Hi Dave, If I was your AHJ then sure but since I’m not, you would need to work through their comfort with this approach since the 690.12 Code language is “PV system circuits installed on or in buildings shall include a rapid shutdown function to reduce shock hazard...” Note the requirement applies to circuits. Since it says “on or in” that might make someone feel that a conduit and disconnect fastened to the building would not be ok, though one installed a foot away from the building wall on its own support structure would be. Personally I feel that if there is a reasonable length of a circuit installed outdoors that remains above 30V, and there is a good reason for it (like in your example) then this is no different than the limited amount of service entrance conductors that remain live after the service disconnect is opened. But I can’t guarantee everyone else will take that position. I’d bring that up in a constructive discussion though.
Jason ________________________________ From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> on behalf of Dave Angelini Offgrid Solar <offgridso...@sti.net> Sent: Monday, September 30, 2019 6:49 PM To: RE-wrenches Subject: Re: [RE-wrenches] Module-Level Shutdown for off grid systems Thanks Jason, I have one question on the sentence, ". If a dc circuit comes from the PV array and enters a home then you need a means to bring that circuit below 30V before attaching to, or entering, the home. That might be a readily accessible disconnect (marked as an RS initiation device) not mounted on the home or some type of remote relay (listed to 1741 RS) operated by an RS initiation switch on the home." An example of what I have done many times. There is a 600v square D disco mounted on the garage exterior wall from a ground mounted array. The garage is attached to the home. Is thIs meeting the intent here please? Dave Angelini Offgrid Solar"we go where powerlines don't"http://members.sti.net/offgridsolar/e-mail offgridso...@sti.net<mailto:offgridso...@sti.net>text 209 813 0060 On Mon, 30 Sep 2019 22:14:10 +0000, "Jason Fisher (STC)" <stc.ja...@gmail.com> wrote: Hi Jay, Ray makes the right distinction between the PV system and other systems that I think applies to your example. This was the big change in 2017 as we pulled all the non-PV stuff out of 690 and created 706, 710, etc. The PV system disconnect is what you identify it to be though. Article 690 doesn't tell you what disconnect is the PV system disconnect, just that one must be identified per system. Also there is no limit on the number of disconnects in a PV system, so you could have one local disconnect located at an array for servicing etc but then add another one someplace else and identify that one as the PV system disconnect if you wanted. The system disconnect is the final one that separates the PV system from other system conductors. Other disconnects found in a system are typically equipment disconnects for servicing etc. 690.12 Rapid Shutdown only applies to circuits energized by PV sources, not circuits energized by other sources such as a utility, a battery, or a generator. The justification for RS was to protect firefighters working in or on buildings performing emergency operations. So if a PV array is attached to the building (not just on a roof, but for example an awning) then 690.12 certainly applies. For a ground mounted system the answer is "it depends". If the circuits energized by the PV array do not enter the building (i.e. a PV system ending at an outdoor battery shed) then it doesn't. If a dc circuit comes from the PV array and enters a home then you need a means to bring that circuit below 30V before attaching to, or entering, the home. That might be a readily accessible disconnect (marked as an RS initiation device) not mounted on the home or some type of remote relay (listed to 1741 RS) operated by an RS initiation switch on the home. The NEC 2020 language regarding 690.12 hasn't changed that much. The most significant change is to further clarify what conductors must be controlled in 690.12(A). That new language and informational note may help some struggling with this issue though. The other changes mainly improve the application of the new draft UL3741 standard to the inside array requirements. Note that in both 2017 and 2020 there should be no inside the array (690.12(B)(2)) requirements for any ground mounted system not attached to a building. I hope no other people out there are suggesting there are. That was never identified as a requirement for 690.12. If an inspector in your area wants that I would personally have a prolonged discussion about that. I don't think that position is supported by the Code language, or public record on the debates around this issue. It's not a who's "right" or "wrong" debate. It is simply how to apply the Code to the installation. Also a heads up to look at new 2020 language in 480, 706, 692, 694, and even 445, requiring the disconnection of all onsite sources from buildings. For 1&2 family dwelling these disconnects must be outside. This parallels the new requirement for outdoor disconnects for utility services outside of these buildings. These new requirements close the loops that can concern in others about what happens to other circuits when I initiate RS for a PV array. None of these requirements are rapid shutdown though. It is all about de-energizing feeders and branch circuits in buildings. I think these requirements will often apply to off-grid systems. They are pretty straightforward though since the requirements are much higher level and not as prescriptive as 690.12. I realize the 2017 (or probably 2020) language isn't 100% clear. It never seems to be unfortunately. While I won't say the language is "correct", the way I describe these issues above is in line with the public inputs/comments/debates during the Code panel's (CMP-4) development process, starting in 2014 and continuing to 2020. If anyone has specific ideas for 2023 improvements please let me know. Hope some of that helps you all. Jason Fisher stc.ja...@gmail.com ________________________________ From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> on behalf of Ray <r...@solarray.com> Sent: Monday, September 30, 2019 1:40 PM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] Module-Level Shutdown for off grid systems The PV system (and 690.12) stop at the PV Disconnect. (see figure 690.1(b), Note (2)). Charge Controllers are part of the Energy Storage system (706) now. We presented this in our plan sets, and we drew clear lines on the wiring diagram showing which articles applied to which parts of the system. The AHJs have not challenged us on this. However, they pulled a bunch of other stuff out, for instance that 705 still applies to off grid.... I still have not seen a good presentation anywhere on applying NEC 2017 to off grid, outside of the RE Wrenches list. Everyone is still figuring this all out for off grid after all the changes in 2017. Can't wait to see what 2020 looks like.... Ray WaltersRemote Solar303 505-8760 On 9/28/19 11:33 AM, jay wrote: HI Jason Does that mean that 690.12 B 1 would apply with the following. A ground mounted or external array to a living structure and if the CC was less than 1 meter from entry into the building You wouldn't need rapid shut down? jay peltz power On Sep 27, 2019, at 6:56 PM, Jason Fisher (STC) <stc.ja...@gmail.com<mailto:stc.ja...@gmail.com>> wrote: Just a reminder to everyone struggling with this issue that only building-attached circuits energized by PV sources require RSD. So ground mounts generally don't, or at least would only require a disconnect at the building if sending dc circuits into buildings. Energy Storage is covered under article 706 in 2017 and does not require any shutdown, just sensible disconnection requirements. Jason Fisher ________________________________ _______________________________________________List sponsored by Redwood AllianceList Address: RE-wrenches@lists.re-wrenches.org<mailto:RE-wrenches@lists.re-wrenches.org>Change listserver email address & settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.orgList-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.htmlList rules & etiquette:www.re-wrenches.org/etiquette.htm<http://www.re-wrenches.org/etiquette.htm>Check out or update participant bios:www.members.re-wrenches.org<http://www.members.re-wrenches.org> --
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