Split Concentric advice

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speccyget

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Hi,

A friend has asked me to finish a job he started because he is a bit stuck. But so am I. He has started installing power to his detached garage which is in a block about 20m away. He has started from the garage and is working towards the house. It all looks very good so far. Garage consumer unit with 6a mcb for lights and 16a for 2 radial sockets. 16mm meter tails to a dp isolator switch. Then he has used 10mm split con cable which is burried in ducting all the way to the back of the house where there is a massive coil which needs to be connected to the house.

I have never used contentric before and am wondering how to get it to the consumer unit which is at the front of the house.

Can it be terminated in a weatherproof enclosure and then continue with 10mm T&E to the CU? I think I should probably just walk away but I am still curious as to how to do it. Any advice greatly apreciated.

 
one way or the other it needs to get to the ccu.. so why terminate at the back of the house? conduit down the side of the house, hole through the wall into ccu... job done ;)

Guiness Drink

 
Isn't split concentric what dno use. If so surely it would not comply with BS 7671 so you would not be able to certify it.

batty

 
ive not used it myself but I have seen pictures of split concentric with a main line conductor surround by separate neutrals and separate cpcs... ?:|

Guiness Drink

 
The stuff dno use is different aluminium centre core and copper outer core which is combined neutral and cpc. I cannot comment on the batt stuff as I have never used it.

Batty

 
one way or the other it needs to get to the ccu.. so why terminate at the back of the house? conduit down the side of the house, hole through the wall into ccu... job done ;) Guiness Drink
The house is mid terraced, the split con looks like it could be a real pain in the ar*e to route through the house without ripping the walls down. Plus, I forgot to mention, he hasn't left enough cable to reach the CU.

 
The house is mid terraced, the split con looks like it could be a real pain in the ar*e to route through the house without ripping the walls down. Plus, I forgot to mention, he hasn't left enough cable to reach the CU.
Don't you hate it when they do that.

 
yeah thats the stuff.. so long as its mechanically protected(external)you should be able to run it straight to the ccu. ;)

Guiness Drink

 
Hi Speccy.

I dont see anything wrong with terminating it then carrying on in T&E to the C.U.

I have one question for you though ...as the job will have been completed between the two of you who is going to issue the EIC and Self Certify it. It deffo comes under the Building Regs !

 
:( :( :(

i see your problem..

well terminate on the back wall in some conduit round terminal or if not an adaptable box. T&E up the outside wall in conduit. Drill through lift floor boards across to front of the house and down to ccu in a nice LARGE piece of surface trunking ; \... just as a little reminder for your friend ! :^O :D

Guiness Drink

 
:( :( :( i see your problem..

well terminate on the back wall in some conduit round terminal or if not an adaptable box. T&E up the outside wall in conduit. Drill through lift floor boards across to front of the house and down to ccu...
That sounds like a good idea.

:( :( :( ...in a nice LARGE piece of surface trunking ; \... just as a little reminder for your friend ! :^O :D

Guiness Drink
Oh I think he would love that. lol

 
DNO commonly use straight concentric. this has a central live core, and unsheated outer cores used to neutral&earth. you can only get TT or PME from this cable, so cant be used under 7671

Split concentric is slightly different. it has a central live core, and surrounded by uninsulated cores for earth part way, and insulated cores for neutral the rest of way. this is sometimes used by DNO for TNS, and there is nothing wrong with using it for7671 wiring. can be easier than SWA for many things, just it doesnt give the full protection that SWA does

to terminate, simply strip outer black sheath, and seperate neutral & earths and continue as nomal T&E (just you have more cores for neutral & earth. you will need a large size sleeving for earth, or split it into 2 and stick into terminals as normal

you can get heatshrink breakouts which cover where the outer sheath is removed, but there is no need to use it. it can safely be terminated direct into a normal CU, just make sure outer sheath is exposed inside the CU like you would any other cable

 
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