Hydraulic crimping of 25mm 19 strand cables in flat crimp pins?

[TheArcMan]

Evening chaps. What's the rules on this? I can't specifically see anything relative to the 19 stranded cables.

My boss says he won't crimp in consumer units, avoid it all costs, he rather strip a whole house down or add additional boxes than use a single crimp inside a CU. Fair play to him.

However on commercial jobs I've seen crimped solid core cables (mind you a gazillion solid strands) with mega amperage going through no probs.

So anyway, I tried it out on Doncaster Cables finest 25mm2 19 stranded tails cables, terminated via flat pin crimps using a hydraulic crimper, no gaps, I mean it literally looked like 19 strands became one lol...

I then shrinked the crimp, and then inserted the pin into a din module, worked a treat, very solid... please note, this was only done in a test unit and not at an actual job.

Question is, why is the boss and everyone else against this method of terminating in domestic installations?

...I'm still blossoming, but my mind tends to do too much critical thinking, which then leads to my mouth going rambo lol

 

[TheArcMan]

this is the flat pin sort.



and this is the crimping tool sort.

 

[James]

I like crimp connections. Can’t see an issue.

 

[TheArcMan]

Agreed.

 

[littlespark]

Isn’t this exactly the situation for why crimps were invented in the first place?

Has your boss looked at any link cables that come with new CU’s? (Usually between RCDs and neutral bars) some are solid copper, but others are a fine stranded flex with a crimp on each end.


The trick is the right crimp for the right cable type.

 

[mainline]

The right crimp and the right crimping tool jobs a good un.

 

[Zerax]

The right crimp and the right crimping tool jobs a good un.

Agreed... all 3 should match; Cable size, Crimp Terminal and Crimp Tool.

 

[davesparks]

You don't normally need to use those type of crimps in a domestic CU, could you explain what application you want to use them for?

Those crimps are designed primarily as a way to connect an oversized cable to a screw or tunnel type terminal.

19 strand tails are a coarse stranded cable so are suitable for direct connection to a screw terminal without the use of ferrules so no crimped connection is required if the terminal is suitable for the size of conductor.

 

[TheArcMan]

This was more a test than anything.

Just because things aren't 'normally' done this way, doesn't mean it is a bad way, it is simply just 'another way' IMO.

Recently another sparky joined us in a larger job, not our choice, and that spark comes from Poland originally. The comments he made regarding us being stuck in the dark-ages drove my boss insane to the point he just stopped talking to him, didn't even bother debating/discussing. I discussed, and was blown away.

I'm open minded, without question the bottom line is always safety and reliability whilst meeting required functionality, if these are met then indeed there are always more ways than one to skin the proverbial cat.

But then again we're at the final stage constrained by the manufacturers of devices who strictly instruct what connections/termination types they permit, so yes even though another method may very well work, for compliance we have to adhere to manufacturer guidelines. However in many cases they don't go into that detail and tend to leave it open to sensible appropriate methods of compatible termination.

 

[nicebutdim]

A lot of sparks seem to work by tradition and know little about what's out there, much less have any interest in using it. Similarly a lot of sparks seem to rush into each new product that comes along, which isn't always ideal either. A common sense approach should be adopted and generally I find that newer tech is best used where it has proven reliability and reduces labour costs to increase profit and get you onto the next job more quickly.

 

[davesparks]

This was more a test than anything.

A test of what?

Just because things aren't 'normally' done this way, doesn't mean it is a bad way, it is simply just 'another way' IMO.

Sometimes it is a worse way, sometimes it is a better way way, sometimes it is just another way.

In this case, which i assume is using 19 strand tails into a main switch, then adding an unnecessary crimp into the connection adds an extra point of potential failure.
Also those reducing pins don't necessary make as good a connection into the main switch terminals which are designed for coarse stranded cable.

 

[TheArcMan]

Went into an MCCB, terminated very nicely thank you very much, however it was just me doing some training with crimping.

'introducing extra point of potential failure' - yes indeed. However, EVERY thing is a point of failure. From the screw threads in terminals, to even a run of cable failing due to some bizarre manufacturer defect. Not to mention the losses due to coatings on copper. I get the fight between corrosion vs conductivity is a never-ending battle, but in the ideal world we would have the least connections possible, and stick to pure copper all the way through at every termination etc.

To be fair, if life was about reducing the number of points of failure, well then, we should have probably remained in caves and never discovered fire, ever since then, every little step comes with a 'potential' point of failure.

Humour aside, yes I understand. Next week I get to do 120mm crimps, looking forward to it