Code faults ????

[MDJ]

If the cable is accidentally screwed or chewed by vermin, there is no guarantee that both the line conductor and the CPC will be caught by the screw or vermin.
This is why, RCD protection is a method of providing additional protection for cables concealed in walls.
Are the downlights installed in walls by the way?
RCDs do not require a CPC to operate, if they did, then there would be no point in plugging your hedge trimmer into an RCD protected socket.
A CPC is not there to protect the cable.
It is there to earth exposed-conductive-parts which may become live under fault conditions, and to provide a path for earth faults which may occur in equipment conected to the wiring system.

I have a good Idea then, lets banish all CPCs and remove carpets in the house and replace with rubber mats and rcd everything and hope they work.

 

[Deleted member 26818]

It's not a question of why, what or how it's done.
It's a question of whether the situation is dangerous or can give rise to danger.
If everything on the circuit that needs to be earthed is earthed, where is the danger?

 

[MDJ]

No you said continuity of cpcs wasn't required in the circuit if exposed parts were earthed, I'm saying okay thats fair enough but in a domestic situation how would you make that Work if switches are metal? Obviously we would have to join the cpcs out and ensure continuity wouldn't we?

 

[Deleted member 26818]

The metal parts of the switches are exposed-conductive-parts, they would require earthing and continuity of the CPC between them and the main earth terminal.
If you were to install 6 downlights in your living room, and feed them from your existing ceiling rose, would you need continuity of the CPC between all the downlights?
Why?

 

[MDJ]

I would ensure all cables had an cpc connected yes, whether they were actually connected to the downlighter would be depending on whether they needed to be or not, usually they would be, but not always, however with your view we may as well wire the whole house in 2 core cable and run seperate cpcs to the switches as most pendants are plastic (1) not practicable and (2) unheard of, I say show me just one spark who wires a house without ensuring continuity of the cpcs is ensured, you just won't find one, so why the silly comments, the cable we use has a cpc, why not ensure it has continuity, it's school boy stuff, talk about overcomplecating a minor issue, if there is a cpc present then it is usuable if needed,if not still connect it so continuity is at all points just incase it is ever needed, we had a chat about this a few days back and regs were mentioned regarding cpcs in cables, I can't think of anyone not ensuring continuity, why the big issue?

 

[Deleted member 26818]

No that is not my view at all.
I don't know personally of any sparks that would not ensure continuity of a CPC, although I could introduce you to some (myself included) who have run circuits with out a CPC.
However ther must be some out there that carry out this practice, otherwise we wouldn't have the OP, and I wouldn't have come across the very same thing myself on a number of occasions. Perhpas ther's just the one spark that does it, and I and the OP keep finding their work.
I'm at a loss as to how you find my comments to be silly, considering some of the comments you have made.
Yes the cable we use (if it's T&E) has a CPC.
One reason for not ensuring continuity, could be cost.
I don't think there is any need to discuss overcomplicating the issue, you seem to be doing a prety good job as it is.
By alll means connect the CPC in case it is ever needed. I don't have a problem with that.
Yes we did discuss a similar matter a few days back, yes the Regs were mentioned, however as no Regulation in BS7671 requiring that a cable incorporate a CPC exists, I think you may have misunderstood.

I'll reiterate.
There is no requirement in BS7671 for a CPC to be incorporated in a cable.
It is prohibited unless the manufacturer provides a specific termination, or in certain conditions where circuit conductors pass through the enclosure, to terminate a CPC in a double insulated enclosure.
Yes the 17th edition requires that a CPC be terminated at each wiring point and at every accessory in a circuit, however that does not mean that circuits wired to earlier editions of the Regulations, which do not have a CPC at every wiring point and accessory are unsafe for continued use.

Now I've asked a number of times for you to explain what you consider as being dangerous with the OP's scenario.
Is there any chance that you could answer?

 

[MDJ]

I never said it was dangerous, However in modern wiring it is unusal IMO and not normal practice, as for bs 7671, I couldn't give a flying monkeys for that TBH regarding this instance, there is such a thing as good practice and cpc continuity in a circuit is one of those, I am aware some old cabling has no cpcs and plastic lugs are used in switches due to this, however we have departed from that and the conversation got around to modern methods concerning why cpcs needed to be connected and continuity assured, you tried to lecture us about it not being required unless exposed parts was evident, I agreed but asked you to confirm wiring methods in a modern domestic situation regarding this, you then tried to ask me a homework question about downlighters, I will look through the thread again but due to your commects regarding asking me specifically several times about explaining my views regarding the OPs question I will look again, I cannot recall this question previously, when it comes to a cpc in a cable, I will have to look back, but I think murdock gave a reg number suggesting it was required, well certainely in most instances at least, and in the domestic enviroment I'm sure this was one instance, so my question to you again would be if you wired a house then would you not use T&E and just use 2 core if pendants were the lights preferred by the customer and run a seperate cpc only to exposed parts/ or like the rest of the UK electricians ensure continuity of the cpc is carried out?

 

[MDJ]

going back a few threads this was your comment Why does the CPC need continuity throughout the circuit?
If there's continuity to the parts and equipment that needs to be earthed, what is the danger if there is no continuity to other parts and equipment?

I asked how you would ensure exposed parts Ie metal switches would get earthed in this instant considering T&Es would be used, I just can't see a problem with this question and yet a huge debate has errupted haha

 

[Silly Sausage]

What a bizzare discussion this is!
Is it worth re-reading with a fresh mind tomorrow?

