Spur from domestic circuit

[Supasox]

Hi

I'm a fairly competent DIYer with some previous electrical DIY experience but no training and I'd really appreciate some professional advice from someone with more knowledge than me.  Both my regular electricians are on holiday and others I've contacted have not replied, so I'm considering doing the job myself.

In my living room I am planning to add a double socket near the centre of the room.  This socket is intended for use by a new 2KW electric fire and a plasma TV.

My plan is to take a spur from an existing double socket, which is approx 2 metres away.

The existing socket has two cables connected and is original wiring and not spurred.  I have not checked whether the circuit is a ring or radial - I'm assuming ring, due to the age of the house (11 years) but, as far as I'm aware, that has little bearing in this case (happy to be corrected).  The ciruit is proteced by a 32A RCD.  I don't know what cable has been used, but I am aware that it's likely to be 2.5mmsq for a ring and 4mmsq for a radial.  Either way, I'm not sure I could tell just by looking at it or comparing it with known cable samples.

Given the above scenario, is it safe and legal to simply take a spur straight from the socket in 2.5mmsq T&E cable to a new double socket?  I am thinking that the spur cable would be protected from overload by the 13A plugtop fuses and from fault by the 32A RCD so a FCU is not required.

Assuming the above is OK, I'd appreciate advice about cable rating.  Given that I am not sure what cable has been used for the existing circuit, is 2.5mmsq cable OK to use for the spur if it turns out that 4mmsq has been used in the main circuit?  As I've said above, I understand the spur would be protected by the 13A plug fuse but I have read that spurs should use the same cable as the rest of the circuit.  Should I use 4mmsq cable instead, or is that just as bad if the rest of the circuit is 2.5mmsq?  I imagine getting 3 cores of 4mmsq into the socket terminals would be tricky!

The spur will run behind plasterboard on a block wall.  As it is in a 'safe zone' (horizontally level with existing socket) and the circuit is protected by an RCD, am I correct in thinking that no cable protection is required? - I'd clip the cable to the block wall.

One more thing: Am I correct in thinking that this work would not come under part P - i.e. doesn't require inspecting signing off.

Thanks for any help you can offer.

 

[Davethsparky]

My first thought is that you could do better than locating a 2kW heater so close to a plasma TV. 

my second thought is that one or the other of your regular electricians will surely be back from his holiday in the near future so you'd be better off waiting. Electricity kills in a fraction of a second and you don't get a second chance, so better to wait a week or two than risk it.

 

[SLIPSHOD & SLAPDASH]

Hi

In my living room I am planning to add a double socket near the centre of the room.  This socket is intended for use by a new 2KW electric fire and a plasma TV.

Thanks for any help you can offer.

Why are you putting a fire and your tv in the middle of the room, is the floor wood or concrete :tongue in cheek

 

[Blue Duck]

Went to see someone the other day and their TV was on the floor next to the cooker.

Yes he was watching it and yes it was in the kitchen.

He was rather unwell though.

 

[shanky887614]

Why are you putting a fire and your tv in the middle of the room, is the floor wood or concrete :tongue in cheek

typical diy'er probably means in the middle of one of the walls lol

 

[Doc Hudson]

One more thing: Am I correct in thinking that this work would not come under part P - i.e. doesn't require inspecting signing off.

Thanks for any help you can offer.

No you are incorrect. Inspecting is a requirement of BS7671 wiring regulations, which for a long time has recommended that all wiring alterations and additions should be correctly designed, installed, tested and certificate issued recording the test results. Part P is a separate building regulation where certain works should be notified for the issue of a compliance certificate. This work does not require Part-P notification. You should also note that BS7671 is non-statutory whereas Part P is statutory. DIY electrical work is legal in this country and if you so wish you can undertake the work, but in this instance I would recommend that you wait for your local electrician, as you need someone who can accurately identify the composition of the existing circuit first before deciding if it is safe to extend.

Doc H.     

 

[binky]

2 cables at a socket doesn't necessarily mean it's on a ring - it should be, if its on a 32A MCB, but it needs to be confirmed.

A 2kW heater on a spur. In theory all OK, but I would suggest a load like that running for long periods of time would be better on its own circuit. The other option would be a lower wattage heater, say 1 kW convection unit or something similar

 

[Supasox]

typical diy'er probably means in the middle of one of the walls lol

Yes, the TV will be in the centre of the room - and that's funny why?

