Using cpc as neutral

[Wilko]

You can even oversleeve a green and yellow insulated core with brown in a multi core cable and that still complies with the regs

Hi - not to joust, but not a good idea imho and may be prohibited by 514.4.2 .

 

[johnduffell]

Hi - not to joust, but not a good idea imho and may be prohibited by 514.4.2 .

Agree it's a terrible idea when designing from scratchs but i don't agree it's dangerous and it would be picked up straight away by anyone working on the circuit.
That reg says you can't identify with green and yellow but you can insulate with green and yellow and identify by over sleeving just like identifying any other. And also you aren't allowed to use over sleeving to identify single core cables.
It's a bit like the two circuits in one accessory problem, or rings split side to side. Might confuse people but they probably are the kind of people who connect all reds and Black's in a light and wonder why the switch pops the MCB

 

[Octopus]

Cpc has to be present at every termination but in fact you can get it from wherever you like.
You can even oversleeve a green and yellow insulated core with brown in a multi core cable and that still complies with the regs. But you'd only do that if you were struggling to avoid a lot of redecorating!
The bare cpc is not insulated that would be your main problem.

So you've given me a disagree ............ hum

Reading the OP between the lines I imagine he wants to use the CPC as SL or similar .............. hence my reply.

 

[Darkwood]

MODs... Is this 'blocked profile' a glitch as the last member who had this said they hadn't changed anything?

I don't have any blocking issues as a Mod but yes it doesn't allow me to view if I log out and try view as a visitor, I assume its part of the approval system all new members are now on, it's part of the fight against spamming that we now approve all posts and activities from new members hence you haven't seen any of the spam for a while.

 

[johnduffell]

So you've given me a disagree ............ hum

Reading the OP between the lines I imagine he wants to use the CPC as SL or similar .............. hence my reply.

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.

 

[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......