Garden Shed Question

[mcole79]

Hi All,

I'm planning to get power to my newly erected 10 x 8 garden shed, and was planning to do in the following way. Would like thoughts and suggestions if i'm about to do something drastically wrong!!

Armoured Cable from Shed to House.

Inside house I was simply going to wire a plug which plugs into the existing house socket, the other end would go through to meet the armoured cable in some kind of junction box attached onto the outside wall for its journey to the shed.

I assumed that inside the shed I would simply attach the armoured cable into some kind of RCD unit similar although smaller than the one under the stairs?

Does this sound extremely redneck or fairly standard? I should point out this is only going to be used for 2 x flourescent strip lights and and a double socket for use with household powertools, nothing with a particularly heavy drain.

I have done some general electrical work with no consequence so far but wanted to check on this one as its a little more complicated than wiring a couple of strip lights in the loft!

Thanks for any help or advice in advance

Mcole

 

[f42]

You need armoured cable, I usually use 4.0mm armoured 3 core depending on what you are going to be using in the shed.

I wouldn't wire it to a plug however, I'd run it back to your CU under the stairs and stick it on a 32amp MCB.

At the shed end I would use a 2way RCD CU with a 6 amp breaker for lights and a 16amp for a radial socket circuit. ( usually found in shops as a garage CU)

 

[electronicsuk]

If you must take the supply from a ring final then you would be better doing so by using a Fused Connection Unit, taking the supply to the shed from the load terminals. You could then go straight out through the wall behind the backbox and into a suitable weatherproof (ideally metal) adaptable box, where you could gland in the SWA.

There is no point in installing a CU, even a small one, in the shed. If the supply is derived from a plug or FCU fitted with 13A fuse, you could wire a metalclad socket straight onto the SWA at the shed end. There's no need to fuse down any further except for the lights, and this would easily be accomplished with a switched FCU in the shed fitted with 3A fuse to supply the lighting.

This is, of course, notifiable work.

 

[ericmark]

There are a 101 ways to wire a shed but Electrical installations outdoors: a supply to a detached outbuilding (243 k) from IET is good place to start.

The problem is no one knows what you already have and if you house is wired to BS7671:2008 then a metal box which could be a standard metal clad to gland SWA into with a connection strip and stuffing gland for flex entry one end and switched FCU (supply to lights) and socket at end may be all that is required.

However the whole reason why Part P was brought in was DIY people do make mistakes and this is not helped by people like me telling you how easy it is.

If your house was wired to BS7671:2001 then likely in the house you will need a RCD this of course could be built into the plug.

I used a 13A fuse connection unit for my shed and it worked well. But do read the PDF in link as it's not quite as easy as it looks.

 

[ColJack]

there are numerous posts on here detailing how to get power to a shed and detailing most of the pitfalls ( it's impossible to detail all of them since unforseen thing do happen.. one guy I know personally put a pickaxe through a sewer pipe while trenching for his SWA.. ).

while in general a 4mm 3 core SWA would suffice on a 20A breaker in the house, you haven't detailed how far away the shed is etc so we can't say for certain.