Shed wiring

[richbarley99]

Afternoon, Ok, I wired the shed witha SWA that was already at the location... 3 core 2.5 Br/Bl/Gr. It is on a breaker at main CU 16 amp and to a new CU in the shed

When i wired sockets and lights etc from my new CU in the shed and tested the sockets, no earth. All terms are good/continuity in shed good etc. I went back to main CU and it only has 2 core red/black, so there has to be a joint buried somewhere!

Can I drive an earth rod in the ground and run earth to earth point in the CU in the shed itself?

As regards to current draw in shed, max will ever be maybe a grinder now and then, a small heater maybe.

Spoken to a friend who is an electrician, says not ideal but will protect you if earth fault.

Any extra thoughts would be greatly appreciated.

Regards, Rich.

 

[Murdochcat]

So you went live before you did any dead testing. Are you sure you are competent to do this work?

 

[richbarley99]

No, No... Was just doing checks on all aspects of install and found the earthing issues, nothing is live and will not until all commissioned in accordance with correct work procedures,RAMS and regs, was just asking for advice, its a forum isnt it?

 

[Murdochcat]

TBH you should have identified this issue before you started IMHO. Then you could have walked away

Call your CPS help line?

 

[pete01]

Is the armouring the earth?

 

[richbarley99]

The SWA is earthed at the CU in the house, then does not continue to the shed as it turns to 3 core armoured at a joint somewhere underground.

the swa at the shed end is not earthed and checked continuity back to house but does not pick it up.

 

[jj4091]

Have you got suspended or solid floors either at the base of the wall the consumer unit is installed on or where the 3 core passes through the wall to the outside.
Just wondering how hard it would be to find a joint.
So the armour is connected to earth at the main consumer unit?

 

[ericmark]

This is why we should look at the installation certificate before doing alterations, but with domestic we know that certificate is unlikely to exist.

So one could make the shed TT, but the tests show a joint somewhere, and we simply don't know where, if an insulation test shows clear you could take a chance, but you are taking a chance, you know you should without the installation certificate abandon the old cable, but as to what you do is really down to looking at the general installation and decide was the earth isolated intentionally so shed is TT, or was it an error?

I think I would say can't use this cable without seeing the installation certificate, which one would be very surprised to see existed.

You can look at the council website in Wales to see if the work is registered as it still required in Wales, but I found Powis was good, but Flintshire's website had a load of errors, work I know was registered was not listed on their website.

 

[richbarley99]

Have you got suspended or solid floors either at the base of the wall the consumer unit is installed on or where the 3 core passes through the wall to the outside.
Just wondering how hard it would be to find a joint.
So the armour is connected to earth at the main consumer unit?

Yes and cable buried in solid floor.

 

[richbarley99]

This is why we should look at the installation certificate before doing alterations, but with domestic we know that certificate is unlikely to exist.

So one could make the shed TT, but the tests show a joint somewhere, and we simply don't know where, if an insulation test shows clear you could take a chance, but you are taking a chance, you know you should without the installation certificate abandon the old cable, but as to what you do is really down to looking at the general installation and decide was the earth isolated intentionally so shed is TT, or was it an error?

I think I would say can't use this cable without seeing the installation certificate, which one would be very surprised to see existed.

You can look at the council website in Wales to see if the work is registered as it still required in Wales, but I found Powis was good, but Flintshire's website had a load of errors, work I know was registered was not listed on their website.

Installed in the 80s, its a good installation and carried out competently as the SWA glanding back at the CU is a high standard

 

[ericmark]

OK 80s so no council records before I think 2004, so if to good standard I would just TT the installation to shed, but it's up to you, you're the one who has to sign the certificates and register the work, so ask your scheme provider.

In England one could just do it and run, but since in Wales, the work needs registering, so you need to consider what an inspector will say, so ask the scheme provider or LABC if not a scheme member, or if your own house, take a chance no one will ever find out.

 

[ebee]

Well finding the joint would be the first priority, then doing L to L then N to N then E to E (example you might find that SWA is E to E on Both so continuiy righ thru or you might not - are both the third conductor and the armour connected together anywhere.

Therefore disconnect both ends safely an test continuity end to end to establish what is what the insulation resistance betweel all conductors (including SAW) that should give you a picture of what is what.

Next, make your best attempt to find where the joint might be and if you find it then you can inspect ant test it then OK.
If you are completely happy with it you then haave L & N both correct you can decide whether to just use L & N and provide your own Earth rod/plate at the Shed end or renew the part from the joint to the shed or the whole lot from start to finish so you have a good earth from the house.
In any event an RCD at the supply end is pretty much paramount.

I will not mention Part P and notification etc.

 

[Murdochcat]

Installed in the 80s, its a good installation and carried out competently as the SWA glanding back at the CU is a high standard

If it’sa good standard then why is there no continuity?

When was the floor made v solid ?

Something doesn’t add up here