The Future of Fuse boards...?

[westward10]

Yes, you're correct if fire got into that partition it would be an issue.

A hole that was cut much bigger than was needed.

No it wouldn't be as there should be cavity barriers. The size of entry shouldn't be relevant as there will always be passage around the cables regardless of size.

 

[nicebutdim]

No it wouldn't be as there should be cavity barriers. The size of entry shouldn't be relevant as there will always be passage around the cables regardless of size.

I could be wrong, and will happily stand corrected, but doesn't BS7671 make reference to holes in a domestic DB solely with regard to finger access in front, bottom or sides and holes larger than 1mm on top, with no reference made about rear?

 

[westward10]

I could be wrong, and will happily stand corrected, but doesn't BS7671 make reference to holes in a domestic DB solely with regard to finger access in front, bottom or sides and holes larger than 1mm on top, with no reference made about rear?

No reference is made regarding the rear.

 

[Dustydazzler]

Perhaps every single fuse board sold should come with a Free tube of this just to make sure any gaps and holes are filled up after Install ?

AC95 Intumescent Fire & Acoustic Adhesive & Sealant 900ml | Toolstation

• +/- 5% flexibility • Fire rated - EN13666-4 • Acoustic rated - BS EN ISO 140/3 • Solvent free • Interior use only

www.toolstation.com

 

[Midwest]

I might be wrong, but when 421.1.201 first came out in the BYB, it was about removing the source of fuel for a fire, and nothing to do with containment of a fire.

Has this recently changed?

 

[mainline]

I might be wrong, but when 421.1.201 first came out in the BYB, it was about removing the source of fuel for a fire, and nothing to do with containment of a fire.

Has this recently changed?

The intent of Regulation 421.1.201 is considered to be, as far as is reasonably practicable, to contain any fire within the enclosure or cabinet and to minimise the escape of flames.


It is important for the installer to seal all openings into the enclosure or cabinet for cables, conduits, trunking or ducting that remain after the installation of cables - see Figure 6. The intent of the sealing is to ensure that, as far as is reasonably practicable, any fire is contained within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or enclosure or into conduits trunking or ducting is minimised, as intended by Regulation 421.1.201.

Good workmanship and proper materials must be used, and account must be taken of the manufacturer’s relevant instructions if any.

 

[brianmoooore]

Metal box, with restricted air inlet, opening into a vertical cavity is a definition of both the CU in the OP, and the wood burner beside me, that my wife has just lit.

 

[westward10]

The intent of Regulation 421.1.201 is considered to be, as far as is reasonably practicable, to contain any fire within the enclosure or cabinet and to minimise the escape of flames.


It is important for the installer to seal all openings into the enclosure or cabinet for cables, conduits, trunking or ducting that remain after the installation of cables - see Figure 6. The intent of the sealing is to ensure that, as far as is reasonably practicable, any fire is contained within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or enclosure or into conduits trunking or ducting is minimised, as intended by Regulation 421.1.201.

Good workmanship and proper materials must be used, and account must be taken of the manufacturer’s relevant instructions if any.

At no point does that Reguation infer to containing a fire.

 

[Mike Johnson]

Just for information not massively known is that Fire Proof Filing Cabinets are not fire proof if not locked, the expanding air in the event of a fire will open the drawers.

 

[mainline]

At no point does that Reguation infer to containing a fire.

https://electrical.------.org/media/1438/consumer-units.pdf

 

[westward10]

If that is an IET link it won't work here. Show where that Regulation infers what you suggest.

 

[mainline]

The IET site say's
The intent of Regulation 421.1.201 is considered to be, as far as is reasonably practicable, to contain any fire within the enclosure or cabinet and to minimise the escape of flames.

Take it up with them, I'm just stating what they say.

 

[Midwest]

The intent of Regulation 421.1.201 is considered to be, as far as is reasonably practicable, to contain any fire within the enclosure or cabinet and to minimise the escape of flames.


