Pir sensor and extract fan

[Matt0410]

Can anyone tell me if its possible to wire an extract fan to a pir sensor? And if you can, HOW?!?!?!?

thanks

 

[JRspark]

The PIR is just a switch. Feed in and switch wire out. May need a junction box in there somewhere as you may need to take a permanent feed to the fan as well as a switched feed. Or take the feed cable to the fan, then out to the PIR with the return switch wire to the fan.

 

[worzol99]

You can buy extracts with built in sensors now, might save messing around

 

[Matt0410]

So if I understand correctly I use my live, common and earth to the pir, putting a junction box in the live line to go off to the fan, then I take the common and earth around the lighting ring, incorporating the fan in with it?

 

[JRspark]

Take a twin + earth to the fan off your nearest lighting point, so you have a permanent live, neutral and earth at the fan. Then take a another twin + earth to the PIR from the fan. Brown as the permanent live and blue as the switch live (flagged up brown). So PIR gets its permanent feed from the fan and when it's switched energised the switched live back to fan. Probably best to leave out JB if possible. Why do you want this set up by the way?

 

[Matt0410]

Ok thanks ill try that! Because our en suite is so small there isn't really the space to put a switch inside. Therefore a PIR! Thanks for the help!

 

[JRspark]

Well usually the fan would come off the lights in the room with a permanent live for the over run of the fan. So when lights are on the fan comes on and when lights go off the fan stays on for an adjustable amount of time. So no need for a PIR at all.

 

[Matt0410]

Would I not need a switch for that to work tho?

 

[JRspark]

If you were to wire it off your lights like you should then the existing switch for your lights would turn the fan on and off. So when lights come on the fan comes on. I recommend gettin an electrician in mate.

 

[shagbite]

If you were to wire it off your lights like you should then the existing switch for your lights would turn the fan on and off. So when lights come on the fan comes on.

I recommend gettin an electrician in mate

.

i concur.

no offence op, but if you're asking about pir's for a bathroom fan, when you've already got a lighting circuit + switch installed, then it's time to get an electrician in.

 

[Matt0410]

The reason I'm putting the PIR in is because the location of the switch at the moment is crap, and don't want one inside. I'm gonna give what u said a go this week when the fan is delivered. Cheers for the help

 

[JRspark]

Oh dear...

 

[Matt0410]

Meaning....?

 

[JRspark]

You will be putting holes in your ceiling for PIRs for no reason. The fan can be controlled with the lights in your en suite. Which means when you turn the lights on by the existing switch the fan will come on too. Your knowledge on this subject really suggests to me that you need an electrician to have a look and do the work. Sorry if I have confused you.

 

[Matt0410]

But if you look at my previous reply I said I didn't want the switch because of, amongst other things, it's location. The ceiling isn't an issue considering ill be completely refitting it. I know the fan can be controlled by the lights via the switch as this is what was there originally. There's only one way to learn how to do it, and that is to do it!

 

[HandySparks]

Given the way the question's been asked, I would query whether any of the following will be taken properly into account in this proposed installation:
Regulations applicable to rooms containing a bath or shower?
Testing before and after energising?
Notification under Part P of the building regulations?

There you are Murdoch, I've said it for you! :biggrin:

 

[MDJ]

You beat me too it as well, I was at a dinner party, thank god thats over haha, right then back to the original question

HOW?!?!?!?

thanks

eh?????? as you have asked and have no idea at all and it's in a bathroom/ensuite, I just won't tell you unless you can confirm you have the relevant qualifications, electricity is serious stuff fella.