Shed supply

[algas]

We have an old Wylex CU with a spare outlet that was for an electric shower, if i connect into this and add a RCD before running cable up the fence line would that be ok, also will T&E be acceptable or would I need 2.5 flex, run is about 30m, only for lighting and a kettle, its more of a garden room than a shed.

Tia Alan

 

[ericmark]

This is a bit outdated 2005 but gives the basics as to what is considered as a new circuit, one can argue until the cows come home, I added RCD's to an old Wylex fuse box many years ago, around 1992, at that time no Part P and to get a consumer unit which had twin RCD's was hard, times have moved on. However to put the old supply into a RCD FCU and then to shed may be possible.

It will depend on what the shed is made of, and what your earthing system is, where I live in Wales it would be against to law to DIY what you are talking about without paying the LABC £100 plus vat plus any charges for an inspector. Simply not worth doing it as DIY, I am sure many do, just like I am sure not everyone driving through our village is doing no more than 20 MPH. But no one on here would condone either.

There is a lot more to electrics in the garden than meets the eye. this report about a broken PEN may seem nothing to do with a garden shed, however it all depends on what the shed is made of, so hard to give an answer as to if what seems a straight forward job is really that straight forward.

 

[Murdochcat]

T&E absolutely not

Flex - almost certainly not

SWA or Hituff

2.5 mm - probably not big enough - what is the design load ?

 

[SUNRAY]

TLC online calculator shows 2.5mm² is good for 40 m at 16A.

The discussion about T&E outdoors is another old chestnut topic.
Back in 60s & 70s I installed plenty. Those I still know about are seemingly still sound and 2 of the properties have passed an EICR in the last year.
Would I use it outdoors now? Not without some additional protection like PVC conduit, but then that introduces condensation issues.
I know some will currently use it outdoors (I even saw one of the recent YouTube experts showing it) but I don't have the confidence to stop them.

 

[ericmark]

I use to have a caravan on my father-in-laws drive, it was supplied with a blue 2.5 mm² flex with 13A plug on one end, and 16 amp socket the other, I know it was the wrong thing to do, as not a TT or TN-S supply, but I could not really complain as I was using his electric to maintain my caravan.

Between his caravan, motor caravan, and mine, that socket must have had caravans on it for likely 20 years or more, and nothing went wrong. However that does not make it right.

If I want to use my shed, and extension is run through the cat flap to the shed, same if I want to charge car batteries, cat flaps are not designed to run electric cables through them, but it works fine. However this is a once in a blue moon sort of thing, and each time cable put away it is inspected.

Old house more permanent supplies to shed and green house were with SWA cable. As it should be, and I would not have run cable on the wood of the fence, but may have run it on the concrete panels on the bottom. And even the SWA went to a box and then flex to 13 amp plug so it could be easy isolated.

But I have given advice to guys at work, then seen what they have done, I thought oh no, that is not what I mean.

 

[blup]

I ran 2.5mm to the shed in ho7 rubber cable, rcd and plug at the house end and neutrik connector at the other so can disconnect when not needed

 

[jurassic sparkk]

As mentioned above, 2.5 is too small. Use at least 4mm.
If you're going to use 2.5 get it protected by a 20amp breaker.

 

[blup]

Too small for permanent but ok for occasional use via what is essentially an extension lead

 

[SUNRAY]

Too small for permanent but ok for occasional use via what is essentially an extension lead

2.5mm² is good to 40m on 16A MCB and 27m on 25A MCB according to TLC online calculator. It will of course have to be verified by the designer/installer.

 

[JohnW2]

TLC online calculator shows 2.5mm² is good for 40 m at 16A.

... and it's right if one wants to stick to the guidance of a maximum of 5% voltage drop. However, if it's really only going to be supplying lighting and (presumably very occasionally, and for brief periods) a kettle, I really don't think that guidance is very relevant - particularly given that even a 50% voltage drop would merely mean that the kettle would take longer to boil

Kind Regards, John

 

[SUNRAY]

I ran 2.5mm to the shed in ho7 rubber cable, rcd and plug at the house end and neutrik connector at the other so can disconnect when not needed

Ho7 is not as long lasting in sunlight as pvc in my experience

 

[JohnW2]

2.5mm² is good to 14m on 16A MCB and 27m on 27a MCB according to TLC online calculator.

Eh? why on earth would it 'be good for' virtually double the length if it was protected by an MCB of neearly double the rating?

... and where is anyone going to find this "27A MCB"?

Are we perhaps dealing with some 'typos'??

Kind Regards, John

 

[SUNRAY]

Eh? why on earth would it 'be good for' virtually double the length if it was protected by an MCB of neearly double the rating?

... and where is anyone going to find this "27A MCB"?

Are we perhaps dealing with some 'typos'??

Kind Regards, John

Mum working on a phone with a cracked screen which is affecting operation

 

[Mottie]

T&E absolutely not

I have a single 2.5mm T&E going from a 16A breaker in my consumer unit to my garage - about a 10m run. That feeds two double sockets and a light. Don’t really use the sockets much - occasional battery charger for motorcycle and electric bike and used to be used for the lawnmower before I got a petrol one. From there, another 2.5mm T&E going approx 8m to our shed with one double socket. Spurred off that for the light, permanently running an under counter freezer and next to that, a tumble drier. Been fine for the last 10 years or so.