What crimp terminal connections do I need for 25mm cable.

The Continental Op

I've a 12V solar set up I want to finish off and I need crimps for some 25 mm cable.

I've 25mm crimps but they are a fraction too small. When I push them on some of the strands of copper get pushed out.

Am I doing something wrong or do I need different bigger crimps if so what size?

2011

There can be variations in size between different brands. Try another brand.

Also ensure that the strands are not twisted together when inserting in the lug as this increases the diameter of the cable as the strands bunch up.

The Continental Op

I've actually tried 2 brands so far the second was much better than the first but still a tad to small. In the second lot I bought today I noticed there was some variation with at least half being way to small even though the are all marked up as 25mm2.

I'm back in town on Wednesday so will take a sample of cable and the terminals back and ask them to solve it. Both cable and crimps came from the same place.

I've even gone as far as heating one of the crimps to see if it would expand just enough to do the job and stripping back only a couple of mill of cable just to keep the ends really tight to go in the crimp but all to no avail.

2011

Is it tri rated panel flex (fine stranded flexi type cable) ?

This sometimes requires a larger lug.

2011

As I am sure you know it is important that all strands fit properly into the lug.

The Continental Op

Thanks, yes and yes, but don't know about tri rated but it is panel flex. If I didn't know the importance of getting all the strands in the lugs I wouldn't have spent so long trying ;-) Its only a few strands each time and I can see the temptation just to trim them off :-( I've worked with crimps on thousands of smaller cables and this is the first time I've encountered the problem. I suspect the lugs are chinese quality.

2011

Tri rated = panel flex

Yes I thought you knew alright.

The data sheet for the cable may specify the lug size.

The Continental Op

But you didn't know I was stupid 😣

Did the calculation on the lugs for how big a cable they would take. Biggest ones on average are a tad short of having an internal diameter of 7mm. With a bit of pie squared that means they'd take a cable around 35 mm2 😥

So light bulb moment how come my 25 mm2 cable won't fit into a 35 mm2 hole?

Checked cable its 35 mm2 in my defence I'm fairly sure I ordered 25 mm2 cable because I also ordered 25 mm2 lugs at the same time but does explain everything 😮