I am shortly going to install some 4mm 3 core SWA from an existing MCB (new split load board will be installed in the house) to a garage with a 30mA RCD and 2 x MCB (16 / 6 Amp) for sockets and lights. SWA buried to 24", marker tape e.t.c. The cable run is approx. 25 metres.
1. The new split load CU: is it best to get a metal one or are the plastic ones equally as good? The garage unit has a 40A RCD, would I have to make sure I used a 40A CPD at the main consumer unit?
2. The kitchen is fed by a radial cct on a 20A MCB for dishwasher, washer, dryer, sockets. However, part of the ring main also goes through the kitchen and the fridge/freezer runs off the ring. The socket ring would be fitted to the RCD side of the new CU, but this means the fridge/freezer being on it. Is this the normal thing or do people generally try and fit it onto the non-RCD side of the CU with the lighting ccts??? [u]What other ccts go on the non-RCD side? [/u]
Are split load boards with adjustable RCD/non-RCD sides better??? Am I using too many question marks
I cannot extend the radial and have this on the Non RCD side to serve the fridge freezer as it is is impossible (or very hard) as I have a slate floor. The only way would to be to channel up the wall one side of the kitchen, under floor boards and channel down the other side to the fridge position. Lot of work indeed. So what are the implications Standards wise of having it on the RCD side if any?
3. OUTSIDE lighting. I am going to install some outside lighting. Am i best using mains lighting or opting for extra low voltage? I know with mains I would have to run all cabling within conduit and bury it or use SWA. With LV you can run the cabling on the surface (I intend to run the cabling within a planter running around my garden). If I opt for ELV I would then have to run SWA to a weatherproof socket outlet capable of housing the ELV transformers. I would rather not have to go out into the garden to switch the lights on.
Hope all this makes sense, all answers very much appreciated! I know this work will be notifiable.