Do you have a link to the data sheet for the device or a picture of the terminals ?
 7.6mm2 is a very odd cable size, is it intended for the American market perhaps ? Generally ferrules (or crimp pins)are a recognized way to fit cable to the 'wrong' terminal, as is doubling back a wire that is too thin. However, which is the 'right' method rather depends on the design of the terminals, and also which set of regs apply - is this a UK installation ?

Mike.

It is an EU (NL) market - the leaflet is at the following link: https://www.elektramat.nl/amfile/file/download/file/4911/product/1261088/ . So, the solution seems good then, right?

Regards

Ah and all is revealed.

you mean hole diameters when you talk about the 7.6mm and the output is 5.6mm- thats' the circle and line symbol.

so the large holes take 10- to 25 square mm, and the small holes take 1.5sqmm to 10sqmm


So in your shoes, looking at the picture, I'd either just use the small holes for everything, or if I had to then double over the end of the 6mm into the larger hole, so that the screw has something to bite down onto. The risk to avoid is that the wire goes beside, and not under, the screw, and is damaged by the threads but not well gripped.
What I  mean by 'double back'

Personally, for those terminals I'd only ferrule for stranded (hairy) wires. However to an extent it is a personal house style thing, and I'd give it about 10 mins before someone else says the opposite.

note that in the UK 6mm2 would normally be 7 strands, not solid core. I'd still fold if the  hole was too big,  so the terminal was better filled.
Mike

You should not put a ferrule on a solid wire.

Matvey Teplov said:

I can use aluminum pressed ferrule

Hopefully NOT aluminium on copper wires and brass terminals - we had awful problem with aluminium conductors in the 1960s and 1970s - I wouldn't advise going down that road. Tin or nickel plated brass or copper maybe.

  I need to fit a 3-phase distribution block

Just out of curiosity, what's the application? It' not a common problem - normally smaller cables are fed from overcurrent protective devices (MCBs or fuses) rather than from a multiway terminal block (except for N of course, but the DB N bar usually serves that purpose).

   - Andy.

mapj1 said:

note that in the UK 6mm2 would normally be 7 strands, not solid core. I'd still fold if the  hole was too big, 

German ferrules (DIN 46228-1 and DIN 46228-4) at least, are intended for use with Class 2 (7 strand + rigid), Class 5 (flexible) and Class 6 (extra flexible) stranding ... but NOT Class 1 (solid) conductors.

However, I'd be careful with csa > 6 sq mm Class 2 stranded conductors, to not flex the cable too much after crimping the ferrule, until the terminal is tightened. Whilst some screwless terminals are suitable for use with ferrules, I would not use ferrules and screwless terminals for class 2 stranded conductors with csa > 6 sq mm.

If you took a Class 2 conductor, and "doubled it back" in a twin ferrule for the suitable CSA, would that be OK I wonder?

looking at the actual terminals he has, which have more in common with a UK MET than a UK junction box of any kind let alone screwless terminals I'm not convinced that it needs a ferrule at all, it just needs to be in one of the smaller holes, or folded.  Had it been some sort of cage-clamp, maybe  a ferrule would be needed, Solid core 6mm will  be quite willful however and probably wont go easily into a ferule anyway,

We commonly stuff extra strands along side into crimp bodies to ensure a good fill for the crimper when the chosen wire is too thin for the crimp terminals on things like the mil spect 38999 connectors - but it is always fine stranded in that case.

Mike

mapj1 said:

Solid core 6mm

I thought OP said it was 'rigid' - i.e. Class 2 or Class 1 ?

• s - solid, Class 1 only,
• r - rigid, Class 1 or Class 2,
• f - flexible, usually Class 5 but may be Class 6

It would be unusual to find Solid 6 sq mm wiring in domestic ... but I agree not necessarily 4 sq mm could be either Class 1 or Class 2 dependent on cable type ?

given the confusion of diameter and area in mm2, and a few other odd choices of words, I'm not too sure if the OPs use  of the phrase "IMHO, I can use aluminum pressed ferrule to increase the solid wire size" should be taken as what we would normally mean either - I think we should allow the possibility for things "lost in translation".

But I'm not that sure of current Netherlands practice either - maybe their 6mm is solid cored. And I missed the 'aluminium' on the first pass, or I'd have said that unless the wire is aluminium, tinned copper would be better, if we need it at all,  mixed metals things usually end badly.

M

Chris Pearson said:

You should not put a ferrule on a solid wire.

Well, not one to DIN 46228, NF C 063-023 or UL486-F because they are for Class 2, 5 and 6 conductors only (but Class 2 is rigid, as discussed in my earlier post) ... but that would rule out Aluminium because the standards are for brass tube ferrules. Having said that, Aluminium not a good idea on a copper cable anyway ...