radial from ring main

[iconnect]

Sorry no offense intended I just always do it lol Sorry. I dont understand why this is still going really its the same as an extention lead you can plug what the hell you like in it as long as it does not go over 13a. The reason is not because of the ring being in balanced but more to protect the cable in the spur as the balance is maintain as it enters the ring in the same place and is no different to pluging in something that pulls 10a hello in balance!
if you spur off the spur without a switched fused spur the only limit is the mcb 32a. The idea is sound without problems no way the spur can take more than 13a s. Am I making sense lol

 

[moosey86]

This topic is very bitchy, I think everyone knows how to do it properly (probably an overstatement there) but I'd imagine most people that take the time to read through a forum like this would want to do it properly.

If your going to take a 4mm up just take two 2.5mm's up, split the ring and then it's done in a proper and recognised way. If I saw that 4mm method done at a job I'd instantly think DIY.

It's pointless getting so ---- about doing it a different way for such a nothing job. And I don't mean that in an offensive way. I'm more talking about peeps that start studying the BRB for reasons why or why not to do it. Let it go people there's more to life than ********.

Hope this helps


Sent from my iPhone using Tapatalk

 

[iconnect]

I agree 100% more to life

 

[Paul.M]

I've just done a search on Google for:- balanced ring main, to find out once and for all what the intelligence of the world wide web had to offer. Guess what came top if the list? My rant on this thread post 42. Just goes to show that you can't believe everything on the internet.

 

[KFH]

On the issue of the unbalanced ring. Assume 3 X 3KW fires connected on unfused spur (I have seen it done in one room in order to dry plaster/paint) assume that the spur is connected 1/5 of the way around the ring and there is no other load on the ring.

9KW = 39A which will not trip a 32A MCB in a hurry. 1/5 of 39A will go the long way around (7.8A) and 4/5 will go the short way (31.2A) this is in excess of the 23 A for 2.5T&E installed to method B.

I will leave it to others to do the calcs on how long before the 2.5 T&E gets a bit hot and to access whether the scenario is reasonable. A load of 28.75A would not overload the short leg of the ring in the above scenario (23A = 4/5 of 28.75)

 

[jaresquire]

Kinda wish this thread would die but....
If you extended the ring at the same point as the spur the current in each existing leg would be?

 

[KFH]

Jaresquire,
The load on the short leg of the extended would be the same as my example, an unbalanced overloaded segment of the ring. Which is what I suspect your question implied.

A good reason not to have rings, the users do not know/care about unbalanced loads. After all it has been properly installed, how can they overload it without a fuse/breaker tripping, they will ask when their house has burnt down. Having said that how many fires have been caused by an overloaded ring never mind an overloaded segment? Stats appear to show very few if any.

As someone said before why all this fuss about something we would not install? But I am one of the guilty parties by continuing to post:-(

 

[jaresquire]

Yeah I think this is just a regs issue and as I posted earlier best just to avoid such a spur but I would only do an advisory if I came upon it.

 

[marky sparky]

yes ! but they were talking about radials from ring main and not other configs

 

[bennett3291]

regs state u r only allowed to spur off the ringmain with one double skt or 2 single skts at anyone point.

 

[con-site guide]

As long as JB accessable there is no problems.

 

[kmcgold]

only one single or double socket etc

 

[j.mawer]

And so the cycle begins again!

 

[Adam W]

Reasons you shouldn't:

1. It is prohibited by 434.2.1 - "The part of the conductor between the point of reduction of cross-sectional area or other change and the position of the protective device shall not exceed 3m in length..."
2. It is prohibited by Appendix 15 - "An unfused spur should feed one single or one twin socket-outlet only..."
3. It is unprofessional - ingenious little 'solutions' like this are the hallmark of the DIYer.
4. It's easy enough to do it properly, ie in accordance with the regs.
5. It creates unnecessary confusion for someone unfamiliar with the installation - the spur appears to be an A2 radial but leaves the consumer unit as an A1 ring.This could even be dangerous when it comes to isolation.

Reasons you should:

Apparently it's easier to take 1 cable up to the loft, although it's easier to get 2x2.5mm cables into the terminals than 2x4mm.

... And that still doesn't explain why you can't fuse it down, like an extension lead.

 

[kmcgold]

Reasons you shouldn't:

1. It is prohibited by 434.2.1 - "The part of the conductor between the point of reduction of cross-sectional area or other change and the position of the protective device shall not exceed 3m in length..."
2. It is prohibited by Appendix 15 - "An unfused spur should feed one single or one twin socket-outlet only..."
3. It is unprofessional - ingenious little 'solutions' like this are the hallmark of the DIYer.
4. It's easy enough to do it properly, ie in accordance with the regs.
5. It creates unnecessary confusion for someone unfamiliar with the installation - the spur appears to be an A2 radial but leaves the consumer unit as an A1 ring.This could even be dangerous when it comes to isolation.

Reasons you should:

Apparently it's easier to take 1 cable up to the loft, although it's easier to get 2x2.5mm cables into the terminals than 2x4mm.

... And that still doesn't explain why you can't fuse it down, like an extension lead.

The end........