I never install ring circuits, the potential for danger is unacceptable

[ZEDEZ]

I’d like to know if anyone else here refuses to install ring circuits in domestic premises.

For me it’s either a 20a radial / tree circuit with 2.5mm, or a 32 radial / tree circuit with 4.0mm.

Frankly I’m tired of finding broken ring circuits on 32a CB’s, as well as mismatches on end to end tests. It drives me nuts on jobs that should be simple.

I wish we would get rid of this ridiculous practice here in the UK.

I know some of you will say there’s nothing wrong with it when it’s properly installed and tested, but inevitably at some point in the future someone will come along and disconnect a conductor unknowingly while changing outlets on the circuit.

Testing is more complicated, and diagnosing faults on a ring also.

 

[ZEDEZ]

Nothing wrong with a ring final circuit. It’s the uneducated/ unqualified who mess with them that causes the problems.

That is exactly my point. The moment you walk out of the door, someone will mess with that ring circuit in time

 

[ZEDEZ]

Nothing wrong with a ring final circuit. It’s the uneducated/ unqualified who mess with them that causes the problems.

That is exactly my point. The moment you walk out of the door, someone will mess with that ring circuit in time

I think your overestimating the danger somewhat

Rfc's are great but i only really use them in kitchens now and unless its a large house would opt for 20a radials everywhere else

But lets be honest here, even in the case of a broken ring, the circuit will likely never see anywhere near enough load for any duration to be a danger of overloading the cable, unless maybe an exceptionally loaded kitchen circuit, especially given the case that even most ovens etc are on their own 16a radials now

Ive found probably hundreds of open ring circuits but next to none that i can remember with any signs of overload unless connections are loose

Id wager 90% of 32a ring circuits have never seen past 20 amps

Ok, so 10% of ring circuits do see more than 20 amps, and then what is the chance that on those ring circuits at some point a conductor will be disconnected?

This is what I find unacceptable

 

[ZEDEZ]

Absolutely nothing wrong with a ring circuit. I would never install a 'tree's circuit for sockets. Ever.

... yes, there is something wrong with ring circuits - as I stated in my post.

Why would you never ever install a tree circuit?

 

[telectrix]

That is exactly my point. The moment you walk out of the door, someone will mess with that ring circuit in time


Ok, so 10% of ring circuits do see more than 20 amps, and then what is the chance that on those ring circuits at some point a conductor will be disconnected?

This is what I find unacceptable

that is not the fault of the design of the circuit.what is unacceptable is numpties messing with things they don't have a clue about. would you condemn gas supplies in case some idiot turned the gas on then lit a match?

 

[Deleted member 9648]

A disconnected cpc on a RFC and the circuit will almost certainly remain safe. A disconnected cpc on a radial and everything downstream of the break will be potentially dangerous but still working. There are pro's and cons to both types of circuits, the OP has not considered the danger of a faulty radial, which can be equal to a faulty ring. Whist there are good reasons for radials, the OP's logic is not a reason to ditch rings.

 

[ZEDEZ]

A question for the OP, what is the potential for danger, please explain as then I may make a decision as to whether it's acceptable or not?

A leg gets disconnected, no one is wiser because everything still “works” and the circuit is overloaded

 

[ZEDEZ]

that is not the fault of the design of the circuit.what is unacceptable is numpties messing with things they don't have a clue about. would you condemn gas supplies in case some idiot turned the gas on then lit a match?

Yes but the point is people will mess with these things. With a radial or a tree, a disconnected live conductor means whatever is downstream stops working - fault is obvious and it gets checked out.

Not the case with a RFC. In my opinion that’s bad design. You have to factor this inevitability into the design, and I do, that’s why I don’t install RFC’s.

 

[Deleted member 9648]

Someone can replace the 32a mcb for a 50a on a RFC, that's their problem,you cant blame the circuit because someone cocks it up.

 

[freddo]

The only time I've ever heard a reference to a tree circuit was in this awful book.

 

[ipf]

The only time I've ever heard a reference to a tree circuit was in this awful book.

Says it all.....with that wazzock involved....probably why I've never heard of 'tree's......except at Christmas, of course.

 

[HappyHippyDad]

Funny that.

The RFC is an artefact of materials shortage during WWII, and isn’t really used anywhere else in the world spare a few exceptions.

If it were the best method, it would have been taken up elsewhere.

I don’t know why so many electricians love the RFC other than it’s familiar

I think you have to question ZEDEZ if it is likely that you are right or if a much larger number of people are right? It would be good if you could acknowledge you 'may' be wrong. I think testing a 'tree' would be a nightmare and people could add to it all over the place making it even harder. I do agree though that you do find quite a few broken rings but I still prefer them as 90% of the time they are intact and they still use less copper than a 4mm radial which can only be a good thing.

 

[littlespark]

The only time I've ever heard a reference to a tree circuit was in this awful book.

I just checked this link, and apparently the book is out of stock. Have you all been buying a copy?

 

[telectrix]

the dreaded CockUp strikes again.

 

[Deleted member 26818]

I instal radials all the time.
Mostly for lights.
Though one time when I added a couple of flouries to an existing circuit, I ended up making it into a ring to counter the volt drop on start up.

 

[Leesparkykent]

All this 4mm 32A radials that people bang on about, boils my pee. A 4mm radial on a 32A OCPD will hardly ever comply.