CU change pricing?

[riveralt]

I don't think I've read a more ridiculous or pointless thread in many a year

What a load of drivel and pontificating about this hijacked post.
For those who are required to fit new Consumer Units - they will fit what's available and 'meets the new standard' - if Wylex say its okay then so be it - I don't have the time or inclination to worry what the definition of combustible is or is not and whether customers will prefer plastic consumer units, metal or even ceramic ones.
Most working sparks won't give a toss about the above arguments particularly as everyone knows that the new 'solution' does not solve the undermining cause of the
problem that of substandard cable connections - it simply seeks to contains it.

 

[RF Lighting]

A world where all that matters is proving he's never wrong.

We all know the reg was introduced to stop this sort of thing happening:

We know metal will for sure. Plastic might or might not, so metal it is.

Simple.

 

[JohnW2]

We all know the reg was introduced to stop this sort of thing happening: We know metal will for sure. Plastic might or might not, so metal it is. Simple.

Yes, that's simple, but even the reg implies that some materials other than ferrous metal would be acceptable, but without telling us which.

.. but, in any event, do we actually know that fires originating in CUs are any more common than those originating in wiring or accessories? (I think we probably already know that fires originating in electrical appliances are far more common than any of these things) If not, then why restrict this change to CUs etc.? - why not require all wiring to be within 'fire-resistant' (hopefully not 'non-combustible'!!) conduit or similar, and all accessories (and their backboxes) to also be 'fire-resistant'?

I have no significant data, so I can but speculate, but I cannot help feeling that what we are seeing may be at best a 'knee-jerk' and at worse the result of those with 'an agenda' and/or vested interests ... and it certainly won't surprise me if one result will be an increase in (some fatal) electric shocks, particularly (but not exclusively) amongst non-electricians.

Kind Regards, John

 

[ban-all-sheds]

Aren't these spec writers the same people who call 'Low Voltage' something which can easily kill you?

So can a low bridge.

BAS is in sympathy with this as I understand it. (Images of signs saying: 'Danger - Low Voltage!".)

That is a term which is DEFINED, and that concept is so crucial to all of this that I hope you can understand it, because if not your presence here is pointless.

But to define a term 'non-combustible' to mean 'however ferrous metal behaves' is suddenly not allowable according to BAS.

That's the whole point. They have not defined "non-combustible". And as they haven't, it means what it says. Non-combustible.

Either a spec may define its terms or it may not.

It may. It probably should. This one does not.

It says "non-combustible". Later it has a note which says, paraphrasing "oh, and FYI, as far as we are concerned something which is combustible is non-combustible".

It really is not on.

Nevertheless: Clearly there is a problem with the wording. I would assume that behind the scenes, the people who need to demonstrate compliance have been having contact with the spec writers and agreeing what was meant. There is no other possibility with so much money on the line. But these people have no remit to help out interested observers, so we may have to wait a long time for a clarification.

Until it is "clarified", which will mean re-writing with references to actual standards against which people can evaluate their products, and which will mean qualifying "non-combustible" so that there do become substances known to man which can be thus described, the regulation is meaningless, and impossible to comply with.

Let me put this plainly - nobody can "deem" something which burns to be "non-combustible" - that is a physical impossibility, so anybody who actually believes that 421.1.201 is a regulation which can be complied with will not be complying with it if they install a metal CU.

 

[ban-all-sheds]

If you truly believe that them deeming pitch covered papier mâché to be non-combustible would make it so then there is no point discussing this with you any firther.

I am NOT saying that their deeming pitch covered papier mâché would make it so - but I am saying that if they wrote that in the context of the regulation we are talking about it, I would have no problem in regarding that as saying (no matter how daft it may be) that they would regard pitch covered papier mâché as being compliant with their regulation.

Then you are saying that you would have no problem with them saying that their requirement can be met by something which does not meet their requirement.

There is no point discussing this with you any further.

 

[EFLImpudence]

We know metal will for sure. Plastic might or might not, so metal it is.

Simple.

Then wtf didn't they say so?



For years I have said "Never assume those in charge know what they are doing" - why do they keep proving it?

 

[JohnW2]

There is no point discussing this with you any further.

That is clearly the case. However, if you really think that any credible electricians are going go follow your 'advice' and totally ignore the new reg come January 1st, on the grounds that the wording is 'invalid', then you must have far less intelligence than I have always thought to be the case.

