Why aren't ring circuits banned?

[Andy78]

With all 3 doubles on it?

Yes, why not ?

 

[Pat H]

Yes at 2.5mm T&E I'd be limited to 20A but will have a 16A breaker anyway.
I would save 6m of 2.5...
Not sure what's happening yet with under floor insulation but I don't think that will have much impact.

 

[DPG]

A radial for each socket in a summerhouse? Am I missing something here?? Daz

 

[Andy78]

Why a 16A mcb ?

 

[Hellmooth]

Run a 2.5mm for the 3 sockets and stick it in a 20a, or 4mm on a 32a as long as it isn't covered in insulation not going to be a problem.

 

[Pat H]

I have a hot tub coming off the CU in the summer house and need some capacity later for the heatpump.
Don't need more than 16A don't even need that. I'd rather the local 16A breaker tripped should some idiot add 6 electric fire in the future.

 

[westward10]

They are sockets has to be a ring final even if it is just one socket.

 

[Midwest]

RFC were supposedly designed just after or during WWII, because of copper shortage, although other reports/pieces dispute this. But I suppose a RFC at it's maximum design length, achieving an acceptable Zs result. Whereas a 4mm radial, with similar acceptable Zs result, would possibly have to be made from two radials, therefore costing more in materials?

 

[valleybilly]

Is is not ideal to have immersions on a ring final but they are nearly always on the lightly loaded bedroom circuit. Can only assume the 20A was put on because it wasn't switched through a FCU?

\
It was a spur off the ring with no fcu . 16 amp rcbo sorry . It did feed an fcu to some external lights / now disconnected due to faied insulation when connected. Give this man a free xmas tree !

 

[westward10]

Why not put a FCU on the immersion so you can upgrade to 32A.

 

[sam400]

Absolutely hate them! Can't see a place for them in a domestic situation.
Have spent 6 hours this week repairing one. ( boiler mounted over socket with broken
CPC + multiple non-compliant spurs)
I ve got another 3 to repair on other jobs - can't wait!

 

[valleybilly]

Why not put a FCU on the immersion so you can upgrade to 32A.

They are going to have a combi fitted so spur being removed. Also populated cu so can split this ring to feed 2 x bed sockets only and use the return to go on an 6 amp rcbo and put the outside light on there own curcuit . PS my name is Kevin and im a kitchen fitter .

Only went to fit the Kitchen n got this = pic

all the house was on on 1 general Failed tested rcd and when she put the electric heaters on as the rads where off (boiler change) the house shut down . The light ins tests are.85

Any one near Prestwich Manc want this one ? LOL

 

[kingeri]

Absolutely hate them! Can't see a place for them in a domestic situation.
Have spent 6 hours this week repairing one. ( boiler mounted over socket with broken
CPC + multiple non-compliant spurs)
I ve got another 3 to repair on other jobs - can't wait!

So you hate them because somebody poorly installed one?

 

[sam400]

So you hate them because somebody poorly installed one?

Yea that's right

 

[kingeri]

Yeah I hate lighting circuits cos I found a metal switch that wasn't earthed.

 

[sam400]

Yeah I hate lighting circuits cos I found a metal switch that wasn't earthed.

Ban them!

 

[7029 dave]

I for one do not understand this thread, RFC are the recognised circuit,been going for decades.Is the dislike just pure laziness.?Is the today Electrician unable to fault such a circuit or even able to install it.? This is annoying me big time."!!

 

[chronyx]

I for one do not understand this thread, RFC are the recognised circuit,been going for decades.Is the dislike just pure laziness.?Is the today Electrician unable to fault such a circuit or even able to install it.? This is annoying me big time."!!

The today electriciam are able to fault find it. I was is fault finding when I done found the fault what made me post this.

 

[7029 dave]

The today electriciam are able to fault find it. I was is fault finding when I done found the fault what made me post this.

I read your OP, they weren't even about in 1949, it was all radials 15amp at that, with electric trees growing out of them. Do you know what I am saying.?

 

[chronyx]

I read your OP, they weren't even about in 1949, it was all radials 15amp at that, with electric trees growing out of them. Do you know what I am saying.?

Give or take a decade or two

 

[7029 dave]

Give or take a decade or two

I have just googled it, and they do say it came out after the war, Rubbish all the rewires I have done in that era, it is all radials, the RFC took off big time in the early 60's.

 

[7029 dave]

Just to add, PVC was not in till the late 50's, I for one have never seen RFC wired in VIR rubber never.! But if so I stand corrected.

