just brushing up on the 18th edition before I take the refresher this week. Iv seen Regulation 521.10.202 which basically states cables need to be supported throughout the installation in such a way they do not get in the way in the result of a fire. Does this mean cable clips on ceilings / upper floors are not longer used due to them being plastic?
- Thread starter Scott Jacob
- Start date
In a nutshell yes there is a thread about this wait and I’ll have a dig about to find it here’s a report on fixings makes good reading if your looking to see which fixings to use
https://electrical.------.org/media/1578/fire-performance-of-cable-supports.pdf
https://electrical.------.org/media/1578/fire-performance-of-cable-supports.pdf
Yes indeed, plastic mini trunking or conduit cant be used anywhere in the building either without fire proof supports at suitable intervals.
This used to only apply to escape routes but in the 18th it applies throughout the building.
This used to only apply to escape routes but in the 18th it applies throughout the building.
Here is one of the threads I’m sure there’s at least a couple of debates about it but the link I posted earlier was published by the IET so that’s about as good as it gets for clarifying regs New cable support regulation 521.10.202 (18th) - https://www.electriciansforums.co.uk/threads/new-cable-support-regulation-521-10-202-18th.169272/
T
The Ghost
Personally I have thought this to be somewhat puzzling, the whole requirements around this subject. Remembering this all came out of the greater London Fire fighter observations that there operatives were being electrocuted from live wires I suppose breaking and dangling and making contact. The puzzle for me is what happened to protection. A cable subjected to flames should surely cause the migration of conductive parts to short out and activate the protection for that circuit. So in a home 6242y or whatever similar type should start to melt and set off the MCB, why doesn't it?
It's not just a case of the possibility of electrocution during a fire but a trip and building accessibility hazard from hanging cables
Plastic mini trunking or conduit is not the problem, they just melt in a fire. Cables within the trunking/conduit are the problem as they can cause entanglement with fire fighters.
Then surely they are exactly the problem, because in the event of a fire they are not doing an adequate job of supporting / protecting the cables within.
To clarify; the new regulation is regarding cable supports.
Sorry mate.... Monday morning and all that....
I missed the bit from your post about "without fire proof supports at suitable intervals."... I'm sure it wasn't there before...
but my reply has it in as well...That's why I posted. It sounded like you were saying plastic trunking was not allowed... end of...
I think I need to go home....
Yes plastic cable clips are now banned, as are red rawl plugs
These regs are mostly for large public buildings but not for your average domestic household.
Places you would normally use metal trunking or tray anyway. Just have to add metal cable ties along with the plastic ones.
I read somewhere else on the forum that ceiling plasterboard is sufficient to stop any cables dropping into the firefighters in the domestic situation.
These regs are mostly for large public buildings but not for your average domestic household.
Places you would normally use metal trunking or tray anyway. Just have to add metal cable ties along with the plastic ones.
I read somewhere else on the forum that ceiling plasterboard is sufficient to stop any cables dropping into the firefighters in the domestic situation.
I thought that 521.10.202 applied to "your average domestic household"... or have I misread another post???
It applies to all wiring systems as far as I know.
That's how I interpret it too but you wouldn't usually surface mount cables on a new domestic installation anyway would you?
D
davesparks
This regulation has come about as a result of the deaths of firefighters who became trapped in cables which had fallen down in burning buildings.
The coroners in these cases made the recommendations.
Your post is the first I've heard of any electric shock incident related to this.
I think note 3 makes it reasonably clear, although I did have to check the meaning of 'precludes'!
You can't use non-metalic fixings as the ONLY means of support where cables are clipped to exposed surfaces, I take this to mean that above plasterboard (i think standard board is 30min fire rated?) it is fine to use plastic clips etc.
Think about old pubs with all the cables just clipped to the exposed joists etc - big no no now.
Non metalic trunking as sole means of support is not allowed - so must also use metal fixings within the trunking.
What's not so clear is if you can apply some common sense to this - knowing what the intention of the reg is (firefighter safety predominantly) so what are we saying about low level trunking, or even dado trunking around offices?
You can't use non-metalic fixings as the ONLY means of support where cables are clipped to exposed surfaces, I take this to mean that above plasterboard (i think standard board is 30min fire rated?) it is fine to use plastic clips etc.
