M

mattcos1972

Morning all.

A few of you may know that I am changing / relocating a consumer unit as one of my jobs for NICEIC assessment to get Part P.
I need a bit of advice.................

I have a big shed / office out the back of my garden fed at the moment by a SWA looped into the mcb for my final ring (yeah I know.....I didn't put it in :D)
The problem arises at the shed end of the installation.......The shed is taking its earth from the main house cpc (literally just taken off the armour of the cable and terminated at each end). Now I know that as its a separate building it needs a separate earth to comply with 7671, so an electrode is needed to provide earthing for the shed.
My question is this? When I do the PIR, can I put in the notes that the shed is not earthed correctly, mark it as a category 1 fault, and hook it back up using the house earth as was, or do I need to make it good with an electrode, even though the work was not mine? I am asking as when I change a consumer unit does that make all the circuits "my responsibility"? :confused:

Cheers in advance

Matt
 
No reason why you dont just install a rod at the shed, bond the armour at the supply end and thats it.

And no, you do not become responsible for everything just because you changed the CU.

There is a sticky at the top of the forum detailing this.

:)
 
No reason why you dont just install a rod at the shed, bond the armour at the supply end and thats it.

And no, you do not become responsible for everything just because you changed the CU.

There is a sticky at the top of the forum detailing this.

:)

Cheers Jason. I think the rod is the best bet and thanks for clearing up the CU matter for me. That was the sticky bit for me; just wasn't sure if I immediately took responsibility for the lot or not.
Nice one chap. Thanks, yet again.

Hi Flukey.
I know what you are saying with the extraneous metal etc. but the shed installation cant take any earth from the house whatsoever, the only thing that can be earthed from the main earthing block in the house is the armoured cable, and that must not be bonded to the shed earth. The shed installation must get its earthing (for cpc and bonding) from elsewhere (ie a spike) and be completely independent from the house, so that earth faults can't be transmitted from building to building....... That's how I understand it anyway :confused:

I'll just wait for the lynch mob to tell me I'm totally wrong!!! :D :D :D

Thanks again guys.
 
That's how I understand it anyway :confused:

I'll just wait for the lynch mob to tell me I'm totally wrong!!! :D :D :D

Thanks again guys.
yes mattcos, you are wrong :p

you can export the earth but it has to meet certain criteria and if you have no extraneous conductive parts you are best leaving well alone ;)
 
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i had a job that the nic inspected, an existing 6mm armoured was feeding a shed c/u (PME system) he said that it should really have a seperate earth , But as it was existing he advised that i disconect earth conection at the house end and install earth rod , as he didnt like the fact that under a fault it would have to travel via the house,
 
i had a job that the nic inspected, an existing 6mm armoured was feeding a shed c/u (PME system) he said that it should really have a seperate earth , But as it was existing he advised that i disconect earth conection at the house end and install earth rod , as he didnt like the fact that under a fault it would have to travel via the house,

Argghhh!! :eek: :eek: :eek: lol! Cheers Eddie. That's what I originally heard - don't export earths! However master Flukey above has made a blooming relevant point and it seems to have been backed up on a few chats in Voltimum where Select have said almost exactly the same thing as Flukey.
The system feeding my house in TN-S so should be even more reason to leave the existing earth arrangement in place (assuming it performs as it should), and there's no extraneous conductive parts in the shed, the whole thing's wood and the inside is raised floor and plastered walls.
At the end of the day, like with your job, the NIC can only advise me to drop a spike in if they don't like how things are arranged. Also like you I didn't put the installation in, just inherited it. I think a call to the NIC may be in order in the morning as I can't find anything in 7671 that gives a definite instruction on it and just about everyone has a different and valid take on it!! :eek: :eek:

Grey area? Much?? lol!!
 
i had a job that the nic inspected, an existing 6mm armoured was feeding a shed c/u (PME system) he said that it should really have a seperate earth , But as it was existing he advised that i disconect earth conection at the house end and install earth rod , as he didnt like the fact that under a fault it would have to travel via the house,
think i would have argued that one eddie :p

Its not a code 1 fault
its not a fault of any code
 
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its not a fault of any code[/QUOTE]


True, As long as youve got a good earth via the armour, and there is no equipotential bonding and youve got an RCD, whats the problem?
 
think i would have argued that one eddie :p


its not a fault of any code


Flukey,
Sorry to be a pain chap, but do you know where your info is verified in 7671? I am not doubting you for a second but I'd love to actually see something official on the subject. The nearest I can get to it is 542.1.8, p126, but I am not sure that it's relevant to this situation.

Really appreciate your input; and everyone else, too.

Matt

its not a fault of any code


True, As long as youve got a good earth via the armour, and there is no equipotential bonding and youve got an RCD, whats the problem?[/QUOTE]


I am with you Simon. The problem is that there is a school of thought that says separate structures need separate earthing!! :eek: :eek:
Curse them!! lol!:D
 
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I am with you Simon. The problem is that there is a school of thought that says separate structures need separate earthing!! :eek: :eek:
Curse them!! lol!:D[/QUOTE]

At last! And also if a spike is installed it does not need to be connected to the armour of the supply cable, or any other earth coming from the house. Because what is the point of installing a TT system only to connect it to a TNS?
 
will look it up in morning for you mate as books in van :p

Cheers mate!! You are a star!!

I am with you Simon. The problem is that there is a school of thought that says separate structures need separate earthing!! :eek: :eek:
Curse them!! lol!:D

At last! And also if a spike is installed it does not need to be connected to the armour of the supply cable, or any other earth coming from the house. Because what is the point of installing a TT system only to connect it to a TNS?[/QUOTE]

Yeah absolutely. The armour of the cable is earthed at he house not to the spike.
 
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Advice needed on job for NICEIC assessment
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NICEIC Certification Scheme 
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Certification NICEIC, NAPIT, Stroma, BECSA Forum
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