'Safe Zone' created by 'current using equipment' ??

[JohnW2]

John, I think that, inevitably, it means that they may be buried anywhere in said zones and should always be treated as if they might actually be anywhere in said zones unless we have conclusive proof that it is buried in more restricted bands within such zones.

May I be excused for saying "Arrggghhh !!" ?

I totally agree with what you say, but it still leaves the (my original) question as to what are the "said zones" in the case of a large item of current-using equipment fixed to the wall - in other words, where does BS7671 permit cables to be buried in such a situation?

Are you saying that you believe that it is permitted to bury cables anywhere in the zones I indicated in my ('silly') diagram in post #26 ? If so, that would very simply answer the simple question I asked in my OP nearly 5 pages ago, although I'm not sure that I (or others) would regard that situation as sensible (my #26 diagram has already been 'ridiculed', with more than a little reason!).

Ideally, an international law making all items connections within say 100mm of the centre or within 100mm of the top right of the item in in its normal intended mounting orientation or some alternative convention might be helpful but will never exist.

National would do me, not necessarily international However, as I'm sure you understand, I was simply offering a suggestion as to how the regs could address (could have addressed) this issue had they wished to, with no expectations that such will necessarily ever happen.

So , anywhere they might be is the answer, even if it includes almost the whole wall. ... Its not what we like but it is what we have.

It does rather sound as if you agree with my #26 diagram as indicating what would (per BS7671) be 'permitted routes' for buried cables (probably even the 'diagonal' ones). Is that the case?

Kind Regards, John

 

[EFLImpudence]

May I be excused for saying "Arrggghhh !!" ?

Yes, of course. Everyone else is saying it.

Please see post #52

 

[ebee]

Yes John, the zone itself must be level horizontally or vertically but your cable is permitted diagonally or curved etc within the zone boundaries if that’s what you mean

 

[ebee]

Well that’s what I think

 

[ebee]

Right I have just looked at no 26. Yes permitted IMHO. Most of us would probably run them more vertical or horizontal within the zones in practice. If it is possible for one of us to locate the actual point of actual entry then we might be inclined to assume that the installer has run so but we would actually be in error to rely upon that. Be it on our own heads. I once came across a building officer who insisted cables ran in neat lines from hole to hole to the man on site but I informed him that I agreed it was good practice but I stated it still complied with regs to run them like a sawtooth wave if you wanted to plus he did not have C&G regs exam and I did. That shut him up and he got down off his high horse

 

[JohnW2]

Yes, of course. Everyone else is saying it. Please see post #52

Everything which has caused me to think "Arrggghhh !!" (including post #52) has resulted from people addressing a question other than the one I asked, despite my repeated attempts to bring them back "on question". To repeat myself yet again ...

I have NOT been asking about where 'a man with a drill' should consider the possibility of cables being present (i.e. what they should regard as "dangerous zones") - since that is fairly obvious, even if not necessarily of much use to them.

The question I have been asking, from OP onwards, is:
522.6.202 etc. says that (unless the cable has an earther covering or is in metal conduit etc.) it is not permitted to bury cables <50mm below surface other than in the 'zones' defined in the reg. That being the case, where (if anywhere!) is one permitted (per BS7671) to bury a cable when all there is to see (once item is fixed to the wall) is a large current-using item, such as an illuminated mirror? Is it what I depicted in my (I would say silly) diagram in post#26, or what?

 

[JohnW2]

Yes John, the zone itself must be level horizontally or vertically but your cable is permitted diagonally or curved etc within the zone boundaries if that’s what you mean

Yes, that's part of what I mean but, more generally, that those diagonal/curved/whatever meanderings of the cable are permitted anywhere within the 'zones' created by the height and width of the visible large object.

Right I have just looked at no 26. Yes permitted IMHO

Many thanks. That makes you the one person who has actually given their view as to the answer to my question - even if I find that answer a little odd/surprising, and despite the fact that my suggestion of it was (I would say understandably) somewhat 'ridiculed'.

