Concerns on pre-insulated crimp terminals on solid conductor

[Adam_151]

After looking at some thru-crimps on some redundant cables I had dragged out of a fuseboard and being a bit concerned that they didn't seem too good of a joint I set about doing some tests..

I was using a CK rachet crimp tool, so reasonable brand etc. What I found was when crimped a joint initially seems sound, but if you put a 90 bend in the conductor and try and twist it, it'll twist a few degrees side to side... not a massive amount, but enough that its evident that the conductor is moving inside the terminal, this is even evident even if 2.5mm conductor in a blue crimp is crimped using the red/1.5mm dies!. This seems to be caused by the deformed part having sideways play as the crimp is still able to resist lateral force; a 2.5mm² through crimped conductor snapped at a point other than the joint when pulled to breaking point... yet if you tried turning the conductors, you'd get movement

Either I need a new crimp tool urgently, or there is a fundermental problem with this kind of joint... I don't have a problem with crimping in general, its just that the small ones seem a bit... micky mouse

 

[nozspark]

I had some crimps that felt loose a year or so ago.. I found that it was the crimps (Pik a pak - or something like that) SWA crimps seem to hold solidly.

I have a SWA crimper BTW

 

[BigJon]

I'm never a fan of crimps, they never feel totally "right".
I know its seems the preferred method of joints but atleast with decent connector block you know you can get a solid sound connection.

 

[ericmark]

Working for GEC large steam turbines we had to use single size crimp pliers and they were calibrated every 6 months. Seems they had some problems with the multi-red-blue-yellow crimp pliers.

We were not allowed any of our own hand tools seems their insurance had pointed out that if they provided a hammer or spanner and it proved faulty they can take it out of service but if we provide a hammer and stale becomes damaged it is much more likely we will continue to use it.

 

[TicklyT]

I've found the insulated sleeving on some crimps pulls away from the metal a bit after crimping, giving the illusion the crimp is loose on the wire when really it's just the plastic sleeve that's loose on the crimp.

 

[crystal ball]

I have found quite a few loose crimps on solids, I seem to remember being told during my apprenticeship that solid cores were not to be crimped, I think it was an MOD stipulation

I still do not crimp solids, always screwed connection

 

[SUNRAY]

I have found quite a few loose crimps on solids, I seem to remember being told during my apprenticeship that solid cores were not to be crimped, I think it was an MOD stipulation

I still do not crimp solids, always screwed connection

I'm with you on this

 

[industryspark]

I agree with the OP that crimping on solids can sometimes result in a connection that doesnt feel 100% secure. Ive found that using a decent brand of crimps and decent crimpers usually negates the problem though (bit of a bugger cos my wholesaler only seems to stock rubbish!).

I never shy away from using crimps on solids if the situation arises-never seen it stated by any manufacturer that its a no-no so as far as im concerned its ok. i wont use terminal blocks with fine stranded conductors without fitting a bootlace ferrule , but thats another argument

 

[Monkeh]

Wow, someone else who uses ferrules!

 

[industryspark]

from some of the installs ive seen Monkeh, we are a rare breed!

 

[Monkeh]

from some of the installs ive seen Monkeh, we are a rare breed!

It's not all that easy to find them in small amounts, which doesn't help. There's a reason almost every device comes with ferrules from the manufacturer though.

 

[ban-all-sheds]

 

[Monkeh]

Those are pins, not ferrules.

Nice case though, assuming that's yours, where'd you get it?

 

[SUNRAY]

Those are pins, not ferrules.

Correct.
Shame some people don't know what theyre using.

Nice case though, assuming that's yours, where'd you get it?

Thats a new one still on the shelf.
Most suppliers have something like this, ie Screwfix, RS, CEF and the like.

 

[Monkeh]

Nice case though, assuming that's yours, where'd you get it?

Thats a new one still on the shelf.
Most suppliers have something like this, ie Screwfix, RS, CEF and the like.

Suppose it might be. Never seen a good quality one with a tool compartment is all. Would be great for all my 8P8Cs and the crimp.