It is important for the installer to seal all openings into the enclosure or cabinet for cables, conduits, trunking or ducting that remain after the installation of cables - see Figure 6. The intent of the sealing is to ensure that, as far as is reasonably practicable, any fire is contained within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or enclosure or into conduits trunking or ducting is minimised, as intended by Regulation 421.1.201.

Good workmanship and proper materials must be used, and account must be taken of the manufacturer’s relevant instructions if any.

You've appear to have copied & paste some lines in your reply. If you could citations. Edit IET.

I'm no longer up to date on BS7671, so I'll tilt my hat to you.

If you going to spend time and money 'to seal all openings', what are you going to do with the big flap on the front of a consumer unit, that covers all the inner workings of said CU? Seems little pointless 'sealing' everything, when this is flawed by the CU cover?

 

[nicebutdim]

Metal box, with restricted air inlet, opening into a vertical cavity is a definition of both the CU in the OP, and the wood burner beside me, that my wife has just lit.

DBs aren't intended for lighting fires in.

The same argument could be applied to kitchens fitted with an extractor fan and trickle window vent and the likelihood of fires starting in a kitchen are considerably higher, than one starting in a DB installed in line with regulatory requirements.

 

[mainline]

You've appear to have copied & paste some lines in your reply. If you could citations. Edit IET.

I'm no longer up to date on BS7671, so I'll tilt my hat to you.

If you going to spend time and money 'to seal all openings', what are you going to do with the big flap on the front of a consumer unit, that covers all the inner workings of said CU? Seems little pointless 'sealing' everything, when this is flawed by the CU cover?

The debate is over whether to leave an oversized hole in the rear of a CU that goes into a wooden partition.

 

[nicebutdim]

The debate is over whether to leave an oversized hole in the rear of a CU that goes into a wooden partition.

You stated in post #11 that this involved a partition.

The reality is that it's a studio set and we don't know what they intended it to represent. I'm going with the previous suggestion of it representing a board spaced off a wall with battens, because I like that idea.

 

[brianmoooore]

DBs aren't intended for lighting fires in.

The same argument could be applied to kitchens fitted with an extractor fan and trickle window vent and the likelihood of fires starting in a kitchen are considerably higher, than one starting in a DB installed in line with regulatory requirements.

No one intends to light a fire in a DB, but we all know that they manage to do this themselves, usually when one of the poorly designed connections isn't assembled properly.
Don't think a wall mounted extractor in a kitchen is going to fan a kitchen fire to any significant degree, and there's a minimum distance between a hob and and extractor over it for just that reason.

 

[nicebutdim]

No one intends to light a fire in a DB, but we all know that they manage to do this themselves, usually when one of the poorly designed connections isn't assembled properly.
Don't think a wall mounted extractor in a kitchen is going to fan a kitchen fire to any significant degree, and there's a minimum distance between a hob and and extractor over it for just that reason.

My point was that a cored extractor, combined with trickle vent, provides an ideal means of fanning a fire.

How many fires start in DBs each year and how many start in kitchens?

I also note that no one arguing against rear knockouts has adressed my point about whether or not they insist on homes having interlinked smoke/fire detection as a prerequisite to board changes.

 

[mainline]

You stated in post #11 that this involved a partition.

The reality is that it's a studio set and we don't know what they intended it to represent. I'm going with the previous suggestion of it representing a board spaced off a wall with battens, because I like that idea.

And I'm going with a stud wall partition.

 

[westward10]

Metal consumer units are suggested as they do not readily promote the spread of fire, they will not contain it so in my opinion the IET are misrepresenting the intention of the Regulation. Cable entries do not require fire stopping unless the rear entry breeches a fire compartment and this is possible if the reverse side of the cavity wall is also breeched for example by an accessory cavity back box.

 

[westward10]

My point was that a cored extractor, combined with trickle vent, provides an ideal means of fanning a fire.

How many fires start in DBs each year and how many start in kitchens?

I also note that no one arguing against rear knockouts has adressed my point about whether or not they insist on homes having interlinked smoke/fire detection as a prerequisite to board changes.