Kind Regards, John

 

[ebee]

Nope John it is to the letter of the regs so is permitted

 

[ebee]

Sorry for missing your particular point till now. Away from usual tech at the moment. PS - although I do not favour horizontals in general i don’t mind them in such as kitchens etc where I feel they are more expected. But that is merely my querk as they are indeed permitted. It is the corner ones that irk me more though

 

[EFLImpudence]

I have NOT been asking about where 'a man with a drill' should consider the possibility of cables being present (i.e. what they should regard as "dangerous zones" - since that is fairly obvious, even if not necessarily of much use to them.

But that's all there is.

The question I have been asking, from OP onwards, is:

We know the question but it is silly -

because:

522.6.202 etc. says that (unless the cable has an earther covering or is in metal conduit etc.) it is not permitted to bury cables <50mm below surface other than in the 'zones' defined in the reg. That being the case, where (if anywhere!) is one permitted (per BS7671) to bury a cable when all there is to see (once item is fixed to the wall) is a large current-using item, such as an illuminated mirror?

how do you install any cable when "all there is to see (once item is fixed to the wall) is a large current-using item, such as an illuminated mirror?"

Is it what I depicted in my (I would say silly) diagram in post#26, or what?

I will say no - but until further inspection the zone might be in any of those areas.

 

[JohnW2]

Nope John it is to the letter of the regs so is permitted

maybe - but only if the mirror qualifies as a 'point, accessory or switchgear'. If not, the 'letter of the regs" would appear to be saying that buried ('unprotected') cables are not allowed anywhere as a result of the presence of the item.

... but thanks again for actually addressing the question I asked.

Kind Regards, John

 

[JohnW2]

We know the question but it is silly -

It's not silly from the viewpoint of an electrician who wants to comply with BS7671 and hence wants to know where, if anywhere, BS7671 permits a buried cable to be installed in the sort of situation we are discussing.

because: .... how do you install any cable when "all there is to see (once item is fixed to the wall) is a large current-using item, such as an illuminated mirror?"

Dunno - but it seems clear to me that 522.6.202 etc forbids the installation of a buried cable (anywhere) unless it is in one of the permitted zones' defined in the reg

I will say no - but until further inspection the zone might be in any of those areas.

I'll leave you to argue with ebee about that but, if you don't think that an item generates 'permitted zones' such as I depicted in #26, what 'permitted zones' (if any) do you believe that it generates?

 

[EFLImpudence]

It's not silly from the viewpoint of an electrician who wants to comply with BS7671 and hence wants to know where, if anywhere, BS7671 permits a buried cable to be installed in the sort of situation we are discussing.

Yes it is silly because once the mirror is fitted the cable cannot be installed - but IF it could be then you can see where it is and where the zones will be.

Dunno - but it seems clear to me that 522.6.202 etc forbids the installation of a buried cable (anywhere) unless it is in one of the permitted zones' defined in the reg

Yes, obviously.

I'll leave you to argue with ebee about that but, if you don't think that an item generates 'permitted zones' such as I depicted in #26, what 'permitted zones' (if any) do you believe that it generates?

None.

The zones will relate to where the cable emerges from the wall when you fitted it.

 

[ebee]

No EFLI I disagree. Not determined by where the cable emerges from the wall but rather in line with the borders of said accessory/point/switchgear. Does the mirror qualify as any of those? Does an electric shower qualify? If not then what the heck do you do?

 

[JohnW2]

I've thought of another possibility, that may make sense.

I have up until now been thinking that the authors of BS7671 'overlooked', decided to 'dismiss' or otherwise 'did not consider' the situation in which the only 'electrical thing' visible on a wall is a (possibly large) large current-using piece of equipment.

However, I'm now wondering whether they might actually have considered that situation and, perhaps because poitentially very large 'permitted zones' would have very limited value in terms of reducing the risk of cable damage (and/or its possible consequences, such as electric shock), decided that buried cable should only be allowed in the wall if it satisfied the requirements of 522.6.204 (i.e. with an 'earthed metallic covering' or suitably mechanically protected).

If that were their thinking, it might explain why they defined permitted zones for buried cables in relation to just "points, accessories & switchgear", rather than "points, accessories, switchgear & current-using equipment" ?