Power To My Sheds

[Burnt01]

I`ve been toying with the idea to put mains power to my 2 sheds in my garden.
It was done by someone else before i moved in because theres an old cu in the first shed (not useable)
What i want to do is first connect power to the cu in the house the problem with this is there are no more spaces to and another circuit
Then the cable has to go into our outdoor loo and into the ground to go under a path that goes behind our house (access to all gardens for next door houses) then up into the first shed (our garden) gap is about 2 meters
Now this in the part i need to find out about to get power to the second shed, so needs the cable to go at least 60 meters!! I`ve not really done outdoor wiring and need to know how saftely to do this.
It would be very hard for my to dig a cable the whole way because of concrete and was told i may be able to attached the cable to the fence? Is that legal? also if i can what would be the cheapest way of doing this
I only want a light and one socket in the first shed and same again in second but will need far more sockets in the second
WHAT ARE ALL THE COMPONENTS I NEED (START TO FINISH)

 

[xxxxxxrich]

quick solution would be to plug it into a 13A socket in the house if you have no more space in your CU, but it must be protected by an RCD.
Fixing a cable to the fence is OK AFAIK but it should be an outside grade cable and the right size for the load. I wouldn't go running a bit of 13A extension cable up there for example. There are some funky cables about these days with Aluminium conductors that I think are outdoor grade, you might want to investigate that route, I think I would still use SWA and dig a trench. I guess you could double up on a breaker with a circuit in the house (not sure if that's allowed) but ideally you would want an independent breaker, Also would be a smart move it the RCD was on the socket in the shed and the lights were not on an RCD. So in the event of an accident you are not left in the dark when the RCD pops out.

 

[nstreet]

The quick fix might work, but they have a hiabit or becoming permanant. Lots of sockets running from one 13A socket in the house in my opinion wouldn't be a good idea.

If I understand the regs correctly shouldn't outbuildings that are not connected to the main building have their own earths?. I would do it properly, maybe a new CU RCD protected in the house 40A breaker for run to sheds, new 2 way RCD protected CU in the shed, run a 6A for lighting and 16A or 32A for sockets. SWA to the sheds, if you dont like digging you maybe able to run catenary wire and attach the cable to this, although its a long run so you may need some additional supports for the cable.. Any comments from our experts?

Why not move the second shed closer?, maybe join the two, at least it would save a lot of work and probably work out cheaper than all that SWA cable .

 

[ban-all-sheds]

I`ve been toying with the idea to put mains power to my 2 sheds in my garden.
It was done by someone else before i moved in because theres an old cu in the first shed (not useable)
What i want to do is first connect power to the cu in the house the problem with this is there are no more spaces to and another circuit

It's better in many ways to have it on a separate circuit anyway.

Then the cable has to go into our outdoor loo and into the ground to go under a path that goes behind our house (access to all gardens for next door houses) then up into the first shed (our garden) gap is about 2 meters
Now this in the part i need to find out about to get power to the second shed, so needs the cable to go at least 60 meters!!

From your sketch the total run will be more than that - 70-80m? Unless your load is small, that'll require 16mm SWA to cater for voltage drop.

I`ve not really done outdoor wiring and need to know how saftely to do this.

In the house, take the meter tails to a Henley block so that you can feed the house CU and a switchfuse or mini CU for the outdoor supply.

Buried SWA, 3-core, with armour connected to earth. At least 450mm below ground(750mm if the area is subject to double digging), bedded in sand, marker tape above. Outdoor (CW) glands at the shed CUs, indoor (BW) will be OK for indoors, but as they come in pairs, you'll end up with all CWs anyway. I'd advise against trying to terminate 16mm SWA in plastic enclosures, so a metal switchfuse and metal CUs will be the order of the day.

It would be very hard for my to dig a cable the whole way because of concrete and was told i may be able to attached the cable to the fence?

Not really - Whatever you attach it to should be structurally sound and a permanent structure, your typical garden fence doesn't qualify. Also it must be your fence and not your neighbours, or they can ask you to remove the cable.

An alternative to burying or using the fence is an overhead run supported by a catenary wire, but it'd need to be pretty meaty wire to support 16mm SWA, and 60m is one heck of a span.

Is that legal? also if i can what would be the cheapest way of doing this

With all things to do with electrical installations, particularly those outdoors, you should focus on the best way to do it, not the cheapest.

I only want a light and one socket in the first shed and same again in second but will need far more sockets in the second

You really do need to work out what your maximum load will be so that you can size the cable appropriately.

 

[ban-all-sheds]

If I understand the regs correctly shouldn't outbuildings that are not connected to the main building have their own earths?

AFAIK, yes if it's a TT supply, no if it's TN-S, and debateable but probably a good idea with TN-C-S.

But that is only AFAIK - I could easily be wrong

 

[AdamW]

What would happen if the fence blew over? OK so the RCD back at the house should prevent anything too bad happening, but I still wouldn't do that personally. But, if it is one of those fences with a few courses of brick at the bottom that would be OK (unless there is a reg on minimum cable height).