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
From: RE-wrenches [mailto:[email protected]] On Behalf Of Ray Walters via RE-wrenches
Sent: Wednesday, September 3, 2025 1:40 PM
To: [email protected]
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:
