junction box to feed double socket and alarm system

[surface3]

I am planning to bring the power source for an alarm system off the ring main via a junction box and while I am at it I though I might as well put in a double socket as well.

Firstly, what cable do I attached the junction box to? there are several cables, one marked immersion, one marked kitchen, one marked kitchen ring with an arrow pointing away from the kitchen and two other unmarked cables.

Is it O.K. to bring a cable from the junction box to the socket, then bring a cable through a fused spur to the alarm? If so can I used a normal 3 core flex to go from the socket to the alarm?

Any help would be appreciated

 

[ban-all-sheds]

Firstly, what cable do I attached the junction box to? there are several cables, one marked immersion, one marked kitchen, one marked kitchen ring with an arrow pointing away from the kitchen and two other unmarked cables.

You connect the FCU, ideally, not a JB, to the cable for the socket circuit from which you wish to spur. How you expect us to know which one without being there I really don't know. The only tip I can give is that it won't be the one labelled immersion and it might be the one labelled kitchen ring.

But I have alarm bells ringing about your basic competence to do this work if you can't even work out which cable is which, and don't appear to know which one you should use even if you could identify them..

Is it O.K. to bring a cable from the junction box to the socket, then bring a cable through a fused spur to the alarm? If so can I used a normal 3 core flex to go from the socket to the alarm?

The alarm and the new socket should be fed by an FCU from the ring. Ideally this should be fitted directly to the ring, if not then the next best thing is to spur from an existing socket in 2.5mm² T/E to the FCU, and only as a last resort break into the ring with a JB (remember this should be accessible for inspection). You will need a 2nd FCU after the spurred socket to supply the alarm. Fixed wiring should be T/E, not flex.

Finally, if you do this work in the kitchen then it is notifiable in terms of Part P.