Question re: power to shed

[Andy Lloyd]

Hi guys, just completed my level 2 C&G and looking forward to Level 3 in September but I hope you can help me with a little project I got going on at home please.

In the back lobby of our house near the back door is a twin switched skt which is on its own 16amp breaker on CU, I was looking to spur off this socket to fix an outside twin RCD socket for both lighting and our lawnmower etc, this is straight forward enough I belive. My question is this, can I then spur off of this to my shed as I am in the process of converting this into a kind of garden/TV Games room which will require two sockets and some downlighters and some kind of heating, is this possible? and what cable size would you suggest? this would need to be SWA also? The final question I have is would I need to put this underground or can I use conduit and run it along my fence?

Thanks

 

[somersetsparks]

You can certainly extend that radial circuit, however, I would hazard a gues that with lighting heating and sockets you would be better off with a larger dedicated circuit and a small CU in the shed. Im not a real fan of final ccts. supplying outside buildings(especially not other CU's), although you may get away with it and it may comply, as a trainee sparks, in 2 years you will want to rip it out and do it proper cos you will be ashamed!!!

 

[malcolmsanford]

You have a twin socket on a 16amp cable, so that is a radial circuit ...............so providing for cable size for CCC and volt drop you can add as many sockets you wish onto this socket.

So what size is the cable from the CU to this lone socket 2.5mm ?

I would personally just loop of that socket into your RCD socket outside. Then loop off again for a couple of sockets into the shed. There I would fit a spur unit for your lights, using a switch spur to control the lights.

That is what you could do but now you will have factors like

1. Volt Drop
2. Size of cable for protection device CCC
3. If you in England and Wales Part P
4. What cable are you going to use to feed the shed
5. RCD protection for the sockets in the shed

 

[Andy Lloyd]

You have a twin socket on a 16amp cable, so that is a radial circuit ...............so providing for cable size for CCC and volt drop you can add as many sockets you wish onto this socket.

So what size is the cable from the CU to this lone socket 2.5mm ?

I would personally just loop of that socket into your RCD socket outside. Then loop off again for a couple of sockets into the shed. There I would fit a spur unit for your lights, using a switch spur to control the lights.

That is what you could do but now you will have factors like

1. Volt Drop
2. Size of cable for protection device CCC
3. If you in England and Wales Part P
4. What cable are you going to use to feed the shed
5. RCD protection for the sockets in the shed

Hi thanks for that, it is 2.5mm cable to the existing skt, I was then planning on running 2.5mm to the outside socket and then was unsure from there, I have seen the MCB units for garages and sheds at screwfix, this looks ideal for sorting the skts and lights in the shed but between that and the house is where I was looking for advice really. Thanks

 

[Snapester]

Can you get an RCD spur in the house to provide RCD protection for both outdoor and the shed sockets? As you will need to provide RCD protection to the shed equipment to and having the RCD at the house end will cover both outdoor sockets and shed and work out slightly cheaper.

 

[malcolmsanford]

As it is a dedicated radial for that one socket you could put the whole circuit on a RCBO back at the origin. Your really limiting yourself to 13amp in an RCD spur where there is every possibility that you could fit a 20amp RCBO depending on the erection methods

 

[Snapester]

Also depending on the boarding being able to take an RCBO.

 

[malcolmsanford]

That don't make much difference really. Remove the cable from the existing protection device and then feed a single RCBO in an enclosure from that way, and you can divert the circuit cable into the RCBO