, add a few superfluous sockets upstairs to comply with the regs), or if I want to have my first floor and ground floor sockets on separate circuits, I really have no sensible options other than running a new circuit from the CU, up to the first floor, and then around under the floorboards, with no sockets directly on it, but junction boxes here and there with spur cables. A 20A radial or two would work just as well - in fact it would probably be safer than a 32A ring, as all the 2.5mm spur cables would have more appropriate protection, but I'd have more single points of failure in the CPC, and a greater chance that a failure would affect multiple sockets than if the new circuit were to be a 20A ring with no sockets and several spurs. But hey - if a ring like that is less safe than a radial, who am I to argue? Saves me money on cable anyway

Sorry if this sounds stroppy - it's not meant to be,

Ditto - and if I have got a bit of a strop on (well, OK, I have ), it really isn't personally directed at you, paulfromswindon, you're just the unlucky sod who stuck his head up over the parapet - it could just as well have been Breezer, or il78, or any of the other people here.

but we can strip anything down to 'logic' if we want to because we can find easier ways to do it. Easiest is not always best or safest though.

No, but sometimes enough realism has to be introduced to say that easiest is safe enough because best is just too hard.

I'm sure there are many other reasons why the regs for rings say what they do. I may look into it next time i'm bored, but I won't be bored for a while.

Not for as long as you've got me to argue with, eh?

Seriously, I hope we can part here in the same frame of mind as two friends who've just had a blazing "exchange of views" over football or politics, rather than two grumpy enemies. I'm not sitting here thinking "I wouldn't cross the road to p!ss on him if he was on fire", and I hope you're not.


But I do feel better now

 

[il78]

Think its going to be neons at dawn....for you boys....

Good few points though......

Not going to get involved....I'm too much of pup (25) in the electrical world

 

[paulfromswindon]

I wonder why you spend so long criticising and arguing with someone who simply found and joined this site to offer advice to people who requested it? My god, what the hell does it matter? The question was asked what the regulations were, and I answered.

For your information, I am not obliged to say the regs are good because I earn my living from them. I have not worked as a sparky for over two years, I am in IT now (though I am considering going back). I say the regs are good because I did a 4 year electrical apprenticeship, and spent over a decade after that working on electrics. You seem to assume that all us sparkys are robots who simply memorise the regs. Believe it or not, we know enough about electrics to have a clear view of whether we think regs are appropriate, and why. And I doubt any sparkys think that every single regulation is appropriate. But they are wieghed on the side of safety, and that's what counts.

I have some points to raise, but as far as I am concerned, if I contribute to this forum in future, I will respond to issues but not debate them.

1) I never said that radial circuits are unsafe, just that in my professional view, rings are safer. A car without an airbag is safe if it never crashes, but wouldn't you rather have one if it did, even though the crash may not be serious? Please do not put words into my mouth. Radails are safe, rings are just a bit safer.

2) The doubled earth-wire capacity. In a rare type of fault condition, should a failure of a safety device occur, you could be very grateful for a doubled earth capacity. I'm sure I don't need to explain this in depth. Very rare it may be, but not impossible.

3) As for your insulting and rude paragraph about me being a jobsworth, I feel truly sorry for any tradesman who works in your house, if they encounter a barrage of abuse simply for trying to do a job correctly. I have worked in many people's house when they go into shock mode because they thought that a full flush rewire didn't involve any disruption. Not one of them ever got angry simply because I never told them what they wanted to hear.. Most times there is a happy medium. In your case, do ringed circuits everywhere but the kitchen and just spur those few. You may well have a bit of redecorating to do. It could be worse.

3) A rewire will not half destroy your house - there is some disruption to decor perhaps, as it is a major job, but one that is only done every 20 years(ish). As for the reg impossible to justify (or shaky), I admire your absolute conviction - based on what? The fact that you don't want to wire a ring circuit? why don't you write to the IEE asking for clarification? Perhaps explain why you think it is wrong - ie, because it's inconvenient for you.

4) How on earth does it add thousands of pound in cost to put the upstairs and downstairs sockets on different circuits? I must strongly suggest that you find a new supplier for your materials. To have two ring cuircuits instead of one will add approximately £15 to the cost. It's one more length of cable, and an extra MCB. Probably another hour's labour - not relevant if a DIY job.

