I would tend to agree. 

It would be great if the manufacturers came up with reasonably priced intumescent sealant solutions that still enabled reasonably easy installation of extra circuits.

Personally I use fuse box CUs and they have plastic inserts that reduce the size of the rear holes. I think they have passed the glow wire test, not sure if this is good enough.

Occasionally I use intumescent spray foam, but very reluctantly as it's going to make any additions challenging for the next guy. Especially reluctant with cables running inside walls as gaining access to make a hole for a new cable without putting a hole in the wall is going to be difficult.

There is the option of cutting 20 or 25mm holes in the back lower down and using intumescent glands. But only good for rewires as in most cases existing installs don't have enough slack cable to enable this solution.

I would think an intumescent gasket stuck to the back of the board would expand enough to block standard cable holes. And if supplied as standard with CUs would not cost that much.

I can see the possible issue, but I can also see that the slot knockout is a very sensible solution to cable wrangling. Ideally the CU would be sunk into a masonry wall but stud walls are here to stay, and they will provide a lovely duct for cables, smoke, hot gas and so on. Given the odd mix of cables in the typical installation it would be hard to make a one size fits all hole, that is not 'too large' under some conditions.
I think that things that expands in a fire are the way forward. Perhaps intumescent pillows or similar could be either in the CU or posted into the slack space of the hole, as a removable filler. There are also cable wraps that are made of the same stuff.

Mike.

It is a pleasure to see tidy workmanship, although perhaps the radii of the bends in the circuit neutrals are a little tight.

The route of the smoke in that incident must have been a bit tortuous - between the studding, across the floor/ceiling void, and up some more studding.

If there is a noggin above the CU, that should keep any smoke confined, but then you would need to coordinate the chippies and the sparks. 

Sometimes things are a little more obvious!

Cables leave the CU neatly enough - it fails at the next one...

"Using a suitable tool, create a small  hole in the plasterboard and thread the cables though, some making good may be required"

beyond ready mixed filler but nothing a few cans of spray foam would not fix in the ceiling, though its messy stuff to get out of places it should not be, so some board would be better.

Oh and the breakers are not labelled, and CU cover is missing leaving live parts exposed to tall people.

I agree, it's a 'could do better'

Mike.

Is it time the regulations change and state that LSZH (Low Smoke Zero Halogen)cable be used in ALL domestic dwelling installs/retospective installs/repairs and alterations?

Remember LSF (Low Smoke Fume) is not the same as LSZH

BS 7671 is a minimum standard for electrical installtions, a floor not a ceiling. The designer of the installtion, and all installtions temporary and permanent have to be designed,  the designer can and should make additional provisions based on their engineering judgement. I design electrical installtions and I always specify LSZH cables because I know that oridnary PVC cables generate toxic vapours and gases includuding hydrochloric acid when heated. 

XLPE cables also don't char in the same, with the consequetial breakdown of cable insulation,  way as PVC cables so you have to ask why we need AFDDs on circuits supplying sockets in some builings and recomended in all buildings? I would be interested in your views?

JP

John Peckham said:

so you have to ask why we need AFDDs on circuits supplying sockets in some builings and recomended in all buildings? I would be interested in your views?

Not sure where you are hoping this might go JP, but you asked for views, so here goes;

I am someone who has an abiding interest in fire safety. It is part of what I have done almost every day of my working life for 30 years. I have studied fire events that were deemed to have been caused by an ignition source in the fixed electrical installation, right across the board from the Rosepark Care Home to a fire that gutted our own parliament building (Stormont) in 1995. 
Whilst I would not dismiss the merits of AFDDs out of hand, they would be right at the bottom of my list of suggested control measures. If one had to pare things from a limited budget, they would be first to go.

So I am, at best, a sceptic. I can see no significant body of evidence that would lead me to be persuaded otherwise. Interestingly, with respect to the requirements of AFDDs in BS7671, I have witnessed how easy it is to persuade fire risk assessors and other fire safety professionals who have no electrical background to jump on a compliance bandwagon without really understanding the technical nuances. 

I suppose views on the subject will inevitably be wildly different. Even the electrical standards emanating from a specific source cannot agree. Compare this from the 2024 amendment to IS10101-2020 to the requirements of 7671. Small wonder it leaves many scratching their heads!

edit to pare pair! Thank you MapJ1!

Would it be a good idea for an organisation like electrical safety first to do some research and testing in this area. With the objective of finding a solution that's reasonably easy to.install, makes future upgrades reasonably practical, looks OK and has a reasonable price.

Or maybe it's another organisation that has access to a suitable test environment.

After reading many comments from other installers of AFDD'S and the problems they have had over the last couple of years there is no way in this world that I would bother quoting for a job that required them. 

Gary