 

[Deleted member 26818]

I never said it was dangerous, However in modern wiring it is unusal IMO and not normal practice, as for bs 7671, I couldn't give a flying monkeys for that TBH regarding this instance, there is such a thing as good practice and cpc continuity in a circuit is one of those, I am aware some old cabling has no cpcs and plastic lugs are used in switches due to this, however we have departed from that and the conversation got around to modern methods concerning why cpcs needed to be connected and continuity assured, you tried to lecture us about it not being required unless exposed parts was evident, I agreed but asked you to confirm wiring methods in a modern domestic situation regarding this, you then tried to ask me a homework question about downlighters, I will look through the thread again but due to your commects regarding asking me specifically several times about explaining my views regarding the OPs question I will look again, I cannot recall this question previously, when it comes to a cpc in a cable, I will have to look back, but I think murdock gave a reg number suggesting it was required, well certainely in most instances at least, and in the domestic enviroment I'm sure this was one instance, so my question to you again would be if you wired a house then would you not use T&E and just use 2 core if pendants were the lights preferred by the customer and run a seperate cpc only to exposed parts/ or like the rest of the UK electricians ensure continuity of the cpc is carried out?

If it's not dangerous, then there is no requirement to make a note about it.
If there is no requirement to make a note about it, then it doesn't warrent a code.
I don't think I'm lecturing, just stating my opinion.
Perhaps it was a homework question, did you answer it?
Murdoch quoted 411.8.5 and 412.2.3.2.
I would probably use terminal blocks and chock boxes and ensure continuity of the CPC.

 

[MDJ]

The op stated the cpcs at each light had been cut, therefore unless he or she didn't clarify otherwise then My comment about ensuring continuity is merited, it sounded as if no cpcs were evident anywhere due to being cut, although some metal back boxes on switches have plastic lugs most don't, I suggested it would be a code 2 and need improvement, it is possible it is not the case, but unlikely, however knowing domestic wiring methods and materials I expect there are exposed parts unprotected on this circuit somewhere, as for the home work question, I think I have answered it however it was a poor question and not worthy of an answer, I was trying to talk to you about good practise and real life regarding modern installations, I understand you saying it wouldn't even be a code unless dangerous, but can't imagine any sparks doing a PIR or whatever it is called these days thinking it to be acceptable to not consider coding it, a short run to a plastic switch or light may be something which gets away with it, but wiring through to downlights without any cpc would get a mention on the certificate IMO and rightly so, as mentioned before we can always rip up the carpets and put rubber floors down, by the waY, I would never use a chock box ever, but maybe a terminal block, either way I would ensure continuity of a cpc in a domestic circuit whether plastic fittings or otherwise, as the cpcs were cut then at the very least a reconnection would be something to consider, again good practise IMO.

 

[Deleted member 26818]

MDJ, the OP stated: All the earths at the downlights have been cut away, they are plastic downlights but surely it is still potentially dangerous if the earth doesn't exist ie.. Change to chrome fitting etc..... I marked this is a code 2, am I right or wrong??
The choice of codes was not because the CPC was not continuous, but because the class II fittings may be changed to class I at some point in the future.
Yes if the defect was that exposed-conductive-parts were not earthed, then it would warrent a code C2.
There's nothing to stop you mentioning the fact that the CPCs have been cut out at the down lights.
However applying a code to the situation is another matter.
You mentioned something in an earlier post about silly comments, and now you repeat your comment about rubber mats....
Why would you not use a chock box?
What would you use to enclose the terminal block if you were to use one?

Yes I found recently on an EICR a situation where I beleive it was seven downlights had been installed, and the bare CPCs had been twisted together.
I explained to the householder that I considered this to be poor practice and that it did not comply with the Regulations, I suggested that it should be rectified.
The cheapest option was to use terminal blocks, chock boxes and some G/Y sleeving.
I ended up using a whole pack of ten chock boxes, as there were some other connections in the lighting circuit which were not enclosed.

 

[MDJ]

I would use a JB with cable clamps actually, yes you can get them, I don't like chock blocks cheap and cheerful IMO, as for plastic down lights, I must have missed that bit, if so I apologise, I have never seen a plastic downlighter actually from memory, I have seen metal downlights without an earth connection though, although I would use a make with a terminal, I just can't think off hand now about a actual plastic downlighter, you wouldnt want to put a 50 watt dichoric in one would you haha, either the op is mistaken or I have been awake too long, Seriously I am not for one minute saying the OP is wrong, but I just cannot think of a plastic downlighter at this moment, a mental block perhaps, I expect it will come to me soon, if changing to a chrome fitting though and no cpc available then yes c2, even without a metal downlight in a house if cpcs were evident and cut off I would still mention it myself, I bet there are exposed parts in the circuit somewhere. I wouldn't just dismiss mentioning it on the certificate myself, not in todays world, good practise to ensure continuity is assured.

 

[Deleted member 26818]

I would use a JB with cable clamps actually

Which kind of leads us back to the other discussion about using 2 core cable for double insulated equipment.
What cable would you use from the JB to the downlight?

 

[MDJ]

depends on the down light, if it was metal a 3 core, if plastic which I cannot recall ever seeing ever TBH a 2 core, but the actual cpc of the 6242Y would be connected through in the JB right by the side of the downlight to ensure continuity to all parts of the circuit, which is my point, I am not saying actual down lights need to be earthed, but continuity needs to be at all points IMO, and yep I know your now going to argue if a foot of 2 core cable can be connected to a plastic downlight with no earth facility why cannot the whole circuit yawn.