insurance company insisit on capping cables chases

[EFLImpudence]

No.

However, with reference to the insurance man 'thinking' he is correct, it has been established that it (metal capping) does not offer mechanical protection well enough so that it can be earthed in order to omit an RCD.

Therefore, apart from the mythical plasterer's trowel, it is pointless.

So, re: your earlier explanation, do you think that the insurance companies' deduction that fewer claims result if metal protection is provided actually relates to conduit and 17thman's insurance man is just mistaken and doesn't realise/know the difference?

 

[JohnW2]

No.

Quite.

So, re: your earlier explanation, do you think that the insurance companies' deduction that fewer claims result if metal protection is provided actually relates to conduit and 17thman's insurance man is just mistaken and doesn't realise/know the difference?

Very probably. As I'm sure you will have realised, that's exactly what I was thinking of when I previously wrote:

In the case in question, the insurer's requirement seems so silly (in assuming than thin metal capping will appreciably protect cables from nails and drills) that it probably represents a misinterpretation (or misunderstanding) of their data, in which case a different insurer may well not have the same requirement.

Kind Regards, John.

 

[ericmark]

So reading what has been said then the water pipes, gas pipes, and any other metal parts are nothing to do with the electrical installation so do not require to be earthed?

Clearly that is not true and any metal likely to transmit a fault from one area to another will require earthing to ensure it can't transmit a fault.

So returning to capping if a cable was to go down the wall within 50mm of surface in one room then was also used to supply a socket in another room the other side of the wall then a fault in one room can be transferred to another. Only way to prevent this is to earth the capping.

 

[JohnW2]

So reading what has been said then the water pipes, gas pipes, and any other metal parts are nothing to do with the electrical installation so do not require to be earthed?

No-one has said quite that. In any event, as far as water and gas pipes are concerned, it would usually be all but impossible (would take a lot of unnecerssary work) to prevent them from being earthed.

Clearly that is not true and any metal likely to transmit a fault from one area to another will require earthing to ensure it can't transmit a fault.

I think that really depends upon what you mean by 'likely to transmit a fault from one area to another'. If it's just a piece of (say, structural) metal which goes from room to another (and not outside the property), the likelihood of that is surely vanishingly small? In the case of metal capping, it's nearly always totally buried, inaccessible and contained only within one area/room, so I don't see that's ever going to qualify.

So returning to capping if a cable was to go down the wall within 50mm of surface in one room then was also used to supply a socket in another room the other side of the wall then a fault in one room can be transferred to another. Only way to prevent this is to earth the capping.

I don't really understand that. Capping is, more-or-less by definition, buried and inaccessible, and it would be extremely unusual (I would say almost unknown) for capping (as opposed to conduit) to travel from one room to another - so how could the capping, even if not earthed, result in the 'transferring of a fault' from one room to another?

Indeed, it could be argued that earthing the capping in one room increases the risk of 'transference of the fault' into other areas - since, for the brief period prior to a protective device hopefully operating, if the capping (in one room) were to become live, so would the entire CPC system of the installation (including all exposed conductive parts) - whereas without earthing of the capping, nothing but the (buried and inaccessible) capping would become live.

Kind Regards, John.

 

[EFLImpudence]

So reading what has been said then the water pipes, gas pipes, and any other metal parts are nothing to do with the electrical installation so do not require to be earthed?

But, although not part, they are connected because they go into the ground.
If they do not, they do not require bonding.

Clearly that is not true and any metal likely to transmit a fault from one area to another will require earthing to ensure it can't transmit a fault.

Only if it is an extraneous conductive part, surely.

So returning to capping if a cable was to go down the wall within 50mm of surface in one room then was also used to supply a socket in another room the other side of the wall then a fault in one room can be transferred to another. Only way to prevent this is to earth the capping.

I don't quite understand that bit.

If NOT an extraneous c.p., which the capping is not.
Anyway the capping does not go through to the next room.

It could be worse if a fault in the 'other' room caused the capping to become live, if earthed, (although it is not accessible).


D'oh - too slow.

 

[JohnW2]

D'oh - too slow.

That's really pretty amazing - although you were slightly slower than me, our responses to eric's several points were more-or-less identical - perhaps you are my soul mate!

Kind Regards, John.

 

[RF Lighting]

Get a room...

 

[EFLImpudence]

perhaps you are my soul mate!

.
.

 

[ban-all-sheds]

The metal work does not need to be accesible, but the joint to it would as per 526.3.

Not if you pop rivet it.

 

[ban-all-sheds]

In the broadest and most literal of senses, I suppose so, but that argument could be taken to even more absurd lengths - to bring, for example, every plumbing joint in a copper plumbing system which was in continuity with the MPB within the scope of BS7671!

Thank you for (inadvertently) solving the mystery.

David Cockburn has decided to give up electrickery and forge a new career as a loss adjuster.

 

[EFLImpudence]

David Cockburn has decided to... ...forge a new career...

 

[17thman]

I have had a result on this. After much correspondence, i met today on site, with the main contractor, the owner, the insurance inspector and an actuary who came along to understand my arguement. I had 5 layers on, they were freezing. they would not go into any claims history with me about this owner but, I read and distributed 522.6.6 and 522.6.7 to them and after much discussion and misinterpretation on their part. The actuaries piped up and said "if you did not instruct the owner about where safe and agreed cable routes were and he wanted to hang a picture, what would happen if you did not protect the cable with the capping"?

I simply got a piece of galvo capping out, popped in on the floor over a piece of lathe and drove a nail through it, in one blow.

Then he said "why are those 2 holes in that joist too close to each other"? i r told him that they were original holes and i did not want to drill anymore if neccessary. He even got up on the steps and checked for shavings or aging of the open surface.

you should have seen the bristling minds in there, 2 of them drove off in BMWs, i drove off in a 5 year old fiat van.

 

[Taylortwocities]

 

[securespark]

perhaps you are my soul mate!

It's the 14th quite soon.

 

[17thman]

I dont want anyone to give me the clap