Regulations Re Attic Light

JOHNPT

Regarding installing a single light in an attic - if its not possible to fish cables to a light switch in rooms below - is it acceptable to take a supply (live neutral & earth) from a mains smoke alarm in the ceiling below?

M cebee

prob not

its no biggie but the alarms generally may be on a dedicated radial

meercat

smoke detectors should be on their own dedicated circuit
some electricians double up this circuit with a light mcb at the board to give early indication if the trip activates
never really had a problem fishing a live and neutral into the attic though
sometimes its possible to find the permanent feed in the attic(usually the loop between bedrooms)and if there is enough slack,put the switch there or use the loop to pull another 1.5 pvc/pvc up and then have a loop feed in the attic switch
the neutral is taken from a bedroom ceiling rose
the earth is then taken from the immersion switch

M cebee

taking the earth off another circuit wont be allowed
-newish lighting circuits will prob have one available-no biggie if its only a pendant

JOHNPT

Thanks for replies -neutral and earth is usually easy to pick up off an existing light but getting a permanent live is more difficult - sometimes no space to feed a cable down to switch - is there any rules about cutting permanent live feed and putting in a junction box - then use a PVC cable to feed light switch attic?

meercat

JOHNPT wrote: »

sometimes no space to feed a cable down to switch

you wont need an extra cable in,if you pull the existing feed up(with a new feed attached)
you can then use these 2 cables (connected to com)in your new attic switch

paddymick

JOHNPT wrote: »

sometimes no space to feed a cable down to switch - is there any rules about cutting permanent live feed and putting in a junction box - then use a PVC cable to feed light switch attic?

Thats what I would do but I would use one of these round jb`s so you dont need to actually cut the feed just strip it back a bit and slot it down into the connector and add in your new feed.That way your not messing around trying to get a wire down the wall and its one less wire in the switch.


Way off topic how do I put the picture straight into the post?

M cebee

not aware of any issues with jb

but imo an extra wire at switch is preferable to joints

no big deal either way

Bruthal

paddymick wrote: »

Way off topic how do I put the picture straight into the post?

You have to use a host site, i use photobucket for my ones. When you upload the photo to the host site, you get a link for each photo you want to embed here.

Click the "insert image" icon above the window when you typing your post, add in the link for the hosted photo, and thats it.

Bruthal

paddymick wrote: »

Thats what I would do but I would use one of these round jb`s so you dont need to actually cut the feed just strip it back a bit and slot it down into the connector

Its probably just me, but i never liked them round JB`s with the slots much.

paddymick

robbie7730 wrote: »

Its probably just me, but i never liked them round JB`s with the slots much.

I wouldnt really be that keen on using them as a major J.B myself..

But I think they are ideal for the only two jobs I`d ever use them for and thats under counter lights where the small 10A one is nice and slim and is easily hidden up under pelmets.

And the other is when you need to join a new wire into an existing wire that has no slack as you can just strip back the insulation and slot it down into the connector without actually having to cut the wire.

There is an issue if you over tighten the screw you can split the connector apart but thats where experience and a gentle touch comes in:D