Kirk:
It is fortuitous you would write on the subject when you did. I was connecting an Envy inverter at that moment. We have settled on the copper sheeting method: We cut a strip of thin copper sheeting to wrap about 1-1/2 times around the bare strands, insert the conductor in the screw lug and tighten to the specified torque. I have done this multiple times over decades without failure. We sometimes take the cable back out of the lug to inspect. All indications are this technique is acceptable. This solution is inexpensive and portable. William William Miller Miller Solar www.millersolar.com CA License C-10 77398 *From:* Kirk Herander [mailto:[email protected]] *Sent:* Friday, January 23, 2026 9:44 AM *To:* [email protected]; RE-wrenches *Subject:* Re: [RE-wrenches] Ferrules for large fine-stranded wire. William, All, I was at a workshop on the (sort of) new Fortress battery product the other day. I brought up this very issue of the terminal lugs of the Envy not accepting a 4/0 ferrule, even though 4/0 cable with ferrules are recommended in the manual. The instructor had no comment, except to imply that maybe one should use 3/0 max. Huh? Anyway these Greaves pin adapters are by far the best I've found for working with the 4/0 terminal block. The pin diameter matches 4/0 cable and thus fits great. Preferable IMO to a reduced 4/0 barrel to 2/0 pin of AL or AL-clad others. And the barrel has a generous flange which makes it quite easy to insert high-strand flex cable. #PT 222FX40. But @ $50 ea, not cheap. [image: image.png] On Wed, Sep 3, 2025 at 7:10 PM William Miller via RE-wrenches < [email protected]> wrote: 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:[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: _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/[email protected]/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org --
_______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/[email protected]/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
