Around here, AHJs require that the GEC is not connected to the service disconnect or any supply-side interconnected PV AC disconnect. They require a GEC from the meter socket enclosure to the GE system with a N-G bond in the meter enclosure (the N and G lugs are one and the same typically anyway in a meter enclosure). The GEC must be continuous or irreversibly spliced from the meter socket to the ground rods or a confirmable ufer ground or other approved GE system.
The service disconnect is connected to the meter socket lugs with L1, L2, and N with no equipment grounding conductor, although in many circumstances, the meter enclosure is electrically bonded to the service disconnect enclosure if a metallic raceway is used. The service disconnect is bonded (N-G). And supply side interconnected disconnects only have L1, L2, and N with no EGC, and they are also bonded. 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 Wed, Feb 19, 2025 at 10:53 PM Corey Shalanski via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > Kris, > > As far as I know, taps to GECs need not be irreversible. I believe you > might be thinking of the NEC 250.64(C) requirement for GECs to be installed > "in one continuous length" or otherwise be spliced together via one of > several options, with one option being to use irreversible compression-type > connectors—but I'm pretty sure that refers to *individual* GECs (as in, > *each* GEC must either be run continuous or can be pieced together via > irreversible means). > > It sounds like your scenario is a supply-side connection, which introduces > an additional service equipment enclosure in the form of the PV system > disconnect (additional to any existing service equipment) and would > therefore be covered by NEC 250.64(D). One option, described in (D)(2), > would be to run a new GEC from the PV system disconnect directly to the > (existing) grounding electrode system. The other option*, described in > (D)(1), is to run a GEC "tap" from the PV system disconnect to a "common" > GEC. In cases where there is only a single existing service equipment > enclosure - and therefore only a single existing GEC - my interpretation is > that the existing GEC can serve as the common GEC (essentially doing double > duty as a "common/tap" GEC, if it helps to think of it that way) and you > can therefore connect the new GEC tap directly to it. Notably, this method > allows for the use of "connectors listed as grounding and bonding > equipment"—we commonly use split bolts for the purpose. > *There is also a third option [(D)(3)], but, in my experience, it is > uncommon to have wireways on the supply side of service disconnects. > > So, I would suggest there is no need to use compression connectors - but > you can certainly do so as an 'above-Code' measure. > > Corey Shalanski > Cherry Street Energy > Atlanta, GA > > > On Wed, Feb 19, 2025 at 8:18 AM Kristopher Schmid via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > >> Hi All, >> >> What are you all using for an "irreversible" tap to an existing GEC? I >> have been looking at compression CTAPs. Do they require a special crimper >> die? >> >> Thanks, >> Kris >> >> >> Shine On! >> >> Kris Schmid >> Legacy Solar, LLC >> 137 West 1st Avenue >> Luck, WI 54853 >> www.legacysolar.com >> 715-653-4295 >> NABCEP Certified PV Installation Professional >> Licensed Wisconsin Master Electrician >> BSEE >> > _______________________________________________ > 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 > >
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