Using cpc as neutral

[joel89]

Not the same size as the phase conductor & a total no no

 

[Pete999]

No offence, unfortunately i can't do any more detailed explanation at that point! But i was addressing a part of your post not your usual excellent standards!
I do think that when people are asking this kind of question, we should be precise about why it's not allowed, and appeal to both the regs and to common sense specifically where appropriate.i think a lot of things that are uncommon in domestic are actually within the regs, and sometimes the boundary between what is allowed and what isn't seems to defy common sense, but as long as we discuss properly we will help everyone to learn something new.

Can't really what there is to discus John, you shouldn't use the cpc as a live conductor under any circumstances.

 

[Baddegg]

Why would you want to anyway? Just price accordingly do it properly or not at all and sleep easy......

 

[johnduffell]

Can't really what there is to discus John, you shouldn't use the cpc as a live conductor under any circumstances.

Shouldn't according to what reason though? My point is try to be specific. If this was an eicr you can't just code things because it's not common practice.
In a t&e yes as i said definitely not allowed because of the lack of insulation, however under the regs you can identify the green and yellow insulated conductor in a multi core cable as neutral or line by over sleeving.
Making sweeping statements about how you shouldn't do it isn't really helping anyone to learn something.

 

[Pete999]

In a t&e yes as i said because of the lack of insulation, however under the regs you can identify the green and yellow insulated conductor in a multi core cable as neutral or line by over sleeving.
Making sweeping statements about how you shouldn't do it isn't really helping anyone to learn something.

So what would you use as the cpc in your scenario? and can you say which Regulation says that doing what you suggest complies with BS7671.

 

[johnduffell]

So what would you use as the cpc in your scenario? and can you say which Regulation says that doing what you suggest complies with BS7671.

There's no need to have a cpc in every cable, you just need it available at every termination.
And the reg mentioned earlier covers over sleeving. You can identify any cable by over sleeving, the only restriction is you can't use green yellow identificationide anything other than cpc and you can't use over sleeving to identify a green yellow insulated single.
Don't have access to the regs right now but i can look later if necessary

 

[Octopus]

Shouldn't according to what reason though? My point is try to be specific. If this was an eicr you can't just code things because it's not common practice.
In a t&e yes as i said definitely not allowed because of the lack of insulation, however under the regs you can identify the green and yellow insulated conductor in a multi core cable as neutral or line by over sleeving.
Making sweeping statements about how you shouldn't do it isn't really helping anyone to learn something.

Best you stop digging

"is it dangerous to use the cpc in a twin / earth cable? I know it's not safe in case someone else thinks it's still an earth but is that the only reason?"

Only the OP knows what he is doing and asking and he's made no attempt to clear this up .........

 

[Octopus]

There's no need to have a cpc in every cable, you just need it available at every termination.

Best you explain that as I do disagree ............

 

[Pete999]

There's no need to have a cpc in every cable, you just need it available at every termination.
And the reg mentioned earlier covers over sleeving. You can identify any cable by over sleeving, the only restriction is you can't use green yellow identificationide anything other than cpc and you can't use over sleeving to identify a green yellow insulated single.
Don't have access to the regs right now but i can look later if necessary

Yes please would be interesting, just a point how are you going to have a cpc at every termination if you don't as you say, need a cpc in every cable, and why would you use a cable with an earth core if you didn't need it? seems very counter productive in my book, are you sure you are not misreading/misunderstanding the regulations, still if you get hold of your copy and quote the Reg number we can all have a look.

 

[Baddegg]

Got to be a wind up,if he’s considering doing it to T&E I can’t imagine he’s used many single core cables ever anyway......

 

[johnduffell]

can you say which Regulation says that doing what you suggest complies with BS7671.

514-03-02 - Every core of a cable shall be identifiable at its terminations and preferably throughout its length.
So brown sleeving at the terminations would comply, although not be preferable
411.3.1.1 - A cpc shall be run to and terminated at each point in wiring and at each accessory
So as long as one cable that has a cpc arrives at the accessory you're ok

 

[Baddegg]

Got to be a wind up,if he’s considering doing it to T&E I can’t imagine he’s used many single core cables ever anyway......

