My 2 cents are related to the very few times I have had to do RS for offgrid. My advice is to install whatever the inspector wants, assuming he can't be convinced of the mindless requirement. Complete the installation. Do the right thing after by abandoning it. Have the client remove the RS signing so fire folks do not get misled.
I am testing the Schneider RS here on one array, but XW is out of the loop. Just logging. Dave Angelini Offgrid Solar "we go where powerlines don't" http://members.sti.net/offgridsolar/ [1] e-mail offgridso...@sti.net [2] text 209 813 0060 On Wed, 29 Apr 2020 10:17:33 -0400, drake.chamber...@redwoodalliance.org wrote: Clearly, rapid shutdown increases cost and reduces reliability. Given the excellent safety record of PV, prior to rapid shutdown being required, it is unnecessary. The few anecdotal incidents of PV fires were not enough to justify the requirement, especially on smaller systems. According to a friend who worked for a local installation company that went under, a big part of the reason for their failure was the chronic replacement of microinverters and optimizers. What steps can be taken to create some balance in the rapid shutdown requirements that are in the NEC? --- On 2020-04-29 07:27, Sky Sims wrote: So far rapid shutdown has been a nightmare. It's added a lot of cost for no measurable benefit. Using always off devices like midnight solar and Tigo makes it impossible to test open circuit voltages. Which opens the door to tons of problems when commissioning systems. Also we've been trying out midnight Solar's product and have had an absurd failure rate. Which means lots of truck rolls and troubleshooting and system downtime. They send replacement product but they aren't paying for the lost weeks of productivity. We have Tigo product in hand and are deciding which project to try it on. But our big concern about using it is not only the inability to confirm open circuit voltage of the strings but also the way panels bypass if the device doesn't allow the panel to connect properly. Both of these features are a recipe for problems and potential troubleshooting nightmares. The warranty from Tigo doesn't cover our expense if the product fails. And that's really what our reservations about the product boil down to right now. If we're on a job with 50 units and one fails, the contractor or the homeowner will be the ones eating the expense of finding it and replacing it. There has to be a better option. Sky Sims Https://EcologicalSystems.biz On Apr 28, 2020, at 7:46 PM, Corey Shalanski wrote: Now that 690.12 of the _NEC_ 2017 has been in effect for several years, I am curious how designers and installers are meeting the associated requirements with string inverter-based systems (*not* considering microinverters or DC optimizers). I am generally a fan of the KISS principle, and as best I can determine the _Tigo_ TS4-F device is one of the simplest options currently available on the market. What are others finding? I'd love to hear about favored options for complying with rapid shutdown. Any success stories? or better yet, any early failures? -- Corey Shalanski Jah Light Solar Portland, Jamaica _______________________________________________ List sponsored by Redwood Alliance 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 List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules padding: 0; font-family: monospace;">_______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org [3] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org [4] List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html [5] List rules & etiquette: www.re-wrenches.org/etiquette.htm [6] Check out or update participant bios: www.members.re-wrenches.org [7] Links: ------ [1] http://members.sti.net/offgridsolar/ [2] mailto:offgridso...@sti.net [3] mailto:RE-wrenches@lists.re-wrenches.org [4] http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org [5] http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html [6] http://www.re-wrenches.org/etiquette.htm [7] http://www.members.re-wrenches.org
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