 

[chronyx]

Now you mention it I think you're right, not that I've seen much VIR

Slight side track, who knows the cause of 'weeping' older cables and green copper? I had it at the back of my mind it was a bad type of plasticiser that was used but I'm not certain.

 

[7029 dave]

Now you mention it I think you're right, not that I've seen much VIR

Slight side track, who knows the cause of 'weeping' older cables and green copper? I had it at the back of my mind it was a bad type of plasticiser that was used but I'm not certain.

Yes you are correct, with the early pvc cable, nothing wrong with it other than quite messy, just wipe it off. green gooey mess.

 

[7029 dave]

 

[Andy78]

Yes you are correct, with the early pvc cable, nothing wrong with it other than quite messy, just wipe it off. green gooey mess.

When I have encountered the goo before, the insulation has been wrecked.

 

[7029 dave]

When I have encountered the goo before, the insulation has been wrecked.

I have never experienced this Andy. Learning all the time.

 

[Andy78]

I have never experienced this Andy. Learning all the time.

One example was a house with estimated 40+ year old twin pvc cable. Only one circuit had evidence of goo, the downstairs lighting, but it was evident at all points on the circuit. All circuits displayed degraded insulation values, but this circuit was by far the worst.
It had been running at around 6-7A for decades due to chandeliers full of 60W lamps. My theory is that the heat involved in the load combined with the already degraded insulation helped to displace the plasticiser which added to the cable degradation, and so on and so on.
No goo was present in any of the other circuits of the same age, but these had probably not seen a sustained load as high in relation to their CCC.

Only a theory mind you and I would wecome education from others experiences.

 

[kingeri]

This is exactly what my house was like when I moved in, the lighting circuit had the green goo but the other circuits didn't, and I believe they were all of the same age.

 

[westward10]

The green goo is a component of the insulation and should not give poor IR readings.

 

[Andy78]

The green goo is a component of the insulation and should not give poor IR readings.

If the goo is a component of the insulation, and it's running out of the ends of the cable, is this not indicative of a breakdown of the insulation ?
In my example there were poor IR readings on all circuits mind you, but the worst featured on the gooey circuit. The insulation was also physically degraded on this circuit, being brittle and cracking at the stripped ends.This could have been just due to current related heating, but I feel that lack of a plasticising agent cannot have helped.

 

[Midwest]

The video Dave posted does describe the fault, if you have a watch. I've come across it numerous times and I advise my client and referenced this pdf file;
http://www.napitonline.com/downloads/CP 6 07 P 28 Ask Eddie Green Slime.pdf
Quoting from it;
'The green slime is Di-isoctyl Phthalate. It is a bi-product of a reaction between the plasticiser in the insulation and the copper conductor. This plasticiser had an anti-oxidant added to it between 1965 and 1971 – and so is not so common, although these symptoms could have become more noticeable following the installation of a central heating system, for example, as it is thought that high ambient temperatures accelerate the process'.

In the situations I've encountered, mostly minor works, the IR readings have been acceptable but lower than other similar installations not affected by slime. In these instances, my client's have chosen not to replace cabling. However on one job, the green slime was quite bad at the light switches and in numerous JB's under the floor. In this instance, my client decided to rewire. But his decision was influenced by the poor general state or the wiring, diy additions made and the fact that he was renovating the property.

This fault will affect the flexibility of the cables, so will not present an issue, until cables are moved. Most likely, when the client has swanky new metal pate fittings installed!

Personally, if I found this in a property I had bought, I would rewire regardless of any test results. We are talking of cabling over 45 years old, and at some point would require rewiring in any case.

 

[David Prosser]

I have just googled it, and they do say it came out after the war, Rubbish all the rewires I have done in that era, it is all radials, the RFC took off big time in the early 60's.

Hi my house (built 1960) had a one RFC for all sockets in rubber insulated. Most of the insulation crumbled as I removed the cables. I will have look through later for some pictures but I think I only took a few of the lighting circuit as the rubber had melted in thatone.

 

[mydigitalhome]

All types of circuit have their place !
Generally find people who like radials test with a plug in socket only and hope all the sockets work.. Saves time having to do continuity test and limit everything else out. Tick for continuity only with no values. Fell about laughing first time I saw it on a test sheet. Often happens in Europe as often don't need need to be a sparks to sign off tickets just need to have a degree in any subject. Madness but still don't seam to have loads of deaths from it.