Regulation 521.10.202 - Wiring systems

[Scott Jacob]

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?

 

[MFS Electrical]

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?

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....

 

[Toneyz]

true, ive seen and used the metal clips designed to go in trunking, whats the solution for plastic conduit?

White or black metal saddles. We have the white on site and assume that they do black if above ceiling we use galv.

 

[*-jester-*]

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!

 

[Spoon]

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!

Maybe they will have to ban metal tooth fillings, as they will need bonding with 10mm.... so you end up looking like a Borg

 

[The Ghost]

Yes thanks all having looked into it a bit more I can see the problem was/is entanglement. Never too old to learn!

 

[satori]

View attachment 45991

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.

 

[johnduffell]

Plumbers are using plastic piping these days, they're just as likely to collapse and cause entanglement issues; are they having this regulation too?

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.

 

[DefyG]

I read somewhere else on the forum that ceiling plasterboard is sufficient to stop any cables dropping into the firefighters in the domestic situation.

Not when the board has got wet and collapsed from water sprayed from a fireman's hose!

 

[Spoon]

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.

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.

 

[Pete999]

Maybe they will have to ban metal tooth fillings, as they will need bonding with 10mm.... so you end up looking like a Borg

Well you know what they say Spoon "Resistance is futile"isn't that right Lucutus?