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

[Iknowcraig]

I wouldn't put in an unnecessary joint.

So you would recommend my suggestion of taking the internal cable from the SWA straight to the CU? Or the whole SWA?

 

[securespark]

Yes to the first, subject to running in safe zones as per other's suggestions.

 

[JohnD]

Now that new domestic CUs are metalclad, it seems to me simpler to run SWA into the CU rather than interpose an adaptable box.

 

[JohnW2]

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.

If it were fairly easily and aesthetically acceptably, I would personally prefer to have the junction box inside, and in the dry, rather than outside and exposed to the elements.

I would be very surprised if problems due to water ingress into external accessories (including JBs) was not far far more common than problems due to an additional 'unnecessary' joint in the cable!

Kind Regards, John

 

[JohnW2]

I wouldn't put in an unnecessary joint.

I'm not sure what you're suggesting. If you're suggesting taking the 'whole SWA (including armour and outer sheath) back to the CU, then fair enough. However, as I said, if one were thinking of the OP's plan to take just the cores of the SWA and their 'inner covering' from JB to CU, I don't think that would be acceptable without some 'mechanical protection' would it?

Kind Regards, John

 

[Iknowcraig]

If it were fairly easily and aesthetically acceptably, I would personally prefer to have the junction box inside, and in the dry, rather than outside and exposed to the elements.

I would be very surprised if problems due to water ingress into external accessories (including JBs) was not far far more common than problems due to an additional 'unnecessary' joint in the cable!

Kind Regards, John

Any advice on how to hide the junction box inside? It is a masonry cavity wall construction house with dot & dabbed plasterboard on top. I plan to bring the SWA (OR T&E) in at ground level to avoid having an ugly black cable coming up the wall by the front door and then need to bring it up about 6ft to the CU at ceiling height preferably hidden out of sight behind the plasterboard.

 

[Risteard]

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?

No sheath is for insulation. But in answer to your question the bedding is not a sheath and therefore I would expect to see it contained/enclosed throughout its length otherwise the cable is not being used as designed to any standard.

 

[JohnW2]

... in answer to your question the bedding is not a sheath and therefore I would expect to see it contained/enclosed throughout its length otherwise the cable is not being used as designed to any standard.

Exactly my point.

Kind Regards, John

 

[JohnW2]

Any advice on how to hide the junction box inside? It is a masonry cavity wall construction house with dot & dabbed plasterboard on top. I plan to bring the SWA (OR T&E) in at ground level to avoid having an ugly black cable coming up the wall by the front door and then need to bring it up about 6ft to the CU at ceiling height preferably hidden out of sight behind the plasterboard.

If I understand correctly, if the CU is that close to the point of cable entry, I'd probably take the (full) SWA all the way to the CU, hence avoiding the need for any JB.

Cable entry 'at ground level' (if you mean that literally) is likely to present problems, with or with out a JB. If you would be prepared to have the cable going at least a few inches up the outside wall, you could then bring it through the wall into the back of a sunken backbox (housing the 'joint'), with a ('flush') blank plate over it.

Getting the cable (whatever type) behind the plasterboard may well not be a trivial exercise, and is likely to be at least a bit disruptive.

Kind Regards, John

 

[Iknowcraig]

If I understand correctly, if the CU is that close to the point of cable entry, I'd probably take the (full) SWA all the way to the CU, hence avoiding the need for any JB.

Cable entry 'at ground level' (if you mean that literally) is likely to present problems, with or with out a JB. If you would be prepared to have the cable going at least a few inches up the outside wall, you could then bring it through the wall into the back of a sunken backbox (housing the 'joint'), with a ('flush') blank plate over it.

Getting the cable (whatever type) behind the plasterboard may well not be a trivial exercise, and is likely to be at least a bit disruptive.

Kind Regards, John

Thanks John,

I am happy for the cable to come up the wall a few inches, didn't mean ground level literally, just something like 6 inches above. The sunken backbox and flush blanking plate could be a good route to go, would look tidy and allow me to terminate the SWA outside of the CU to make wiring into the CU easier.

 

[Iknowcraig]

2017-01-06 23.08.00

• Iknowcraig
• 6 Jan 2017

2017-01-06 23.08.06

• Iknowcraig
• 6 Jan 2017

This is the CU and location I am trying to get to

 

[JohnD]

is the CU enclosure metal or plastic?

 

[chivers67]

One could run 6mm T&E to a 45amp "Cooker outlet switch" or rotary isolator then run an SWA from there outside.

 

[Iknowcraig]

planning on earthing the armour at both ends as you say, CU is plastic I believe, will take a closer look tomorrow. What is the best way to join the SWA to T&E inside a sunken box like Johnw2 mentioned? Don't see the need for a cooker switch or rotary isolator as the circuit can already be isolated at the MCB in the CU, plus this won't blend into the background, so the wife won't like it!

 

[JohnW2]

I am happy for the cable to come up the wall a few inches, didn't mean ground level literally, just something like 6 inches above. The sunken backbox and flush blanking plate could be a good route to go, would look tidy and allow me to terminate the SWA outside of the CU to make wiring into the CU easier.

OK, but I should have pointed out that terminating the SWA into the box would not be a trivial exercise, and would probably require some ingenuity.

Kind Regards, John