Power supply to shed

[wombats]

I know there are loads of posts discussing this and i have read lots of them but still not found an answer, so please can someone help?

I have a fuse in the CU that used to be used for my central heating but not any more. The cable is still there in the CU and runs to a Switch with red light on in the kitchen ( nothing else is on this circuit). The cable used is 2.5mm twin & earth. Can i use this to supply power to a shed (Not yet got it) but will be about 3-4 metres from the kitchen and will probably only be powering light power tools and a light?

 

[mikhailfaradayski]

making a few assumptions, i would say it can be used, subject to installing an appropriate RCD

 

[ban-all-sheds]

You can use the circuit, but trying to use T/E out to the shed in a way that is legal will be more trouble than it is worth - use SWA for the external section.

 

[wombats]

Thanks for the replies.

So if i connect SWA from the point in the kitchen to the shed then that will be ok? As long as there is a trip switch on the CU.

 

[ericmark]

Thanks for the replies.

So if i connect SWA from the point in the kitchen to the shed then that will be ok? As long as there is a trip switch on the CU.

OK with what in mind? If we for moment forget Part P and assume you will either used a registered electrician or use council building control route then to use SWA cable from the kitchen to some box in the shed it likely the best route.

It is likely to comply you will need an RCD as it is likely you will have some socket under 20A in the shed. The RCD can be at house consumer unit. Could replace the switch which was for immersion or could be in shed.

Depending on location of RCD the earth loop impedance requirements will vary. There is also the prospective short circuit current and volt drop. This is where remote advise falls down as it is all too easy to miss out some vital requirement.

Earthing is also a problem as the existing twin and earth is quite small and to advise one really does need to know where it is in relationship to other homes. Where a shed is in a garden surrounded by houses often the TN-C-S earth can be used but in more rural areas a TT system may be required.

As an electrician we absorb the information often without realising and can just get on with the job. Often a double socket and a fused switched connection unit for lights is all that is required.

But this does not mean every shed is so simple. If you go here and down load the PDF Electrical installations outdoors: a supply to a detached outbuilding it does go into all the information required although being pre-2008 it does not tell you about new RCD requirements.

 

[wombats]

Thanks ericmark i will take a look at the links you posted.