outdoor wiring

[0hm]

i'm sure this question has been asked before, but i couldn't find anything via the search that matches what i want to do.

i've just built a pond outdoors, which needs power for a pump + filter. it's 20-25m from the kitchen, so that's the closest electrical circuit. when ordering the pump i got a nice 1-in 6-out outdoor switch with illuminated buttons that will go somewhere near the pond for ease of switching lights / pump / filter on + off.

the plan is as follows:

take a spur off the kitchen ring-mains into a junction box (indoors) with standard twin+earth (heavy gauge) into a junction box near the outside wall. run SWA 2.5MM 5-core `down to the pond (as i said ~ 25m) into my nice switch. run a length of SWA (about 8m) 1.5mm 4-core over to the pump and filter (so they can be switched individually). use the first 2 switches for the pump + filter respectively, and then run lighting off the 3rd switch (this will go a-top a pergola to be built a little later). this leaves me 3 spare switches on my switch box (i was thinking of one of those robus outdoor sockets for another switch). i then have 2 switches for expansion at a later stage if required.

i will also be powering a shed further down the garden at a later stage, will this 2.5mm SWA suffice, or should i go up to 4mm?

any questions or clarifications, just ask....

thanks,

dave.

 

[Steve]

how far is the shed? from the house.

A spur from the ring main such as this must be fused.

the pond pump / filter should never be turned off in normal use, only for cleaning. I wouldn't put the switch anywhere normally visible.

I built an enclosure round my filter, and fitted a weatherproof switch inside that. You could do this and have a junction box here too, to feed the lighting you want.

I would recommend having a seperate supply to the shed, probably end up being 6-10mm² depending on distance and anticipated load. You might be better feeding the pond etc from the shed. And the shed will need its own circuit from the house consumer unit.

 

[0hm]

hi steve, thanks for coming back to me.

i wasn't entirely clear about the shed.... it hasn't been built yet, and probably won't be this year. the garden is 120' long, 40' wide (a long straight strip of land). the pond is about 40' from the house, and the shed will be right down the end (120') of the garden.

the pond is built and ready to be powered, hence my question about running on from the pond power supply at a later date.

EDIT:

forgot to add, the house was fully rewired last year, and there is full elcb protection on all circuits... if that helps?

 

[Steve]

120ft is about 35 metres (we use metric here sorry)
40ft is about 12 metres (conversion rate 3.3)

Anyway, You'll need an 18 inch deep trench to the pond area, then carry this on to the shed area. I would strongly recommend two cables. The one for the pond can be from the ring main, as a fused spur. But the one for the shed must be from the consumer unit. Lay both cables in now while the trench is open.The cable size for the shed depends on the loading.

 

[bernardgreen]

If you cannot yet decide on the size of cable needed for the shen then while the trench is open lay in a duct for the shed cable so you can draw in the cable after the trench is back filled.

And maybe lay in a trench for other services. ( door bell, phone, shed to house intercom, video from sky box etc etc etc )

 

[0hm]

ok, i'm taking the shed out of the equation completely.

i'm thinking now of running 4-core 4mm from the kitchen (via a fused spur from the ringmain), down to the 6-pole switch box i mentioned earlier (one of these -> http://www.aquatix-2u.co.uk/cgi-bin...tched_junction_box_6_way.html#aTRE101#aTRE101 ).

from this i want to be able to switch on + off the filter and pump, which are located at the end of another short (8m run from the 6-pole switchbox) of 4-core 1.5mm swa. L1 on the switch goes to live on the pump, L2 on the switch goes to live on the filter, using 2 cores of the 4-core swa, neutral and ground are shared using the other 2 cores, is this correct?[/url]