1. I use a MLPE residential ground-mounted solution - rapid shutdown or not. w/Accessible MLPE.
2. There is a maximum physical string length for me to keep in mind, for instance, found here: "In the context of this document, string length refers to the number of optimizers and modules in the string. When designing the installation make sure to maintain the maximum physical string length as well: The total cable length of the string (excluding power optimizers’ conductors) should not exceed 1000ft./300m from DC+ to DC- of the inverter (2,300ft./700m when using the SE14.4KUS, SE30KUS,SE33.3KUS, SE43.2KUS, SE66.6KUS and SE100KUS inverters)" https://www.solaredge.com/sites/default/files/string_sizing_na.pdf All the best, Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified Master Trainer ™ for Photovoltaics (PV) Installation Professional #IREC 10037 Contract Training Provider (CTP) Adjunct Professor, Energy California Solar & Electrical Contractor License #00833782 C46, C10, D56, D31, C-7 Solar, Electrical, Trenching, Pole Installation & Maintenance, Instrumentation Contract Solar (PV) Technical Inspector - 3rd Party Inspections Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30 OSHA-Authorized Construction Trainer #32-0105338 CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG * Professional Member, International Association of Electrical Inspectors (IAEI) #7035507 - Since 2006 * Accredited and Registered North American Board of Certified Energy Practitioners (NABCEP) Continuing Education (CE) Training Provider On Wed, Apr 29, 2020, 8:17 AM 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 > >
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