NICEIC Certification Scheme NICEIC’s Connection magazine (using CPC as a live conductor)?

[BigSi]

I was reading the latest issue of the NICEIC’s Connection magazine, when came across an article about wiring extractor fans. I didn’t read it in depth (was in the library at the time!!!), but from what I can gather you can now use the cpc in a flex (flex only, not hard wired) as a live conductor from the connection point to the fan.


It refers to changing a fan for a unit with a timer, and the now sleeved cpc can be used as a live cable (presumably the switched feed)? But I couldn’t quite figure out how this would be of benefit as it’s still connected to the connection point which when I looked last only had one live in, one live out.


Or have I totally missed the point altogether? :stupid:

 

[chilliwilly]

I think you have.

Its refering that you can use the green and yellow core wthin a flex as a live/neutral conductor, as long as you flag it thus at both ends. But certainly not a cpc within a twin and earth cable, as it would only be single insulated and carrying a voltage over 50 volts and not satisfying basic protection.

As most fans are class II/double insulated/reinforced insulated, they don't require to be connected to earth, and as most modern fans incoroporate a run on timer. It will save having to rewire them with 4 core to replace the 3 core.

There are still electricians that think you can't use a green and yellow core within a flex as a live/neutral conductor? And they are just veryifyng, its not a departure if used as one.

 

[stuartcourt]

also I get the fan rarely has an earth but surely the cable still needs an earth

 

[gazzamikes]

I agree with bigsi I read it as even though sheeved with brown it can't be done, no explanation as to why in there though just a couple of pics showing

 

[telectrix]

well, i wouldn't do it. 514.4.2. for one.

 

[chilliwilly]

How would you go on with a multicore all the same colour?

 

[telectrix]

guess?

 

[Amp David]

also I get the fan rarely has an earth but surely the cable still needs an earth

For what reason?

 

[stuartcourt]

for instance incase someone puts a nail through it

 

[Guest55]

for instance incase someone puts a nail through it

and what guarantee is there than the nail hit will operate the circuit device ?
absolutely none.
you can hit the live and nothing else with a twin & earth cable and nothing will trip.
there is no requirement for a cable to contain a cpc just for the sake of protecting the cable.
that is only achieved with swa & pyro , hence the relaxation of rcd protection.
;-)

 

[Amp David]

And the CPC is there for that reason is it?

 

[stuartcourt]

amp david I did not think it there for that reason but did think it part of the reason (Biff now know after 20 years my mistake ha ha) so I could run 2 core cable and a separate earth if I felt so inclined

 

[Guest55]

yes.
its one of the ways available of improving cpc free lighting circuits in millions of homes within the uk.
;-)

 

[Amp David]

It made me chuckle when i was told I couldn't run a single insulated and sheathed cable as it didn't contain a CPC.

 

[Amp David]

amp david I did not think it there for that reason but did think it part of the reason (Biff now know after 20 years my mistake ha ha) so I could run 2 core cable and a separate earth if I felt so inclined

You could, but would be a nice 4mm if not in any containment.