shed electrics

[bertoli]

I would be grateful for some advice on the installation of electricity to my shed.

I'm going to put 4mm or 6mm SWA cable underground with junction box either end, as the entire run from main consumer box to shed consumer box is approx. 20m.

I'll be using a 30A MCB in the main consumer unit, and have a dedicated shed consumer box with a 63A RCD, along with a 16A and 6A MCB's.

This will be to power a light or 2, along with maybe 3 sockets for lawnmower/portable stereo/exercise bike, though not all used at once.


My query is with the SWA cable.

I was reading a DIY manual on electrics, and they recommended the conduit/standard cable route, as opposed to the SWA cable option.
This because of having to fit the glands, and to prevent deterioration of the cable interiors.
Surely fitting the glands to the SWA isn't a hard job? I am a keen DIY'er and thought this job wouldn't be too advanced.

My second query is with the earth cable, and was advised to fit an earth rod next to the shed, and connect the earth cable to this from the shed consumer unit. But do I still connect the earth from the main consumer to the shed consumer unit?

Lastly, is 3 core SWA simply just 2 core and earth?

Thanks very much for help on this

Kind regards.

[breezer]

it depends on your type of supply, but i would not recomend an earth rod (how are you going to test it any way?)

3 core swa is just that 3 core and the armour

so long as you make the glands off well they will never be a problem

__________________
Do you like music Mr Finch?
Forum = Opinions

[bertoli]

breezer wrote:

it depends on your type of supply, but i would not recomend an earth rod (how are you going to test it any way?)

So a standard straight earth connection from main to shed consumer units(via junction boxes) would suffice?

Would you be aware why the use of an earth rod is advised? It was recommended as the shed was 15m away from house.

thanks for your help

[breezer]

bertoli wrote:

So a standard straight earth connection from main to shed consumer units(via junction boxes) would suffice?

so long as the boxes are metal, and you connect to the box or use the "banjo" supplied with glands it wuill be fine

bertoli wrote:

Would you be aware why the use of an earth rod is advised? It was recommended as the shed was 15m away from house. thanks for your help

no idea, i didn't write the book, but it may be the writer thought it a good idea, but it can cause motre problems, and also as i said, how would you test it?

__________________
Do you like music Mr Finch?
Forum = Opinions

[bertoli]

breezer wrote:

no idea, i didn't write the book, but it may be the writer thought it a good idea, but it can cause motre problems, and also as i said, how would you test it?

With you quite rightly asking how I would test it, how would I test that earthing the shed consumer unit to the main consumer unit would be enough, or is it accepted that all wiring connected would be earthed properly as long as it is installed correctly to the main board?

Again, thanks for your help.

[breezer]

so long as you install the glands corretcy use suitable galvanised boxes and or banjos yes it should be fine, that said get a an electrician to do it for you

__________________
Do you like music Mr Finch?
Forum = Opinions

[bertoli]

For the final connections I intend to get a sparky to finish the job, but I hope to do as much as I can to minimise costs.

Could I use 4mm 3 core SWA as an equivalent to twin and earth, with me using the 3rd core as earth using the appropriate sleeving.

Should this method be used in tandem with using the armour as earth? Or is it better to always use one earth exclusively?

regards

[breezer]

the armour on its own is fine for an earth

__________________
Do you like music Mr Finch?
Forum = Opinions

[ban-all-sheds]

1) Are you aware of the requirements of Part P of the Building Regulations vis-a-vis this work?

2) Do a search here for terms like shed, garage, garden, outside, outbuilding, outhouse - this general topic has been covered many times before.

3) Testing is important - don't just assume everything is OK.

4) Re the earth rod/house earth question - you should read this http://supplychain.org.uk/phpBB2/viewtopic.php?t=41 concerning the issues surrounding the export of earth if you have a TN-C-S/PME supply.

__________________
I mustn't warn people that the "experts" on the plumbing forum can't be trusted to tell the truth.

[breezer]

he has no worry about part p he did say he was going to get alec to finish/ check it

__________________
Do you like music Mr Finch?
Forum = Opinions

[bertoli]

ban-all-sheds wrote:

1) Are you aware of the requirements of Part P of the Building Regulations vis-a-vis this work?

Does Part P regulations apply the same in Scotland, as it does in the rest of the UK? I thought this only applied to England/Wales, and what if the job was finished last year ?

ban-all-sheds wrote:

2) Do a search here for terms like shed, garage, garden, outside, outbuilding, outhouse - this general topic has been covered many times before.

I always make a point of searching through the forum before asking questions. Maybe I failed to see it, but I couldn't find a similar query regarding earth rods, or using the 3rd core in a 3 core SWA cable as an earth. With me failing to see similar questions having been asked, I thought it proper to ask just to be on the safe side.

ban-all-sheds wrote:

3) Testing is important - don't just assume everything is OK.

I am aware of this, but breezer asked me on two occasions "how would/could I check that the earth rod was working properly?"

ban-all-sheds wrote:

4) Re the earth rod/house earth question - you should read this http://supplychain.org.uk/phpBB2/viewtopic.php?t=41 concerning the issues surrounding the export of earth if you have a TN-C-S/PME supply.

thanks to breezer and yourself for your help and advice.