creating a series of spurs Ask questions and find answers to many subjects relating to electrics and electrical work

[laufy786]

Hello,

Recently (about 4 months ago) had a room re-plasted & the twit who did it took all the sockets except for the main one. Now I'm pretty sure I'm allowed to create a series of spurs from this as long as the socket only has two wires. (please correct me if I'm wrong)

The problem i have is I'm going to have to create a pipeline by either routing or drilling through the new skim & plaster all the way along the walls of the lounge as I really don't want to use pvc trunking, but I read somewhere that depending on what I fill the pipeline with (probably a mix of cement & bonding, don't want to use polyfiller for such a long line) & depending on how much heat the plaster & the skim hold will affect which type of wire should be used & possibly the lengths also? Is this correct?

I did have some 1.5mm T&E remaining from the new spotlights fitted but have also read that this isn't suitable for sockets would 2.5mm be OK? I was thinking maybe an even higher thickness (4.0mm) to be safe side. Or am I being paranoid??

If someone could please give me some pointers for this as it would really help me put my mind @ rest, i don't really want to be thinking the wiring could catch fire @ any second.

Apologies for the long details but would like for everyone to understand what I mean!

Thanks

[kuzz]

Get an electrician in to do the job properly. You can't put a price on your/your family's safety. Whatever it is your trying to do sounds wrong and dangerous

[ericmark]

2.5mm² is smallest twin and earth allowed direct onto ring.
Only one spur i.e. one double socket allowed if unfused 433.1.5
For spur using an fused connection unit connected directly or not connected directly (the latter with 2.5mm²) to the ring the number of socket-outlets supplied from a fused connection unit is dependent upon the load characteristics, having taken diversity into account. After the fuse 1.5mm² twin and earth is allowed.
I don't know what you mean by a pipeline? You may go up or sideways from socket directly but no diagonals. There are zones and once to leave zones you must be 50mm from surface of wall this includes back of the wall.
As to materials which may contact the cables I am not sure. There is a problem with some compounds removing the polymers from the cable.
Two wires into a socket does not guarantee it is part of a ring main.

[laufy786]

Thanks for the response ericmark.

What I mean by a pipeline is to create a route within the walls by 'chain-drilling' into them to create a parth horizontally along the wall so can create a new double socket outlet into the wall & follow this arround to the other side, creating four new double socket outlets. Then to fill in the pipeline I have made by routing or 'chain-drilling' as I've heard it being referred to, is with a mix of bonding & cement.

I am aware i can only go vertically or horrizontally but I will be going horizontally just above the skirting boards. What I would like to know is will there be a danger if the T&E is packed in with a mix of bonding & cement to fill in the pipeline I will have made for the actual wire to go into?

Also how can I find out if that is socket is off a main ring? Because it is the only outlet in the room.

[ericmark]

The leaching of plastiser in PVC cables is complex and I don't understand it myself so I will not comment on fill material. Also there are socket heights to consider and this is building regulations and again I am not sure if you are permitted the heights or if it would be considered your method would seriously weaken your wall. As far as ring main is concerned only acid test it to measure with meters. With all power off you should get continuity between both lives, both neutrals, and both earths. Approx 1 ohm. You should also check the earth loop impedance and according to what trips it is protected by calculate if this is within allowed results. This is why kuzz is telling you to get an electrician to do the job. I take the view better to tell you what you ask rather than allow you to botch the job. As an electrician I would use plastic oval conduit for going through walls so any cement does not touch wires them selves. Before plastering we use capping but once plasters we use conduit as it requires less plaster to be removed and as long as no wall paper has been used easy to plaster over again.

[laufy786]

OK, so if I used a FCU which replaces the only double socket thats in the room, it would be ok to run a length of wire to create one outlet, then from the newly created outlet, I would run another length of wire to create the second. I intend to create new outlets, so running the wire from the FCU would be ok to do this?

This is just very confusing for me as the outlet that is currently in the room is the only one in there & it is a large through lounge. However I do understand that it would be better to use a FCU.

Please advise, thanks

[ericmark]

I have already given you what the regulations say. Yes you can run a load of socket outlets from a fused spur. You are allowed one socket outlet from unfused spur. If those before you have followed the rules then two x 2.5mm² cables in a socket supplied from a 30 amp fuse should be a ring. But if someone before you has broken the rules then this does not hold true so you must test it is a ring. Any electrical work must be inspected and tested once complete. Work in kitchens, bathrooms or involving new circuits or change in consumer unit must also have the paper work logged with the council. You seem uncertain of what you are doing and mistakes with electricity can be fatal. You would never forgive your self if any of your family got injured. Is it really worth it? or would it be worth the extra money to get someone in to do the job? Remember the professional will have special chasing machines and will do the you in a fraction of the time it takes you and likely with less mess. Plus all the paperwork required if you ever sell your house.