Extractor fan wiring - bank holiday confusion

Joined
6 May 2013
Messages
2
Reaction score
0
Country
United Kingdom
:help:
Hi,
Extractor fan stopped working (greenwood axs100svit with timer) so thought I would replace it (Manrose gold with timer). Bit confused with the current wiring though...

Both the bathroom fan (stopped working) and the shower room fan (still working) are wired in as follows:
- neutral - brown
- switch live - grey
- permanent live - black
Plus, earth - yellow/green not wired in or exposed, just cut back to sheath.

But, the isolator switches are both wired as follows:
- neutral - grey
- switched live - brown
- permanent live - black
- earth - yellow/green - Ends in connection block.

Should the wiring not be consistent at fan and at isolator switch re which is neutral and which is SL???

Advice much appreciated, thank you
 
Sponsored Links
Joined
2 Jun 2005
Messages
14,841
Reaction score
477
Location
Cumbria
Country
United Kingdom
An isolator switch is just a switch, it doesn't really matter what each pole is used for as long as it is same in the top as the bottom. Where the pole has N on it though it should be used as neutral, some isolators just say L1 L2 and L3.

Your wiring is a little bit odd though - usually we'd use brown and black as the lives and grey as the neutral, oversleeving with brown or blue to say if it is being used as a live or neutral where the wire is a different colour to what we'd expect.
Wether brown is permanent live and black switch live or vice versa depends which way I got out of bed in the morning!
 
Joined
28 Jan 2011
Messages
51,061
Reaction score
3,503
Location
Buckinghamshire
Country
United Kingdom
Wether brown is permanent live and black switch live or vice versa depends which way I got out of bed in the morning!
FWIW, I have to say that I always get out of bed the same way in that respect. Wherever possible, if brown (or red, in old colours) is available, I've always used that as the permanent live, so that I've known that anything oversleeved (brown or red) is some sort of non-permanent (i.e. 'switched') live.

However, that's only of any value to me if I know that I did the wiring (e.g. in my own house), since others may get of bed any way!

Kind Regards, John
 
Joined
30 Jun 2009
Messages
21,627
Reaction score
2,567
Location
Londonderry
Country
United Kingdom
It's bad practise to use the brown core conductor as anything other than a live conductor, the fact that the cables have also not been identified correctly means it does not comply to BS7671.
So the person who performed this installation was obviously ignorant to BS7671, therefore should be shot at dawn, in accordance to the cowboy/girl code.

 
Sponsored Links
Joined
27 Jan 2008
Messages
19,974
Reaction score
1,957
Location
Llanfair Caereinion, Nr Welshpool
Country
United Kingdom
In the old days we could get cores all red for two way lighting wiring, but with the new colours the option seemed to vanish, so three phase colours are used. Clearly if it was three phase all cores would be line, so only by over sleeving can one show which is neutral, or line. To me the three colours are handy with the old three black cores or even one brown and two black before we went to using grey it was a pain to ring out the cores. But be it two way lighting or fan wiring there is no convention as to what colour is used for what function so you do need to trace.

The earth should be at the cable end even if cut back and one would hope enough is left to make a connection but where it was not in use before I would always test to see if connected at the other end. I know it should be but it may not be. For electricians this is easy we use a loop impedance tester which shows the connection all the way back to sub station but for DIY this is not so easy.

You should not be using a multi-meter as the rules say it must use at least 200ma for the test but in real terms a multi-meter is better than nothing and if I had forgot my test set I would still use a multi-meter rather than go home for test set. Wrong I know and I would always intend to return to retest but know often would never get round to it.
 
Joined
28 Jan 2011
Messages
51,061
Reaction score
3,503
Location
Buckinghamshire
Country
United Kingdom
In the old days we could get cores all red for two way lighting wiring, but with the new colours the option seemed to vanish...
CA1BR.JPG

Click Here for details

Kind Regards, John
 
Joined
27 Aug 2003
Messages
69,782
Reaction score
2,884
Location
London
Country
United Kingdom
Well if you spent less time dancing you might be able to respond quicker here...
 
Joined
28 Jan 2011
Messages
51,061
Reaction score
3,503
Location
Buckinghamshire
Country
United Kingdom
It's bad practise to use the brown core conductor as anything other than a live conductor, the fact that the cables have also not been identified correctly means it does not comply to BS7671.
Although I would struggle to think of a situation in which one would want to do it, I don't think that use of a brown oversleeved with blue for neutral would actually be non-compliant - and I suppose it would be no more 'bad practice' (except,perhaps, by virtue of its 'rarity') than is oversleeving a blue with brown for use as a live conductor. All BS7671 requires is that conductors be correctly identified, and it allows oversleeving to be used for that identification.

However, in the OP's case, using an unsleeved brown as a neutral is just plain non-compliant!!

Kind Regards, John.
 
Joined
24 Sep 2005
Messages
6,338
Reaction score
264
Country
United Kingdom
I wonder if the OP has a white ceiling in either room ?
:?:
 
Joined
30 Jun 2009
Messages
21,627
Reaction score
2,567
Location
Londonderry
Country
United Kingdom
I don't think that use of a brown oversleeved with blue for neutral would actually be non-compliant -
I didn't say it was.
and I suppose it would be no more 'bad practice' (except,perhaps, by virtue of its 'rarity') than is oversleeving a blue with brown for use as a live conductor.
Which is not that rare, when it comes to standard identifying of switch lives on lighting circuits.
All BS7671 requires is that conductors be correctly identified, and it allows oversleeving to be used for that identification.
Which was never in question regarding my post but although compliant, I would still say the practise oversleaving browns with blues on a three+E installation is bad practice and illogical captain!
However, in the OP's case, using an unsleeved brown as a neutral is just plain non-compliant!!
Now we are getting there, that is what I said!
 
Joined
28 Jan 2011
Messages
51,061
Reaction score
3,503
Location
Buckinghamshire
Country
United Kingdom
I don't think that use of a brown oversleeved with blue for neutral would actually be non-compliant -
I didn't say it was.
I know you didn't. However, you appeared to be saying that you felt it was 'bad practice' - and, as I said, if one ever found a situation in which there was a legitimate reason for wanting to do it, I'm not sure that it would be any more 'bad practice' than is the accepted common practice of oversleeving blue with brown. That's all :)

Kind Regards, John
 
Joined
28 Jan 2011
Messages
51,061
Reaction score
3,503
Location
Buckinghamshire
Country
United Kingdom
Which was never in question regarding my post but although compliant, I would still say that the practice of over-sleeving browns with blues on a three+E installation is bad practice and illogical captain!
If I could think of any situation in which one might have a reasonable and legitimate reason for wanting to do it, then I might try arguing - but, as I've said before, I can't think why any such situation should arise :)

Of course, if one needed T+E, but only had twin brown+E to hand, one might then feel that a 'need' to oversleeve one of them with blue had arisen - but I agree that it would not be particularly good practice (albeit compliant with BS7671, as far as 'identification' is concerned) to do that!

Kind Regards, John
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Top