One ring main query

[andysefc]

Hi guys this is my first post so not too sure how it all works.

I have a question I need help with. Im doing a job for a friend who lives in a house built around the 50s. The house has only one ring main (upstairs, down stairs and kitchen) all on the one ring on a 30amp breaker.

I'm understood that there should be separate for each floor and also another ring for the kitchen. My question is is this safe to have?

Also two Double sockets are required in the kitchen. can I come from a socket in the bedroom above the kitchen down to the kitchen to two double sockets and then back up to the other socket in the bedroom upstairs keeping the new sockets within the ring. Ino this isn't ideal but as there is only one ring main is it ok?

Thanks for your help

Much appreciated[/b]

 

[SaladFingers]

You can spur one double socket off another. There's no need to have to ensure that new sockets are put in a ring.

Not particularly practical, but eventually it would be worth a rewire with separate circuits.

 

[AdrianUK]

You shouldn't really have TWO double sockets on an unfused spur. The max is one double or two singles.

If you create a fused spur then you could have two doubles, but, considering this is a kitchen & its likely that higher power devices will be plugged in then this may not be the best answer.

Your options are:

i). Two separate spurs into the kitchen, one from an existing socket & the second from a different existing socket or a junction box, each feeding one double socket.

ii). A (13A) fused spur feeding two doubles

iii). Put both the new doubles onto the ring.

Considering that its a kitchen, option iii would be the best.

Adrian

 

[SaladFingers]

You shouldn't really have TWO double sockets on an unfused spur. The max is one double or two singles.

I don't think he wanted to do that anyway, I think he wanted to put them all in the ring at first, but spurring off another socket is fine if you just want one extra here and there.

 

[333rocky333]

Also two Double sockets are required in the kitchen. can I come from a socket in the bedroom above the kitchen down to the kitchen to two double sockets and then back up to the other socket in the bedroom upstairs keeping the new sockets within the ring.

Much appreciated[/b]

Assuming the two bedroom sockets are at present linked between, and that link is removed or rerouted to incorporate the new kitchen ones thus keeping one entire ring and not a figure 8 and that the cables are in safe zones then that sounds acceptable.
You may have issues of exceeding your 30 amp limit if too many appliances are used together though

 

[bernardgreen]

You do show a lack of knowledge about electrical installations.

I would advise your friend to employ an electrician to design and install the new sockets. You also need to ensure the EXISTING wiring is able to take the extra loading from the new sockets. The fuse fitted may have been changed by a un-informed person to a value that is too large to ensure safety of the existing cable.

 

[ericmark]

The max is one double or two singles.
Adrian

No the max on any cable where the fuse is at the termination rather than origin which is what we have with an unfused spur is one device. And cable limited to three meters.

So one single or one double. You are not allowed two singles.

The problem when extending an existing circuit is:-
* - Keeping within the maximum values for the loop impedance specially with a single ring for whole house.
* - ensuring that there is in fact still a ring.
* - ensuring RCD protection for any cables which are not on the list BS 5467, BS 6346. BS 6724, BS 7846, BS EN 60702-1 or BS 8436 where buried in the wall.
* - ensuring that all sockets are RCD protected.
* - ensuring existing cables have not degraded.

Often in old houses one has two options either fit a new consumer unit or use RCD FCU (Fused connection unit) and then take extra sockets from that.

My parents house moved into in 1952 as new build had restrictions due to war at what could be fitted and it would seem except for council houses where the restrictions did not apply the norm would be 5 sockets in the house with a socket in every room which was a huge advance from pre-war where 2 sockets one upstairs and one down stairs would be the norm.

So when you go into a house with 20 sockets likely most of them are spurs and likely spurs off spurs which is dangerous. So job one is a good inspection and test to see what is really there. One can't assume two cables at a socket means it's a ring. Even today as seen at the top of the post some people think they can fit more than one socket to an unfused spur.

Also remember when you do work on a system you take responsibility for all from the DNO head to bit you have worked on your minor works or installation certificate will include everything about the circuit including earth type.

 

[Scoby_Beasley]

The max is one double or two singles.
Adrian

No the max on any cable where the fuse is at the termination rather than origin which is what we have with an unfused spur is one device. And cable limited to three meters.

Got my BGB on me knee at the moment, reading 433.1 and I can't see that. I was on the lash last night though.

 

[EFLImpudence]

Got my BGB on me knee at the moment, reading 433.1 and I can't see that. I was on the lash last night though.

It links to 434.2.1

 

[Scoby_Beasley]

Got my BGB on me knee at the moment, reading 433.1 and I can't see that. I was on the lash last night though.

It links to 434.2.1

Cheers EFLI. Things become clearer after a few coffees and a good fry up!

 

[ban-all-sheds]

Im doing a job for a friend who lives in a house built around the 50s.

Why, when you clearly don't know enough about it? Some friend.

You do show a lack of knowledge about electrical installations.

I would advise your friend to employ an electrician to design and install the new sockets.