If first responders are the point of all the rapid shutdown, there needs to be better exemptions. I personally have a 20kW solar array on a 100 year old unused barn at my farm. The roof is at 50 degrees slope and needs a 60ft boom lift to access. There was significant extra expense and effort for the rapid shut down. And there is absolutely zero chance that a first responder would do anything other than watch the barn burn. And now I have an array that needs a $1,000 piece of rental equipment to get to the back of any module.
There is a big difference between the stuff that is in big cities and what is in rural and what is in remote locations. For my telecom customers in Alaska and Antarctica, what is the point of decreasing reliability by putting module level electronics on solar arrays that require a multiple hour helicopter flight to get to. That's not protecting anybody other than the MLPE manufacturer's profit. -James Jarvis APRS World, LLC +1-507-454-2727 http://www.aprsworld.com/ On Thu, May 7, 2020 at 8:43 AM Christopher Warfel < cwar...@entech-engineering.com> wrote: > I believe Rapid Shutdown was mostly a solution looking for a problem. > The only way I see this becoming "reasonable" is to present "grievances" to > the Code Making Panel WITH a solution for their consideration. Based on > experience from being part of an outreach program that taught approximately > 10k firefighters over four years, I have asked that they add to the > Directory, the language that states what type of solar electric system is > on site (Microinverter, dc optimizer, string, multimode, grid isolated) so > that First Responders don't have to guess. I realize this is different > than MLPE, but it targets the person who Rapid Shutdown came into being > for, and that was the First Responder. Chris > > > On 5/6/2020 10:37 PM, Ray wrote: > > Spending more time on the roof, while putting more equipment and parts to > meet MLPE, means more trips up the ladder, which increases, not decreases > the #1 worker safety danger: Falls. Please correct me if I have somehow > misunderstood this, but MLPE is not making installers safer based on OSHA > information provided. Also after installation, which system is more > likely to require workers to return to work on the roof, pulling up > modules, trying to find problem equipment? More connections is More safe? > Really? I haven't had to climb back up on the roof on any of my older, > lower voltage off grid work in almost a decade. > > Once again, MLPE has its place, (larger systems, multiple subarrays, > higher voltage) but we should have sensible exemptions as have been > mentioned already. We are endangering ourselves and our employees > needlessly, to comply with 690.12. > > Ray Walters > Remote Solar > 303 505-8760 > > On 5/6/20 8:41 PM, drake.chamber...@redwoodalliance.org wrote: > > Interestingly enough, the data on the link > <https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1&acc_description=&acc_Abstract=solar&acc_keyword=&sic=&naics=&Office=All&officetype=All&endmonth=05&endday=05&endyear=2002&startmonth=05&startday=05&startyear=2021&InspNr=> > provided > shows accidents from gas explosions, falls, health problems and industrial > injuries. None of these incidents could have been prevented by module level > power electronics. This is typical of the data that I've seen so far. > --- > > > > On 2020-05-06 17:22, Martin Herzfeld wrote: > > There could be an issue of encouraging MLPE for worker safety? > > 1. This is data involving incidents with workers in the OSHA Fatalities > and Catastrophe Investigation Summaries found here: > > https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1&acc_description=&acc_Abstract=solar&acc_keyword=&sic=&naics=&Office=All&officetype=All&endmonth=05&endday=05&endyear=2002&startmonth=05&startday=05&startyear=2021&InspNr= > > 2. In the past I've observed an arc fault at the module level with > traditional string systems without a listed arc-fault circuit interrupter > NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - to *reduce the > shock hazard *- for *emergency responders* or *firefighters? (NEC 2020).* > However, I've observed thermal events in the panelboard with plans and > workmanship issues. > > On the other hand, falls are the #1 reason for incidents in the > construction industry. > > 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 - Since 2004 > 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 > #7035507 - Since 2006 > * Accredited and Registered North American Board of Certified Energy > Practitioners (NABCEP) Continuing Education (CE) Training Provider > > > On Thu, Apr 30, 2020, 8:29 AM <drake.chamber...@redwoodalliance.org> > wrote: > > > I would like to see real data on the fire risk of string inverters. > Anecdotal problems are not data. > > The industry is definitely heading toward MLPE due to the rapid shutdown > requirements. In many cases MLPE makes sense, in other cases it doesn't. > > Systems that are more cost effective and reliable can often be built by > using string inverters. > --- > > > > > On 2020-04-29 22:05, Jason Szumlanski wrote: > > "Rapid Shutdown does not prevent fires." > > Not true. If the effect of RS is to steer the market to MLPE, I believe it > has a significant impact on reducing fire risk. As one who has watched a DC > conductor fire smolder out of control, I am sold on an AC module or > microinverter architecture. While RS on a DC array doesn't necessarily > reduce fire risk within the array, it still has the potential to reduce > severity and spread. Nothing is going to prevent all fires. I get that. > We're talking about risk mitigation when it comes to RS. > > As for "dependable string inverters," the one dependable feature is > failure at least once in the module lifetime, accompanied by a shocking > repair bill. > > I'm not a shiny object following kind of guy, but the writing is on the > wall. MLPE is the future. Modular, serviceable, disposable if you will. > Like it or not, Edison is going to lose this battle to Tesla (Tom vs > Nikola). And I live less than 5 minutes away from Tommy E's winter home in > Fort Myers, FL. And I "grew up" in the industry living off-grid in DC > power. But AC distribution wins for safety at various scales. > > > > > > > On Wed, Apr 29, 2020, 9:42 PM <drake.chamber...