Discuss Can SWA be run in the same metal trunking as singles? in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net
Yes, complete SWA. We have installed trunking for an installation with 2.5mm, 4mm and 6 mm singles.do you mean complete SWA? with the armour? or glanded into the trunking, and the inner cores within trunking?
"Singles" cable has a slightly tougher insulation than something like the inner basic insulation of t&e... Can take a bit of rough treatment no problem.
Thanks for the reply, the fault current will be 10Ka (theoretical maximum at origin) for the swa as we are right by the site intake.You are fine with that. Of course usual good installation practice needed, but SWA won't move that much unless you are looking at really high energy faults, and more so for sets of AWA singles making up a really high current 3P set.
Thank you! We have a massive amount of space left on the trunking. A maximum of 10% capacity before the 10mm SWA goes in.I can think of reasons why the clerk of works might not want SWA eating up space in trunking, but none that involve wiring regulations.
For some reason he doesn't like it clipped direct. Unfortunately it's at the beginning of a 70m run so glanding into trunk is not an option. Clerk also refuses to allow us to clip direct.Possible future plans require the space in the trunking?
Whats wrong with running the SWA alongside the trunking? Its mechanically protected already. Or, as i said earlier, gland it in and run it through without the armour.
He has refused to make suggestions on how to actually do it as he states 'that's not his job'.Clerk of works will have the final say. I wouldn't waste time arguing with him and would instead ask how he'd like it to be routed - limitations with regard to support might actually result in him having a change of mind. Do whatever he wants and invoice accordingly.
He has refused to make suggestions on how to actually do it as he states 'that's not his job'.
100x100 metal trunking, only 1 SWA to run. After SWA goes in with the other circuits.we are at approx 10% capacityIf I had more than one run of SWA I would be tempted to put up cable tray and clip to that. If the tray is vertical (parallel to wall, supported off by short lengths of strut, for example) then you need the occasional metal tie for fire support in addition to regular ties of any other sort.
If the SWA sits on top of a horizontal tray (so it can't fall if clips melt), for example supported on cantilever arms, or suspended from a roof, then standard cable ties are OK. Personally I would always use the black UV-tolerant type even indoors as sometimes it will get sunlight from windows, etc, and it saves me keeping multiple bags.
However, I also get the feeling this person is being difficult for no obvious reason. I would be tempted to present your suggestions for alternatives in writing (e.g. email) and make sure they respond also in writing just to cover yourself.
Incidentally, when you said trunking I was thinking of the metal stuff, 50x50mm upwards, not plastic. Can you confirm the type?
The beginning of the swa run is internal (where the trunking is), then runs externally to an outbuilding to upgrade a feed there.You’re still going to have to gland the swa into the trunking somehow, even leaving armour on.
I have to agree that there is no valid reason that it can’t be clipped surface. It’s perfectly ok in every other building.
Entry and exit to trunking will be 32mm metal compression gland, there is then a 30m run beyond trunking to the next dB that the swa continues to.Just one other thought, how would the SWA armour be connected?
I can see both sides of this, whilst I also cannot see a reason why it is Non compliant, it will take up more room in the trunking than the equivalent in singles?!
Personally I would if in trunking be using singles for ease and space saving.
When they ask you back again at a later date to install more circuits you will either be wishing for more space or thinking, glad I left some spare capacity in that trunking!
Just my 2pennies worth.
Sy
He hasn't suggested a way at all, says that's our job. Drawings only specify location of accessories and what circuit.You keep saying its only going to be 10% full with the swa in.... like its a reasoning to do it the way he's suggesting....but if that's the case, there should be some paperwork with the design saying something like... "have oversized the trunking to accommodate the SWA cable"
A conscious decision to not do it the way its done everywhere else.
100mm square does seem oversized for what you say is going in.... which does suggest they think there will be more added in the future.
OK, it will save some time, not having to separately clip the swa along the route, and maybe its an aesthetic decision... One square metal trunking might look neat against the wall, but not a black cable with tray, or cleats alongside.
"doesn't comply" is an absolute cop out, but one that is easily debunked if you've got the book there.
So it's the aesthetics he objects too, not something in the Regulations?He has said no to clipped direct because 'it will look ---- ' his words. Also a no to SWA in the trunking with singles. Time to email a superior imo
Reading the second sentence it would tend to indicate this is a change to the specification, do you have a COW Site Instruction to carry out this extra works, if so get them to specify how they wish it to be done, just don't do it until they instruct you, perfectly legitimate not to carry out the work until you are satisfied with the instruction as it's an extra, have you priced it or is it on day works at your enhanced rate?Yes, complete SWA. We have installed trunking for an installation with 2.5mm, 4mm and 6 mm singles.
