I have a rectangular garden 24m x 12m, which is walled on all four sides. A path (from my house to my drive way at the bottom of the garden) runs down one side of the garden. At some point in the future, I would like to light the path and the brick walls around the perimeter of the garden. I would also like to install an outdoor 13A double-gang socket about 6m from the house.
To make provision for this now, I intend to run mains cable underground around the perimeter of the garden and install ten 240/12 transformers at approximately 8m intervals along the length of the cable (see diagram below). Each transformer would be rated to feed up to five 20W lamps. Where the path runs, I would like to use inground transformers as there is no foliage to camouflage a wall-mounted transformer.
12m| | |house| .| |
------.------- |XO....X X| | . | | . | |X . X| | . | 24m | . | |X . X| | . | | . | |X . X X|
---.---------- . | drive | . | way |
X = transformer O = socket ... = path
My questions are:
(1) Should the circuit connecting the transformers to the consumer unit be a radial or ring circuit? (I can easily configure them as either type)
(2) Can I run the outdoor socket off the same circuit as the transformers?
(3) What current rating of mains cable should I use?
(4) What other cable should I lay so that I can switch the garden lights on from the house or the drive way?
(5) I can lay 240V cable underground in either a flexible heavy-duty conduit or SWA sheath. Which would be the best method and how should the connection to the primary flying leads of the inground transformers be made so that it is watertight?
By the way, the reason I want to make these decisions now is so that I can dig the cable trenches, lay the cable and backfill, and then plant up the garden before making a final decision on exact location and type of outdoor lights.