[RE-wrenches] Buchanan Crimp in 1000v Applications and the NEC

Tue Nov 11 16:30:02 PST 2025

We're talking about inside a junction box (NEMA 3R or 4, for example), not
an "outdoor environment." Wagos (and other connectors like wire nuts,
Polaris Taps, power distribution blocks, terminal blocks, etc) are allowed
inside of a rooftop junction box, just like they are allowed in various
switch boxes, enclosures, and cabinets that are suitable for the
environment outdoors.

For the same reason you can put circuit breakers inside of a NEMA 3R load
center outdoors, you can use splice connectors of many kinds inside of a
NEMA 3R enclosure. They do not need to be listed for "outdoors" because it
is not outdoors. It's enclosed and adequately protected from the
environment.

In other words, any AHJ that challenges me on this, I just ask them to show
me a circuit breaker that's listed for use in a wet location. That's
usually enough to shut them down.

Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956
Florida Certified Electrical Contractor EC13013208

On Tue, Nov 11, 2025, 7:11 PM Glenn <glenn.burt at glbcc.com> wrote:

> I have not found a listing for Wagos in an outdoor environment.
>
> -Glenn
>
> On Nov 11, 2025 18:01, Jason Szumlanski via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> We have had terrific success using Wagos in rooftop junction boxes for
> splicing #12 Enphase cable to #10 home run THWN. We have no issues
> whatsoever with these.
>
> Unfortunately, the #10 PV wire insulation is too large for the Wago
> 221-6XX series. We have been buying #14-#4 Polaris taps and it's getting
> very expensive. I would like an alternative.
>
> For a while we were using the King Innovation AlumiConn purple "suitcase"
> connectors for Enphase, but they are only 300V rated and I don't think the
> PV Wire insulation fits in those, either, for <300V applications.
>
> I have seen people using MC4 connectors in rooftop junction boxes like
> Blake suggested, but I wasn't sure if that is acceptable practice to use
> them this way (in an enclosure), and it does require a pretty large
> junction box. We prefer to use the EZ Solar JB-# series of boxes. The rail
> mount ones (JB-3) are pretty small, but the tile roof JB-2 is huge, and the
> shingle JB-1 is sizable as well. I guess if there is no prohibition against
> using them in an enclosure, then it should be allowed. I do like the
> watertight nature of this solution.
>
> I have seen some clowns using MC4 connectors with #10 THHN wire to make
> these splices. That's obviously no bueno. Crazy stuff...
>
>
> Jason Szumlanski
> Principal Solar Designer | Florida Solar Design Group
> NABCEP Certified Solar Professional (PVIP)
> Florida State Certified Solar Contractor CVC56956
> Florida Certified Electrical Contractor EC13013208
>
>
> On Tue, Nov 11, 2025 at 4:44 PM Dave Tedeyan via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> Hi Adam,
> This response is just to you. Is NYSERDA the inspection agency you are
> talking about? Cause they have given me issues about using Wago Nuts inside
> a 3R box, even after I got a statement from Wago saying that it is okay to
> put it inside a 3R box. But squirting a bit of No-Ox in there seems to make
> them happy about it. The one time we put one inside a 3R panel board to
> extend a short wire and forgot to put No-Ox on that one, they gave us a 2
> out of 5 on the inspection, even though that was the only thing noted in
> the entire inspection report! But I would be curious if the point you make
> above will work with NYSERDA?
>
> Cheers,
> Dave
>
> On Tue, Nov 11, 2025 at 4:16 PM AE Solar via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> We had an inspection agency that was giving us a hard time about using
> buchanan crimps in junction boxes because they aren't rated for
> outdoor/damp locations. The point was made (on this listserve) that "*if
> the inside of a 3R enclosure isn't considered dry enough for a buchanan
> crimp/cap, then there's millions of 3R panels with breakers and busbars in
> them that would have the same problem*". The inspection agency finally
> relented. We put a little No-Alox in the cap. I know that's not what your
> initial post was about, but tossing that in for consideration just in
> case...
>
> Adam Katzman (he/him)
> Autonomous Energies | Owner/Operator
> www.AutonomousEnergies.com <http://www.autonomousenergies.com>
> (518) 567-1468
>
>
>
>
> On Tue, Nov 11, 2025 at 3:51 PM Jay via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> Hi Sam
>
> I can’t imagine being just copper it would matter, the AHJ might have a
> different opinion however
>
> Question.
> How are you insulating them?
>
> Jay
>
>
> On Nov 11, 2025, at 11:15 AM, Sam Haraldson via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> 
> Wrenches,
>
> On the attached product spec sheet for Ideal Copper Crimps (aka Buchanan
> crimps) you'll see that max voltage for the crimp is rated at 600V but an
> asterisk indicates up to 1000V when "in fixtures and signs".  In our
> application this is a 1000v system and we are joining pairs of #10 PV
> wires.  The junctions are made in a rail-mounted, plastic j-box.  We could
> not find the definition of "fixture" as it might pertain to this situation
> in the NEC and as such are interested to learn more about using Buchanan
> crimps for 1000V applications.
>
> <image.png>
>
>
> Cheers,
> Sam
>
> [image: OnSite Energy] <https://onsiteenergyinc.com/>
>
> Sam Haraldson
> Operations Specialist
> (406) 551-6135
> 1515 N. Rouse Ave Bozeman, MT 59715
> <https://www.google.com/maps/search/1515+N.+Rouse+Ave+Bozeman,+MT+59715?entry=gmail&source=g>
> Locally owned and operated since 2012
> [image: B Corporation] <https://onsiteenergyinc.com/bcorp>
> <IDEALIndustries-Crimp Connectors.pdf>
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