The Future of Fuse boards...?

[Dave OCD]

At no time have I advocated a huge cable entry hole, and assumptions are being made constantly. The vast majority of CUs that I replace are spaced off on small battens to facilitate all cables entering through the rear knockout. So in fact there is no hole going into a cavity at all. But when some people are convinced they're right and no one else knows what they're talking about then it's probably a waste of time posting at all.

 

[Dave OCD]

Out of interest. Do those who object to holes in the back of a DB insist upon installation of an interconnected smoke detection system, prior to upgrade of any domestic board?

Surely early detection of all types of fire would be of much greater importance than the short term containment of one unlikely source of fire.

Regardless of the soundless/ strength of the argument I'm afraid some people argue just for the sake of it.

 

[nicebutdim]

At no time have I advocated a huge cable entry hole, and assumptions are being made constantly. The vast majority of CUs that I replace are spaced off on small battens to facilitate all cables entering through the rear knockout. So in fact there is no hole going into a cavity at all. But when some people are convinced they're right and no one else knows what they're talking about then it's probably a waste of time posting at all.

To my mind this is the ideal method of installation, where practicable. Neat and provides for future repair or addition, without major upheaval.

 

[mainline]

But it isn't a fire barrier and is the partition a fire compartment boundary. Do you want a spade.

The issue is about leaving a massive hole into a wooden partition.

If some are happy to leave an installation like that, then good on them.

 

[ipf]

The metal CU should be treated as a form of fire barrier/containment, that being the whole reason for having metal CUs in the first place.

Cutting a hole that size in a wooden partition and leaving it cannot be said to be the work of a decent electrician.

No. The reason was because many of todays highly qualified dipsticks were incapable of installing non metal CU's correctly, causing an increasing danger of domestic CU fires. (in the London area, at least)

 

[nicebutdim]

The issue is about leaving a massive hole into a wooden partition.

If some are happy to leave an installation like that, then good on them.

The video that sparked this debate was set in a studio as a demonstration of how easily a particular DB could be installed. This was not a wooden partition in someone's home.

If one is to assume the intention was such, then one might wish to consider all possible alternatives - like that posted by @Dave OCD

 

[SparkySy]

I space them off the wall if going through the back makes life a lot easier on installation and future additions.

 

[westward10]

The issue is about leaving a massive hole into a wooden partition.

If some are happy to leave an installation like that, then good on them.

If it breeches a fire barrier then it is an issue. Define the parameters of a massive hole.

 

[ipf]

At no time have I advocated a huge cable entry hole, and assumptions are being made constantly. The vast majority of CUs that I replace are spaced off on small battens to facilitate all cables entering through the rear knockout. So in fact there is no hole going into a cavity at all. But when some people are convinced they're right and no one else knows what they're talking about then it's probably a waste of time posting at all.

That is much the preferred way.....and my way, mounted on ply wood with the timber hole filed smooth, smaller than the metal one, negating the need for grommet strip.

 

[mainline]

If it breeches a fire barrier then it is an issue. Define the parameters of a massive hole.

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.

 

[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