I think I am, yes. Most likely because I think it is stupid so sub-consciously I am probably interpreting it to suit what I want.
I wouldn't call an attached garage an outbuilding though, although I suppose it could be. I've only really half read some of the guidance on the subject, I can see how anything that is physically attached to the dwelling could be included, but as I have said before where does it end? If the main CU is in the house and there is a sub CU in the garage does this sub CU need to be non-combustible? Does it depend on what size the sub is? If so, does this mean that all circuits over a certain size should have all non-combustible accessories? Could you then bend this rule if the main CU was in the garage to make it OK to fit a combustible one, could you fit a non-combustible switch fuse to feed your combustible CU?
The problem is that there isn't an inherent problem with consumer units so I can't really apply any logic to this ruling.
That's pretty much where my argument comes from, if I ignore amendment 3 all I need to do is be able to stand up in court if something happened and prove my competence.
Unlikely scenario for a dwelling.
OK, I think I need to make one thing clear at this point.
I hate the idea of metal CU’s being foisted upon us by LFB, due to incompetent installers dragging the industry and its reputation into the gutter.
I agree with you that it is stupid, there are several issues with this pathetic idea.
However, we are stuck with it until a metal CU on a TT kills someone, which almost every one of the “industry figures” I have spoken to believe will happen.
Then and only then may something be looked at.
The other hope is that manufacturers can come up with an alternative material that meets the definition of non-combustible as in building regulations descriptions of non-combustible.
They this would need to be proven by independent testing and certified by the equipment manufacturer.
I think the definitions of which bits of a building are which are already defined in the guidance, and dictionaries, remember the understanding of the common man, and the man on the Clapham omnibus requirements of law.
The requirement extends to ALL CU’s and similar switchgear, so if it’s “under” EN 61439 then it’s “under” 421.1.201.
Unless it’s DNO kit, at this point in time.
There is a good chance that this will change as changes to BS7671 normally trigger changes to ESQCR.
Which in turn triggers changes to the DNO technical manuals, plus the Construction Products Directive is now fully fledged.
This is one of the reasons for the demise of BS6004.
Anyway, yes, a sub-cu anywhere in the main dwelling, or attached outbuilding, or closely located detached outbuilding where there is the chance of spread of fire would need to be of non-combustible material. (Or, in a non-combustible enclosure).
Unfortunately it does not matter on the size or current rating of the sub main to the CU.
It doesn’t mean that any circuits require non-combustible accessories, unless those circuits originate from or terminate in an “accessory to EN 61439”, which would be a CU, or a piece of switchgear, not an accessory.
You have to fit a non-combustible CU in an attached garage, or one closely located to the main dwelling.
Your switch fuse would come under EN 61439 so it would need to be non-combustible.
I’ve gone through this with a fine toothed comb looking for a loophole for various reasons. This in itself is a long story as to why.
I rarely, if ever do domestic CU changes or installs in the same way that most of you do here.
Then there is the issue that there is not a valid product standard for a metal CU meeting the requirements of BS7671 Amd 3!
The only domestic work I really do these days is pseudo medical.
The market around here has been raped and is right at the bottom of the pile in terms of getting people to pay a reasonable rate, so I don’t bother.
I have a big issue in that I have a potential requirement for an IPx5 rated CU for use within the main dwelling, there is only one in the market at the moment, and I’m not sure if it complies until I get some more data from the OEM, yes it is metal, but, it’s not steel, and may contain a metallic element that could pose a fire risk, and this is specifically mentioned in the requirement for non-combustibility in the building regulations.
The issue is the poor quality of installation has set fire to the bodies of the CU’s which in themselves are a ready source of fuel which then causes the fire to spread, and liberates high volumes of acrid smoke.
By switching to metal (steel) the fire load is removed, thus, the body of the CU cannot fuel the fire.
It’s a huge pain, and it is going to cause debate for a long time yet.
I don’t like it, but we’ve simply got to get used to it.
Now as far as the second post goes, yes, you can prove your competence but, you can’t prove removal of the flammable material if you carry on fitting plastic CU’s.
So, you’d still be in the firing line, and as you had gone against BS7671, you would have to prove that your design offered the same level of safety, which it can’t because you have the flammable material present.
So if it went wrong, you’d end up in the dock possibly with no insurance to back you.
I’ve been told you can’t insure against defending criminal charges, but I don’t know if that is true or not.
You could well be looking at manslaughter, and that is serious stuff!
You could only hope that your PII would cover you for the design decisions you made in selecting a flammable CU, when BS7671 says that they must not be fitted, and, the whole of the “industry” agrees with BS7671.
