rcd socket placement/spur

[James]

Hi,

This is actually somewhat of a follow up to a previous posting I did, but I thought it best to start a new thread after getting some feedback/advice and doing some research.

I have a ring main plug socket in the garage that I either want to feed off, or split the cable with a junction box just before it, and provide a spur out to the garden. I have had some advice on this newsgroup to make this a seperate circuit altogether, but my skills and willingness to attempt do not extend to tampering with the main fuse box.

1. I realise that I must provide an RCD spur that will feed off into the garden. So basically I want to spur off inside the garage to a fused RCD spur, then take this into the garden where I want to provide a double plug socket. Can this double plug socket be a bog standard weatherproof one?

1. Now I also want to split off to place another plug socket within a different area of the garage. Once the garden spur is in place, I am assuming that I cannot spur off the RCD fused spur to another socket, but I could spur off to a FCU, then a socket after this? Otherwise I could spur off the other side of the socket (i.e another junction box in the cable) to a standard plug socket, thus creating two spurs off the ring main.

Can I also just clarify that with an RCD fused spur scenario I described above, if something causes the RCD to trip, this will stop at the RCD socket or will it cause the entire socket circuit to go down? I can't have this happen as my house is on one socket circuit throughout and I need some electrical devices to be up 24/7.

Thanks,

James

[David Hansen]

On 17 Aug 2006 18:12:02 -0500 someone who may be "James" wrote this:-

Why not just run the spur cable from the socket? This can be cramped in a single gang socket, but is easy enough in a double gang one.

Why not extend the ring to this new socket?

You could provide a spur cable to a local fuse, or indeed an MCB up to 20A. From there the circuit becomes a fused spur and you can position sockets as you wish.

Note however, that sockets in garages may have large loads plugged into them. Given that there is only one ring circuit in the house it may well be heavily loaded and large loads in the garage may well overload it. Thus a separate circuit for the garage and garden is advisable. If it all goes wrong you may have to justify your decisions.

That rather depends on the protective devices installed on the ring circuit and the house. The worst case is that all may operate and isolate every circuit in the house. Discriminating between devices can be difficult, which is one of the many reasons why a separate circuit is advisable.

[James]

David,

Thanks for your advice. I think I will extend the ring main using two junction boxes to split the other side cable trailing from the socket, I didn't think of that before. As for the garden one, at least I know I can spur off in the way I decided, althouth there is the other option you mentioned.

Thanks,

James