New cable support regulation 521.10.202 (18th)

[happysteve]

I think if your worried about plastic wall plugs failing the surrounding structure will have failed anyhow.
I don’t buy into the fact that you can’t use them at all to be honest.
I need more information to be sure tho

Your wish is my command

 

[Yplan]

Just as an observation I have used linian fire clips and they are spot on and meet the 18th edition but also agree with people on here that by time rawl plugs fail the building would be down anyway.

 

[bigspark17]

@ elecshow the niceic did a talk aboit 18th and stated plastic rawl plugs are ok. So not sure why youve got a problem them. They are embeded into the fabric of the building by the time they melt and give way the buiding will be in a terrible state!

 

[happysteve]

Regarding pastic plugs...

From the PDF report on the link in #21, page 10:

Similar to the first experiment, all the plastic clips on each lintel failed, resulting in the cable dropping down. A new observation from this experiment was that the supports in the centre of Lintel 2 had dropped out of the lintel. This was not a failure of the support but rather a failure of the plastic plugs used for fixing the supports to the lintel.
​

Page 12:

The findings from the short fixings study show that combustible wall plugs in concrete substrates demonstrate signs of weakening of mechanical strength from 300°C and above and that these fixings can fail at 400°C after up to a one hour exposure in controlled conditions.
​

Of course, I'm just picking and choosing bits of the report, it's a bit lengthy but gives a fuller picture.

 

[SparkyChick]

I have a close friend who lost at least one colleague as a result of entanglement due to a collapsed wiring system.

I've been lucky enough to be able to go on an industrial chemical plant training exercise with crews from Lancashire Fire and Rescue Service. If you've never tried on fire fighting gear, trust me we should be doing everything we can to minimise the chances of our work killing another fire fighter (or anyone else for that matter). Even on a cool night, it was stifling, heavy and limited my movement somewhat. I can't imagine the panic of not being able to see what's going on, trying to get yourself out of it.

Don't forget in some situations fires can be directed jets of combustible materials that could potentially create localised heating in the building structure.

They have made changes and crews are being issued with wire cutters, but surely it's better to try and ensure they never need to use them?

 

[MFS Electrical]

I think if your worried about plastic wall plugs failing the surrounding structure will have failed anyhow.
I don’t buy into the fact that you can’t use them at all to be honest.
I need more information to be sure tho

Page 8 onwards is worth a read
https://electrical.------.org/media/1578/fire-performance-of-cable-supports.pdf
Edit- hadn’t realised you had posted this too @happysteve

 

[johnduffell]

yes that BRE doc that's been quoted is very useful.
If people are interested in the tragic reason for this new reg, this is a bit of a sobering eye opener and gives a new respect for what otherwise seems like yet another reg.
https://www.hantsfire.gov.uk/EasySiteWeb/GatewayLink.aspx?alId=4478

 

[MG201]

Like previously said the plastic plug is within a casing of either concerete or block and maybe even behind gypy this will provide the fire rating, same as if cables are above a ceiling the board will provide the rating the raw plug will still there if the fire blazes the cable will melt before the plug

 

[MFS Electrical]

Like previously said the plastic plug is within a casing of either concerete or block and maybe even behind gypy this will provide the fire rating, same as if cables are above a ceiling the board will provide the rating the raw plug will still there if the fire blazes the cable will melt before the plug

The sheath and the insulation may melt before the plug but the rawlplug would melt before the copper the BRE report basically says a red rawlplug won’t cope for very long at all and fails so I personally won’t use them any more for holding up cables/wiring systems where there is a risk of premature collapse I agree though that if it is above a fire rated ceiling like solid gyproc then all will be good

 

[Timbo]

The Napit guys at Elex today said premature collapse is under 30 mins, and the plastic wall plugs in the test lasted for 40 mins. So don't panic.

 

[Toneyz]

Anyone found custom designed replacements for plastic SWA cleats without resorting to the bodge of all purpose banding ?

When I visited Elex Coventry I visited the stand as in SparkyChick's post 5 they had an SWA clip like their fire cable clip coming out soon.

 

[MFS Electrical]

The Napit guys at Elex today said premature collapse is under 30 mins, and the plastic wall plugs in the test lasted for 40 mins. So don't panic.

Did he have anything to back that up or was it just some more hot air from a scheme?

 

[Toneyz]

Anyone found custom designed replacements for plastic SWA cleats without resorting to the bodge of all purpose banding ?

When I visited Elex Coventry I visited the stand as in SparkyChick's post 5 they had an SWA clip like their fire cable clip coming out soon.

Regarding pastic plugs...

From the PDF report on the link in #21, page 10:

Similar to the first experiment, all the plastic clips on each lintel failed, resulting in the cable dropping down. A new observation from this experiment was that the supports in the centre of Lintel 2 had dropped out of the lintel. This was not a failure of the support but rather a failure of the plastic plugs used for fixing the supports to the lintel.
​

Page 12:

The findings from the short fixings study show that combustible wall plugs in concrete substrates demonstrate signs of weakening of mechanical strength from 300°C and above and that these fixings can fail at 400°C after up to a one hour exposure in controlled conditions.
​

View attachment 45186

Of course, I'm just picking and choosing bits of the report, it's a bit lengthy but gives a fuller picture.

If the method of fixing via using a rawplug and screw is found to fail why have we been allowed to fix fire alarm cables with P clips screws and rawplugs for years.

 

[MFS Electrical]

The Napit guys at Elex today said premature collapse is under 30 mins, and the plastic wall plugs in the test lasted for 40 mins. So don't panic.

Did he have anything to back that up or was it just some more hot air from a scheme?

When I visited Elex Coventry I visited the stand as in SparkyChick's post 5 they had an SWA clip like their fire cable clip coming out soon.

If the method of fixing via using a rawplug and screw is found to fail why have we been allowed to fix fire alarm cables with P clips screws and rawplugs for years.

probably like everything else there wasn’t enough, if any research done on it.

 

[johnduffell]

The Napit guys at Elex today said premature collapse is under 30 mins, and the plastic wall plugs in the test lasted for 40 mins. So don't panic.

If they had spent that half an hour reading the hants fire report instead of guessing they would realise that they don't have a clue what they're on about.

 

[Wilko]

Did he have anything to back that up or was it just some more hot air from a scheme?
Probably like everything else there wasn’t enough, if any research done on it.

I guess if there's no plastic involved it will "never" fail. But what is "premature" failure? The shortest fire rating is 30 minutes and I'm guessing that may be where he's pulled it from. But that would mean he's tested the metal clip and plastic plug combination and given it a 30 min fire rating .

 

[soms]

I guess if there's no plastic involved it will "never" fail. But what is "premature" failure? The shortest fire rating is 30 minutes and I'm guessing that may be where he's pulled it from. But that would mean he's tested the metal clip and plastic plug combination and given it a 30 min fire rating .

Because this is one of the major changes and could be life-saving, I really would like to know what is and isn't acceptable when seeking to comply with this regulation.
The IET is holding an event about the 18th Edition in London in January, I have e-mailed them with a question which I would like submitted to the panel of experts asking for clarity on how to ensure compliance with this regulation, noting the absence of a single source of guidance and what is consider to be "premature failure" as there is no definition for it included in BS 7671.

It may be optimistic to expect to get an answer, but I will wait and see.

BS 7671: 2018 - 18th Edition of the IET Wiring Regulations - IET Events - https://events.------.org/wiring-regs/index.cfm