Could anyone please advise me how to wire an extractor fan with run-on
timer in a bathroom? It needs to be wired into a wall mounted light.
The instructions say that switched live, permanent live and 3 AMP
double pole fused spur are needed. The pull cord switch and the wall
light are run from a junction box in the loft. I'm a complete amateur
so please be as detailed and descriptive as possible.

Cheers!

"Nearly Done!" wrote in message
om...
Could anyone please advise me how to wire an extractor fan with run-on
timer in a bathroom? It needs to be wired into a wall mounted light.
The instructions say that switched live, permanent live and 3 AMP
double pole fused spur are needed. The pull cord switch and the wall
light are run from a junction box in the loft. I'm a complete amateur
so please be as detailed and descriptive as possible.

Cheers!
Usually there is a lighting 'ring' that runs (red, black, and earth) from
the main box round the lights. From this ring are dropped a black to the
light, and a live ("permanent live") to the switch. From the switch comes
the "switched live" which then goes to the light. If you draw it on a bit
of paper it will make more sense.
The "3 amp spur" is probably saying that the live and neutral to the fan
should both be switched, and have a fuse in the live wire. You should be
able to get a suitable socket from Homebase or B&Q - but switches need (I
think) to be outside the bathroom where you can't touch them with wet hands.
safety safety safety. Assume that complete idiots will be in the bathroom
without you there to tell them to not electrocute themselves !!!!!

If you (carefully with the mains off and using a torch) look at the wiring
in the ceiling rose of the light you should find the following connections :
1) "permanent live" ring in, linked to permanent live ring out, linked to
permanent live going to switch
2) neutral ring in, linked to neutral ring out, linked neutral going to
light
3) "switched live" from switch, linked to live going to light
4) earth from ring in, earth from ring out, possibly earth from something
else.

So by tracing where the cables go physically, you should be able to work out
where's the best place to "tap in" to each.

You can get junction boxes from B&Q which have four screw teminals inside
and are used for joining the live, neutral, switched live, and earths. Or
use a ceiling rose if the wires are small (but's that not really a
"professional" way of doing it!)

If you include the switch, then you could always wire in a standard
three-pin socket in the loft as power to the fan, and put a three pin plug
on the wire coming from the fan, and put a 3 amp fuse on the wire from the
fan. This won't be "standard" but as long as you clearly label the socket
as "switched supply fan only" it should be ok - and might be the simplest
and safest for a 'complete amateur'. Make sure the wires won't be trodden
on or pulled inadvertantly.

hope this helps
Neil