Outdoor electrics

[birdnc]

Hi,
Could anyone please offer some advice regarding the following outdoor electrics situation..

(i'm aware it's all Part P, so a qualified electrician will be called in to do all the work apart from digging trenches!)

Currently excavating / renovating rear garden and hope to have 4 or 5 (max) sets of ELV decking lights, a pump (nothing powerful) for a water feature plus a couple of double 13a sockets .

I anticipate that SWA will be taken from the house consumer unit (near front of house) a couple of meters outside and into garage (attached to house further down the side wall) and an additional CU installed in the Garage .
From there SWA again? from the new CU to the back of the garage and then SWA out into the garden.

Questions are:
1) Is it likely that 2 separate circuits (lights/pump + sockets) will need to be run from the garage CU with different rated SWA or is it possible to have 1 larger rated SWA out to some sort of waterproof junction box in the garden and the lighting circuit fused down and out from there?

2) Position of the lights will be more than 10m from inside garage so transformers will need to be housed outside. Is this possible, and are there any issues with heat from them if in confined waterproof space?

3) The plug sockets will be opposite sides of the garden, so is it likely that 1 ring loop would connect the two or a separate feed out to each socket?

Reason I'm asking is I have limited space in the garden and lots of earth, hardcore and gravel to excavate and I'm trying to avoid making piles of stuff in areas where electrics will need to be laid. Trying to plan ahead to avoid problems later on!

Maximum distance outside is 18m

many thanks.

 

[Steve]

What I did was create a 5 amp supply outdoors (in black flex) to a master junction box. From this JB I have a switch for lighting, and cables to the pond (permenantly powered) and lighting.

I have no cables underground so its all in black flex, but you could just as easily terminate a couple of SWA cables to the JB. You could also have several switches for a couple of items.

 

[ericmark]

Hi,
Could anyone please offer some advice regarding the following outdoor electrics situation..

(i'm aware it's all Part P, so a qualified electrician will be called in to do all the work apart from digging trenches!)

Currently excavating / renovating rear garden and hope to have 4 or 5 (max) sets of ELV decking lights, a pump (nothing powerful) for a water feature plus a couple of double 13a sockets .

I anticipate that SWA will be taken from the house consumer unit (near front of house) a couple of meters outside and into garage (attached to house further down the side wall) and an additional CU installed in the Garage .
From there SWA again? from the new CU to the back of the garage and then SWA out into the garden.

Questions are:
1) Is it likely that 2 separate circuits (lights/pump + sockets) will need to be run from the garage CU with different rated SWA or is it possible to have 1 larger rated SWA out to some sort of waterproof junction box in the garden and the lighting circuit fused down and out from there?

Although you may use same size SWA it is the fusing down which becomes a problem. It may be possible never the less.

2) Position of the lights will be more than 10m from inside garage so transformers will need to be housed outside. Is this possible, and are there any issues with heat from them if in confined waterproof space?

There are water proof transformers/inverters but most do need to sink some heat and if this is not possible will likely fail.

3) The plug sockets will be opposite sides of the garden, so is it likely that 1 ring loop would connect the two or a separate feed out to each socket?

Without seeing it is impossible to know if radials or ring is best option but more likely radials.

Reason I'm asking is I have limited space in the garden and lots of earth, hardcore and gravel to excavate and I'm trying to avoid making piles of stuff in areas where electrics will need to be laid. Trying to plan ahead to avoid problems later on!

Maximum distance outside is 18m

many thanks.

The main point is who ever signs off the installation will need to view cable in the trench and it does not really matter what we say here it is all up to the person signing the paper work.

I would direct these questions to him and follow the advice given.