Protective conductor - SWA

[AJS87]

Hi all, first post...

Does a SWA cable incorporating an integral cpc require a protective conductor between the armouring and the earth terminal of metallic enclosure?

I got snagged on this during an NICEIC assessment. I tried to argue the point of conduits and MICC cables relying on joints but it didn't get me far.

GN8 543.2.2 states 'desirable'
Codebreakers state N/A as a defect code.

If the armour acts as the cpc, we always run a protective conductor link.

I've always understood it was good practice as opposed to not meeting regulations?

 

[Fleeting]

The armour may carry fault current therefore all connections must be appropriate it is irrelevant it is not the primary cpc.
Stop quoting Codebreakers it us a waste of paper, burn it.

 

[AJS87]

The armour may carry fault current therefore all connections must be appropriate it is irrelevant it is not the primary cpc.
Stop quoting Codebreakers it us a waste of paper, burn it.

Thats why the armour is connected to earth, albeit through a joint in the same way as conduit and MICC.

There's alot of reputable names and organisations behind codebreakers.

 

[Luckyboy]

I think it's more of a nice to have than a regulatory requirement... couldn't find one anyway!
I'd probably put a banjo or an earthing nut at least on the source side to be safe.

P.S. I use Codebreakers quite often if I'm doubtful about something - recommended by many.

 

[kerching]

Code breakers can be quite useful BUT do not take the coding side as gospel, there are some errors/cock ups etc. It's handy for cross referencing regs numbers, unless your are the sort of person that makes up their own regs. It is written by some very knowledgeable people within the industry. Who knows, they may even visit this site or even ( God forbid )be members

 

[Murdoch]

Hi all, first post...

Does a SWA cable incorporating an integral cpc require a protective conductor between the armouring and the earth terminal of metallic enclosure?

I got snagged on this during an NICEIC assessment. I tried to argue the point of conduits and MICC cables relying on joints but it didn't get me far.

GN8 543.2.2 states 'desirable'
Codebreakers state N/A as a defect code.

If the armour acts as the cpc, we always run a protective conductor link.

I've always understood it was good practice as opposed to not meeting regulations?

the outer sheath of SWA cable should be connected to the CPC at one end or the other!

Sone claim it must be at the supply end but I’m not aware of a regulation that states that.
connections at both ends is how I mainly do it

 

[Murdoch]

Stop quoting Codebreakers it us a waste of paper, burn it.

I think that’s a bit harsh - sure it can be extremely misleading and I’m 99% certain that contributor(s) to it are member(s) on here.

it’s about time Napit issued some clarifications on how it should be understood imho

 

[Fleeting]

I think that’s a bit harsh - sure it can be extremely misleading and I’m 99% certain that contributor(s) to it are member(s) on here.

it’s about time Napit issued some clarifications on how it should be understood imho

"Extremely misleading" but you think I am being harsh, those don't tally. Whether they are members or not isn't relevant it is considered a joke within the industry, a waste of paper.

 

[Murdoch]

"Extremely misleading" but you think I am being harsh, those don't tally. Whether they are members or not isn't relevant it is considered a joke within the industry, a waste of paper.

those do tally 100%

your view is to get them burnt - which would be a waste, but there are aspects of the code recommendations that are wrong / misleading

misleading as some should clearly be C3 codes, not C2

the way I read this guide is that it’s for use when inspecting 18th edition installation sites, when well over 95% of installations are to previous standards and we all know that these are not applied resptrospectively

 

[Fleeting]

If you can't use your knowledge, experience and judgement without resorting to some dodgy guide then people should consider a different aspect to their trade.

 

[AJS87]

If you can't use your knowledge, experience and judgement without resorting to some dodgy guide then people should consider a different aspect to their trade.

Do you say that for guidance notes and 7671??

 

[AJS87]

the outer sheath of SWA cable should be connected to the CPC at one end or the other!

Sone claim it must be at the supply end but I’m not aware of a regulation that states that.
connections at both ends is how I mainly do it

Yes Murdoch.
I'm aware of the need to earth the armour. Just intrigued regarding fly leads when the cpc is integral to the cable as was pulled up on this. Despite all SWA entering galv trunking. My argument as stated above is why any different to conduit??
I'm just going to attach a protective link sized appropriately in accordance with the biggest SWA entering enclosure in future.

 

[Fleeting]

Do you say that for guidance notes and 7671??

You only require BS7671.
Guidance Notes for said BS7671 are also useful but not necessarily gospel.

 

[Sparksfly]

SWA armour earthed at one end or a joint is sufficient. Napit and NIC are not electrically regulated anyway, as far as i'm aware.

 

[Sidewinder]

The armour must be connected to the means of earthing.
This is at the supply end of the cable.
Therefore the armour must be connected to earth at the supply end.