capping

[Buzz-light-bulb]

Does anyone know anywhere in the regulations that it states I have to use capping to protect cables when embedded in plaster as I am currently on a rewire, it says in on site guide that if there's no rcd protection it does require metal earthed capping

 

[DPG]

Really?? Earthed capping to avoid RCD protection?? Daz

 

[D Skelton]

Really?? Earthed capping to avoid RCD protection?? Daz

Like I said, there are at least five other options available to me before I would choose that option. But, if I did have to choose that option (not that I ever would have to) then theoretically there is no problem with it at all.

 

[DPG]

I thought it would need to be 3mm steel ( or equivalent). 2 pieces of thin galv wouldn't be anywhere near equivalent of 3mm steel. Daz

 

[D Skelton]

I thought it would need to be 3mm steel ( or equivalent). 2 pieces of thin galv wouldn't be anywhere near equivalent of 3mm steel. Daz

Like I said, just like SWA, it isn't there to protect the cable, it is there to provide an earth fault path back to the point of origin if ever the cable was penetrated.

3mm steel wouldn't need to be earthed because that is there to stop the cable getting penetrated in the first place!

 

[DPG]

Yeah, I get that but we're talking about cables at a depth <50mm and no RCD. What about what the regs say about suitable protection? Daz

 

[Plonker 3]

I am amazed at how tough metal capping is, you try putting capping nails or clout nails in and in invariably your hammer will bounce of and you have made very impact to it. You put your sds into it for a rawplug and it takes for ever to penetrate it.


But you give a householder a picture hook with a flimsy little nail in it and they will go through it first time no problem.

 

[MDJ]

I am amazed at how tough metal capping is, you try putting capping nails or clout nails in and in invariably your hammer will bounce of and you have made very impact to it. You put your sds into it for a rawplug and it takes for ever to penetrate it.


But you give a householder a picture hook with a flimsy little nail in it and they will go through it first time no problem.

Very True, but try doubling it up, you will be surprised how tough it is then.

 

[D Skelton]

Yeah, I get that but we're talking about cables at a depth <50mm and no RCD. What about what the regs say about suitable protection? Daz

Cables buried in walls <50mm don't need protection when they have either an RCD or an earthed metal screen suitably sized to carry fault current such as: Steel conduit, SWA, Pyro, BS8436 etc...

Without these then yes, they do need protection.

 

[telectrix]

must be an earthed metal screen though. btw, well done testerday, mate. time someone spoke out against the parasites and the under trained.

 

[DPG]

Cables buried in walls <50mm don't need protection when they have either an RCD or an earthed metal screen suitably sized to carry fault current such as: Steel conduit, SWA, Pyro, BS8436 etc...

Without these then yes, they do need protection.

That was kind of what I was getting at in my post (#16). Daz

 

[southsea1201]

Seriously why bother with capping, more expense and time. See the point on new builds, but on rewires and refurbs why not chase and clip (C) rather than capping which must in theory derate the cable to B. I always use the same plasterer who understands my needs and have have never had an insulation resistance test fail.

 

[D Skelton]

That was kind of what I was getting at in my post (#16). Daz

It looked to me like you were struggling with the concept of earthed metal capping, maybe I understood wrong.

My main point being throughout is that earthed metal capping serves exactly the same function as an earthed metal screen

 

[DPG]

I was sort of agreeing with Tel's post (#6). A lot of people still seem to think that the metal capping is to give mechanical protection. Daz

 

[telectrix]

can't see anyone taking the time to earth a dozen or more cappings compared to the cost of a RCD/RCBO. even with steel conduit, unless it's used as cpc, it would be earthed from the knock-out box, but i would assume a fly lead would need to be fitted so as not to be relying on the soxket pins.

 

[Geordie Spark]

I am amazed at how tough metal capping is, you try putting capping nails or clout nails in and in invariably your hammer will bounce of and you have made very impact to it. You put your sds into it for a rawplug and it takes for ever to penetrate it.


But you give a householder a picture hook with a flimsy little nail in it and they will go through it first time no problem.

Use an ordinary twist drill bit - not and sds bit for masonry - and you'll put a hole through it no trouble at all