jpadie Posted February 3 Share Posted February 3 What's the best way of transitioning from 16mm^2 SWA to flat cable please ? Am planning this to be just above ground level on the exterior wall. Link to comment Share on other sites More sharing options...
Jenki Posted February 4 Share Posted February 4 If it's outside run the SWA to where it needs to go clipped direct with cable cleats. If your going inside then IP rated junction with glands and go through the wall (sleeved) with Twin and earth( I've assumed flat = twin and earth cable). NB Twin and earth is not suitable clipped direct outside. Link to comment Share on other sites More sharing options...
TonyT Posted February 4 Share Posted February 4 Or take the Swa inside and do the joint and never have to worry about water ingress Link to comment Share on other sites More sharing options...
Mattg4321 Posted February 4 Share Posted February 4 Better if there’s no joints in the cable and run swa all the way. Link to comment Share on other sites More sharing options...
FuerteStu Posted February 4 Share Posted February 4 16mm swa step down to possible/probable 2.5mm t&e rings a lot of alarm bells. What is the circuit supplying? What is it fed from? What breaker/fuse is protecting the cable? There are situations where this doable, but I'd much rather see a garage board fitted, the swa termination into a main switch and the outgoing circuit fed from a breaker. Link to comment Share on other sites More sharing options...
ProDave Posted February 4 Share Posted February 4 More information needed. Best way is SWA glanded into a mini consumer unit and final circuit(s) from there with appropriate rcd / mcb protection. But you don't give us any idea what you are trying to do. Is the SWA already protected by a 32A MCB and you are trying to make a lollipop circuit? Link to comment Share on other sites More sharing options...
jpadie Posted February 4 Author Share Posted February 4 (edited) 3 hours ago, FuerteStu said: 16mm swa step down to possible/probable 2.5mm t&e rings a lot of alarm bells. That's not the whole situation. this is for a garden room that the electrician has said needs at least 10mm^2 cable. the connection will be from the main consumer unit to a local consumer unit in the garden room. the majority of the wiring from the local consumer unit will be on 2.5mm^2 t+e, all on RCBOs. The extra capacity is to allow for a car charger in the future. 2 hours ago, ProDave said: More information needed. Best way is SWA glanded into a mini consumer unit and final circuit(s) from there with appropriate rcd / mcb protection. But you don't give us any idea what you are trying to do. Is the SWA already protected by a 32A MCB and you are trying to make a lollipop circuit? apologies - this post may shed light. what I was originally looking for was an idea of what type of connection to use and whether there were existing commercial solutions (e.g. wagos for 2.5mm^2 cable in a plastic junction box) for high current connections on large cores. But I see that my question has opened the door to rather more issues which are all valuable knowledge! 4 hours ago, Jenki said: If it's outside run the SWA to where it needs to go clipped direct with cable cleats. If your going inside then IP rated junction with glands and go through the wall (sleeved) with Twin and earth( I've assumed flat = twin and earth cable). NB Twin and earth is not suitable clipped direct outside. the main length of the SWA will be buried in conduit (there is existing sewage pipe that is being decommissioned that will make it unnecessary to dig a trench. the tail at the end of the main consumer board will be brought up by the side of the house and clipped until termination. flat cable = t+e yes. apologies for not being precise. I did not know that. the house already has a reasonable number of t+e cables clipped to the outside of the building; i made an assumption that this was ordinarily legitimate. 4 hours ago, TonyT said: Or take the Swa inside and do the joint and never have to worry about water ingress the bend radius for the swa (to me) makes it look impractical to clip to the wall and take inside. I might be misunderstanding though. the electrician recommended terminating on the outside of the building. possibly he meant that the armoured section could be terminated and then just run the inside of the cable up the building and into the house? is that feasible? Edited February 4 by jpadie Link to comment Share on other sites More sharing options...
FuerteStu Posted February 4 Share Posted February 4 With the greatest respect.. If you have an electrician doing this job, then this is HIS job, not yours. You aren't qualified for this. Guesswork is dangerous in this scenario Link to comment Share on other sites More sharing options...
ProDave Posted February 4 Share Posted February 4 4 minutes ago, jpadie said: That's not the whole situation. this is for a garden room that the electrician has said needs at least 10mm^2 cable. the connection will be to the main consumer unit to a local consumer unit in the garden room. the majority of the wiring from the local consumer unit will be on 2.5mm^2 t+e, all on RCBOs. The extra capacity is to allow for a car charger in the future. So no doubt about it, SWA glanded into consumer units at each end, and final circuits wired from garden room CU as normal. No need to bodge direct connections from SWA to flat. 1 Link to comment Share on other sites More sharing options...
jpadie Posted February 4 Author Share Posted February 4 11 minutes ago, FuerteStu said: With the greatest respect.. If you have an electrician doing this job, then this is HIS job, not yours. You aren't qualified for this. Guesswork is dangerous in this scenario the electrician is doing the sign off. i am doing everything else. He has expressed a preference for _not_ taking the SWA up the wall and into the house. 10 minutes ago, ProDave said: So no doubt about it, SWA glanded into consumer units at each end, and final circuits wired from garden room CU as normal. No need to bodge direct connections from SWA to flat. ok - how does one get the SWA to bend sufficiently to come up the wall and go through a window frame, bend right and then down to the consumer unit? (this is the entry route). it looks like the bend radius is min 130mm which makes this kind of routing seem challenging. Link to comment Share on other sites More sharing options...
