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

[JohnW2]

Yes I too have seen cables installed with tails left hanging out then boxes mounted so that the cables were then out of zones - never underestimate the determination of complete fools. PS all done by the same person

That doesn't surprise me, since the world is not devoid of complete fools (and/or people have no dea about the reguklations wiuth which they are meant to comply).

I'm a bit confused, since I find it almost impossible to believe that EFLI has not come across a good few examples of the sort of things we've both mentioned, but his rather scathing response to my reporting what I recently saw seems to imply that he doesn't believe it ever happens!

Kind Regards, John

 

[JohnW2]

Oh FFS I despair.

Fair enough, but despairing is not the same as answering the question.

 

[EFLImpudence]

Post # 52

I shall try again although it is beyond me why you refuse to understand.


There is no intended interpretation of the rule in relation to a large piece current-using equipment attached to a wall; just common sense.

When being installed the cable will (hopefully) obviously be placed where it should be in relation to 522.6.202.

It is just that after fitting a large appliance over the point denoting the safe zones that point is no longer visible so anyone wanting to drill will have to be aware that the cable might be in any of the areas horizontal or vertical from the whole width and height of the appliance
OR
determine where the point actually is to narrow the areas of (so called) safe zones.

Safe zone for cabe equals danger zone for drill.



It is no different than the safe zones from, say, a socket being in all four directions but three of them might not contain any cable(s).

 

[JohnW2]

Post # 52

I'm somewhat tiring of constantly having to repeat things I've already written In post #52, you wrote:

There is no intended interpretation of the rule in relation to a large piece current-using equipment attached to a wall;

As I have said (more than once), 522.6.202 explicitly defines the (usually few, and relatively small) places on a wall where one is permitted to bury 'unprotected' cables <50mm below the surface. The 'default', if one wishes to bury cables anywhere other than in those (few and small) explicitly-defined places, then the cable has to have either an earthed metal covering or protection by metal conduit etc.

If you really believe that the regulation has "no intended interpretation" in relation to large pieces of wall-mounted current-currying equipment, that would therefore surely leave us with the 'default situation' (for any situation not explicitly 'dispensated' by the reg) - namely that (unless something else was creating 'permitted zones', any cable buried in the wall would have to be 'protected (earthed covering or conduit), wouldn't it?

 

[EFLImpudence]

I'm somewhat tiring of constantly having to repeat things I've already written In post #52, you wrote:

As I have said (more than once), 522.6.202 explicitly defines the (usually few, and relatively small) places on a wall where one is permitted to bury 'unprotected' cables <50mm below the surface. The 'default', if one wishes to bury cables anywhere other than in those (few and small) explicitly-defined places, then the cable has to have either an earthed metal covering or protection by metal conduit etc.

Ok?

Why does my post #52 answer not satisfy you?

If you really believe that the regulation has "no intended interpretation" in relation to large pieces of wall-mounted current-currying equipment, that would therefore surely leave us with the 'default situation' (for any situation not explicitly 'dispensated' by the reg) - namely that (unless something else was creating 'permitted zones', any cable buried in the wall would have to be 'protected (earthed covering or conduit), wouldn't it?

I am not exactly sure what you are getting at - or more precisely why you are getting at it - but I shall say "Yes, it would".

Are you thinking that there can be situations where nothing is 'creating' a safe zone for a cable that is to be used for an appliance?

 

[ebee]

Put it another way , said box in wall then mirror over it.
How would anyone not technically qualified be able to open it up/remove it from wall prior to drilling by a safe manner.
The safe manner is everybody sticking to rules about zones (well in theory) so how can that person guess the zone locations unless they use the whole portion of the wall where zones might be . Imagine the new mirror had been changed to a multi socket outlet of the same size. Our zones are vertical from both lh and rh side and horizontal from top and bottom , a massive zone that could even be nearly as big as the wall itself. So long as we are contained within the extremities then everybody is ok..

For ordinary everyday zones created by sockets we do not allow a dispensation to allow a person to remove fixing screws, pull forwards then see which backbox holes contain cables then deduce from that, do we?

 

[EFLImpudence]

Put it another way , said box in wall then mirror over it.
How would anyone not technically qualified be able to open it up/remove it from wall prior to drilling by a safe manner.

If they can't then they should not be doing work that requires that.

The safe manner is everybody sticking to rules about zones (well in theory)

Who is disputing that?

so how can that person guess the zone locations unless they use the whole portion of the wall where zones might be .

They can't but that doesn't mean the installer was allowed to have fitted a cable where it should not be.

Imagine the new mirror had been changed to a multi socket outlet of the same size. Our zones are vertical from both lh and rh side and horizontal from top and bottom , a massive zone that could even be nearly as big as the wall itself. So long as we are contained within the extremities then everybody is ok..

Yes, for caution when drilling; not for installing the cable in the first place.

For ordinary everyday zones created by sockets we do not allow a dispensation to allow a person to rmove fixing screws, pull forwards then see which backbox holes contain cables the deduce from that, do we?

Also no one allows a dispensation for installing cables behind mirrors where my red lines are.


I really am at a loss as to what you two are getting at.

 

[JohnW2]

Ok? Why does my post #52 answer not satisfy you?

I don't think I can explain that any more clearly that I did in my last post.

