Wiring bathroom fan in loft void

[PrenticeBoyofDerry]

It doesn't matter if the walls are made of wood, providing the cable is not less than 50mm from either side of the wall, and the stud work or wall doesn't include metal parts.
If is not you need either RCD or you can get away with it by using specail cables that have mechanical protection.

 

[RegB]

Thanks to all for the replies. I've got a better idea on how to proceed now. But to return to the OP, if I use a switched FCU can that be used as the fan switch or do you have to have a separate switch as well?

 

[GaryMo]

Thanks to all for the replies. I've got a better idea on how to proceed now. But to return to the OP, if I use a switched FCU can that be used as the fan switch or do you have to have a separate switch as well?

It depends how you wire it.

You could change the existing bathroom switch for a double pole switch, one pole switching the bathroom light as normal and the other pole providing a switched line to the fan. Run a 2 core and earth (permanent line and neutral) from the bathroom fitting to a SFCU then out with another 2 core and earth to the DP switch. Finally a 3 core and earth to the fan.
If you choose this method then you can use a SFCU as the isolator.

Another option is to re-route the permanent line and neutral conductors which go to the bathroom light to a FCU then out from the FCU back to the bathroom light. You then run a 3 core and earth to a 3 pole fan isolator from the bathroom light position and finally another 3 core and earth to the fan.
If you choose this method then you'll require a FCU and a 3 pole fan isolator.

 

[RegB]

Got it. OK thanks Garymo. That gives me a bit to think about. Thanks a lot again.
Reg

 

[GaryMo]

A point to consider would be if you choose the second option then you're altering the circuit involving the bathroom light so an RCD would be required for your alteration.