We've now been asked to run a 10mm swa for a supply to a new dB and a lot of the trunking is along this route.
Aesthetics for clipped direct, and just says swa can't be run in the same trunking as singles so I can only assume he means that regs prohibit it.So it's the aesthetics he objects too, not something in the Regulations?
If it is aesthetics they are complaining about then it is unlikely cable tray will pass muster. However, I have often seen tray near the ceiling in places and most folks just don't notice it.Aesthetics for clipped direct, and just says swa can't be run in the same trunking as singles so I can only assume he means that regs prohibit it.
Indeed, but put down you ideas and suggestions to your superior in an email or so so they have a solid case to take up with the COW to get a decision.Imo this is something for the mep to deal with and is above my role
Reading the second sentence it would tend to indicate this is a change to the specification, do you have a COW Site Instruction to carry out this extra works, if so get them to specify how they wish it to be done, just don't do it until they instruct you, perfectly legitimate not to carry out the work until you are satisfied with the instruction as it's an extra, have you priced it or is it on day works at your enhanced rate?
I honestly don't know, the area it's run in is a welders workshops and a carpenters workshop, with 4 meter tall ceilings with trunking at 3.7m and the ability to clip direct above or below trunking. These aren't aesthetically pleasing rooms as you can imagine.I've been following the wrong thing here...
You say the COW doesn't want it clipped direct, but he also doesn't want it run in the trunking??
How the hell does he want you to get it from A to B then? Some of that magic wireless power?
A second, empty trunking, just to hide the swa in?
A different route so its not seen?
We have a mobile tower which is plenty safe enough. It's been decided that we run 50mm tray below the trunking which is fine. Leave the bosses to sort out variations from scopeJust give him in writing an estimate of how much it will cost to hide all the SWA to his satisfaction and copy it to the client, I think there would be some very embarrassed face's at the next project meeting.
Thinking further, 4M ceiling with the trunking at 3.7M which means working off MWEP or ladders, has the Health and Safety Co-ordinator been involved in this? their main function after all is the Safety of the workforce, easier to do if they do not have to leave the ground, is it possible to run the trunking around the walls?
We're fabricating ourselves due to lack of access to materials. I believe 4 core 10mm has a ten fold diameter for bend radius so definitely need to be careful we.dont fall foul of thatI would add that with 50mm trunking you need to be aware of bend radius of the SWA if the run is not straight. You might need to use a pair of 45 deg bends, etc, to get something sane. Also some suppliers have a very "square" 90 deg bend and others (like Unitrunk) have a bit more curve allowed.
WTF???We're fabricating ourselves due to lack of access to materials.
If you have some cable tray you ought to be able to make a gradual 90-deg bend by cutting V-shaped sections out and bending it in the a fan-shape. You will need some short links to join up the inner edges that you cut away to give it some strength though.I believe 4 core 10mm has a ten fold diameter for bend radius so definitely need to be careful we.dont fall foul of that
We're abroad and it takes a couple of weeks and a lot of money to get anything here, materials were ordered by the office.WTF???
If you have some cable tray you ought to be able to make a gradual 90-deg bend by cutting V-shaped sections out and bending it in the a fan-shape. You will need some short links to join up the inner edges that you cut away to give it some strength though.
Ah, that makes some sense.We're abroad and it takes a couple of weeks and a lot of money to get anything here, materials were ordered by the office.
That's something that strikes me watching some of those North American series (Ice Road Truckers, Wikd Akaska, and the like. We're so used to just popping to the wholesalers to get common stuff from stock, or next day, or withing a few days if it's a special order. And planning on the basis that if we forget something, it's no big problem. Not just electrical, but for other stuff - e.g. I know I can pop round and pick up a bag of cement if I run out.We're abroad and it takes a couple of weeks and a lot of money to get anything here
It's all to do with land area, if you look at any house in rural France, which is vast in comparison to the UK, you will see that nearly every house has a trailer sitting somewhere in the property, this is due to obviously to pick up supplies, but also due to the vast amount that companies charge for delivery.
Wicks in the UK have deliver free for anything on orders over £100.00 in Kent, that is not a lot a large order now days.
He could roll them, scaffold tube or similar through the middle and rope slings on the ends, over the shoulders and pull.Not sure how he'd feel about carrying drums of armoured cable up there
Reply to Can SWA be run in the same metal trunking as singles? in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net
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