Power supply for deck lighting and 13A socket?

[Robert M.]

Hi there, Without going to a massive amount of work to run a new supply from the consumer unit, the next option available for me is to take a spur from the 13A socket ring main from the loft of the single storey extension nearest to where the decking will be located.

I have already run armour cable from that loft, down inside the brick wall cavity and out to an IP65 4-module enclosure box. From that I intend to have a control switch, a breaker for on 2-gang 13A socket and a breaker for the deck lighting.

My questions for help are:-
1) How best to make the spur....i.e. the union with the armour cable into the ring main of the house in my loft?
2) What rating for the control switch in the IP65 enclosure box and should it be an RCD?
3) Rating of the breaker in the IP65 enclosure box for the lighting will be 6Amp, for the one 2-gang socket I'll have in the decking (which shouldn't be loaded any more than me using my Flymo lawn mower off it), should a 32Amp breaker or less be used.

Thank you in anticipation. )

 

[telectrix]

1) How best to make the spur....i.e. the union with the armour cable into the ring main of the house in my loft? T/E from socket to 13A FCU, then maybe T/E to adaptable box i loft, SWA from there.
2) What rating for the control switch in the IP65 enclosure box and should it be an RCD? if socket circuit is RCD protected, then No.

3) Rating of the breaker in the IP65 enclosure box for the lighting will be 6Amp, for the one 2-gang socket I'll have in the decking (which shouldn't be loaded any more than me using my Flymo lawn mower off it), should a 32Amp breaker or less be used. In this box you should fit a 16A breaker for socket, and a 6A breaker for lights.

 

[davesparks]

1) How best to make the spur....i.e. the union with the armour cable into the ring main of the house in my loft?
2) What rating for the control switch in the IP65 enclosure box and should it be an RCD?
3) Rating of the breaker in the IP65 enclosure box for the lighting will be 6Amp, for the one 2-gang socket I'll have in the decking (which shouldn't be loaded any more than me using my Flymo lawn mower off it), should a 32Amp breaker or less be used.

Doing what you propose will not comply with the wiring regulations.
You cannot have more than one point fed by an unfused spur. You need to create a fused spur by installing either an FCU or SFCU.

1) install a switched, or unswitched, fused spur into the existing ring circuit with a metal backbox.
Terminate the armoured cable into the metal backbox using an armoured cable gland. Connect an earth to the cable gland using either a banjo or earthing nut.

2) a switch should be rated for the load it is expected to switch, ideally it should be rated the same as the OCPD or greater. As the OCPD is 6A then a 6A switch would be suitable. In my opinion the switch should not be an RCD, the RCD should be a seperate device not used for functional switching.
RCD protection of the socket and lighting is of course required in accordance with the wiring regulations.

3) don't install any MCB for the socket, it will be a waste of time, the fused spur will be protected at 13A and so any MCB you install downstream of this will be pointless if it feeds a 13A socket.

Once the work is done, and before you energise it you must carry out the correct sequence of inspections and testing and fill in a minor works certificate, once it has been proved safe to energise you must then energise and carry out the remaining tests to complete the certificate.