5) Your long paragraph about me saying you can use radials. I never said it was safer than a ring, I said that a 20A radial conforms to the regs if a ring is not appropriate. Spurs are not an issue because they are not spurs in that sense - they are just legs of the raidial. The use of the word spur is only to compare the wiring method.

6) I think it's a shame that you feel the need to get stroppy at someone who is offering you free advice, and trying to be helpful, just because you don't like the answer. As for not directing it at me personally, you don't have the luxury of insulting my professional skill and my integrity (cop-out, slopy-shouldered jobsworth), and saying it's not personal. I don't mind anybody disagreeing with me, but there are polite ways do do it. You can pick holes in everything I say until the cows come home, but I am not going to change what I say just because you disagree with me or the regs. Read your post again. If it was aimed at you, in your own profession, you would be insulted at the tones and intimations used.

7) Easiest is safe enough because best is just too hard? That's a matter of personal belief. I think there is always a compromise between the two. Even in your house - as I have said, do ringed circuits everywhere but the kitchen and just spur those few.

8) I REALLY DO NOT HAVE TO JUSTIFY THE REGS AND TO CALL THIS A COP-OUT IS INSULTING. Even as a pro, I do nopt have all the facts as to why all regs are designed the way they are. And as a sparky, I certainl;y don't agree with them all, and will say so where appropriate. I will still work to them though.

9) If it's that big a thing, just ignore the reg. Wire them how you like. Don't expect any sparky to tell you that it is correct, even if they may agree that this particualr reg is iffy.

I don't propose to debate this any more. Please feel absolutely free do disagree with everything I say, but please show me enough respect to do it politely. I can actually see some of your points, but it doesn't change the facts, and my role here is to tell you the facts.

 

[il78]

I know I said wasn’t getting involved…but how can you not..

I’m in the same situation as Paul, stuck in an office for 4 years as a Technical Manager, although pretty clued up on the regulations…..because that’s what I do…

I can honestly say that I disagree with what the regulations say every other day…
But its a standard that we must adhere to……in your own home you know the limits in which you can bend the regulations to suit yourself (usually the easiest and cheapest) but as for clients, the regulations must be followed to cover yourself and the safety of the client……I know the argument is about rings or radials and any spark would opt for the ring…personally radials shouldn’t be used anymore (I know they still comply with regs) but for the extra piece of cable…sod it, just do it…decorations will be destroyed, so what! it happens. Lets not do half jobs, we must be the only trade that lets it happen….if you have a problem with gas its gets done no hassle, why because its considered as dangerous/illegal…..so electric doesn’t kill (I know I’m going over the top).
The argument or should I say discussion is about regulations and how they should be interpreted…..and I think is down to the individual spark who is on site etc….. but other factors do come into it….

Example…….RCD’s not installed within schools (x100) we inspect for the local council……we fail electrical installations due to no RCDs installed for equipment to be used outdoors……client comes on the phone saying that “equipment will not used outdoors, so it don’t matter” do we agree with him and keep 20 electricians in work or argue the point and loose the work and the lads…….regulations say that sockets reasonably expected to used, should be protected…….but NICEIC back the school up saying well they are never going to use equipment outdoors……

Regulations loose the battle down to costing…..but in my opinion the work should be done, but the company I work for is not prepared to loose work to some other company willing to do so……so do I quit my job…nope, I get on with it and get some-one else to sign the report…….

Now as I said earlier.....you both said good points…but you have to put it down to a work thing and every spark has different views….
and this was mine…

Regards

Ian

 

[paulfromswindon]

Fair comments il78.

I've been in a similar situation, where the client refuses to pay for the correct job, and I've had to take the choice whether to continue and abort the job. There are some where i've gone along with it, and others where I've refused to do the work.

Your situation about RCDs is a good example. I would probably take the same course of action as you and list the lack of RCDs as a deviation on the test/completion certificate. As you have hinted, we have to use our heads sometimes and make a judgement call. Certainly if we give advice, we have to give the correct advice. No doubt the schools authority will be banging on your door if someone gets a shock that could have been avoided, but by having the discussions, and making your recommendations, you have proved that it is thier decision that caused the problem. At the end of the day, we have to live with the fact that most of the regs are not mandatory. We can but try to ensure clients do the right thing.

Your example is perfect proof that cost sometimes means compromises that we don't like to make, but in a house, obviously, this is not such an issue. I'm sure you'd agree with me that when we give advice, it must be the correct advice, and people must decide for themselves whether to follow it.