@redwoodalliance.org> > wrote: > > Rapid Shutdown does not prevent fires; it was originally drafted to allow > firefighters to vent a roof without being hindered by energized PV arrays. > This rule was expanded to include other DC wiring from PV sources. > > As for PV safety, I'd like to see some significant, statistical evidence > that shows there is a major fire danger from PV relative to other sources. > A fire from a solar array gets a lot more press than one from a gas leak, > bad wiring or an ash tray emptied into a wastepaper basket. > > Large public buildings should have all the protection that is available. > Does one size fit all? > > Would it be reasonable to allow residential installations under 12 kW, > with 1/4 of the roof adjacent to the array available for venting, to be > excepted from 690.12? What about sparsely occupied commercial buildings > with ample roof area open for ventilation? > > Many of us have chosen to work with renewable energy technology to lessen > the harms caused by fossil fuel extraction and combustion. The need for > non-carbon based energy sources has become extremely clear. > > The old string inverters still chug along year after year, with little or > no maintenance. Someone must pay for the ongoing maintenance of module > level electronics. Dependable string inverter systems should be allowed > unless statically significant danger can be demonstrated. > > Drake > --- > > > > On 2020-04-29 16:01, Jason Szumlanski wrote: > > I have been to several PV fires for string inverter systems, both > commercial and residential, and have seen many DC systems at serious risk > of fires or in various stages of melted insulation and connectors. Most of > these systems have exhibited good to excellent workmanship. Things just > went wrong. Some were traceable to animal damage, wind, or other > unmitigated factors, and some were unexplained. I disagree that there isn't > justification for rapid shutdown. > > In my opinion, what we need is some additional innovation and competition > in the MLPE space. Reliability is clearly a key factor, but there is no > denying that MLPE has added safety benefits among other benefits. And if > you do enough volume and set up your business for efficiency > (standardization of product offerings), MLPE isn't much more expensive. It > becomes a negligible cost relative to the benefit. The value proposition is > easy to convey. There are limits to this, but for the majority of > residential and small commercial installations, MLPE has become the de > facto standard around here. String inverters are dinos, and replacing 8-12 > year old transformer based inverters is many times more annoying than some > MLPE swaps. I will admit that the roofs around here are pretty easy to > walk, so that is a factor that might not apply to you. > > If you go under due to manufacturer product failures, you are not writing > your contracts right or not charging enough for service issues beyond your > control. I believe that's a red herring. You might suffer some reputation > damage, but for someone that has been installing MLPE for over a decade, > that is totally manageable. Consumers find a service call to replace MLPE a > LOT more palatable than a surprise inverter replacement that could cost > thousands of dollars. People just don't plan for that. > > Regarding rapid shutdown devices, I have also come across a few that > "someone" has bypassed around here. I don't know if they were never > installed properly or disabled/bypassed due to failure. It seemed > suspicious to me at the time. I remember that it made me wonder what good > is a rapid shutdown device if it is easily defeated? That's another > argument for MLPE. It has pretty failsafe MLPE functionality. > > Jason Szumlanski > Florida Solar Design Group > > > > On Wed, Apr 29, 2020 at 10:59 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 > <https://mailtrack.io/trace/link/48741004c205351e1fd6a97d2252c71188d81e71?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=56977124ac95b63a> > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > <https://mailtrack.io/trace/link/b02b5a7da549db8b06246de6ff83408a2d397f16?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=2505444a6c7e76e8> > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > <https://mailtrack.io/trace/link/14307b48a5cf21a014a9767754fb9e3faa3e7b78?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=c9675ece76eedbfe> > > Check out or update participant bios: > www.members.re-wrenches.org > <https://mailtrack.io/trace/link/917ce495ba8f7369e01489e6fbe01e0c529c5c1a?url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=f07b8c2e5b7272c1> > > > _______________________________________________ > 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 > <https://mailtrack.io/trace/link/53e92374f477c4523c84f04b60d9235e042fe484?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=05c2b8925c2cca9b> > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > <https://mailtrack.io/trace/link/64b8ad23a59b7db17c7803f561209f2ec8fcd931?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=851e5d5b1ad7c5c6> > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > <https://mailtrack.io/trace/link/1b9d76c7044d5f000ec9d0dc76ffe05711e667c0?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=06c42b3c6357f539> > > Check out or update participant bios: > www.members.re-wrenches.org > <https://mailtrack.io/trace/link/df315d52bf0b1d7387cef78766012f742e8a6642?url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=c3967f238393d77c> > > _______________________________________________ > 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 > <https://mailtrack.io/trace/link/293b35354380ac1970c6a01c39adb66144564dbf?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=733dc831fc029701> > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > <https://mailtrack.io/trace/link/4b39d310624bc3f043f6541c22bd38f7ae43620b?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=4568169f724351ec> > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > <https://mailtrack.io/trace/link/1a3c4c9b301c7d3a44855867469231a53c1de036?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=8d57f550c03f31fc> > > Check out or update participant bios: > www.members.re-wrenches.org > <https://mailtrack.io/trace/link/55a1c3702348098b72ae7057204e6fe1c0ee44ad?url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=81fe3e4f78a351f9> > > > _______________________________________________ > 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 > Y > > _______________________________________________ > 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
