Quick earth question regarding putting mains /lights in shed

[uptown47]

Hi all,

I'm going to put mains and lights in my shed (its actually a kind of 'lean-to' that shares one of its walls with the house wall.

My plan (after some advice on this great forum) is to run 2.5mm Twin and Earth cable from a dedicated breaker (20A) in the distribution board (RCD protected). Then put a consumer unit in the shed and feed the lights from a 3A breaker and the sockets from a 16A breaker.

Do I need to run a separate 6mm Earth from the distribution board to the CU or will the Earth in my 2.5mm mains cable suffice ?

All the conduit and boxes will be surface mounted and made of plastic so won't need bonding.

Advice would be appreciated.

Many thanks

John

 

[1john]

Run the 2.5 straight to the sockets and add a fused spur wuth a 3A fuse in it to feed the lights, saves you money on a consumer unit which in this instance is not required, if you are feeling flush bring through a seperate lighting circuit aswell as the socket circuit.

 

[uptown47]

Thanks for the advice. Fused spur sounds good.

Cheers

 

[ban-all-sheds]

When you apply for Building Regulations approval what do you plan to say will be the way that you'll comply with P1?

What do you plan to do about testing? Do you know what tests you would carry out on the circuit - what sequence you'd do them in and at what point you would energise it, and for each test do you know what is being measured, why it is important, how you would carry out the test, and with what equipment, and what sort of results you would expect to get if everything was OK?

And BTW - even if you used metal sockets and conduit it would not need bonding

 

[uptown47]

Hi mate,

Not sure about the answers to your questions. Was going to do the work and then get someone in to check it over for me.

I presume they'll test it all for me in order to sign it off?

Surely metal back boxes should be earthed??

Cheers.

 

[flameport]

Was going to do the work and then get someone in to check it over for me.
I presume they'll test it all for me in order to sign it off?

Not going to happen.

There are only 2 legal options:
1. Notify building control first, and pay whatever their fee is (£100 or more typically), then do the work yourself. They may want test results from you, or might arrange this themselves, and could well charge extra for doing so.
2. Use a member of a competent persons scheme to do the work, and they will test everything and notify via their scheme provider.

Other people can certainly inspect and test your work, however there is the possibility that they don't like what you have installed and/or there are faults which need to be rectified.

Either way, other people can't notify your work to building control, since all of the schemes specifically prohibit this.

 

[ban-all-sheds]

Surely metal back boxes should be earthed??

Earthed yes.

Bonded no.


http://web.archive.org/web/20070314...c.org.uk/downloads/Earthing+Bonding+guide.pdf

 

[uptown47]

Surely metal back boxes should be earthed??

Earthed yes.

Bonded no.


http://web.archive.org/web/20070314...c.org.uk/downloads/Earthing+Bonding+guide.pdf

Thanks for the link.

Flameport, I didn't realise that. I've only run the 2.5mm to the shed so far and not connected anything up. Could I still inform building control at this stage?

Thank you for your advice.

Cheers.