[RE-wrenches] MC4s are listed for THWN, right?

Wed Apr 28 10:37:53 EDT 2021

Keep in mind that Wagos, Polaris lugs, Multi-tap Burndy lugs are rated for
600V. I can see this being a possible use for MC4 connectors in a higher
voltage splice scenario, because of their 1000V/1500V ratings.

On Wed, Apr 28, 2021 at 10:00 AM August Goers <august at luminalt.com> wrote:

> Hi Allan - Good question, I noticed that too. I think it is a typo, and
> they mean 20 AWG through 10 AWG. See attached datasheet.  6 mm^2 is close
> to #9-#10 AWG. There are other variants available as well with smaller
> conductor sizes for data cables and more ports for connecting in parallel.
>
> August
>
> On Tue, Apr 27, 2021 at 6:10 PM Sindelar Solar <Allan at sindelarsolar.com>
> wrote:
>
>> August,
>>
>> Thank you for this suggestion. I went to the site, and under "Two Sizes
>> for All Conductor Types" on that page it appears that there's a model
>> that'll work with 2-10AWG conductors:
>>
>> "With the 6 mm2 (10 AWG) variant, you can connect all conductor types –
>> with cross sections from 0.5 to 6 mm2 (2−10 AWG)".
>>
>> This would contradict what you wrote below, so I'm just checking whether
>> I missed something.
>>
>> Thanks, Allan
>> On 4/27/2021 12:55 PM, August Goers wrote:
>>
>> Hi Jason - I noticed that Tesla is using the Wago connectors in their
>> Powerwalls. They only go up to #10, but they certainly appear to have some
>> advantages such as easy QC inspection, compactness, and price. We are in
>> the process of trying a batch of these out, but I hadn't considered using
>> them in exterior J-boxes.
>>
>> https://www.wago.com/global/electrical-interconnections/discover-installation-terminal-blocks-and-connectors/221
>> August
>>
>> On Tue, Apr 27, 2021 at 10:42 AM Jason Szumlanski <
>> jason at floridasolardesigngroup.com> wrote:
>>
>>> I'd be interested to hear thoughts on Wago 221-6XX series connectors,
>>> specifically for THWN to Enphase IQ/DG/TC conductor transitions or just
>>> THWN splices.
>>>
>>> On Mon, Apr 26, 2021, 8:40 PM Blake Gleason <blake at sunlightandpower.com>
>>> wrote:
>>>
>>>> Corey,
>>>> Thank you!  Agreed, the message from Staubli's Eng dept is much less
>>>> confusing (with the exception of the statement about THHN tending to be
>>>> solid vs stranded).
>>>> All -
>>>> What are you folks using to transition from PV Wire to THHN/THWN-2
>>>> inside a junction box?  We used to use split bolts, which make an awesome
>>>> electrical connection, but are time-consuming and not easily serviceable.
>>>> Wire nuts (the right ones) are Listed, but never felt reliable for that
>>>> purpose.  Same for WAGO levers.  I hear about people using Buchanan splice
>>>> caps, but I wonder about trading one set of crimping problems for another.
>>>> And of course, the only problem with using THHN in an MC4 is that the
>>>> compression gland may not be as watertight as it is with PVWire, and the
>>>> Buchanans certainly are not watertight.  Terminal blocks generally aren't
>>>> listed, definitely aren't watertight, and raise inspectors' eyebrows.  Why
>>>> is this so hard for me??
>>>> Best,
>>>> Blake
>>>> Thanks
>>>>
>>>> On Mon, Apr 26, 2021 at 5:19 PM Corey Shalanski <coresolar at gmail.com>
>>>> wrote:
>>>>
>>>>> Blake,
>>>>> In addition to Bryan's notes, here is some unconfusing information
>>>>> directly from Stäubli's engineering dept:
>>>>>
>>>>> The answer is categorically no: *you cannot use THHN wires with MC4
>>>>>> connectors.*  There are several reasons for this:
>>>>>> 1.     *Certification*: our MC4 connectors are certified to UL6703,
>>>>>> which only covers UL4703 PV wire or USE2 cable.  Any other wire type is not