My first thought is that you could do better than locating a 2kW heater so close to a plasma TV. 

my second thought is that one or the other of your regular electricians will surely be back from his holiday in the near future so you'd be better off waiting. Electricity kills in a fraction of a second and you don't get a second chance, so better to wait a week or two than risk it.

The heater is just a flat, wall mounted convector which blows the heat forward out of a bottom vent.  It won't be radiating much heat directly up to the TV.  I had the same set up at my last house and it was fine.

 

[Supasox]

2 cables at a socket doesn't necessarily mean it's on a ring - it should be, if its on a 32A MCB, but it needs to be confirmed.

A 2kW heater on a spur. In theory all OK, but I would suggest a load like that running for long periods of time would be better on its own circuit. The other option would be a lower wattage heater, say 1 kW convection unit or something similar

As I said in my original post, I imagine it is a ring, but I understand two cables could also be radial, including the possibility that it might be the last in the circuit and spurred, but I am confident, due to the age of the house and lack of previous alterations, that it is not spurred.

The heater (just a wall mounted domestic convector fire) has two power settings: 1 or 2 KW.  It's thermostatically controlled and will only be used as a 'top-up' to the gas/radiator central heating, so wouldn't get endless use.  Rather than have it on a spur, I could extend the circuit - i.e. include the new socket as part of the existing circuit.  I am aware that there are limits to the maximum safe/permissible cable length, so I was thinking along the lines of a spur to keep the cable length down - in other words, adding a 2m spur rather than a 4m circuit extension.  Maybe the circuit extension is the better option?

 

[M107]

If you are going to the trouble of running one length of 2.5mm² why not run in two lengths & just extend the ring?

As said by Doc what ever you (or your sparks) do should be tested & certificated.

Me I'd test to confirm it is a ring, extend the circuit to include a double socket (for TV & sky) & a switched fcu (for the heater).................then present you with the correct certification & an invoice for £60 - £100

 

[Supasox]

If you are going to the trouble of running one length of 2.5mm² why not run in two lengths & just extend the ring?

As said by Doc what ever you (or your sparks) do should be tested & certificated.

Me I'd test to confirm it is a ring, extend the circuit to include a double socket (for TV & sky) & a switched fcu (for the heater).................then present you with the correct certification & an invoice for £60 - £100

Thanks for the advice.  I was only thinking of keeping the total cable length to a minimum as I'm aware that there are max limits - although it would only be an extra 4m total to extend the ring (if that's what it is), and I've read that it's always better to incorporate additional sockets into the circuit rather that use a spur where possible.  Shame you don't cover my area or I'd have you come do it as soon as you're free!  TBH, for that sort of cost I'm coming round to the idea of just getting someone to do it for me.

 

[M107]

where are you, one of the forum members may be close.

 

[Supasox]

Wem, near Shrewsbury.

 

[NozSpark]

Wem, near Shrewsbury.

Just down the road from my brother then... he lives in Northwood,,  however that's an hour away from me

 

[steptoe]

I was in Shrewsbury a couple of weeks ago,  :|

 

[Andy™]

i was down that way a few years ago. got kicked off site for telling H&S bloke what i thought of his elf n safety.

 

[Sidewinder]

No you are incorrect. Inspecting is a requirement of BS7671 wiring regulations, which for a long time has recommended that all wiring alterations and additions should be correctly designed, installed, tested and certificate issued recording the test results. Part P is a separate building regulation where certain works should be notified for the issue of a compliance certificate. This work does not require Part-P notification. You should also note that BS7671 is non-statutory whereas Part P is statutory. DIY electrical work is legal in this country and if you so wish you can undertake the work, but in this instance I would recommend that you wait for your local electrician, as you need someone who can accurately identify the composition of the existing circuit first before deciding if it is safe to extend.

Doc H.     

Actually Doc,

The Society of Telegraph Engineers and of Electricians in their First Wiring Rules dated May 11th 1882, in their first introductory paragraph require inspection & testing of new electrical installations, and in paragraph 17 require periodic testing.

So, yes for a VERY long time!!!

 

[Essex1]

i was down that way a few years ago. got kicked off site for telling H&S bloke what i thought of his elf n safety.

Well done you.  You must be proud.