Capping cables

[lebowski]

I have run my electrical cables in the prescribed zones and have used metal capping,it seems easier to use than plastic.Does all this capping need to be earthed? It will all be buried beneath the plaster.

[simon_d]

lebowski wrote:

Does all this capping need to be earthed?

no

[Pens]

For future reference you only need to earth the metal capping if you run it outside of the prescribed zones.

[ebee]

if you run outside zones then capping not much use anyway.

unless you protecting from plasterers trowel then capping is not much good and metal capping is positively a very bad idea.

Signed

The society against capping cables

[simon_d]

Pensdown wrote:

For future reference you only need to earth the metal capping if you run it outside of the prescribed zones.

but it should be earthed steel conduit. capping has very little resistance to a drill

[Pens]

simon_d wrote:

Pensdown wrote: For future reference you only need to earth the metal capping if you run it outside of the prescribed zones. but it should be earthed steel conduit. capping has very little resistance to a drill

I'm not aware of any regs thats say it has to be steel conduit are you?

[simon_d]

Pensdown wrote:

simon_d wrote: Pensdown wrote: For future reference you only need to earth the metal capping if you run it outside of the prescribed zones. but it should be earthed steel conduit. capping has very little resistance to a drill I'm not aware of any regs thats say it has to be steel conduit are you?

522-06-06 A cable should concealed in a wall or partition at a depth of less than 50mm form the surface of the wall or partition shall:
(i) incorporate an earthed metallic covering which complies with the rewuirements of these regulations for a protective conductor of the circuit concerned, the cable complying with BS 5467, 6346, 6724, 7846, BS EN 60702-1 or BS 8436


now, AFAIK, capping doesnt count as a protective conductor

522-06-06

(iii) be enclosed in earthed conduit, trunking or ducting satisfying the requirements of these regulations....

OK, maybe i was slightly off with the earthed steel conduit, but either way, as far as im aware, capping doesnt comply

[Pens]

Although it's far from ideal, earthed metal capping does comply with 7671. You can't use it where the cable is less than 50mm from both sides but on a normal block wall it can be used.