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

Wed Nov 12 11:19:47 PST 2025

Well this isn’t a totally direct answer to questions on this thread, but I
did want to address wet locations. (I do think the text on the Buchanan
spec sheet in regards to voltage makes it a no-go for 1kV+ systems. It's a
little surprising "fixture" isn't defined in the NEC, though in that case
the convention is to use the generally accepted definition, which matches
the contextual usage in the NEC - a permanently installed light, not
including the bulb).

As defined in the NEC (2026), a rooftop is (no duh, even here in Arizona!)
a wet location:

Location, Wet. (Wet Location)

A location that is one or more of the following:

(1) Unprotected and exposed to weather

(2) Subject to saturation with water or other liquids

(3) Underground

(4) In concrete slabs or masonry in direct contact with the earth

The inside of raceways in wet locations above grade is also a wet location:

300.11(A) Raceways in Wet Locations Above Grade.

Where raceways are installed in wet locations above grade, the interior of
these raceways shall be considered to be a wet location. Insulated
conductors and cables installed in raceways in wet locations above grade
shall comply with 310.10(C). [310.10(C) is requirements for conductors in
wet locations]

314.14 requires junction boxes used in damp or wet locations have to be
listed for such use, as is the case with 3R (which can be marked
“rainproof”) and 4X (which can be marked “watertight”) enclosures (note the
minimum drainage opening size in (C)(1), so as to prevent clogging), but
does not state that their interior is considered a wet location:

314.15(A) Prevent Moisture.

In damp or wet locations, boxes, conduit bodies, outlet box hoods, and
fittings shall be placed or equipped to prevent moisture from entering or
accumulating within the boxes, conduit bodies, or fittings.

314.15(B) Listed.

Boxes, conduit bodies, outlet box hoods, and fittings installed in wet
locations shall be listed for use in wet locations.

314.15(C) Drainage.

314.15(C)(1) Approved Openings.

Approved drainage openings not smaller than 3 mm (1∕ 8 in.) and not larger
than 6 mm (1∕ 4 in.) in diameter shall be permitted in the field in boxes
or conduit bodies listed for use in damp or wet locations.

Enclosures for OCPDs (240.32) in damp or wet locations, and panelboards
(408.37) in damp or wet locations must comply with 312.4(A) and (B):

312.4(A) Weatherproof Enclosures.

In damp or wet locations, surface-type enclosures within the scope of this
article shall be placed or equipped such that moisture or water is
prevented from entering and accumulating within cabinets or cutout boxes,
and be mounted so there is at least 6 mm (1∕ 4 in.) of airspace between
enclosures and walls or other supporting surface (yikes!!!!). Enclosures
installed in wet locations shall be weatherproof. Exception: Nonmetallic
enclosures shall be permitted without the airspace on a concrete, masonry,
tile, or similar surface.

312.4(B) Raceways or Cable Above Live Parts.

For enclosures in wet locations, raceways or cables entering above the
level of uninsulated live parts shall use fittings listed for wet locations.

The OCPDs installed in a typical panelboard are listed and designed to be
installed in that enclosure, which has the proper rating for the location;
and additional requirements stated above prevent direct dripping of
moisture onto energized components such as bussing or breakers.

The only requirement related to listing for connections in 110.14 is that
direct buried connectors or splicing means be listed for such use.

110.11 states, in regard to deteriorating agents, conductors or equipment
located in damp or wet locations must be identified for use in the
operating environment. Note the definition of identified, and that listing
is one means of identification but not the only one, so there is some
latitude for the AHJ:

Identified (as applied to equipment).

Recognizable as suitable for the specific purpose, function, use,
environment, application, and so forth, where described in a particular
code requirement.

Brian Mehalic
Solar Tech Collective
National Electrical Code® CMP-4 Member
(520) 204-6639

On Tue, Nov 11, 2025 at 8:03 PM Glenn via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Having opened and inspected dozens of rooftop installations, I can firmly
> say that anything inside a box of any kind on a rooftop will absolutely be
> exposed to moisture and often water. Whether it is humidity sucked in from
> thermal cycling, or gasket failure through UV degradation, or here in the
> north, snow and ice damage, it will happen.
>
> You will never convince me that it is acceptable to use any device there
> that does not have a published, traceable listing for outdoor use in that
> environment.
>
> -Glenn
>
> On Nov 11, 2025 19:30, Jason Szumlanski <jason at floridasolardesigngroup.com>
> wrote:
>
> 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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