Greetings all - returning to uk.d-i-y after a couple of years absence (mostly due to work. grrr.) Glad to see many familiar contributors still around.
Current project - kitchen extension and complete refit. Have a builder doing this (I'd love to do it but just no time) & electrician to do the electrics/certification (construction being done under Building Notice application, so no chance of any Pee avoidance. I'd want a regs compliant installation in any event).
One part of the work is to run SWA down the garden (about 15m) and connect up the shed. Shed has small garage CU in it, with 30mA RCD, 6A lighting ciruit MCB and 20A socket circuit MCB. 5 double sockets on the latter and about 8 metres of 2.5mm^2 t&e in total.
Now, I'm pretty sure that I have read here before from the 'lectrical cognoscenti that 2 radials into one MCB was unusual, but permissable. Of course I can't find the post now... Due to the layout of the shed workspaces & with thoughts of economy of installation, I'd prefer to install 2 radial circuits rather than one ring, so this is how I wired it.
Quick discussion with electrician today revealed he had a different take on it, and that he didn't think that such an arrangement could be compliant.
Does anyone have chapter & verse on such an arrangement?
Of course I could quickly adapt it to a ring, or even slot an adaptable box or similar so that the 2 x radials go into that, and single t&e to the shed CU, making it a single radial. But if I don't need to, I really would rather not do. A single ring would normally be on 32A MCB, of course, but is there anything fundamentally incorrect about putting the circuit on a 20A MCB? (the cable would if anything be over- protected in this arrangement, surely).
Also, I have an externally mounted socket, RCD protected. I'd rather not have to run two separate circuits to the kitchen (one RCD'd, the other not - for the fridge, etc), arguing that the external protected socket makes the use of internal sockets for external portable equipment very UNlikely. Are there other regs that come into play here?
On a final, OT, note - anyone working in The City know of any useful bookshops or other retailers where I might be able to get my hands on a
16th edition OSG? Decent bookshops in The City seem to be a bit of a rarity these days if my wanderings are anything to go by.TIA