Think about old pubs with all the cables just clipped to the exposed joists etc - big no no now.
Non metalic trunking as sole means of support is not allowed - so must also use metal fixings within the trunking.
What's not so clear is if you can apply some common sense to this - knowing what the intention of the reg is (firefighter safety predominantly) so what are we saying about low level trunking, or even dado trunking around offices?
Will be fine and will actually look quite neat if you resurrect the use of the humble buckle clip.
Dado trunking... Very interesting point! Then you would only need to support the cables when they go over doorways for example.
Been to a job today where surface trunking will be considered due to the upstairs lighting needing rewired in a flat roof house.
Also done a few flats before with concrete floors and ceilings where surface trunking is the preferred option.
Wiring in domestic garages and outbuildings is usually done surface in trunking or conduit too.
In my opinion, I would say that the reg also applies to this as well.
In fires, fire fighters hug walls. The reg is intended to stop entanglement. I don't think the fire fighters would be impressed if their feet were getting entangled in cables..
Use metal. Metal saddles on plastic conduit have been used for years by fire alarm installers. You can get powder coated saddles to match PVC conduit too.
Also saw something lately at a local wholesaler trade event that was like a buckle clip for conduit, can't remember the brand though I'm afraid.
cprfenom
-
Galv saddles. You can get them in white and black now too
G
GBDamo
I've used Galv saddles with metal plugs to overcome this one.
Wall dogs or whatever other names plugless screws go by.
I think it’s more the entanglement risk than the risk of electric shock Vort
Personally i think any wiring or wiring system that has the potential to collapse from its original position, whether it be ceiling wall or dado height would come into this really the only exception in my view would be trunking at skirting level actually touching the floor or similar as if the containment melted the cabling wouldn’t go anywhere it may be a bit overkill but it’s a damn sight better than if the worst were to ever happen knowing you could have easily done something to prevent it.
I have taken the lid off some seriously full dado trunking before and there was a very real risk that someone could fall over and become entangled in the cables that all fell out the install in question was on two walls in an office and removing one piece Resulted in the lid on the adjacent wall coming off from the weight of the cabling and the cables falling quite far into the room....
T
Toneyz
White or black metal saddles. We have the white on site and assume that they do black if above ceiling we use galv.
Remember when the 16th Edition first came out and we were frantically cross bonding anything and everything metal?
...Well I'm anticipating the 19th Edition instructing us to cross bond all these metal clips - *this is a joke!
...Well I'm anticipating the 19th Edition instructing us to cross bond all these metal clips - *this is a joke!
Maybe they will have to ban metal tooth fillings, as they will need bonding with 10mm.... so you end up looking like a Borg
satori
-
What is missing from this discussion is a definition of the word premature, as it is used in the regulation. I don't have a copy of the 18th yet and can't look to see if it's one of those terms that is defined in Part 2.
At some point between the fire starting and the building being entirely consumed, the collapse of the wiring system is not premature - it is inevitable. We'd all look like construction gods if, in the aftermath of an inferno, the wiring was still perfectly in tact while every other trade's work was no longer identifiable. So, at what point is it not premature for the wiring to collapse? Are we talking ourselves into an impossible corner by trying to keep the wiring suspended beyond what is reasonable to expect?
Plumbers are using plastic piping these days, they're just as likely to collapse and cause entanglement issues; are they having this regulation too?
I have no answers, but I'm not sure the discussion has been entirely about the right question.
Plastic pipes would melt themselves, and for gas only metal piping is allowed.
I think premature has the obvious meaning that the wiring system doesn't fall before the elements it is attached to fail.
So if the ceiling is down, the wiring can be down, but if it was almost like a trap where the wiring is supported by plastic supports that melt when a fire comes in, that is premature.
As per @johnduffell post #37 above.
I'm sure if one of your relatives was a fire fighter (Not that any of mine are) you would be wanting to look out for them.
Just think about it logically. Again, see post #37.
Well you know what they say Spoon "Resistance is futile"isn't that right Lucutus?
OFFICIAL SPONSORS
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc
Advert
Thread starter
Thread Information
Thread Tags
Advert
Thread statistics
Advert
TrueNAS JBOD Storage Server
-
-
Understanding TrueNAS JBOD Servers: A Comprehensive Guide- Started by Dan
- Replies: 8
-
