making loft ring from single radial

[danlightbulb]

Hi all,

I have a fan heater in the bathroom powered from a radial from the fuseboard in 2.5mm2 T&E.

I don't need this fan heater, so I want to utilise the radial to make a loft power point with a fuse spur off for loft lighting. The radial cable goes into the loft before dropping into the bathroom so it is a ready made cable run.

Is the radial of adequate size to be able to this? Are there other ways of using this radial in the loft eg a small additional CU?

Cheers

 

[JohnD]

A 2.5mm radial can be supplied from a 20A MCB (provided it is not buried in insulation and does not pass through hot areas), which is usually more than enough for a loft. You can supply a couple of working sockets for tools (say, one at each end of the loft) and a 5A FCU for lighting if you want to (but why? I bet you a pound there is already a lighting circuit in the loft... feeding the lamps on the ceilings of the rooms below) and an FCU for e.g. a TV Aerial amplifier or anything else that is not supplied through a fused plug.

There is no need for a CU. The circuit is too small to be treated as a submain, and you can use FCUs to run off subsidiary circuits. However, i personally recommend that you put the sockets on an RCD. This is because one of my former colleagues, shortly after completing his apprenticeship, was sent to report on an accident where the householder had dropped his electric wander-lamp into the water tank, and instinctively tried to grab it while leaning on the copper pipes. The story has stayed with me. Not everyone would bother.

I recommend having the light switch on a pull-cord fixed so the cord dangles into the loft hatch so it the the first thing you can reach when you climb in, and the last thing when you climb out.

 

[danlightbulb]

Thanks John D.

Yes there are loads of cables strewn all over the loft joists which go into the rooms below.

But using these for the lighting will mean JB's and extra cabling. Just think it will be neater to use a single feed that already exists.

Only problem I suppose is that if I need to repair a socket I have no lighting either. What about feeding a small CU would that be acceptable?

Edit: have you just edited your post JohnD?

 

[JohnD]

I cannot believe that would be less work than taking it from the existing lighting circuit.

Edit: Yes