Bathroom fan neutral

[Alimo123]

Hello
Hope im posting in right place
Im renovating my downstairs cloakroom with an openable window and thought about adding a fan
As you can see from the pics i have neutral and switched live at ceiling rose and 2 permanent lives and switched live (3 single core and earths) at pull cord, so there is no permanent live at ceiling rose and there is no neutral at switch.
Am i right in thinking a bathroom fan needs a live neutral and switch live?
Can i run a single core neutral from ceiling rose to switch or run a permanent live from switch to ceiling rose (if can which way better?) then use a 3core&earth to isolator switch then to fan.
I know regs say you do not need a fan in a cloak room with just a toilet and sink with a openable window, so is it worth the hassle to put a fan in (asuming i can run a single core neural from ceiling rose to switch or single core permanent live from switch to ceiling Rose)
Many thanks

 

[pete01]

Run a 1 core and earth (blue) from ceiling rose and a twin and earth from the switch straight to the fan, ( or isolator if you want one)

But I wouldnt bother myself, fans are pretty rubbish.

 

[Alimo123]

Thanks for replying pete01 does it have to be 1core and earth or can it just be 1 core, i was thinking take 3core&E to isolater then to fan so i have option of putting a timer fan
Thanks

 

[morqthana]

Im renovating my downstairs cloakroom with an openable window and thought about adding a fan

Is there a practical reason for wanting that?

Am i right in thinking a bathroom fan needs a live neutral and switch live?

If you want the fan to run on after the switch which triggers it has turned off, yes.

I know regs say you do not need a fan in a cloak room with just a toilet and sink with a openable window, so is it worth the hassle to put a fan in

Whatever the regs say, you can have one if you want, and I can see how you might sometimes want one (e.g. it's brass monkeys outside but you could do with removing the air from the room).

I don't know what access to the wiring above the ceiling is like, but one considerable hassle will be core-drilling a 4" (or whatever) hole through the wall, making good where it breaks through, fixing a shutter to the outside..

 

[pete01]

You could take the blue from the light to the isolator and the twin brown from the switch to the isolator then take a 3 core to the fan.

 

[Alimo123]

Morqthana drilling the 4 inch hole isn’t a problem, its just the wiring thats throwing me off, iv wired a fan in my previous property but that did have permanent live neutral and switch live at the light fitting, as there is no permanent live at the light fitting and no neutral at the switch, all i wana make sure is if i run a neutral from light fitting to switch then run the 3 core to isolator then to fan will that be ok and not trip anything

 

[Alimo123]

Thanks pete

 

[pete01]

Just as a side note, the earths at the pull cord look a bit rubbish, while you're at it put some earth sleeving on them separately and re-terminate.

 

[Alimo123]

Yes pete i will put earth sleeving on them the tape just temporary there was no sleeving on them when i opened pull cord

 

[blup]

Trace where the second switched live goes, it might be suitable for the new fan. Then only a neutral to install. No need for 3 core and earth if the fan has no overrun, it just comes off and on with the switch. Worth considering an isolator as it is annoying and unnecessary for it to come on when not needed.

 

[Harry Bloomfield]

Im renovating my downstairs cloakroom with an openable window and thought about adding a fan

It would be absolutely pointless, adding a fan which only runs, for the few minutes whilst the light is turned on. If spending the effort, do the job properly, with a fan which includes a run-on timer. That will need - neutral, permanent live, and the switched live.

Better, would be a PIR triggered version of the fan, plus timer, which would run whether the light was turned on or not. That would need just the neutral, and permanent live.

Worth also ensuring the fan, includes some sort of automatic shutter, and the outside outlet, includes a gravity shutter. Both help in retaining the heat in the room, whilst the room is not in use.

 

[morqthana]

Better, would be a PIR triggered version of the fan, plus timer, which would run whether the light was turned on or not. That would need just the neutral, and permanent live.

There's that Vent-Axia someone posted about a week or two ago which can work off a PIR and the light, but triggered by a photocell, not a connection to the light.

 

[Risteard]

You could take the blue from the light to the isolator and the twin brown from the switch to the isolator then take a 3 core to the fan.

View attachment 390384View attachment 390385

PVC/PVC single blue is fine. The T&E already has the cpc - no need for blue and Earth.

 

[pete01]

PVC/PVC single blue is fine. The T&E already has the cpc - no need for blue and Earth.

Yes I just choose to run an earth, old habits die hard

 

[SUNRAY]

If you are buying all of the materials from scratch, it may be cheaper to buy 3C&E by the meter than a drum of single blue. Replace the single red&E between switch with 3C&E then run 3C&E from either the light or the switch to the fan.
It might seem more work but as an example:

and you probably don't need 10m of 3C&E