SWA Cable from outside into FCU

[Jupiter01]

I am glanding a 1.5mm 3 core SWA into a wiska box externally. This wiska box will be directly opposite a FCU on the inside of the house. The SWA cable needs to connect to this switched FCU. Should I leave the SWA cores long enough so that they bend and go through the wall to connect to the FCU or should I bring a 1.5 T&E from inside and join the two using wagos inside the wiska?
Also, do the cables going through the concrete wall need to go through conduit or anything like that?

Thanks in advance.

 

[Murdochcat]

Personally I would leave the swa cores long enough to go directly to the FCU

And you need to earth the outer strands of the SWA and connect that to earth as well, preferably at the supply end

 

[plugwash]

If you are going to run the inner cores of the SWA through the wall, then you should use conduit.

 

[crystal ball]

Earthing Kit for Combi 308 Enclosure (Pack of 2)

Speeds up installation of SWA cable

www.cef.co.uk

 

[Jupiter01]

Personally I would leave the swa cores long enough to go directly to the FCU

And you need to earth the outer strands of the SWA and connect that to earth as well, preferably at the supply end

I have a banjo nut "thingy" that goes inside the wiska and as part of the gland assembly. I plan to connect an additional earth lead to this and take through to the FCU. This will mean that I have two earth wires going through to the FCU. Which begs the question, what is the role of the ear cable that is part of the inner cores? All my external lights are class 2.

 

[plugwash]

BS7671 requires an earth to be taken to "each point and each accessory". The point of this is that fixed wiring tends to outlast the equipment connected to it. Even if the lights you have installed right now are class 2, doesn't mean the next lot will be.

If you wish, and if the EFLI is low enough, you can use 2 core SWA and use the armour as the only earth. This seems to have fallen out of favour in recent times (as does using metal conduit as the earth path) but BS7671 still allows it in most situations (IIRC there is an exception for marinas, requring use of explicit earth conductors there).

 

[davelx]

I would (and have) run the entire inner flex though conduit into the FCU, not just the cores, plus a separate earth conductor for the armour.

 

[sparkwright]

I would (and have) run the entire inner flex though conduit into the FCU, not just the cores, plus a separate earth conductor for the armour.

Me too.

 

[Jupiter01]

UPDATE - used the galvanised Y boxes with the SWA Glands. I’ve now got earth continuity all the way through. Thanks for your help with this.

I’ve used the outdoor SWA glands, outdoor stuffing gland where the cable goes off to each light and rubber gaskets under the lid for the conduit box. This all looks robust.

However, the light fitting - which is surface mounted - has a small length of cable that is factory fitted and I need to join my cable, coming out of conduit to this. Presumably I need to use wagos behind the light. I can try and put some silicone over where the light meets the brick but it definitely feels like a weak link.

Can you please advise. Thanks.

 

[EFLImpudence]

Presumably I need to use wagos behind the light.

Why? Any suitable connectors will be fine.

 

[Jupiter01]

Why? Any suitable connectors will be fine.

I was thinking that they will come in contact with water. All my other efforts to waterproof seem to be weakened by this.

 

[Jupiter01]

Here is a picture of the light. The Wago connectors will sit in the back of the light and inevitably come in contact with moisture

 

[Harry Bloomfield]

I was thinking that they will come in contact with water. All my other efforts to waterproof seem to be weakened by this.

The trick is to stop water getting in at the top, but to still ensure what water does find it's way in, can easily escape. No fitting is ever truly water tight - heating and cooling, creates a vacuum in the enclosure and that is enough to suck moisture inside. Seal the top and sides against ingress, but always drill some small holes in the bottom, for the escape of water.

 

[flameport]

Here is a picture of the light.

If that light really must be used, then a box such as this: https://www.toolstation.com/raytech-happy-gel-box-ip68/p31078 could be used for the connectors.

In reality, that light is junk. Much better light fittings are available.