It is a good point about extraction fans, how do we fire seal the hole made for them because if they breech a fire compartment you have problems. We fit fire rated down lights but ignore the extractor which has made an even bigger hole in the ceiling if that is where it is fitted.

 

[brianmoooore]

whether or not they insist on homes having interlinked smoke/fire detection as a prerequisite to board changes.

I insist on interlinked mains power smoke alarms, with battery back up, on any domestic property I've done extensive work on, whether the customer asks for or even wants them. If they refuse, then they find another sparky.

 

[brianmoooore]

It is a good point about extraction fans, how do we fire seal the hole made for them because if they breech a fire compartment you have problems. We fit fire rated down lights but ignore the extractor which has made an even bigger hole in the ceiling if that is where it is fitted.

Most ceiling extractors are in shower and bath rooms, which aren't exactly hotspots of domestic fires, but if you do breach a fire compartment with fan ducting, then it should be fitted with an intumescent fire sleeve.

 

[mainline]

Metal consumer units are suggested as they do not readily promote the spread of fire, they will not contain it so in my opinion the IET are misrepresenting the intention of the Regulation. Cable entries do not require fire stopping unless the rear entry breeches a fire compartment and this is possible if the reverse side of the cavity wall is also breeched for example by an accessory cavity back box.

The non-combustible enclosure or cabinet must provide a complete envelope (e.g. base,
cover, door and any components such as hinges, screws and catches) as necessary to
maintain fire containment.

Sealing of wiring entries
It is important for the installer to seal all openings into the enclosure or cabinet for cables,
conduits, trunking or ducting that remain after the installation of cables. See Figure 6.
The intent of the sealing is that, as far as is reasonably practicable, any fire is contained
within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or
enclosure or into conduits trunking or ducting is minimised, as intended by Regulation
421.1.201.
Good workmanship and proper materials must be used, and account must be taken of the
manufacturer’s relevant instructions, if any




Your opinion obviously differs from the IET who are involved in actually writing the regs to which you quote.

 

[Dave OCD]

I insist on interlinked mains power smoke alarms, with battery back up, on any domestic property I've done extensive work on, whether the customer asks for or even wants them. If they refuse, then they find another sparky.

Are you worried your work is going to catch fire Brian ?

 

[westward10]

The non-combustible enclosure or cabinet must provide a complete envelope (e.g. base,
cover, door and any components such as hinges, screws and catches) as necessary to
maintain fire containment.

Sealing of wiring entries
It is important for the installer to seal all openings into the enclosure or cabinet for cables,
conduits, trunking or ducting that remain after the installation of cables. See Figure 6.
The intent of the sealing is that, as far as is reasonably practicable, any fire is contained
within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or
enclosure or into conduits trunking or ducting is minimised, as intended by Regulation
421.1.201.
Good workmanship and proper materials must be used, and account must be taken of the
manufacturer’s relevant instructions, if any




Your opinion obviously differs from the IET who are involved in actually writing the regs to which you quote.

Can you quote where in that Regulation it cites any of this.

 

[mainline]

Can you quote where in that Regulation it cites any of this.

Again, it's the IET

 

[westward10]

Again, it's the IET

No tell me where in that Regulation you are getting that all from.

 

[nicebutdim]

Are you worried your work is going to catch fire Brian ?

I get people's concerns, but this debate is theoretical (having been sparked by images from a studio set). It seems as though everyone involved is seeing something different in their mind's eye.

 

[mainline]

No tell me where in that Regulation you are getting that all from.

From a publication by the IET.

 

[Dave OCD]

I get people's concerns, but this debate is theoretical (having been sparked by images from a studio set). It seems as though everyone involved is seeing something different in their mind's eye.

I'd like to know the true figures for overheating Consumer Units resulting in the spread of fire in a home, there are many warning signs before that stage would be reached, in my view dodgy connections under floorboards or in lofts have resulted in far more fires over the years.

 

[westward10]

From a publication by the IET.

So you can't then because it doesn't.

 

[mainline]

So you can't then because it doesn't.

Are you saying that the IET didnt publish that ??