Thanks for your thoughts

Paul

 

[mikeh2000]

I only wanted to know where to put my ring main!

Seriously though I'm a maintenance engineer in a food factory and deal with 415 volts regularly,and we have a couple of machines that pull 400 A when started up so I'm all for safety! Luckily as it's a factory nothing is buried in walls like in a normal residential dwelling but we still have wire for fuses in places because our company won't pay to have it upgraded.I've eved found on occasion the earth wire being used for the neutral which isn't nice when you find out the hard way I can tell you! Also coming from a telecommunications background I found the hardest phone faults to diagnose were when junction boxes were in use because they could literally be hidden anywhere,even,sometimes,plastered over!
Regulations are obviously put there to for the right reasons,but,like my old boss,it's up to you whether you use them.Personally I'm trying to move my consumer unit and re-wire my house as safely as I can,one of the main reasons being I don't want my 5 month old son either getting killed or not having a mummy or daddy

 

[Damocles]

Hi BAS and company. been reading old posts. Don't know if anyone ever answered your query re limit on the number of spurs. I would say the answer is a safety issue, and it is simply this.

A ring is designed to supply 32A through two cables. A spur has only one cable. Somehow it must be protected. It is protected by several compromise measures. One is to insist that at least half the sockets must be on the ring. That way half the current available will be used up by the sockets on the ring. Only 32/2 is available for a spur socket, comfortably within the cable capacity.

Ok, I know this is playing statistics, but it is not the only statistical assumption about rings. Putting the whole load on one end is also theoretically possible and dangerous, but also unlikely.

I guess the exact number of allowed spurs is arbitrary, but an easy rule of thumb to remember. I seem to remember that the number limit was introduced to tighten up spur safety.

 

[plugwash]

junction boxes are generally fornwed upon anyway as they usually end up at least partially hidden and they make it much harder to follow what is going on with a cuircuit

i believe the idea of extending a ring as part of an expansion is fairly new (its hard to do without crimps or junction boxes which both have issues of theier own) and the original point of that rule was to force rewiring when the additions got beyond sane levels

the IEE don't want to put fixed restrictions on socket counts because that only encourages use of powerstrips and other typed of adaptor

unfortunately when it comes to codifying good practice into regs a line has to be drawn somewhere in the gray area between good and bad practice and this can sometimes leed to examples of silliness

 

[Damocles]

hi plug,
i think there was a habit of using spurs to provide sockets either upstairs or downstairs without running a second ring. Still is. This does not work so well when there are lots of sockets in each room, which there are nowadays. The rule about spurs does go some way towards restricting spurring, but you can still have as many fused spurs as you like. 13A may sound a big restriction on a whole string of spurs, but is not so bad if you consider the ring only provides 32A total amongst maybe 30 sockets...1A each on average.

Therin lies the point. The rules are different if the spur is fused or not. The rule is about restricting maximum current available to a spur.

 

[ban-all-sheds]

Damocles - your argument doesn't wash. Be it on a ring, or on a spur, you mustn't take more than 13A from a socket anyway, so the spur cable does not need protecting - by the time you get to overloading that your socket will be on fire.....

 

[andy]

the IEE don't want to put fixed restrictions on socket counts because that only encourages use of powerstrips and other typed of adaptor

i originally had 2 double sockets in my room... my comp is fed from a 6 way adapter and other stuff from a 4 way adapter. nxt 2 1 socket is a FCU which powers 4 2way sockets on my other desk. i dont use many high powered stuff, just lots of very low powered stuff so i need sockets

nd before ne1 complains bout the way i have this, i kno itz again the regs but it IS safe

 

[Lectrician]

Its not 'against' the regs.

 

[ban-all-sheds]

Its not 'against' the regs.

Indeed not.

But what is against the regs (of English) is the way you've written your post, Andrew.

Will you please stop using constructs such as "nxt 2" instead of "next to", and "ne1" instead of "anyone", and do your readers the courtesy of using proper language.

 

[Damocles]

It could be against regulations if the two original sockets were themselves spurs.

Bas, you argue that a double socket can only deliver 13A. Well you may know that and I may know that, but try telling it to the double socket with electric heaters plugged in on a freezing day when the heating has failed. The socket doesn't know that, and will do its level best to supply.

Fortunately the situation may be saved because the equipment connected in other rooms comes to another 15A, and we get a trip.

Its kinda belt and braces