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

 

[SparkySy]

Could you use the old technique of twisting a strand around the cable to keep the cores bunched and increase the size?
I have in the past used finger lugs or reducing lugs and ferrules for that size of cable but it depends, what size terminal are you trying to get them into are we talking way larger like 50-70mm?

 

[westward10]

Could you use the old technique of twisting a strand around the cable to keep the cores bunched and increase the size?
I have in the past used finger lugs or reducing lugs and ferrules for that size of cable but it depends, what size terminal are you trying to get them into are we talking way larger like 50-70mm?

I still do this today. The 35mm bond is rock solid.

 

[pc1966]

Ferrules are a start, though they are thin and more about keeping the strands together to face up to the clamping force. I prefer to use tri-rated for those sizes if at all possible to make wrangling them easier, so ferrules are a must in my case.

 

[SparkySy]

@westward10 beautiful example there! I still do this myself occasionally especially if I have nothing else to prep the end with.

 

[Pete999]

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

Are you using the right crimps and crimpers for the particular cable you are trying to crimp the lugs on?

 

[westward10]

Once wrapped as can be seen at the bond the strands never move.

 

[Strima]

Maybe use pin crimps and then cut the pin off?

 

[SparkySy]

Now that is a cunning plan @Strima , blackadder cunning!!

 

[Rockingit]

Could you use the old technique of twisting a strand around the cable to keep the cores bunched and increase the size?
I have in the past used finger lugs or reducing lugs and ferrules for that size of cable but it depends, what size terminal are you trying to get them into are we talking way larger like 50-70mm?

Yes, terminals designed for 125-400A kind of stuff.

I'd forgotten that old technique of twisting a strand around the others, seems like a faff though?

 

[Rockingit]

Are you using the right crimps and crimpers for the particular cable you are trying to crimp the lugs on?

The point of this post is that at the moment I've not used any, but I have proper hydraulic compression crimps for when I'm doing normal lugs and things.

Proper end/bootlace ferrules do exist https://www.cablecraft.co.uk/25mm-uninsulated-cord-end-terminals-7994 so I might just get a pack and see how I find them in practice.

 

[loz2754]

The point of this post is that at the moment I've not used any, but I have proper hydraulic compression crimps for when I'm doing normal lugs and things.

Proper end/bootlace ferrules do exist https://www.cablecraft.co.uk/25mm-uninsulated-cord-end-terminals-7994 so I might just get a pack and see how I find them in practice.

Cord end terminals are for fine stranded flexible cord and are not suitable for normal stranded cables.

 

[SparkySy]

To be fair wrapping a strand around is a bit of a faff if you have several to be done in one go but for the odd one is quite satisfying.

 

[Rockingit]

Cord end terminals are for fine stranded flexible cord and are not suitable for normal stranded cables.

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

 

[PEG]

.....your honour,i call Klauke to the stand....

 

[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.