Or multi core cable Either

 

[Octopus]

514-03-02 - Every core of a cable shall be identifiable at its terminations and preferably throughout its length.
So brown sleeving at the terminations would comply, although not be preferable
411.3.1.1 - A cpc shall be run to and terminated at each point in wiring and at each accessory
So as long as one cable that has a cpc arrives at the accessory you're ok

I’ve given you a disagree on the basis that op asks about using the cpc as a live conductor - this could very easily be a single cable arriving at an accessory and therefore will not comply with the regs ....

 

[Andy78]

I think this has drifted quite far from the specific original question of using a cpc in T+E as a live conductor.

 

[johnduffell]

I’ve given you a disagree on the basis that op asks about using the cpc as a live conductor

Fair enough but i feel having stated at least 3 times that it's not acceptable in t&e due to lack of insulation and been very specific about when it isn't an is allowed and for what reason, I'm actually quite disappointed that members i respect on here are throwing around disagrees without explanation beyond that it's shouldn't be allowed.
If you read the op carefully you will note he is trying to learn and he's asking for exactly which reasons it is not allowed, i didn't take away from that that he's planning to do it. Let's try to be constructive and learn something, if the op wants to do something dangerous then that's up to him, we are here to help, right?
Hope that came across ok, I'm not trying to start a disagreement i just think i only learn something from people i disagree with (if they are also happy to discuss)
Happy Monday (just to try to relax the mood

 

[Octopus]

Fair enough but i feel having stated at least 3 times that it's not acceptable in t&e due to lack of insulation and been very specific about when it isn't an is allowed and for what reason, I'm actually quite disappointed that members i respect on here are throwing around disagrees without explanation beyond that it's shouldn't be allowed.
If you read the op carefully you will note he is trying to learn and he's asking for exactly which reasons it is not allowed, i didn't take away from that that he's planning to do it. Let's try to be constructive and learn something, if the op wants to do something dangerous then that's up to him, we are here to help, right?
Hope that came across ok, I'm not trying to start a disagreement i just think i only learn something from people i disagree with (if they are also happy to discuss)
Happy Monday (just to try to relax the mood

Posters need to learn to post better threads and answer questions

For a non spark you seem to be going out of your way to pxss people off.....

 

[johnduffell]

Posters need to learn to post better threads and answer questions

For a non spark you seem to be going out of your way to pass people off.....

Ok fair enough I'm not the thread police so maybe the op broke the rules.
Second i have no desire to annoy people, as that would be pointless. i was purely here to help everyone's knowledge including my own, if you'd rather i leave this thread just let me know and I'll unwatch this thread and let you all to it.

 

[Wilko]

There's no need to have a cpc in every cable, you just need it available at every termination.

Hi - I'm struggling to think of installing a circuit without a cpc. Some have been installed historically, but I don't think that's been since the '60s. As I've started to practice for the regs exam ( ) the two regs I could find that seem relevant are 543.6.1 and 543.2.9 .

 

[KentSparky]

Shouldn't according to what reason though? My point is try to be specific. If this was an eicr you can't just code things because it's not common practice.
In a t&e yes as i said definitely not allowed because of the lack of insulation, however under the regs you can identify the green and yellow insulated conductor in a multi core cable as neutral or line by over sleeving.
Making sweeping statements about how you shouldn't do it isn't really helping anyone to learn something.

Well said

 

[johnduffell]

I'm struggling to think of installing a circuit without a cpc

Thanks for the regs help! I can't think of a circuit without a cpc either, that would certainly not comply and i have not suggested it.

the two regs I could find that seem relevant are 543.6.1 and 543.2.9

"Where overcurrent protective devices are used for fault protection, the protective conductor shall be be incorporated into the same wiring system as the live conductors or in their immediate proximity."
Same wiring system, but not necessarily the same cable, as i understand it.
The latter reg is talking about the special case of rings which are not under discussion but it states that the cpc should also be a ring.