Taking cables from a house to a garage

[bengie]

oh and i forgot to say, i wasn't implying this was a new thing since the 17th came in its just that i was told this on my 17th edition update course.

 

[ianmacd]

Disinformation everywhere. I suggest you guys who have been told that 7671 IS a law (or as good as) go back to your tutors who told you that and ask for proof. As mentioned a few times above, Part P only suggests using BS7671 to comply with the Building Regs but does not require it. Any other method can be used as long as it provides the same level of protection/security but you would need to prove that in a court rather than using 7671 as a defence.

Remember 7671 is not a law but gravity is.

 

[spinlondon]

I was told on my 16th course, that BS7671 was not statutory in England and Wales, but that it was in Scotland.

I've since been told by a Scot that it isn't?

Simplest thing to do, is search Online for the Part P approved document, and have a look. It's possible to download it and save it to your hard drive.

 

[steptoe]

so when have you exported on tnc-s??

NEVER,

but a few guys on here have argued that under certain circumstances then they would see no reason not to export it.

this is when the judgement of a competent person comes into play to take the responsibility of leaving (what in my opinion would be) an installation in a lethal condition.

 

[ianmacd]

AD P says:

In the Secretary of State

 

[ianmacd]

NEVER,but a few guys on here have argued that under certain circumstances then they would see no reason not to export it.

this is when the judgement of a competent person comes into play to take the responsibility of leaving (what in my opinion would be) an installation in a lethal condition.

You have to wonder how culpable the DNO would be for running PME networks if something bad happened. How many other countries have PME networks?

P.S. Lets not have another missing neutral debate.

 

[PBC_1966]

There is no legal obstruction preventing anyone from using a standard from another EU country

Or indeed any other non-EU/EEA standard. The Building Regs. themselves require only that:

"Reasonable provision shall be made in the design and installation of electrical installations in order to protect persons operating, maintaining or altering the installations from fire or injury."

And that's it! That's all the law demands.

The Approved Document for Part P (which is not law either, merely government guidelines) says that in the Secretary of State's view (as if he's going to know anything about it!) that requirement would be satisfied by adhering to the fundamental principles given in BS7671:2001 Chapter 13.

It goes on to say that following BS7671 would be one way of demonstrating compliance with those principles, and that following the equivalent standard of another EEA country would be another.

But that doesn't preclude following any other standard. If you want to wire to the American NEC or Australian AS3000, there's nothing to stop you.

I was told on my 16th course, that BS7671 was not statutory in England and Wales, but that it was in Scotland.I've since been told by a Scot that it isn't?

I'd also been under the impression for some time that following IEE Regs. (now BS7671) had long been mandatory under the Scottish Building Regs., but I've not been able to find anything to support that. The handbooks appear to quote the requisite requirement of the Scottish Regs., which seems to be as vague as Part P:

"4.5 mandatory. Every building must be designed and constructed in such a way that the electrical installation does not:

(a) threaten the health and safety of the people in, and around, the building ; and

(B) become a source of fire."

 

[gselectrical]

Disinformation everywhere. I suggest you guys who have been told that 7671 IS a law (or as good as) go back to your tutors who told you that and ask for proof. As mentioned a few times above, Part P only suggests using BS7671 to comply with the Building Regs but does not require it. Any other method can be used as long as it provides the same level of protection/security but you would need to prove that in a court rather than using 7671 as a defence.Remember 7671 is not a law but gravity is.

I was not informed that BS 7671 is a law. I was told by my tutor during the 2391 course the reason why BS 7671 is not a law, which is what Bengie originally quoted. I am aware 7671 is non-stat, If I remember correctly it was the 1st question on my 2391 paper. J

 

[ianmacd]

I was not informed that BS 7671 is a law. I was told by my tutor during the 2391 course the reason why BS 7671 is not a law, which is what Bengie originally quoted. I am aware 7671 is non-stat, If I remember correctly it was the 1st question on my 2391 paper. J

7671 is not law either directly or indirectly. What you agreed with was the statement that 7671 is as good as law which is not the case.

 

[PBC_1966]

How many other countries have PME networks?

It's the norm in the U.S., although unlike here the NEC requires an earth electrode bonded to the neutral at the service entrance to the building.

It's also the norm to "export" the earth from that point to any other outbuildings, and to provide a further earth electrode at the outbuilding.

 

[spinlondon]

There's no Regulation in BS7671 prohibiting the exportation of a PME earth.

The only danger that should be considered, is that of a broken supply neutral.

Another consideration is that of cost. The sizing of earth conductors is such, that it may well be cheaper to TT a very remote buiding

 

[androiduk2002]

I dont know the rules enough to argue to much, but we was told differant by our tutor,

BS7671 is not law, but it is almost as good as.

If you have to deviate from guidelines, and can show good reason as to why you deviated and that the installation is still as safe then it will be ok.

For example tho it is a bad example if there was a reg (i know there isnt) that all socket outlets be mounted at 400mm up a wall but the house you was rewiring was next to a flood plain and reguarly flooded to 600mm and you mounted the sockets at 1000mm to avoid the flooding.(I know its a bad example) the wiring would still be upto regs but you have departed from height regulations because of the flooding issue.

 

[ianmacd]

So its just our implementation of PME thats crap then? That sounds much more sensible. Does the 'exported' earth have to be of sufficient size to carry the fault current at the head?

 

[gselectrical]

7671 is not law either directly or indirectly. What you agreed with was the statement that 7671 is as good as law which is not the case.

I have not agreed with anything, I am just stating what I was told.

 

[ianmacd]

I have not agreed with anything, I am just stating what I was told.

So if you didn't agree which that when you were told it, did you question it?

 

[spinlondon]

So its just our implementation of PME thats crap then? That sounds much more sensible. Does the 'exported' earth have to be of sufficient size to carry the fault current at the head?

I don't know that I would call it fault current. Perhaps diverted neutral current.

PME earthing Regulations require that the earthing and equipotential bonding conductors be the same size throughout, and are selected in relation to the size of the neutral.

 

[gselectrical]

So if you didn't agree which that when you were told it, did you question it?

Well, to tell you the truth Ian, I did not question anthing my tutor told me. If he was wrong then he should not be in the position he is in. I was a 22 year old in a class of lads i'd never met before and did not want to look like a "wanabe" "mr-Know-it -all"

 

[ianmacd]

Good point. I can imagine what that would have been like. I think I may have approached him afterwards to 'clarify' it.

 

[gselectrical]

Good point. I can imagine what that would have been like. I think I may have approached him afterwards to 'clarify' it.

Shame he rushed off to another lecture before I put my books back in me bag!!

 

[Dambo]

it depends on what type of earthing system you have,if you have TN-S then it is fine to take an earth from the MET,

if you have TT then you don't usually take the earth out, you provide another spike for the garage outside

if its TNC-S you don't take it outside (never, in normal circumstances), you need to make your garage into a TT system and provide a separate spike for it on its own earthing system.

Why on a TNCS system would it not be acceptable to take the earth to the garage from the MET?