[ I'm not sure that your bit in parenthesis is all that relevant since, although the manufacturers differ, the use of the name "Wagobox" presumably implies a close collaboration between Wago and the box manufacturers.]
It is relevant, as it's a scenario where Manufacturer A declares his product when used with ones from Manufacturer B to be compliant with a BS. It's not as if A is buying in parts from B and reselling them, or vice versa - the end user can buy the parts separately, at different times and from different sellers, possibly neither set of parts from either of the makers.
We have no idea how close the collaboration is between Wago and Connexbox, or Wago and Spelsberg (who make another box which takes Wago connectors), nor how close it needs to be. (Note - above I was confusing the Wagobox XL/XLA and the Abox sold by Wago - the former
is made by Connexbox).
How close does the collaboration need to be between Wago (or Ideal) and anybody with a 3D printer? Or anybody selling boxes with a DIN rail and instructions on how to install Wago connectors and their rail mount holders?
This is what I mean about
flexibility in assembling a complete MF "accessory".
We do not yet know whether BS 5733 includes any requirements in relation to the enclosure, other than (according to mfarrow) that it should include cable restraint. To do as you suggest would at least require knowledge that the "enclosure of one's choice" was compliant with any requirements in BS 5733 as regards the enclosure.
It would. Maybe a compression gland provides adequate restraint. Maybe a standard cable clip fixed to a pad in the box using a self-tapping screw would do. Maybe compliance with a BS EN 60670 standard for enclosures makes compliance with BS 5733 for the enclosure itself superfluous.
Remember this is what Wago say:
You need to bear in mind that BS 5733 isn’t a product standard. BS 5733 is more like a generic set of rules for products that aren’t covered by their own standard. The standard for Junction boxes is BS EN 60670 and the Wagobox with Wago 773 and 222 connectors is fully compliant with this standard up to and including the performance standard BS EN 60670-22.
That would mean that there are no rules for junction boxes in BS 5733 because they are covered by their own standard.
We do not yet know details of how what BS 7533 brings about the degree of down-rating and imposition of a maximum aggregate current for Wagos in a Wagobox. Are these generic requirements for any 'MF' connectors or are they perhaps Wago-specific? If you wanted to use connectors other than Wagos, you would need to know the answer, and what (if different) would be the corresponding requirements in relation to whatever connectors you had chosen.
This is an educated guess: the de-rating is based on conductor size, so using Ideal connectors with 2.5mm² conductors and derating them to 20A would be compliant.
Not a sound enough basis to go to market. But sound enough to claim reasonable skill and care, and best of knowledge and belief etc? Quite possibly.
Do we know that Ideal connectors, or other 'alternatives to Wago connectors' conform with the requirements of BS 5733 for MF connections? To do as your suggest would obviously require that they did.
I don't think we even know if any connector on its own can comply, or whether it has to be in an enclosure.
The 'enclosure of your choice' would presumably not bear an MF symbol, and it appears that BS 5733 probably does not require it. However, if you wanted to be BS7671-compliant, there would have to be such a symbol. Are you suggesting that one should do as EFLI suggests and 'add that marking' oneself? (BS 7671 appears to be silent as to who may do the marking).
If it's silent then adding it oneself cannot be invalid, prima facie.
Similar discussions here, and not the only place I've seen a suggestion of undue influence from Hager.
https://www.electriciansforums.co.uk/threads/maintence-free-jbs-mfjbs.113647/
It's academic really - this does not look like a low-cost product.
