To crimp or not?

[Rockingit]

Finding myself doing a number of terminations at the moment where the cable dia (16-25-35mm) is at the smaller scale for the clamp or screw terminations they're going in to, so they're flattening or splatting more than I'd like. Toying with re-doing them using ferrules but I know there's two schools of thought on this - what are other people doing these days?

NB - not talking about fine stranded/tri-rate etc, just normal stranded singles/tails

 

[Lister1987]

I still do this today. The 35mm bond is rock solid. View attachment 61992View attachment 61993

Never heard or seen that done before. Would love a video demo.

 

[loz2754]

OK - I'm going to ask you to defend that claim......

Yikes!!! I'll go fetch my lawyer...
I guess I'm just basing this on personal experience. And the fact that the metal tube walls are much thinner on the cord end terminals (ferrules) than they are on the tubular crimps.
Could be wrong I guess...
Maybe we should get John Ward to conduct an experiment the results of which can be used as a legal precedent.

 

[Lucien Nunes]

Never heard or seen that done before

I still use it a lot.

Whipping the end of a cable was more popular in the days before bootlace ferrules. Unlike using a ferrule, you can choose the diameter of the whipping wire to make the finished end the ideal size for the terminal. Like using a ferrule, it could theoretically increase contact resistance due to an extra layer of contact surface (cable contacts whipping, whipping contacts terminal) and some writers suggested this made it inherently bad practice. However the binding wire crossing the strands at right-angles creates a grid of point-contacts which is a pretty ideal scenario for both mechanical stability and low resistance.

Places you might still find it are small meter tails in normal meter cable entries, and older MEM EXELs and similar switchgear that have large terminals that do not clamp smaller cables effectively where some similar technique is required to make a satisfactory connection.

 

[pc1966]

I have only ever done the wire-wrap style when soldering a couple of difficult wires together, so impressed to see it used for a cable clamp connection.

Certainly for 1.5mm-4mm conduit wire (7 strands) I frequently use ferrules as it reduces damage to the clamped end, more so for screw terminals on neutral/earth bars, etc.

 

[littlespark]

legal precedent.

President??

Chance would be a fine thing.

 

[Marvo]

....they're flattening or splatting more than I'd like..........

I wouldn't worry about the course strands flattening out in the cage clamp, the more the better as long as the clamp has a secure grip of the wire after all is done.

I didn't realise whip wrapping was still a thing, I haven't dressed a wire like that in 30 years... I assumed it was no longer considered good practice along with soldering.

 

[Rockingit]

Yikes!!! I'll go fetch my lawyer...
I guess I'm just basing this on personal experience. And the fact that the metal tube walls are much thinner on the cord end terminals (ferrules) than they are on the tubular crimps.
Could be wrong I guess...
Maybe we should get John Ward to conduct an experiment the results of which can be used as a legal precedent.

Sorry, poorly worded way of asking for your logic as to why!

I think the problem is less in a clamp, as all the strands can flatten and compress easily, it's in a large screw terminal with a smaller screw where if you lift the connection back out after you've screwed it in you see straight away that only the 'middle' has the imprint of the screw and a good 30% of the strands left and right of it have just been doing their own thing - and a ferrule will prevent that from happening.