old installation, only 1 set of cables.

[rabu]

Hi. can anyone help me, been doing few bits at home, swapping light switches and replacing some old sockets.. anyway after noticing that couple of sockets only had 1 cable in, so was thinking that they were spurs. That got me into tracing them, seeing how the house has been wired, so been looking in sockets to see what cables there is. Not got round to lifing floorboards. However most of the sockets iv opened (most in the house) only have 1 cable, some i know are spurs but some of the origionals from building only have 1 set inside also some are in stranded copper looks quite thick possibly 7 strands others in 2.5mm. Is there a way of wiring circuits that doesnt involve linking sockets directly from last socket? e.g: the use of junction boxes under floors? so can anyone shed any light on why i only have 1 set of cables in sockets? also lights have 2 or 3 (cant remmeber of hand) single red cables, all stranded copper with i think 2 black cables in roses with 1 red (cant be certain withought looking) Thank for any help.

 

[poirot]

The wiring you have discribed sounds like 40yrs+ old approx. Singles on lighting no earth. I would recommend that you contact a local electrician to carry out a periodic inspection report for you. This will determine the condition of the installation and will detail any recommendations. I would not carry out anymore work untill you have contacted an electrician. If there are no earths on the lighting and you have not got any RCD protection it would be unsafe to have any metal/chrome switches or metal light fittings installed. Be safe and get it tested.

 

[Sintra]

In older installations you may well find that the ring final only serves junction boxes and then a leg taken from each jb to the socket outlet.

 

[telectrix]

second that. sounds like JBs under floor. the 7 stranded cable will be 7/029 used up to the 70's. is it pvc though or rubber? if it's rubber, then it's a rewire.

 

[i=p/u]

suppose junction boxes somewhere and all spuring off them

 

[telectrix]

one way of compensating for the high cost of copper.

 

[tonys]

Agree with others on the JB setup, but Ive also seen a single ring either up or down with a socket spurred of each to feed either up or down.

 

[telectrix]

Agree with others on the JB setup, but Ive also seen a single ring either up or down with a socket spurred of each to feed either up or down.

but then he'd have 3 cables in a socket. he's only got one in each

 

[rabu]

thanks everyone. what the last 2 replies described are simalar as what iv been finding,or thinking that a main cable runs under floors with a cable of from JB up to sockets. regards to safty, the wiring is (most of ot) from 1965 when house was built. more new things added over years are 2.5mm solid core. all cable in house is PVC insulated just some is stranded and other is solid core. dont think theres earths in lights. thers been no issues with fuses blowing only cooker fuse (cooker element failed) or any other wiring issues. Might get it checked but wiring seems ok, no known issues. my main thing was the way sockets have been wired with 1 set of cables. Would this type of wiring be a ring final circuit or radial? Thanks again to everyone.

 

[rabu]

just a quick update, this is out main consumer unit/ fuse box. meter and DNO fuse replaced about 2008/09 Thanks again to everyone.

 

[telectrix]

only way to see if it's a ring is to look at the fuse. if 30A it should be a ring. then there will be 2 reds in the top of the fuse. with the main switch off, disconnect these reds and their associated neutrals and cpc's and meter red/red/, bk/bk, cpc/cpc. if you get continuity, then it's a ring.

 

[tonys]

but then he'd have 3 cables in a socket. he's only got one in each

Just thinking out loud about other things Ive discovered what the older generation used to get up too

 

[telectrix]

Just thinking out loud about other things Ive discovered what the older generation use to get up

good job we did get up to things or the younger generation would not exist

 

[IQ Electrical]

You might get it checked but it seems ok?

The wiring is in excess of 46 years old, installations have an average safe working life of between 20 and 40 years!

What were your insulation resistance values? I'm curious how you've arrived at the "seems ok" assessment.

 

[tonys]

just a quick update, this is out main consumer unit/ fuse box. meter and DNO fuse replaced about 2008/09 Thanks again to everyone.
View attachment 3312

Did you get that from boot sale and install yourself?

 

[poirot]

Are you replacing the switches with metal or plastic fittings? Just because the fuses havent blown does not mean that the installation is safe. It is recommended that an installation is tested every 10yrs. If there is a fault on a metal fitting it could become live and with no earths it may not be found untill it is touched.

 

[tonys]

good job we did get up to things or the younger generation would not exist

you ain't one of those baby boomer

 

[IQ Electrical]

I'll bet the Bill Switchgear fusebox has asbestos flashguards too!

Is this post a wind-up?

 

[telectrix]

you ain't one of those baby boomer

yep. daddy came back from the war.............

 

[telectrix]

jeez, that switchgear is nearly as old as me! car boot? more like gipsy horse fair

 

[Spudnik]

That old grey Bill CU will have asbestos flash guards and really should be replaced.

Also, the main switches also have a habit of snapping off when you go to isolate the installation, and it usually snaps in the closed position.

 

[IQ Electrical]

You got some good advice in the below post too, I mentioned IR values too!

http://www.electriciansforums.net/e...fusebox-cu-black-pitch-tar-service-cable.html

 

[tonys]

Nice little rewire for a part p spark

 

[rabu]

well PVC insulation, not rubber. also, if things were faulty (say in terminal connections) this would blow fuse? all fitting old and new are plastic. "average safe working life of between 20 and 40 years!" so every 20 years people need rewires? "seems ok" well apart from insulation still intack, better than being dust and dropping off. only half the wiring is origional, as it was a bungalow so in mid - late 70s dormers were build meaning upstairs isnt as old and is done in 2.5mm T&E. also a mate (semi retired spark) whos not seen instalation yet has said is should be ok, proving its PVC cable and nothing buring or getting hot or fuses blowing, indicating faults. but thanks again to the people who shed the light on the wiring issues.

 

[poirot]

It a bit worrying that theres been additions i.e. extra sockets and you are not sure if it is a radial or a ring main. Has the fuses been checked to make sure they are the correct size, or is there a nail instead. I have found fuses with 2.5mm copper rather than the correct sized fuse wire. Certainly stops the nuisance tripping ( fuse blowing ).