Extractor Fan Connection diagram


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Established Member
25 May 2007
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West Cumbria
I realise this is not a woodworking subject but I welcome your advice.
I need to wire in a Manrose BVF 100 extractor fan.

Safely done with all elecs isolated, I have used a 3 way connector and broke into an adjacent 2.5mm live feed and supplied L, N & E to the "incoming" side of a 5A switched & fused unit.
I have a 3 pole pull cord switch with 2 x sets of L1, L2 & N connections.
The extractor fan has 3 x available connections being; Neutral, Switched Live & Permanent live.

Can any one supply a simple wiring diagram on how I can connect the 5A fused, (load) Live, Neutral & Earth to the 3 pole pull cord switch and then onto the 3 connection extractor fan
I attach a simple drawing which I was to lazy/stoopid/etc etc to add earlier.
I hope it may help in getting answers.


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My guess is that the permanent live input at the manrose fan is needed for the timer circuit.
It probably keeps the fan running for a few minutes after the switched live is turned off.
If the fan is suitably low powered, this may be to allow it to be fed from the lighting circuit in the room - you go into a small toilet, you turn on the light, the fan turns on with the light, you turn off the light as you leave and the fan runs on for a few minutes thanks to the permanent live supply and the timer circuit.

To make this work with the fittings you have, permanent live, neutral and earth all need to go direct from the 5a fused isolator to the corresponding inputs on the fan.
You then bring the permanent live back from the fan to the pull cord switch live in and the live out goes back to the switched live input of the fan.

If you don't know the industry standard wiring colours / which colour to use for what, then seriously pay an electrician to do it, you are not skilled enough to do it safely.

If this is in a bathroom, it is absolutely not a DIY job.
Channeling my inner 3 year old and Microsoft Paint, please see below:


You only really need a single way pull switch if its only purpose is to control the fan.

The live feed to the switch can either come from the isolator as shown or from the fan as suggested above. Pick the easiest/shortest route.

It may be easier, depending on geography, to go from isolator to fan with four core cable (brown, black, grey earth) and from isolator to pull switch with three core (brown, blue, earth) and Wago the switched lines together in the isolator box.

The switched live is drawn in black, not to denote that it necessarily is black, but to suggest that its colour may vary dependent on how you do the install. The most important thing is that it is sleeved at each end with brown sleeving to denote that it is switched.

If you use four core cable, grey with blue sleeve is generally used for neutral and black with brown sleeve is used for switched live. Among other things, that means the blue cable drawn above could be incorrect if you do go the four core route. The most important thing is to make sure both ends are labelled as to their function.

If you use twin and earth between isolator and switch, the blue would be sleeved with brown to denote switched live.

Read up on bathroom zoning. Like the London tube, being beyond Zone 2 leads to a much happier life.

The most important thing to take away is that there is no single correct diagram showing colours. Brown is always live, green/yellow is aways earth. Beyond that, it is situationally dependent.
Thank you Sideways and Chailette for you advice

Chailette:- I attach a new drawing showing the layout with 1 x 3 pole pull switch and also showing a 2 pole pull switch (BTW my numbering is out of kilter now).
What is the best/simplest switch to use.

The pull switch is immediately next to the fused spur and readily available for wires from and to both units.
The extractor fan is further away and more difficult to get wire/s to and from it.

Can I use the 2 pole pull switch to operate the fan with its timer.
I welcome your advice and drawing of connections again please.

My best regards to all....Richard


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What is the best/simplest switch to use.

I welcome your advice and drawing of connections again please.

Any switch of minimum one single pole will suffice.

The challenge with a two pole switch is remembering whether you should use the north pole or the south pole. I always get mixed up; living in the northern hemisphere I can never remember if it should be the like pole, to repel, or the opposite pole, to attract.

Single pole is good as you have no difficult choices to make. Three pole is also good as you can use the equatorial one and bypass the problem above.

Unfortunately the ink cartridge in my Microsoft paint has run out so drawings are no longer possible. There is nothing additional that could be added to the post above that would not be repetition.
As @Sideways has said they are normally taken from the lighting circuit so operation of the light triggers the fan to extract the smell and the permeant live is used to keep the fan running when the light is turned off via the timer.

Can I use the 2 pole pull switch to operate the fan with its timer.
Why take the wiring from the switch, access the ceiling rose wiring and you have the switched live from your pull switch, the permeant live and a neutral.

Don't forget that any wiring in a bathroom or such is a special location under the regs and must be tested and signed off by at least a part P holder.