>>>>>> covered by our certification
>>>>>> 2.     *Internal validation*: we have no internal testing or
>>>>>> validation of how MC4 or Evo2 connectors perform with THHN cables.  We
>>>>>> therefore cannot warranty / accept the use of THHN cables with our PV
>>>>>> connectors.  The allowable cables and applications for our PV connectors is
>>>>>> clearly stated in the assembly instructions.
>>>>>> 3.     *Construction*: THHN cables use very rigid PVC insulators,
>>>>>> which behave very differently than XPLE or TPE insulators that are the most
>>>>>> widely used on PV wires.  PVC has a very low elastic range and easily
>>>>>> deforms permanently under load/thermal cycling.  It is not a well-suited
>>>>>> cable for higher temperature or high temperature fluctuating applications
>>>>>> where compression-type cable seals (i.e. cable glands) are used.  Also,
>>>>>> THHN cables tend to be single-conductor solid core cables, which are
>>>>>> absolutely not allowed with crimp terminations like the MC4 (or any other
>>>>>> PV connector on the market for that matter).  They also are not allowed by
>>>>>> UL6703.
>>>>>>
>>>>> These comments were forwarded to me by Jeff Wang, who works for
>>>>> Stäubli North America.
>>>>> --
>>>>> Corey Shalanski
>>>>> Jah Light Solar
>>>>> Portland, Jamaica
>>>>>
>>>>> On Mon, Apr 26, 2021 at 9:23 AM <blake at sunlightandpower.com> wrote:
>>>>>
>>>>>>
>>>>>> Bryan,
>>>>>> Thank you for the link.  I am confused by the "PVC" section you
>>>>>> referenced.  Here's the complete text:
>>>>>>
>>>>>>>   For safety reasons Stäubli prohibits the use of PVC cables. Cables
>>>>>>> made from PVC can be connected to MC4-Evo 2 since the insulation material
>>>>>>> of the connector (Polyamide) is suitable to be connected to PVC. PVC cables
>>>>>>> usually have an upper limiting temperature of 70 °C, in fixed installations
>>>>>>> sometimes 80 °C.
>>>>>>>
>>>>>> THHN/THWN-2 is made with PVC insulation, so I assume that it falls
>>>>>> under the category of a "PVC cable."
>>>>>> So, the first sentence seems to say that it's not allowed by
>>>>>> Staubli.  But then the second sentence seems to say that is IS allowed.
>>>>>> And then the third sentence doesn't seem to be contemplating the most
>>>>>> common PVC wire type of all (in the US), which is THHN/THWN-2, which has a
>>>>>> 90 degree rating?!
>>>>>> Can you help un-confuse me?
>>>>>> Thank you!
>>>>>> Blake
>>>>>>
>>>>> List sponsored by Redwood Alliance
>>
>> Pay optional member dues here: http://re-wrenches.org
>>
>> List Address: RE-wrenches at lists.re-wrenches.org
>>
>> 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/re-wrenches@lists.re-wrenches.org/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
>>
>> --
>>
>> *Allan Sindelar*
>> allan at sindelarsolar.com
>> NABCEP Certified PV Installation Professional
>> New Mexico EE98J Journeyman Electrician
>> Founder (Retired), Positive Energy, Inc.
>> *505 780-2738 cell*
>>
>>
>> _______________________________________________
>> List sponsored by Redwood Alliance
>>
>> Pay optional member dues here: http://re-wrenches.org
>>
>> List Address: RE-wrenches at lists.re-wrenches.org
>>
>> 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/re-wrenches@lists.re-wrenches.org/
>> 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: RE-wrenches at lists.re-wrenches.org
>
> 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/re-wrenches@lists.re-wrenches.org/
> 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
>
> --
Chris Sparadeo

C_802-369-4458
H_802-728-3059
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches_lists.re-wrenches.org/attachments/20210428/699f75f4/attachment.htm>