Kind Regards, John

 

[ban-all-sheds]

A world where all that matters is proving he's never wrong.

I don't need to prove it to anybody, certainly not in this case, as I know I am right.

Obviously I hope that other people will become right as well, but it is beginning to look as if most people here don't want to be.

We all know the reg was introduced to stop this sort of thing happening:

They may have thought that, but it probably won't.

BTW - that plastic CU didn't burn very well, did it.

We know metal will for sure.

It might.

But that's not what they have required it to do.

Plastic might or might not

It might, if properly formulated.

so metal it is.

Metal does not comply with the stated requirement in 421.1.201.

Simple.

Many people are, it seems.

 

[JohnW2]

We know metal will for sure. Plastic might or might not, so metal it is. Simple.

Then wtf didn't they say so?

If RF was talking about plastics in general, I'm sure it's true that some might, and some might not, comply withg the regulation. However, in writing that that ferrous metal is an example of a material that would comply with their regulation, were they not implying that some other materials (I'm sure titanium would qualify, if ferrous metal does ), quite probably including some plastics, would also comply?

Kind Regards, John

 

[Adam_151]

We all know the reg was introduced to stop this sort of thing happening:

While I've never been much of a fan of plastic boards... most of them bend and flex about far too much for my liking. I cant help think that this issue has been brought about by several different issues, and I'm not sure that the solution can be seen as much more than a sticking plaster and is poorly thought out and has been used as an marketing tactic by manufacturers (I do wonder how much input they had at BS7671 committee meetings...)

Anyway, issues resulting in boards looking like the picture above:

1) manufacturers using plastics which barely scrape through the fire resistance criteria
2) Cage terminals which are less than ideal on the 25mm² 7 strand tails we favor in this country, and that you can miss a busbar 'stab' with
3) Installers who do not tighten said cage terminals properly
4) Meter fixers who move tails about without checking for tightness afterwards.

Perhaps if main switch terminals were re-designed with a brass tunnel with two brass grub screws that might be a better solution. After-all... burnt out henly blocks are almost a non existant issue, where as consumer unit main switches....

 

[EFLImpudence]

...and why did they include "e.g. steel"? For us thickies?

 

[ban-all-sheds]

Perhaps if main switch terminals were re-designed with a brass tunnel with two brass grub screws that might be a better solution. After-all... burnt out henly blocks are almost a non existant issue, where as consumer unit main switches....

Indeed.

But that would cost real money to fix, whereas a lot of CU manufacturers already made metal ones. The regulation is not even a knee-jerk reaction, it's not even a sticking plaster. It is a cynical abandonment of the real responsibilities which a standards body has, it has been done so incompetently that it beggars belief, and everybody is just going to let them get away with it.

 

[RF Lighting]

Quick experiment to see which CU materials are flammable using three wylex consumer units. One metal, one wooden and one plastic.

This is three minutes later when I had to abandon the experiment.

Which would you rather have in your house?

 

[JohnW2]

Quick experiment to see which CU materials are flammable using three wylex consumer units. One metal, one wooden and one plastic. .... Which would you rather have in your house?

Thanks - that's obviously 'as expected'. However, I don't think that many, if any, people believe that (m)any currently-available plastic CUs are particularly fire-resistant - the question being discussed relates to to what non-metallic materials manufacturers could be using to produce Amd3-compliant CUs (whatever that means). AAUI, fire-critical things like Formula I cars and aircraft currently make extensive use of non-metallic materials.

More generally, I also still wonder how common it is for fires to originate in CUs (due to electrical faults, not blowlamps), but that's an entirely different matter.

Kind Regards, John

 

[endecotp]

I hesitate to comment on this "emotional" thread, but I wanted to point out the existence of a definition of "non-combustible" in BS-476 part 4. Perhaps the new regs refer indirectly to this? Perhaps they intended to do so but forgot? I don't know (or care much), but thought you might be interested in the BS-476 definition. It requires that a 40x40x50mm lump of the material be placed in a furnace at 750C. It is deemed non-combustible if it does not flame or reach a temperature more than 50C above the furnace temperature.

My understanding is that no plastics can meet this requirement. Metals, plasterboard, stone etc. are the only things that will.