New Wiring

[MickyD]

Hi, Hope someone can help. We are at present having our conservatory extended. In the original part of the conservatory there is one double electrical socket. The electrician is using this to supply power to the now larger conservatory and is adding five extra sockets. On closer inspection of his work so far, the socket he is taking power from only has a single cable coming into the back of it so in my mind, this socket is a spur. The electrician has created a new ring main coming from this spur so it seems the wiring is going from a ring main to a spur then to another ring main. Now I am no expert but this seems wrong. Can anyone confirm my fears please or is this ok? Also, the electricain has placed the new ring main cables inside the cavity wall of the conservatory and along the floor which has yet to be screeded. I have read that cables should not be put inside cavity walls as damp can cause the cable insulation to rot. is this so??

Many thanks for any help offered.

 

[Modernelectric]

He shouldnt be making a ring main from a spur, are you sure he hasnt just extended the radial as this would be fine.(as long as is fused properly) if hes laying the cable in the floor (less than 50mm embedded) it should have an earthed metallic covering of some sort, either capping or conduit, but from what im aware it is ok to run a cable in a cavity wall and have seen it done many times.

 

[MickyD]

Thanks for the quick reply. The cable in the floor is in plastic conduit and will be covered by 100mm screed. With regards to the ring main, all i can see is a single cable coming into the back of the pattress box from the house and from there the cable goes round the outside of the conservatory to each socket then back to the original power socket. he has done no other work as he does not have access?

 

[Modernelectric]

so that would give you 3 cables in the original socket and 2 at the other points in the conservatory? do you know if an rcd is fitted to your socket circuits?

As long as there is a minimum of 50mm screed on top of the cable then plastic conduit is acceptable for running under floor.

 

[MickyD]

Yes that is correct, three cables in the original socket and two in the rest, also, there is an RCD on the main consumer unit for the whole house. The work this guy has done so far has seemed suspect which is a shame as the other tradesmen have been excellent.

 

[Modernelectric]

is he from a large company or is he a sole trader? do you feel you can speak to this guy about it? also does he have any trade associations such as niceic or elecsa because this should be the case if he is doing work involved with part p of the building regs. all i can say is if you are unsure on his methods then speak to him about it and ask him to explain what he is doing, i wouldnt have any problem explaining to my customers about my installation methods. i hope all works out well for you mickyD.

Martin.

 

[MickyD]

Do not know about any associations he has, I get the impression he is sub contracting for the company that is doing the works. I guess I will ask him but wanted to confirm my fears first., but I do get the impression that he has done this because it is the easy option (just a feeling I get about the guy) many thanks for your help and advice though.....

 

[Modernelectric]

it would be easier to extend the radial though presuming that it is fused from a 13 amp spur presumeably a close distance to the conservatory, maybe he has just made a mistake and pulled an extra cable in, and it is quite easily solved as long as he doesnt connect the cable that would make the ring.

dont lose faith in him just yet, everyone makes mistakes, does the work he has done look of a good quality?

 

[sparks1234]

As said above, he can put additional sockets in if he protects it from a spur, another thing to consider is a bit of engineering judgement, what are you looking at running on your 5 sockets? heating? lighting etc etc, if it is heating then you may be in trouble with the load.
You need to ask him which organisation he is certifying the works through

 

[gaffer]

If the original socket is spured off a ring main ie back to back with a socket in the house,he may be planning on forgeting the spur and back into the socket in the house and breaking into the ring there.He shouldve still checked existing loading on the ring.Been called out a few times in the winter when customers have plugged in 3kw heaters and wondered why the mcb/fuse goes in the board.Bad planning/easist way of doing things atitude of original installers.
RANT OVER!

 

[SirKit Breaker]

Just doing a kitchen at the moment, relocating existing sockets a bit of extending here and there on recently certified circuit....................I found 5 cables in one socket of varying sizes, a ring within a ring on a radial circuit, and a ring circuit with a difference..........one end is labelled up kitchen sockets and it returns to the CU in the one laballed up cooker..........nice. And all this was certified at CU change within last 12 months.....i`ve made the neccesary call to the NIC who the intaller is registered with.

Luckily both correct ends of the ring are accesible, and the cooker needs a 6mm anyway so ripped the lot out and started again, even the plasterer noticed it was a mess and hes scared of electric.

 

[flukey]

He shouldnt be making a ring main from a spur, are you sure he hasnt just extended the radial as this would be fine.(as long as is fused properly) if hes laying the cable in the floor (less than 50mm embedded) it should have an earthed metallic covering of some sort, either capping or conduit, but from what im aware it is ok to run a cable in a cavity wall and have seen it done many times.

since when was it allowed to run cables in between cavities big no no from me

 

[Spudnik]

Cables in cavities has been a big no-no fir some time now.

Still see it though.

 

[flukey]

i am very surprised any qualified spark would see it as acceptable tough

 

[Mark.W]

Let him finish the job first, no use criticizing his work half way through, just give him a chance!