All - Ray has a good point, the discussion here is really about two different types of systems - mainstream ongrid PV, and small scale (and a relatively small market) offgrid PV. It's really tough to design a small offgrid system (especially DC coupled) with rapid shutdown. I think it's just a case that the market is so small that the manufactures aren't focusing their products on it. Our business doesn't do much offgrid, so I'm not familiar with the products but understand the difficulty. For ongrid PV with or without energy storage, I still argue that MPLE or microinverters are 100% the now and future, and fighting against that is a losing battle.
I think we should see more and more offgrid ability coming from the big players SolarEdge, Tesla, (maybe Enphase) etc which will all be easy to pair with rapid shutdown enabled PV. August On Thu, Apr 30, 2020 at 7:12 AM Ray <r...@solarray.com> wrote: > Hi Jerry; > > This isn't about us not being willing to learn the tech. All of us are > constantly learning about new code changes, new inverters, and solar > modules that change specs every few months. We are voluntarily adopting > new technology (like Lithium Ion batteries) when that technology is cost > effective and reliable. > > To continue your smart phone analogy, the current situation is like > forcing people in the country to give up their hard lines, when their is > only spotty 3G service available in their area. Its not that we are > Luddites; the equipment is still not quite ready for prime time. Having > some basic exemptions for small, lower voltage systems off grid is not > unreasonable. > > Ray Walters > Remote Solar > 303 505-8760 > > On 4/30/20 2:33 AM, Jerry Shafer wrote: > > Wrenches > We are taking two very different issues and mixing them together. RSD and > Arc-fault are different, arc fault will and does prevent fires, RSD was > brought out of the need to vent a roof that even with the meter pulled have > 500 volts and resulted shocks to fire fighters by cutting into roofs or > nearby conduite. This is fact not conjecture. > Arc fault is a fire preventer but requires nothing on the roof when using > string level inverters. Now both RSD and arc-fault in off grid increase the > complexity but the new charge controllers fit the arc and Tigo fixes the > RSD issues. > I know everyone of you learned to use a smart phone and can now adapt > again to this new tech, we have to be leaders in this industry and not well > you know. > Jerry > NABCEP PV Inspector. > Been in this industry since 1978 > > On Wed, Apr 29, 2020, 6:57 PM Jay <jay.pe...@gmail.com> wrote: > >> Hi Drake >> >> I will disagree, there have been many roof top fires. >> >> But regardless we have to do these new regulations and I for one welcome >> the safety. >> >> The main issue is accessing the faulty/suspect component under the module >> possibly requiring removing multiple modules, a slow and expensive process. >> >> My technique is to install the MLPE at the edges of the array, using wire >> extensions. That way at most I have to remove a single module. And Im >> working on a drop bracket which would allow better cooling and easier >> access without module removal to the MLPE, greatly reducing time to swap. >> >> Jay >> >> Peltz Power. >> >> >> >> >> >> On Apr 29, 2020, at 7:59 AM, 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 <coreso...@gmail.com> 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 & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> >> _______________________________________________ >> 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 & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> _______________________________________________ >> 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 & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> _______________________________________________ >> 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 & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> > _______________________________________________ > 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 & etiquette:www.re-wrenches.org/etiquette.htm > > Check out or update participant bios:www.members.re-wrenches.org > > _______________________________________________ > 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 & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > >
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