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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Broken Ring https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1086215279 Message started by tidy on Jun 2^nd, 2004, 11:27pm

Title: Broken Ring
Post by tidy on Jun 2^nd, 2004, 11:27pm

A ring does not appear to have ever had a return leg. Is there a quick way of finding the most distant outlet from the cu, or do i have to disconnect at intervals and test??

Title: Re: Broken Ring
Post by Beanzy on Jun 3^rd, 2004, 4:53am

Hmm, there is, but it involves a link at the consumer unit, which I'm not sure should be done unless you've actually been physically shown how to do it safely. It's a visual/safety thing really. I could describe it and you could try but do it wrong or not un-do it correctly and there could be real problems. It's not that I don't think you can do it, just I'm not sure my description would be adequate. Disadvantage of the internet.

What do others think?

Title: Re: Broken Ring
Post by HandyMac on Jun 3^rd, 2004, 6:42am

I agree. You don't want a team of hungry lawyers pursuing you.

Andrew

Title: Re: Broken Ring
Post by rabbit_rabbit on Jun 3^rd, 2004, 7:28am

I know the 'trick' ya mean it also involves use of a very low resolution Ohmmeter (as in R1 + R2) and the average meter is not good enough even a Robin continuity is marginal.

I am afraid Tidy it is a case of going through it rather boringly to find the break (all sockets and junction boxes). May I ask how do you know there is no return?

RR

Title: Re: Broken Ring
Post by Beanzy on Jun 3^rd, 2004, 7:41am

Yup if it's old enough or been bodged could be run back to another fuse or MCB, or to the lights etc etc.

Bit of an unfair advantage here as my Fluke does 0.1 Ohm. at +-9% . Mind you at �180 or so it should do something worthwhile for a living. I should spend more on clothes and less on this clutter.

Mr Beanzy the"Gadget Queen"

Title: Re: Broken Ring
Post by supersparky on Jun 3^rd, 2004, 9:47am

erm...all seem to have ignored one thing;
what if its not ment to be a ring?
no one asked the raiting of the breaker and size of cable
...

ss

Title: Re: Broken Ring
Post by Lectrician on Jun 3^rd, 2004, 10:08am

Very true Super S.

The way he words his most is as if there is simply no cable, not a break in a cable.

Tidy, do you know the cable is missing by looking in the fuseboard?? And seeing just one cable at the fuse??

Title: Re: Broken Ring
Post by plugwash on Jun 3^rd, 2004, 10:24am

yes radials (no return leg) are fine provided the breaker is suitable for the cable that is
2.5mm - max 20A
4mm - max 32A

also if you do decide to convert to a ring bear in mind that rings have strict rules on spurring and radials don't so you must ensure you know about all spurs before you even consider such an operation

Title: Re: Broken Ring
Post by Lectrician on Jun 3^rd, 2004, 10:40am

if it is a radial, then 'if it aint broke - dont fix it'. If you have not had any trouble with overloading, and it is a confirmed radial, i see no problem with it.

Recently, the floor area coverage of ccts has increased.

A 2.5mm radial can serve an area upto 50m/sq.

Title: Re: Broken Ring
Post by L.Spark on Jun 3^rd, 2004, 3:23pm

i was under the impression it was 75sqM, i must check again!.
might be worth checking that circuit breaker just encase tho. �::)

Title: Re: Broken Ring
Post by Lectrician on Jun 3^rd, 2004, 3:40pm

i thought is was....

ring 100m
30amp rad 50m
20amp rad 20m

BUT, someone pointed out on the forum that it has changed since i last looked.....

ring 100m
30amp rad 75m
20amp rad 50m

I checked the regs, and thats it.

Title: Re: Broken Ring
Post by L.Spark on Jun 3^rd, 2004, 3:52pm

yea the latter one seems to be the ticket :P

Title: Re: Broken Ring
Post by rabbit_rabbit on Jun 3^rd, 2004, 9:25pm

lol SS stop asking sensible questions would ya? Hence my question at the end of my last posting.

Beanzy - I was think of one those Wein Bridge instruments that ya can get from RS and cost about �900 and have a resolution of 1mOhm (yes, 1 milliOhm!).

They are superb instruments - I have to laugh seeing some sparkys checking zero with them by linking what look like two croc-clips. No reading, puzzled looks on their faces errr.... err.... "...it's faulty...". Nope mate its a four terminal devices (as in Wein Bridge) look very carefully at those croc-clips cntacts top and bottom on each! Red faces all round!!

Anway with those things ya ca find a needle in a haystack of wiring.

RR

Title: Re: Broken Ring
Post by tidy on Jun 3^rd, 2004, 11:49pm

To clarify: One 32A MCB feeding 2x 2.5mm T&E
One T&E feeds 2 floors of reasonably sized victorian house inc a kitchen extension. The other does not appear to energise any socket outlet in the house. It may be that it is the return leg which is severed/ disconnected. The ring would be way too big even if it were a ring. To top it all, the kitchen, where all the hungriest appliances are, is at the end of the line.

Have told householder that it should be seperated into prob 2 or 3 seperate rings. In fact, I shouldn't even touch it, until she agrees for me to do that-

There is no easier way- I think. Some people just wont be told that something is dangerous.

"But it works!" they say.

"But its dangerous!" :o

"But it works!"

Walk away.

Title: Re: Broken Ring
Post by supersparky on Jun 3^rd, 2004, 11:54pm

just thinking here, are you an electrician? hate to say it but by the sounds of this instalation i wouldent go near it and thats comming from someone qualified, your ring splitting sounds a good idea though

ss

Title: Re: Broken Ring
Post by rabbit_rabbit on Jun 4^th, 2004, 1:07pm

Tidy - sounds like ya a sparky mate. Walk away! I had a like situation, called out cz "..a socket ahs stopped working..." adding "... my son started to be trained as an electrician but gave up..." (so what?).

Anyway get there, socket in question was a spur off the immersion heater radial circuit (gulp), element had blown its lid and took out the fuse, hence no power at socket.

Now if ya think that was bad - the socket in question had been added by the son, using 1.00 t/e lighting cable! Told them the socket is dangerous, they said "...but it's been working.." "So what I reply, its dangerous"... "So ya not going to fix it then?" "Nope, bye". Ya can take a horse to the watering hole but....

RR

Title: Re: Broken Ring
Post by tidy on Jun 4^th, 2004, 5:27pm

I am a sparky, but not a house basher! I now am a maintenance spark for the water board. Pumps, vs drives, motor controllers, plc's, that kinda thing.... and installs.... used to do all kinds of other leccy work, theatre electrics, lighting, rigging etc... but steady job pays the rent now...

If a friend is buying a house, I usually have a nose at the electrics- it is truly shocking, the standard of workmanship to be found, bad installs which have been tinkered with by arseholes with screwdrivers.

Title: Re: Broken Ring
Post by rabbit_rabbit on Jun 4^th, 2004, 5:30pm

Sorry I was wrong about the cost of that low Ohmmeter from RS its a more resonable �237.75 at -

http://rswww.com/ and look up product code 611-953

Really is a fantastic device for fault finding with a resolution of 1 milliOhm!

RR

Title: Re: Broken Ring
Post by Beanzy on Jun 4^th, 2004, 8:22pm

Off fer a snoop. Though I may as well pack it in if all I do is keep spending it on Gizmos.

And so the gadget queen prances of into the forest of kitdom to be savaged by the online wolves.