high voltage fan in bathroom

[wtknsstp]

REcently bought a property and have been advised by an electrician that the fan in the bathroom is a normal high voltage fan and therefore not suitable for above a bath.

I have therefore purchased an extra low voltage fan with transformer and timer.

I understand i need to install FCU outside the bathroom with a 3amp fuse but what I want to know is can I wire it into the exsisting light circuit and use the light switch

If so what is the best way of taking the switch feed and permanently on feed to the fan??

is it possible to take this from the switch box for the bathroom light??

cheers

 

[Spark123]

Fans etc are fine fed from a lighting circuit, personal preference is to fit a 3A fused spur unit (unswitched) and run the bathroom light and fan from it. This means the permanent live and switch live can both be protected by the fuse. A 3 pole isolator should also be fitted to allow maintenance of the fan.
You should note that doing the work is notifiable to your LABC under part p of the building regs.

 

[wtknsstp]

cheers

so fit the 3a fuse before the light circuit in the bathroom,

then just run seperate from there to the fan (via an isolator) and light?

 

[breezer]

check to see is the bathroom light last on the cct. if not a little alteration will be required if you want to fit the 3A fuse

 

[Spark123]

You can if you like, but remember you need permanent live, switch live, neutral and earth for the fan. I like to fit the FCU and the isolator outside the bathroom above the door.
Is the supplementary bonding in place also?

 

[wtknsstp]

yes,
had electrician check everything when the fitted a new ring in the kitchen.
only thing left to sort was the fan.
is there a way to take the supply from the batten holder and then run it back out to fit the fcu and still use the light switch so they come on together but the fan also has a permanent feed for the timer unit?

 

[Spark123]

Not really, the fused spur needs to be fitted before the switch so it protects both the permanent live to the fan and the switched live to the fan.

 

[wtknsstp]

ok
cheers for the help
so would the ciruit go to batten holder then switch or other way round?

 

[Spark123]

Depends on how it has been installed, you may be able to pick up the wiring in the lamp holder or switch. Might be an idea to change the batten lampholder to a bathroom type light too.
Is your electrician still around?, might be worth getting him to have a look.

 

[wtknsstp]

so does the link below seem correct as that seems sensible,
also rather than just an isolator though i could use a combined isolator with the 3a fused control unit, rather than seperate

http://www.ultimatehandyman.co.uk/diy/electrics/extractor_fan/shower_extractor_fan_fitting.htm

 

[Spark123]

The wiring is mainly correct in the link, however the manufacturers almost alway say to protect the fan with a 3A fuse. In that link the fan is protected by the lighting circuit fuse.
I don't follow what you are meaning by a combined isolator/fuse. The isolator needs to cut the live, switch live and neutral to the fan. The same fuse needs to be used to protect the L and Ls supply to the fan.
You can of course use a dual back box and mount the fused spur unit and the isolator together.

 

[wtknsstp]

see what you mean.
Hence why i need to put in the 3a fuse before the light.
is there not a way to get a triple pole isolator with 2 3a fuses in it, one for each live?

 

[breezer]

no.

pointless if one fuse goes the other is still live

 

[GaryMo]

230v is low voltage, not high voltage.

Just use a triple pole isolator if the fan is fed from the lighting circuit, forget about a switched fuse spur.

 

[Spark123]

How do you stand for a manufacturers instruction requiring a 3A fuse though?