outlines new requirements from Jan 2016 for either using CUs made on non combustible material or enclosing in a "non flammable" enclosure.
Have the NICEIC (or anyone else) offered guidelines on what a non flammable enclosure means?
eg would use of Euroclass B/C fire resistant plywood meet the regulation?
As an aside, here's an extract from the justification for the new requirement: "The cause of the fires investigated was almost invariably found to be resistance heating as a result of poor electrical connections due to poor workmanship or lack of maintenance."
Seems to me it will take a lot of effort to put in place regs to ensure that *all* parts of any electrical installation are proof against incompetent installers.
I often wonder while they are busy trying to stop every conceivable possibility of fire in one place, where 20 other places are waiting to bite us in the bottom so to speak. Brian
I thought the reg. actually requires "non-combustible" material for the CU or enclosure.
Wiring Matters had:
"There is no published definition for the term 'non combustible' that aligns with the intent of Regulation 421.1.201. However, as stated in Note 1 to the regulation, ferrous metal, such as steel, is deemed to be an example of a non-combustible material. Steel will no doubt be the material usually employed in the manufacture of the enclosure or cabinet. Nevertheless, it will be open to manufacturers to offer enclosures or cabinets made from other types of material that they claim to be non combustible within the intent of Regulation 421.1.201. In this case, however, the manufacturer would have to provide suitable evidence to support the claim of non combustibility, and it is not presently clear what criteria would be used to judge the non combustibility of a material other than non-ferrous metal."
No government department would get away with legislatuni which is so vague and which AFAICS is backed up by no cost-benefit analysis. But in privatised regulations the IET gets away with it.
It's not just that - many modern CU components are utter crap compared to the old stuff. If you go over to the IET forums, many people want to see proper twin screw brass terminals back (like main earthing blocks) - with screws you can actually do up (not posidrive).
There is talk of dissimilar metals (creep), cage terminals that cannot clamp particularly well[1] onto large conductors, and other generally s**te construction.
[1] Hager use cage terminals - I have not had a problem with these. But some cage terminals are not foolproof and mean you can easily get the busbar prong the wrong side of the clamp.So to my mind, the IET have done a knee jerk and solved the wrong problem - the damn things should not be getting hot, let along catching fire in the first place.
In days of yore, CUs were made of bakelite (or steel) which is non-flammable. I was surprised when all this modern crap came out made of thermo-plastics. Someone else has mentioned twin screw terminals which is exactly right. Back then, fires in CUs were virtually unknown.
Stuff like cooker control units had double screws too. Never came loose.
These Wago connectors are s**te too. They will cause trouble too.
Pozidriv with the correct screwdriver allows a screw to be tightened correctly far more easily than a slot type. But not without the correct screwdriver.
Then they should be using torx screws as they are far more positive than pozidrive.
Don't do much in the way of DIY, dennis?
Much easier to locate a PZ in the head than a Torx.
Trouble with Pozi is of course, if the head ges damaged it just gets worse. I would rather have slotted in a CU - they are down a tube anyway so locating the screwdriver is easy enough.
Another question it raises is the lack of mention of how "insulated" CUs will be constructed for use with high Ze installations (e.g. most TT installs)
+1 - you can get massive torque on a well fitted posi screw - but not if using a philips driver.
Yup. PZ is probably the most common head by far in the UK, but you'll find lots of Phillips screwdrivers on sale in the sheds. But try buying true Phillips screws. ;-)
which might be why I saw pozidrivers with integral torque adjustment at the Tool Fair last year
Phenolic resin?
Odd I'm just a simple DIYer, but manage to tighten terminal screws so they neither break or come loose.
Torque screwdrivers presumably aimed at Adam's apprentices?
Your incompenence astounds me continuously. Torx gives much better control wwhen clamping wires.
And even if you put the RCCB in a separate enclosure, technically this rule applies to that as well!
Just buy plasterboard screws, they are phillips and designed to cam out.
Torque screwdrivers are "pushed" for by the industry.
And I am sure one day you will have to fill in the torque settings on an installation certificate.
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