Lighting Help..mains for light circuit

[Chrisbarham]

Hi need some help....

i think that one of my lights has been wired into the main circuit ring...

basilcy when i turn off the power supply (at my fuse box) to the lights this particluar light remains on, and only goes off when the mains circuits are turned off....

now i want to move the light switch and i though the easiest way would be to cut the exisiting cable and use a chock box to extend the cable,, however i have only got 5amp lighting wire... ( ihave no idea wot rating the other wire is)

so i guess my question is this... will the 5amp cable be safe to use???

thanks

 

[EdwardCurrent]

Hello,

Maybe (hopefully!), there is a 'fused spur' that has been used for connecting this light ??
Just a thought.

Ed

 

[P.S.]

Definitely stays on when only the lighting cct's fuses removed ?

At best it could have been connected to the ring via a fused spur.

As you've already indicated the use of a "chock box", I'd recommend getting in an electrician

 

[Chrisbarham]

yes... there is a 13A Unswitched Fused Spur on the circuit.... does that help me out...

 

[ban-all-sheds]

Does it supply that light?

 

[Chrisbarham]

i assume so... no other lights around and the cables seem to lead from it too the light and the switch....

 

[EdwardCurrent]

If you switch it 'off'/remove the fuse, does the light stop working ???


Ed

 

[Chrisbarham]

yes..

 

[EdwardCurrent]

Ok.


Your next hurdle is the cable size that you have, do you know the number and csa size of the conductors please ?
You may be needing some in line crimps, with a decent ratchet crimping tool and an enclosure to put your 'joint' in.

Ed

 

[Chrisbarham]

wow..this getting complicated....

i got one of these

http://www.wickes.co.uk/Sockets+Control-Units/13A-Unswitched-Fused-Spur/invt/710143

no idea what the conductor size is or what they even are

 

[EdwardCurrent]

Is this in an area where you have access to the cabling, ie the loft ?

Would it be possible to renew the entire 'switch cable', then you wont have the 'jointing' problems ?

Ed

 

[Chrisbarham]

awww....sadly not....

but i do have good access to where i will be joing the cable to will be able to get a good firm joing using the choc box...

will the 5amp cable be ok????????

 

[EdwardCurrent]

I suppose that the correct answer is that it depends on the rating of the fuse in your FCU. Without knowing what the cable is, I cannot guess as to if it can be used. (even if it says 5A ??) Is the cable twin and earth ? does it have a BS number ???

Remember that all 'screwed' connections need to be accessible, so you will be needing those crimps etc if it isn't going to be when you finish your 'job'.

Ed

 

[Chrisbarham]

again not really sure... its the cable from the 13a socket thing to the light switch....

 

[ban-all-sheds]

1) There's no such thing as "5A cable" - the current carrying capacity of cables varies depending on how it's been installed - see this for more info:

http://www.tlc-direct.co.uk/Book/4.3.1.htm

2) Why are you moving the switch, and to where? Are you aware of the rules for where concealed cables may run, and how the removal of a switch may mean that a previous "safe zone" no longer exists?

And are you aware of the new requirements in the 17th Edition of the Wiring Regulations for RCD protection of concealed cables?

• http://www.voltimum.co.uk/files/gb/attachments/niu/l/attachments/c5-43.pdf
• http://web.archive.org/web/20061110111450/http://www.niceic.org.uk/downloads/concealedcables.pdf
• IEE article
• IEE Article on 17th Edition requirements for concealed cables.

Strictly speaking you aren't legally compelled to follow the Wiring Regulations, but it's a BGI, particularly if you don't have the competence to make judgements on when not to....