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 <bl...@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 <coreso...@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 <bl...@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@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 >> >> > > -- > > Blake Gleason, PE | Employee Owner > Director of Innovation and Technical Excellence > O: 510-845-2997 x128 > C: 510-867-5878 > > 1035 Folger Ave. > Berkeley, CA 94710 > www.sunlightandpower.com > License #326203 > > <https://bcorporation.net/> <https://www.amicussolar.com/> > <https://calssa.org/> > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@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@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