They clearly say :
The intent of the sealing is that, as far as is reasonably practicable, any fire is contained
within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or
enclosure or into conduits trunking or ducting is minimised, as intended by Regulation
421.1.201.

 

[Dave OCD]

From a publication by the IET.

The question is [as you know] where is all that written within BS7671.

 

[nicebutdim]

Are you saying that the IET didnt publish that ??

They clearly say :
The intent of the sealing is that, as far as is reasonably practicable, any fire is contained
within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or
enclosure or into conduits trunking or ducting is minimised, as intended by Regulation
421.1.201.

They did indeed state this in Special Edition II 2015 and nowhere else since that date - not even subsequent editions of The Wiring Regulations.

One might reasonably ask if this was their intent, why it was never included regulations?

 

[Pretty Mouth]

The problem with the IET is they contradict themselves. See the Q and A's of this article:

Consumer units: a brief overview

There are over twenty million domestic dwellings in the UK and each has an electrical installation, usually with electricity meter and consumer unit arrangement supplying the lighting and power in the dwelling. There are numerous fires in domestic dwellings every year, many due to electrical...

tinyurl.com

Very confusing.

 

[westward10]

Are you saying that the IET didnt publish that ??

They clearly say :
The intent of the sealing is that, as far as is reasonably practicable, any fire is contained
within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or
enclosure or into conduits trunking or ducting is minimised, as intended by Regulation
421.1.201.

At no point did I suggest this so can you show where in that Regulation or anywhere in BS7671 is any of that stated.

 

[mainline]

The question is [as you know] where is all that written within BS7671.

It's obviously their interpretation of the quoted reg by the people who actually wrote it.

At no point did I suggest this so can you show where in that Regulation or anywhere in BS7671 is any of that stated.

I am simply quoting what they said, I suggest you take it up with them instead of trying to give me the 3rd degree

 

[nicebutdim]

It's obviously their interpretation of the quoted reg by the people who actually wrote it.

I am simply quoting what they said, I suggest you take it up with them instead of trying to give me the 3rd degree

You're quoting from an interview with someone who helped write BS7671 and not a consensus among the many people involved.

Since one individual espoused this view in 2015, there have been a number of subsequent editions of wiring regulations in which it could have been included. That it hasn't been included might be an indication of others not being in agreement. No matter, it seems odd that such clarification (if that's what we're taking it to be) has been omitted from successive editions - if indeed the IET's position was ever such.

 

[westward10]

It's obviously their interpretation of the quoted reg by the people who actually wrote it.

I am simply quoting what they said, I suggest you take it up with them instead of trying to give me the 3rd degree

I am a member of the IET and totally disagree with it.

 

[mainline]

It seems this debate has been played over and over on this forum before.

3rd Amendment Metal Consumer Units - best practice advice please > on Free Electrical Advice - Electricians Forums

Find 3rd Amendment Metal Consumer Units - best practice advice please Advice and Help. How-to 3rd Amendment Metal Consumer Units - best practice advice please in the UK Electrical Forum advice boards on Electricians Forums. 3rd Amendment Metal Consumer Units - best practice advice please on...

www.electriciansforums.net

 

[nicebutdim]

It seems this debate has been played over and over on this forum before.

3rd Amendment Metal Consumer Units - best practice advice please > on Free Electrical Advice - Electricians Forums

Find 3rd Amendment Metal Consumer Units - best practice advice please Advice and Help. How-to 3rd Amendment Metal Consumer Units - best practice advice please in the UK Electrical Forum advice boards on Electricians Forums. 3rd Amendment Metal Consumer Units - best practice advice please on...

www.electriciansforums.net

Yet none of it seems to have influenced the consensus view among authors of The Wiring Regulations.

The thread you have linked was started by someone asking advice on how to drill holes in metal enclosures.

 

[mainline]

I am a member of the IET and totally disagree with it.

Totally disagree with the fact of there being an IET ?

 

[littlespark]

Anyone else think we’re going round in circles?

“You spin me right round, baby right round”

 

[Mike Johnson]

The problem is that the IET are a self appointed organisation that have published a paper called it the "IET Regulations" and it is not a statutory instrument and therefore not regulatory, a BS is advisory only.

