Bathroom extractor - take 2

[corax]

Hello folks

I posted a while ago about putting a bathroom extractor fan into the attic.

I have since managed to run a cable from the existing single way bathroom switch up into the attic (I didn't think I was going to be able to do this last time I posted). Ideally, I want to run the fan on a separate switch, I have a spare 2 gang 2 way switch - can I use this?

If so is it just a case of wiring the fan to the second gang in the switch? Also do I need to use the earth for a bathroom fan?

Thanks in advance for any advice/help

 

[Murdoch]

Hello folks

I posted a while ago about putting a bathroom extractor fan into the attic.

I have since managed to run a cable from the existing single way bathroom switch up into the attic (I didn't think I was going to be able to do this last time I posted). Ideally, I want to run the fan on a separate switch, I have a spare 2 gang 2 way switch - can I use this?

If so is it just a case of wiring the fan to the second gang in the switch? Also do I need to use the earth for a bathroom fan?

Thanks in advance for any advice/help

Re the switch, may be is the best answer ............... where are you planning to get the live, neutral and earth from? and does the circuit have RCD protection?

An earth (cpc) should be run to all points on a 230v circuit, even if the accessory doesn't need it.

 

[Evans Electric]

You need a neutral to be in the switch , sometimes there is , sometimes there isn't one .    

Regarding the earth  , as electricians we are obliged to leave an earth at every point whether needed or not .    However  I doubt your fan will actually need one .  

You can use the spare  switch if you want  but you need to know how to wire your fan  before just dropping cable in .

Your fan will need  :

1)  A permanent live. 

2)  A Neutral .

3) A switched wire  ( On /Off)  

Edit;  And yes , as Murdo says  , the circuit needs to to be fed via an RCD . 

 

[corax]

Hello

Thanks for the replies. The circuit has an RCD at the fuse board.

There is currently a neutral and a live and earth in the switch. Neutral going to COM and the live to L1 earth just going to a piece of connector block.

Would I use a 3 core and earth to wire the fan to the second switch? Or maybe it would just be easier wiring it to the same switch so it comes on and off with the lights?

 

[Murdoch]

Hello

Thanks for the replies. The circuit has an RCD at the fuse board.

There is currently a neutral and a live and earth in the switch. Neutral going to COM and the live to L1 earth just going to a piece of connector block.

Would I use a 3 core and earth to wire the fan to the second switch? Or maybe it would just be easier wiring it to the same switch so it comes on and off with the lights?

Neutral going to Com ? Just because there is black or blue cable doesn’t mean you have a neutral 

I think you’ll find that it’s actually the switched live

 

[corax]

Yes I thought this, it must be the switched live but it is the blue cable, brown is going to l1

 

[roys]

Doesn’t matter the colour, one is the live and the other is the switched live, all that is missing is the bit of brown sleaving or tape round the blue, but it’s function is its function no matter the colour.

if it was live and neutral connected across the switch when you switched it to the on position it would be a dead short tripping the mcb and possibly damaging the switch.

 

[Bruspark]

Just to start the fun some maker's instructions ask the fan be run via a 3A fuse  . .    To avoid the dangers of multiple fuses that usually means the entire circuit run via the fuse
Other makers  'sort of' allow a 6A lighting circuit breaker to serve but often only via a cryptic diagram

 

[corax]

Re the switch, may be is the best answer ............... where are you planning to get the live, neutral and earth from? and does the circuit have RCD protection?

An earth (cpc) should be run to all points on a 230v circuit, even if the accessory doesn't need it.

Ok there is a ceiling rose in the attic (operates the attic light) that I plan to get the live neutral and earth from.

Would it be a case of running a 2 core and earth from the ceiling rose to the switch and a 3 core and earth from the rose to the fan?

 

[kerching]

Is there a permanent live at the ceiling Rose in the attic....or, is it a switched live ?

 

[corax]

Is there a permanent live at the ceiling Rose in the attic....or, is it a switched live ?

Its a switched live...

 

[kerching]

Well,in that's case the attic light will,need to be switched on so the fan will work AND you won't have an overrun timer

just saying

 

[Murdoch]

Ok there is a ceiling rose in the attic (operates the attic light) that I plan to get the live neutral and earth from.

Would it be a case of running a 2 core and earth from the ceiling rose to the switch and a 3 core and earth from the rose to the fan?

Time to get a pro in maybe 

 

[corax]

Yeah think you're right - thanks for all the info everyone who commented