[RE-wrenches] Ferrules for large fine-stranded wire.

[William Miller]

Friends:



My understanding is if the lug has a set-screw that contacts the strands,
fine strands can wind around the set screw, get into the threads and not
tighten adequately.  If you are crimping fine strands inside of some type
of barrel your connection should be OK.



I had been using Outback until they imploded and all of the battery
connections were via studs or bolts that required crimped-on rings.  Now I
am back to set screw lugs and fine stranding became an issue again.



I did try another experiment: I took a 4/0 ferrule that would not fit into
the Envy lugs and snipped a section out of it.  I curled it into a slightly
smaller diameter and it fit into the lug.  I suppose one could cut the
ferrule in half longitudinally and insert a portion of the ferrule between
the set screw and the strands.



I am pleased with the copper sheeting wrapped around the fine strands.
That will be my SOP.



William



Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985





*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
Behalf Of *Ray Walters via RE-wrenches
*Sent:* Wednesday, September 3, 2025 1:40 PM
*To:* re-wrenches at lists.re-wrenches.org
*Cc:* Ray Walters
*Subject:* Re: [RE-wrenches] Ferrules for large fine-stranded wire.



I've got to ask: Are none of the lugs on these Chinese inverters approved
for fine strand cable?  I just have not had a problem with that, but I've
mostly used Magnum, Midnite, and Outback equipment over the years.   What
were the lugs on the old Trace DC 250 boxes?  Were they fine strand rated?
They sure were tough to get 4/0 into, as William mentioned.

Ray
Remote Solar

On 9/3/2025 12:57 PM, Kent via RE-wrenches wrote:

William,

If the only reason the ferrule wouldn't fit after using the hex crimper was
the ridge left where the dies meet, you could rotate the cable 120 degrees
and crimp the ferrule again.

I doubt that the indenter crimper will do a decent job with large ferrules.

I do like your thin piece of copper solution. Not UL approved but I dare
say wrench approved.

Kent Osterberg
Blue Mountain Solar



On 9/2/2025 8:55 PM, William Miller via RE-wrenches wrote:

Friends:



Thank you for all of your input on this question.  I feel it only right I
report back how this turned out



I tried a crimper like this:







It left a jagged ridge on both sides of the ferrule where the dies met.



The crimper below was suggested but I have not tried it:



This was suggested but I have not tried it either:
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