I am not exactly sure what you are getting at - or more precisely why you are getting at it - but I shall say "Yes, it would".

Again, I can't think of how I could more clearly express 'what I was getting at' (essentially simply what I wrote), and the 'why?' seems fairly obvious, and would seem to be 'spelt out' in what I wrote ...

Are you thinking that there can be situations where nothing is 'creating' a safe zone for a cable that is to be used for an appliance?

Indeed I am, at least in terms of what ebee would describe as "the letter of the regs". IF, as you have suggested, the reg 'has no intended interpretation' in relation to such an appliance, then one is left with the situation in which no 'permitted zone' is defined in relation to it, meaning that there is nowhere on the wall where it would be permitted to have an ('unprotected') cable buried.

That might not be as ridiculous as you may try to suggest ... don't forget that this reg exists (presumably) in an attempt to safeguard cables to some extent, not to facilitate the supplying of appliances with power. The question of 'how one gets power to an appliance' is a separate issue, and is "the installer's problem" (even if it means him/her having to use SWA or conduit)

 

[JohnW2]

The safe manner is everybody sticking to rules about zones (well in theory) so how can that person guess the zone locations unless they use the whole portion of the wall where zones might be . Imagine the new mirror had been changed to a multi socket outlet of the same size. Our zones are vertical from both lh and rh side and horizontal from top and bottom , a massive zone that could even be nearly as big as the wall itself. So long as we are contained within the extremities then everybody is ok..

Exactly.

 

[EFLImpudence]

Indeed I am,

Oh well - in that case I am baffled.

at least in terms of what ebee would describe as "the letter of the regs". IF, as you have suggested, the reg 'has no intended interpretation' in relation to such an appliance, then one is left with the situation in which no 'permitted zone' is defined in relation to it, meaning that there is nowhere on the wall where it would be permitted to have an ('unprotected') cable buried.

The cable must exit the wall somewhere so that will define the zone horizontally or vertically for its route to that position.

Perhaps a flex-outlet should always be fitted - then 'point' or 'accessory'; take your pick.

That might not be as ridiculous as you may try to suggest ... don't forget that this reg exists (presumably) in an attempt to safeguard cables to some extent, not to facilitate the supplying of appliances with power.

On the other hand it might be.

The question of 'how one gets power to an appliance' is a separate issue, and is "the installer's problem" (even if it means him/her having to use SWA or conduit)

So what - or why?

 

[morqthana]

But when did common sense apply to BS 7671

Or to anyone who argues that a zone is as wide as a TV because it's inconvenient for him for it to be only as wide as a socket.

 

[JohnW2]

Oh well - in that case I am baffled.

I would suggest that the simple truth is that there is no way in which one could use a large item on a wall to define a 'permitted zone' (for buried cables) which would be sensible and of significant use/value to a 'man with a drill' who only knew about 'what was visible' to him/her.

The cable must exit the wall somewhere so that will define the zone horizontally or vertically for its route to that position.

Yes, but that would serve no useful purpose if no-one other than the person who installed it was aware of where the cable exited the wall.

Perhaps a flex-outlet should always be fitted - then 'point' or 'accessory'; take your pick.

That would at least mean that the 'permitted zones' would be about 90mm wide, rather than possibly only about 12mm if the cable simply 'came out of a hole in the wall'. However, as above, no matter how wide or narrow those zones may be, they cease to have a useful purpose if no-one (other than the person who did the installing) knows where they are.

So what - or why?

So ... the reg would not have to consider the consequences of saying that it was not permitted to bury 'unprotected' cables anywhere in the wall- that being "the installer's problem' (and a problem which could easily be addressed, albeit with some inconvenience/cost).

 

[JohnW2]

Or to anyone who argues that a zone is as wide as a TV because it's inconvenient for him for it to be only as wide as a socket.

Indeed - and, in any event, even ('more convenient'- to the installer) zones as wide as a socket would serve no useful purpose to a person who didn't know where those zones were.

 

[ebee]

Although we realise that mirrors and showers etc do not fit into the zone conditions rules nicely I think that, for practical purposes we only decide to treat that object as a point of utilisation in a similar manner, almost no one will make them exceed 50mm deep or amoured/conduit and getting manufactures in Uk/EU/Worldwide to agree a convention of approach with IEE/Cenelec or worldwide would be more than difficult .

My conclusion, it is a fudge that we must use to let the mirror/shower etc create the dimension of zone decision, unless someone has a better idea that has a chance of universal acceptance.
We have no idea where a backbox might be unless the mirror is merely hung up like a picture and from backbox to mirror is a length of flex in a void behind such mirror, if it is fixed in position we cant be expecting Joe Bloggs to lift the mirror away from the wall to take a peek.

If it was a cabinate with doors we could open and see a cover intended to have said backbox behind and a suitable label then we could make an informed decision but for a mirror on a wall, no such luck, the whole mirror needs to be treated like a point even if we declare the mirror etc not to actually be a point by definitions. What else can we reasonably do?

 

[ebee]

They can't but that doesn't mean the installer was allowed to have fitted a cable where it should not be.

nobody is suggesting an installer fitting a cable where it should not be. Once we establish where it is actually allowed to be then we hope it will be and accordingly others will miss damage to it