ProDave Posted February 4 Share Posted February 4 13 minutes ago, jpadie said: the electrician is doing the sign off. i am doing everything else. He has expressed a preference for _not_ taking the SWA up the wall and into the house. ok - how does one get the SWA to bend sufficiently to come up the wall and go through a window frame, bend right and then down to the consumer unit? (this is the entry route). it looks like the bend radius is min 130mm which makes this kind of routing seem challenging. You re think the entry route. You could do a potted waterproof connection, but it would be to some other cable of the correct size. Your challenge is to find a more flexible cable that is suitable for outside use. Try and get the SWA inside the house somewhere, through a wall not window frame, inside a cupboard or under the floor, then a junction to a more flexible cable is very much easier. Link to comment Share on other sites More sharing options...
Conor Posted February 4 Share Posted February 4 We just used an external double wall socket. SWA up from the bottom through glanded conduit, main house ring straight through the wall behind an existing internal socket. Tough enough getting everything fixed in to the terminals, but all worked. Link to comment Share on other sites More sharing options...
FuerteStu Posted February 4 Share Posted February 4 4 hours ago, jpadie said: the electrician is doing the sign off. i am doing everything else. He has expressed a preference for _not_ taking the SWA up the wall and into the house. What's his reasoning? Because he wants an additional problem for YOU to deal with? There is no reason I can see for this transition. It's asking for problems. Especially considering you plan on using it for EV charging. Link to comment Share on other sites More sharing options...
ProDave Posted February 4 Share Posted February 4 3 hours ago, Conor said: We just used an external double wall socket. SWA up from the bottom through glanded conduit, main house ring straight through the wall behind an existing internal socket. Tough enough getting everything fixed in to the terminals, but all worked. That is a spur from a ring final and not good for anything other than one 13A socket at the far end. Not a way I would advise anyone to do it. Link to comment Share on other sites More sharing options...
TonyT Posted February 4 Share Posted February 4 (edited) 1 hour ago, ProDave said: That is a spur from a ring final and not good for anything other than one 13A socket at the far end. Not a way I would advise anyone to do it. Why not spur on a ring is acceptable by BS7671. Edited February 4 by TonyT Link to comment Share on other sites More sharing options...
ProDave Posted February 4 Share Posted February 4 5 minutes ago, TonyT said: Why not spur on a ring is acceptable by BS7671. Yes, to feed ONE double socket. If that is all that is at the far end of the SWA than fine. However I suspect there might be more connected there..... Link to comment Share on other sites More sharing options...
TonyT Posted February 4 Share Posted February 4 Ok fit a fused switched spur and let them go mad. Link to comment Share on other sites More sharing options...
oliwoodings Posted February 4 Share Posted February 4 4 hours ago, TonyT said: Ok fit a fused switched spur and let them go mad. See where he plans to run an EV charger off this in the future. What you're proposing does not sound suitable at all. Link to comment Share on other sites More sharing options...
oliwoodings Posted February 4 Share Posted February 4 I ran 10mm swa for my garden building which my electrician then hooked up each end for me. To get into the house we did a hole in the wall at a 45 degree angle to reduce the required bend radius, and lined it up so it came out inside pointing right at the side of the CU where it was glanded. Very easy for any competent electrician to handle. Link to comment Share on other sites More sharing options...
jpadie Posted February 5 Author Share Posted February 5 12 hours ago, oliwoodings said: I ran 10mm swa for my garden building which my electrician then hooked up each end for me. To get into the house we did a hole in the wall at a 45 degree angle to reduce the required bend radius, and lined it up so it came out inside pointing right at the side of the CU where it was glanded. Very easy for any competent electrician to handle. Thank you. that's an idea. expanding foam and silicon to seal and water/bug proof the holes? Link to comment Share on other sites More sharing options...
oliwoodings Posted February 5 Share Posted February 5 10 hours ago, jpadie said: Thank you. that's an idea. expanding foam and silicon to seal and water/bug proof the holes? Didn't need foam in my case, hole was snug enough. Just siliconed each side. 1 Link to comment Share on other sites More sharing options...
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