 

[nicebutdim]

The problem is that the IET are a self appointed organisation that have published a paper called it the "IET Regulations" and it is not a statutory instrument and therefore not regulatory, a BS is advisory only.

Perhaps the wiring regulations are not statutory, but they most certainly are regulatory

 

[Mike Johnson]

Only if you are a member and subscribe to the IET as your regulatory body.

 

[Midwest]

The debate is over whether to leave an oversized hole in the rear of a CU that goes into a wooden partition.

Really, I thought it was about 'as far as is reasonably practicable, to contain any fire within the enclosure or cabinet and to minimise the escape of flames' which, if you accept that argument, means you need to do something the moveable flap on the front of a CU.

As most manufacturers seem to leave this 'unlocked' and un-sealed, it does really seem to make that argument flawed, does it not?

I recall linking that video of Elex @ Harrogate 2015, but seems IET insist on you being a member to view it now, scallywags.

However, this ESF piece, calls itself 'Consumer Unit Myths'. I'm not sure of its date;

Consumer Unit Mythbuster | Electrical Safety First

Consumer Unit Mythbuster From 1st January, consumer units and similar switchgear assemblies installed in domestic premises must either have their enclosure cons

www.electricalsafetyfirst.org.uk

It suggests the use of special glands etc, is a myth, which is demonstrated with the Hager hot wire test.

 

[mainline]

Really, I thought it was about 'as far as is reasonably practicable, to contain any fire within the enclosure or cabinet and to minimise the escape of flames' which, if you accept that argument, means you need to do something the moveable flap on the front of a CU.

As most manufacturers seem to leave this 'unlocked' and un-sealed, it does really seem to make that argument flawed, does it not?

Most new consumer unit have the door needed to be held up and there is a big difference between flames coming out of the front being dampened by the metal door than them going up between a wooden partition, especially if the consumer unit is a double stack one and the fire is on the lower bus bar.

I recall linking that video of Elex @ Harrogate 2015, but seems IET insist on you being a member to view it now, scallywags.

However, this ESF piece, calls itself 'Consumer Unit Myths'. I'm not sure of its date;

Consumer Unit Mythbuster | Electrical Safety First

Consumer Unit Mythbuster From 1st January, consumer units and similar switchgear assemblies installed in domestic premises must either have their enclosure cons

www.electricalsafetyfirst.org.uk

It suggests the use of special glands etc, is a myth, which is demonstrated with the Hager hot wire test.

Nobody said you had to use special glands, but it does say :

Is it necessary to use cable glands made from metal or intumescent sealing material for cable entries?

Good working practices such as minimising the size of a cable entry.

In any case, the requirements of regulation group 416.2 for barriers or enclosures must be met and manufacturers’ instructions, if any, should be taken into consideration.

I would also take into consideration sec 527.

The logic behind this is that such items should be of equivalent non-combustible construction in order for the intended requirement to be effective in terms of minimising the spread of fire originating from such equipment.

 

[Midwest]

Most new consumer unit have the door needed to be held up and there is a big difference between flames coming out of the front being dampened by the metal door than them going up between a wooden partition, especially if the consumer unit is a double stack one and the fire is on the lower bus bar.


Nobody said you had to use special glands, but it does say :

Is it necessary to use cable glands made from metal or intumescent sealing material for cable entries?

Good working practices such as minimising the size of a cable entry.

In any case, the requirements of regulation group 416.2 for barriers or enclosures must be met and manufacturers’ instructions, if any, should be taken into consideration.

I would also take into consideration sec 527.

The logic behind this is that such items should be of equivalent non-combustible construction in order for the intended requirement to be effective in terms of minimising the spread of fire originating from such equipment.

The video shows a Hager cu, without any flames coming out the plastic glands, plastic trunking entries and for that matter the flappy cu door.

But nor does it show them coming out of the plastic cu, it just melts and drops burning debris everywhere.

I don’t get your first point in your second bit?

Do you not accept, that intumescent glands, barriers etc etc, are not required?