Installing kitchen extractor fan - different wiring.

[mothsinmywallet]

Hi all,

Recently had a new kitchen fitted and had a sparky to rewire the kitchen adding more sockets and a new hard wire for electric oven. A 13a socket was fitted near the ceiling above the top kitchen units to power the extractor. However when opened up extractor fan unlike our last one this one is non-plug, just the L + N wires.

"An all pole disconnection switch having a contact separation of at least 3mm in all poles should be connected in fixed wiring"

Can I buy a 13A switched fused DP socket and simply remove the old 13A socket and replace it with the new one? Will a DP switched be suffice?

Tech data - power supply 220-240v, motor power consumption 80w, light 9w, total 89w.

If its something I can do to save a bit of money then I'm all for it but will respect if told needs to be done by a qualified sparky.

Many thanks in advance.

 

[riveralt]

Hi all,

Recently had a new kitchen fitted and had a sparky to rewire the kitchen adding more sockets and a new hard wire for electric oven. A 13a socket was fitted near the ceiling above the top kitchen units to power the extractor. However when opened up extractor fan unlike our last one this one is non-plug, just the L + N wires.

"An all pole disconnection switch having a contact separation of at least 3mm in all poles should be connected in fixed wiring"

Can I buy a 13A switched fused DP socket and simply remove the old 13A socket and replace it with the new one? Will a DP switched be suffice?

I take it you mean a DP Fused Connection Unit like:
http://www.tlc-direct.co.uk/Products/AA13SCF.html

In which case yes.

Some people would probably just connect the wires to a 3/5/13 Amp fused plug and plug it in your already prepared socket. Size of fuse set by manufacturers instructions.

 

[DaftPunk]

Just put a plug on the end of the wires. This will more than exceed the manufacturers requirements.

 

[mothsinmywallet]

Many thanks, never thought of connecting via a plug. I think I might still go for the DP fused connection. I've seem to have a spent a small fortune on the kitchen so I might round it off properly for the sake of a few quid.

 

[JohnW2]

Some people would probably just connect the wires to a 3/5/13 Amp fused plug and plug it in your already prepared socket. Size of fuse set by manufacturers instructions.

Indeed, and that would probably be fine, electrically speaking. Most decent modern switched sockets (e.g. MK) have DP switches and at least 3mm contact separation, as specified by the fan manufacturer (and the present socket could be swapped for one of those if the current one doesn't meet those requirements).

The highly cautious (pendantic?) would probably take the view that to use a plug and socket would be non-compliant with the manufacturer's instruction that "An all pole disconnection switch ... should be connected in fixed wiring", but that's not really an 'electrical' consdieration. FWIW, I have to say that it wouldn't worry me, personally.

Kind Regards, John

 

[ban-all-sheds]

Particularly as the Wiring Regulations regard even an unswitched plug & socket as providing isolation.

 

[JohnW2]

Particularly as the Wiring Regulations regard even an unswitched plug & socket as providing isolation.

Quite so - except that some people would probably still stick to their guns and say that requirements of MIs over-ride that!

I think that's one of the main problems with MIs - if they were liberally scattered with "or equivalent" type statements, I think many of us would be happier, and a lot of the potential silliness would go away.

Kind Regards, John

 

[ban-all-sheds]

""An all pole disconnection switch....."

Define "switch".

 

[JohnW2]

""An all pole disconnection switch....." Define "switch".

It's not so much the definition of it that could be an issue in some people's eyes but, rather, that the MIs require that it should be "in the fixed wiring" - which itself raises questions of definition/interpretation.

However, this is all so silly. I do feel sorry for those who feel that (e.g. because of scheme membership) they are constrained to work literally to the every word of the regs, hence the every word of MIs, without any opportunity to exercise their skill, knowledge and common sense.

Kind Regards, John

 

[EFLImpudence]

Do plugs not connect to fixed wiring.

If they are pulled out and placed more than 3mm. away I would consider that satisfactory.

I'm all for pedantry but, although rare, sometimes THIS can be used.

 

[JohnW2]

Do plugs not connect to fixed wiring. If they are pulled out and placed more than 3mm. away I would consider that satisfactory. I'm all for pedantry but, although rare, sometimes THIS can be used.

As I said, I feel sorry for those who feel for whatever reasons ('scheme rules' or whatever) that they cannot exercise common sense. The common sense answer in the case we are discussing is perfectly obvious.

Kind Regards, John

 

[riveralt]

As I said, I feel sorry for those who feel for whatever reasons ('scheme rules' or whatever) that they cannot exercise common sense. The common sense answer in the case we are discussing is perfectly obvious.

Scheme rules say you should be guided by BS7671 and this particular case is a prime example of where common sense should be applied.

The OP has a socket already installed ready for the extractor fan - one hopes correctly installed!
The MI's are demanding, effectively, that the OP opens up the socket - after turning off the power of course- remove the socket by disconnecting the probably two maybe three sets of cables from the terminals.
Then re-connect two, three or four sets of cables to a fused connection unit before re-energising the extractor.

Whereas the common sense answer is to fit a fused plug.

Although not a scheme member anymore, if this was part of my assessment and this issue of MI compliance came up - I would ask the assessor which option do you think is the safer?

 

[JohnW2]

As I said, I feel sorry for those who feel for whatever reasons ('scheme rules' or whatever) that they cannot exercise common sense. The common sense answer in the case we are discussing is perfectly obvious.

Scheme rules say you should be guided by BS7671 and this particular case is a prime example of where common sense should be applied.

As I've said, I certainly agree with the latter part of that. I have to take your word for what you say about 'scheme rules'.

All I know is that I've fairly often (both here and elsewhere) seen electricians saying, or implying, that they sometimes do things only because they feel constrained by their scheme membership to work to the letter of BS7671 (hence, by implication, the letter of MIs), even if that means doing things which do not correspond with their expert judgement or (informed) common sense. From what you say, they may be over-interpreting the obligation placed upon them by their scheme operator - but I'm obviously in no position to comment on that.

Kind Regards, John