I don't have a copy of" BS EN 60670-22 Boxes and enclosures for electrical accessories for household and similar fixed electrical installations. Particular requirements for connecting boxes and enclosures", so do not know if they define what a terminal/termination point is.
Like you, I haven't seen it, and can't find a way of seeing it without paying good money - does anyone have access? It's title is a bit odd, since the first part implies that it relates simply to 'boxes and enclosures' (in which case it would be irrelevant to this discussion), whilst the second part mentions 'connecting', which is very ambiguous. My suspicion remains that it is just a general standard for JBs, of no direct relevance to this discussion, but I may be wrong.
Whatever, I would have thought we could assume that (given it mentions the standard), if the IET felt that some type of joint/terminal defined in BS EN 60670-22 was satisfactory for installation in inaccessible locations, they would have said so in BS7671.
However as I read it Ashley are saying that the encloses meet the standard and they have also carried out additional testing, perhaps exceeding the standard.
That is not in dispute. What we are not sure about is whether or not compliance with BS EN 60670-22 in itself means anything in relation to this discusion. I still rather doubt that it does, but I may be wrong; I certainly have boxes full of (screw terminal) JBs which have "BS EN 60670" written all over them, and they clearly are not suitable for use in inaccessible locations. It is therfore very probable that the 'additional testing' done by Ashley is the only thing which might establish that their product is so much better than screwed terminals as to render it reasonable to use it in inaccessible locations - but I can't see how we can tell whether the IET/BS7671 necessarily agree with their conclusions.
If this forum is anything to go by, it certainly does not look as if many electricians are currently of the view that use of the Ashley/Hager product in an inaccessible location would comply with BS7671. It's almost a daily occurrence that someone on this forum is reminded of the need for JBs to be accessible, and I cannot recall even once having seen it suggested that use of these 'maintainance-free' products would be a possible solution.
Kind Regards, John.