Terminate SWA armour outside and take just internal wires into house/CU?

[Iknowcraig]

Hi all, I am running 6mm 3 core SWA to my garage and am looking at options to hook it up to the main CU in the house.

I was thinking it would be easier to take the SWA via a gland into an external weatherproof junction box and terminate just the armoured portion there (running a suitable earth cable to the junction box to earth the armour) and then take just the internal cable to the CU in the house. This should make manuevering the cable inside a bit simpler. What are peoples thoughts on this? I am thinking this is preferable to terminating the SWA inside the junction box completely and using T&E to the CU from there?

Thanks!

 

[deadshort]

I would terminate the SWA outside in the JB, and drill straight through the back if the box into the house. I use pvc conduit as a sleeve to protect the cable in the cavity.

Regards,

DS

 

[Iknowcraig]

do you mean terminate it completely and use T&E from there? I have read elsewhere it is better to keep the internal cores intact to have one less potential point of failure?

 

[deadshort]

Hi, yes if it's not possible to run the internal cores without containment/protection into the CU.

Regards,

DS

 

[Iggifer]

Hi, yes if it's not possible to run the internal cores without containment/protection into the CU.

Regards,

DS

I think the OP was planning on keeping the internal sheath on, just removing the outer sheath & SWA

 

[deadshort]

I think the OP was planning on keeping the internal sheath on, just removing the outer sheath & SWA

Ah, and earthing the sheath at garage end .

Thanks,

DS

 

[Iknowcraig]

I think the OP was planning on keeping the internal sheath on, just removing the outer sheath & SWA

this is what I was thinking, does this sound like a good solution? I will be trying to hide the cable behind plasterboard etc inside so doing this with the full SWA including armour could be a bit tricky!

 

[Iknowcraig]

Ah, and earthing the sheath at garage end .

Thanks,

DS

I was planning to earth the sheath at both ends, by terminating it outside in a junction box and running the internal insulated cable in to the CU, along with an additional earth cable to connect to the sheath in the junction box.

 

[deadshort]

Yes

DS

 

[Iggifer]

this is what I was thinking, does this sound like a good solution? I will be trying to hide the cable behind plasterboard etc inside so doing this with the full SWA including armour could be a bit tricky!

Just make sure you keep it in safe zones!

 

[Iknowcraig]

Just make sure you keep it in safe zones!

will be in the corner of two walls (one external one stud) going straight up to the CU so will be within the safe zone from what I've just googled!

 

[JohnW2]

I think the OP was planning on keeping the internal sheath on, just removing the outer sheath & SWA

That's what I understood - but I don't think that the 'internal sheath' of SWA is man enough to be used as a second layer of insulation without 'mechanical protection' is it?

Kind Regards, John

 

[JohnW2]

do you mean terminate it completely and use T&E from there?

That would, I think, be the 'usual' way. It's certainly what I would do, unless there was some reason for needing SWA to go all the way to the CU.

I have read elsewhere it is better to keep the internal cores intact to have one less potential point of failure?

That's a theoretical argument, but there are so many connections/joints within an electrical installation, anyway, that one more really isn't going to make any material difference.

Kind Regards, John

 

[Iknowcraig]

thanks john, I don't have a definitive reason for taking the SWA to the CU, just heard somewhere this was preferable.

with regards to changing over to T&E, would you be happy doing this in an external junction box or should I attempt to bring the SWA into the house and terminate in a junction box inside? I fell like this would look messier inside so unless there is a strong reason to terminating outside to T&E would be preferable. I am using 6mm SWA so should 6mm T&E be fine to join to this?

 

[securespark]

I wouldn't put in an unnecessary joint.