The stripping wire would not work so well if covered in insulation.

Z.

Oy, I already said that. My thunder is stolen!

Z.

543.3.201. And as that only applies to c.p.c.s ≤6mm² and comes under the heading 'Preservation of electrical continuity of protective conductors' I guess the official purpose is to increase the physical robustness of the conductor. Personally +1 for insulating it from exposed live parts inside enclosures (to increase reliability if not safety).

   - Andy.

Never underestimate the sheer determination of complete idiots 

During the 60s and 70s it was not uncommon to see socket circuits without sleeving on the bare earthwire

Some great ideas, and yes most of the referenced Regulations are relevant in one way or another.

AJJewsbury said:

543.3.201. And as that only applies to c.p.c.s ≤6mm² and comes under the heading 'Preservation of electrical continuity of protective conductors'

Main reason, of course, is it's actually required by BS 7671 specifically for the purpose covered by 543.3.201 ... well done Andy and anyone else who got that Reg !

The thing that prompted me to the post, was someone saying they always make sure the cpc in relevant cables is covered right back to the sheath ... and not simply a short length for identification purposes.

So if the sleeving was absent in a periodic inspection, how might you code it without understanding it’s purpose? I am aware of one inspector awarding a code 2 to an installation that was erected using T/E where no earth sleeving was used at all. The installation was erected in the U.K. by a Eastern European contractor who may have been unfamiliar with the practice of sleeving. I assume the inspector considered the risk of contact with live parts was unacceptable.

On the other hand, in one of the City and Guilds 2391 modules, the candidate is asked to code the absence of earth sleeving. The exemplar answer is Code 3. 

Surely there will be some about who strive to award lack of sleeving as a code 1, Lyle. 

Hi lyledunn ,

lyledunn said:

So if the sleeving was absent in a periodic inspection, how might you code it without understanding it’s purpose?

Hope you don't mind if I pass on answering that, given the differences of opinion

lyledunn said:

I am aware of one inspector awarding a code 2 to an installation that was erected using T/E where no earth sleeving was used at all.

lyledunn said:

On the other hand, in one of the City and Guilds 2391 modules, the candidate is asked to code the absence of earth sleeving. The exemplar answer is Code 3. 

But regarding points above, just to note that current BPG4-1 (page 16) says it's worthy of a note, but doesn't warrant a classification code.

543.3.1 protection required against mechanical, chemical, and electrodynamic effects.

I doubt that the last will be relevant to the average back box.

It is difficult to see how a loose sleeve could keep out chemicals.

Which leaves mechanical effects. Is half a millimetre of soft plastic really capable of providing significant protection?