Wiring for an extractor fan

[MyNameIsUrl]

I’d like to get an extractor fan fitted but I’m unsure of the wiring requirements – on the face of it my situation is very simple, but much of the advice online seems to be only appropriate for different situations:

- the fan is to be in a study/craft room – no water supply in the room, so no need for a corded ceiling switch

- the fan doesn’t need to be wired to operate when the light is switched on (unlike some bathroom arrangements), but to operate completely independently

- there is no need for a run-on timer, so no need for a permanent live at the fan

What I’ve gleaned is I can have a 3A fused switched spur installed adjacent to an existing 13A ring-main socket, with a twin-and-earth wire leading to the fan. This switch can be used to operate the fan. Does this sound suitable?


(The actual connecting up of the wiring up I expect to be done by an electrician, but if I know in advance what holes to make in the wall and what size wire to route, I can take my time doing this with minimal damage to décor.)

[richlist]

Have you considered fitting a 3 pin plug and plugging it into an existing socket ?
No electrician required for that.

[csearle]

the fan is to be in a study/craft room – no water supply in the room, so no need for a corded ceiling switch

Even if there was water in the room there is no basic "need" for a pull-cord.

What I’ve gleaned is I can have a 3A fused switched spur installed adjacent to an existing 13A ring-main socket, with a twin-and-earth wire leading to the fan. This switch can be used to operate the fan. Does this sound suitable?

Yes that sounds suitable; use 1sqmm twin and Earth or alternatively flex. Not normal, but safe.

Many fans these days say in their instructions that their supplies are to be fused down to 3A. This can be achieved in the way you describe. Usually fans are supplied from the lighting circuit (even when they have no timer-overrun). Now that many fans have a 3A requirement they are producing fan isolators with 3A fuses built into them. Sometimes it is necessary to source 3A circuit breakers for the fuseboard.

In your case the fused connection-unit you envisage is adequate for maintenance isolation (a requirement).

So I would say go ahead. When you cut out the hole for the fused connection-unit make sure it is either positioned exactly right so that the socket outlet and the fused connection-unit butt up against each other, or, leave a, say, 5cm gap in between them.

This can all be done DIY so long as you feel up to it and that you ensure the power is switched off at the board whilst working on it.

Cheers,
Chris

[Mike4]

Have you considered fitting a 3 pin plug and plugging it into an existing socket ?
No electrician required for that.

I'm reasonably sure the electrical regs require fixed wiring for fixed appliances. 3 pin plugs are for portable stuff.

Delighted to be corrected if this is wrong though.

[csearle]

Have you considered fitting a 3 pin plug and plugging it into an existing socket ?
No electrician required for that.

I'm reasonably sure the electrical regs require fixed wiring for fixed appliances. 3 pin plugs are for portable stuff.

Delighted to be corrected if this is wrong though.

Well somewhere in the regs it does say that a plug and socket is an acceptable means of isolation. Boilers spring to mind, which are quite often simply plugged in. C.

Edit: BS7671 537.1.1, Table 53.2 specifies it. (The copy I'm looking at is from 2008 but I don't think this has changed.

[pochisoldi]

Have you considered fitting a 3 pin plug and plugging it into an existing socket ?
No electrician required for that.

I'm reasonably sure the electrical regs require fixed wiring for fixed appliances. 3 pin plugs are for portable stuff.

Delighted to be corrected if this is wrong though.

I've used one of these
https://www.screwfix.com/p/crabtree-cap ... hite/29716
to feed a fixed/solid core cabled installation from a short length of flex going to a 13A plug. (In my case it was to present a clear "demarc" between my tidy semi-permanent non-part P computer closet wiring and house wiring and also to permit the easy insertion of a UPS at a later date)

[dspp]

Have you considered fitting a 3 pin plug and plugging it into an existing socket ?
No electrician required for that.

I'm reasonably sure the electrical regs require fixed wiring for fixed appliances. 3 pin plugs are for portable stuff.

Delighted to be corrected if this is wrong though.

I believe that one can use 3-pin plug/sockets on their own for fixed appliances, provided that the plug/socket is accessible. If the socket is inaccessible then there must also be an accessible switched fuse. The most obvious example is an under-counter tumble drier, fridge, freezer, etc. - they can be an inaccessible plug connection behind them, but that should be fed from a switched fuse above the counter.

The OP's description of what to make provision for in the first post sounded correct to me, and is exactly what I have done on one ventilation fan at my GF's.

regards, dspp

[swill453]

I believe that one can use 3-pin plug/sockets on their own for fixed appliances, provided that the plug/socket is accessible. If the socket is inaccessible then there must also be an accessible switched fuse. The most obvious example is an under-counter tumble drier, fridge, freezer, etc. - they can be an inaccessible plug connection behind them, but that should be fed from a switched fuse above the counter.

Is a plug connection in a cupboard treated as accessible?

Scott.

[richlist]

I could give you a long list of fitted appliances that are plugged into accessible 13amp sockets inside my house......fridge, dishwasher, oven, microwave, wall mounted electric fires & fan heaters, fixed garden sockets & lighting etc.

It's the poor man's way of meeting requirements without paying for an electrician and an installation certificate.

[jfgw]

I could give you a long list of fitted appliances that are plugged into accessible 13amp sockets inside my house......fridge, dishwasher, oven, microwave, wall mounted electric fires & fan heaters, fixed garden sockets & lighting etc.

It's the poor man's way of meeting requirements without paying for an electrician and an installation certificate.

That, in my experience, is by far the most common method. Sometimes, the socket is hidden but there is a switch above the worktop. Newer installations may have the switches all on one plate. Sometimes they are above the fridge-freezer so you have to open the fridge door to get to them. Sometimes, some donk who doesn't understand kitchens fits the connection point immediately behind the appliance. In such a case, it is often necessary to hardwire the appliance using a flex outlet as a plug and socket stick out too far.


Julian F. G. W.

[quelquod]

Sometimes, some donk who doesn't understand kitchens fits the connection point immediately behind the appliance. In such a case, it is often necessary to hardwire the appliance using a flex outlet as a plug and socket stick out too far.

Julian F. G. W.

When I moved into this house I discovered that the kitchen fitting donk had done just that for the dishwasher. However being an innovative donk, after finding that the dishwasher wouldn’t go back far enough he managed to sink the socket, back box and plug right through the leaf and into the cavity. I didn’t find it for some years until we redid the kitchen.