Hi,

Had to change a bathroom fan at the weekend for someone and they wanted it to be on a timer, but couldnt as the cable was buried in the wall and wouldn't move etc..

the cable that fed it was a three core flex, I the earth was not being used anyway due to the load on the end etc.

I know you are not meant to use the CPC as a live conductor, but if its flex and the same CSA and you were to correctly identify it with brown etc, would it have then been acceptable?

I didn't do it, but it made me think, oh i so could have used it, but it just seemed wrong. I can understand why you wouldn't do it in twin and earth, but surely where its flex or all conductors are the same CSA and have their own sheathing on them inside the outer, would it have been acceptable or not?

I am going to say not on the basis CPC is CPC and nothing else, any thoughts would been welcomed.
 
Yes but I still needs a switched live as well as permanent, if I had a bloody three core and earth you are right, we wouldn't be having this damn conversation.
you can take a 3 core and earth from the bathroom light to the transformer and then disconnect the existing 3 core flex from the circuit and re-route to the new transformer, change the LV fan to a Selv fan and it is job done, easy.
 
you can take a 3 core and earth from the bathroom light to the transformer and then disconnect the existing 3 core flex from the circuit and re-route to the new transformer, change the LV fan to a Selv fan and it is job done, easy.

Not sure how that works out MDJ ?

He still wouldn't have a SL (or PL) it would be one or the other at ELV ? unless I am misunderstanding you ? It would not be the first time. lol
 
Not sure how that works out MDJ ?

He still wouldn't have a SL at ELV ? unless I am misunderstanding you ? It would not be the first time. lol
yes he would, he can take a live, switch live, neutral and earth from the bathroom light to the new transformer, then he can re-route the existing flex to the selv side of the transformer, with selv fans you only need 2 cores, the timer is in the transformer.
 
yes he would, he can take a live, switch live, neutral and earth from the bathroom light to the new transformer, then he can re-route the existing flex to the selv side of the transformer

The transformers have two connections minus the CPC at the primary side, where would the other L (PL or SL) go to ?
 
If it's only a couple of feet why not use singles in conduit or flexible conduit or even make up your own 3-core and earth using singles in heat shrink?

Over-sleeved or not, regs or no regs...... I'm not keen on using a gr/y for anything other than CPC. I've never done it and I never would.
 
The transformers have two connections minus the CPC at the primary side, where would the other L (PL or SL) go to ?

You as I have just said get a transformer with thew over run built in, take PL-SL-N-CPC to 230 side of transformer, only need a LV L&N neutral to fan as all controls are from the transformer rather at the fan.
 
What about moving the timer out of the fan as I said and putting that into an enclosure , It would be exactly the same and using the existing fan ..

The Airflow Icon 15 or 30 can be got without a timer module and you can also get the timer module separately , this can go in the enclosure ,,,
 
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here have a looky
 

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514.4.2
Single core cables that are coloured green/yellow throughout their length shall only be used as a protective conductor and shall not be overmarked at their terminations,except as permitted by reg 514.4.3

It then goes on to say,and by the way the green/yellow in multi core cables "can" be oversleeved so crack on

Sorry about the last line that was a downright lie

The reason i included that is to try and show that there is no problem deciding that the actual reg does not include multi core cables
It is no problem because multi core is not included
(If it was the case that multi core is included,then it would not specifically mention, in isolation, single core cables green/yellow throughout their length)

Where is this grey area or doubt that has been talked about,its as clear as night and day
You can colour code a multi core green/yellow to another colour and you break no reg


I have never and will never do this,but if it was found it is permitted
 
Must admit, I've done it.....but it was on 400w sons 30 ft in the air, before we had internal photcells. The photocells had to be fitted to the brackets with 3 core flex from the fitting, about a foot long.

Shoot me for that you word for worders.......NIC ban on the way, no doubt!!!:cowboy:


Agreed - Following a reasoned risk assessment, why not do it?
 
I think I have not made myself clear, the fan is mounted in the wall and tiles in as it the wire, I changed the fan, but cannot replace the wire to it, this is the problem. Short of ripping tiles of the wall I cannot change the wire, its a non starter.

This is why I was wondering about using the CPC...
 
I think I have not made myself clear, the fan is mounted in the wall and tiles in as it the wire, I changed the fan, but cannot replace the wire to it, this is the problem. Short of ripping tiles of the wall I cannot change the wire, its a non starter.

This is why I was wondering about using the CPC...

Why not take the timer module out of the fan and put it in an enclosure in the loft and use the LNE down from the timer module
 
I think I have not made myself clear, the fan is mounted in the wall and tiles in as it the wire, I changed the fan, but cannot replace the wire to it, this is the problem. Short of ripping tiles of the wall I cannot change the wire, its a non starter.

This is why I was wondering about using the CPC...
In principle reg 514.4.2 allows us to over sleeve a core, coloured green and yellow, of a multicore cable at both ends to be used as a live conductor as long as it is the same CSA as the other live conductors within the cable.
but the chances are that the circuit feeding your extract fan does not comply with 411.3.1.1
 
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Flipping heck, the fan is in the wall, the wire goes down the wall then into a vanity unit thing with a light on it with its own pull cord, when you pull the cord the light and fan comes on. It goes nowhere near the ceiling. There's no transformer, it's 230v bot ELV, the cable to the fan fel. The vanity unit thing is buried behind the tiles and is three core flex.

theres nothing I can do with it other than pull tiles off the wall.
 
So the circuit is all in the wall then and spurred from the vanity unit , is that what your saying , also the pull cord brings on the fan and vanity unit together is that right ,,
 

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Using CPC as live conductor.... ok i know, but...
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