As far as ground mounted arrays are concerned there is one clear protection mandated by the NEC-the requirement for protection from physical damage for all conductors under 8'.. although this isn't as specific or redundant as rapid shutdown requirements, it typically means conduit or at least some kind of physical barrier with the intention often referenced as protection for children or other unqualified personnel. Not sure if that fits into the point you were making but it seems worth mentioning. Sunny Regards,
Tyrone Houck Oregon Solarworks LLC CCB #204937 LRT #076 541-787-1366 tyr...@oregonsolarworks.com On Mon, Feb 17, 2025, 8:42 PM William Miller via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > Rebekah: > > > > Thank you for your post. > > > > I have looked at UL3741 over and over. Here is what I have gleaned: > After module level RSS was mandated there was a reevaluation of what > voltages were actually dangerous for firefighters to be exposed to. It > turns out 80 VDC is not dangerous and, given all of the circumstances for > firefighters, exposure to voltages that are much higher is safe enough. > For some reason I have not yet grasped, all of the components need to be > matched and tested to achieve the hallowed UL3741 rating. > > > > Module level RSS would have presented a big enough upheaval in the > industry if the equipment needed to comply was safe and reliable. There is > evidence that in many cases it may not be, and that amplifies the > skepticism many feel about the current solutions, and frankly, any future > solutions. > > > > It appears the code making panel, when writing the original module level > RSS requirements, may have been a bit “chicken little” about the need for > RSS. This presents a real credibility issue for code makers. You are > seeing that credibility problem reflected in the discussions here on this > forum. Given the back-peddling, how can we understand and believe what is > really necessary? > > > > Forgive me for being skeptical, but why is it that systems with components > that have been tested together are demonstrably safer than any collection > of high quality components installed carefully and competently? > > > > In my mind there is another disconnect here (pun intended): I can put > high voltage, arc producing and sustaining wiring on a residential roof or > free-standing rack and not be required to protect that wiring in any > specific manner. If I were to install a 240VAC, over-current protected and > de-energizeable air conditioning feeder without conduit, I would be > red-tagged in a hot second. It may be that fire-fighters in protective > clothing can withstand voltage above 80VDC, but can children not wearing > protective “turn-out” clothing? Children mess around on roofs and > underneath ground-mount arrays. Why is the NEC not protecting them by > mandating specific, listed and tested wire management and guarding systems? > > > > Thank you very much and I look forward to your reply. > > > > Sincerely, > > > > William Miller > > > > Miller Solar > > 17395 Oak Road, Atascadero, CA 93422 > > 805-438-5600 > > www.millersolar.com > > CA Lic. 773985 > > > > > > *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On > Behalf Of *Rebekah Hren via RE-wrenches > *Sent:* Monday, February 17, 2025 10:26 AM > *To:* RE-wrenches > *Cc:* Rebekah Hren > *Subject:* Re: [RE-wrenches] RSS: Is it necessary? > > > > I read the wrenches post regularly, as does Brian Mehalic. We have both > been on CMP-4 (responsible for Article 690) for the past three code > cycles. I believe a few other CMP members probably read too. The > International Association of Firefighters ("largest and most influential > labor unions in North America") is represented on CMP-4 and yes they do > have had a lot to say about this issue. > > > > This is definitely not the first time we have heard that certain RS > devices are on balance causing more trouble than they are curing - though > on the other hand some manufacturers have certainly figured out how to make > safe and effective MLPE. > > > I'm a big fan of UL3741, I have been on that UL technical committee for > about 5 years, and it is the best approach I see to expand both off-grid > and grid-interactive solutions that don't require MLPE for RS. SMA for > example is very present and working hard at revisions on that standard > right now. At this point I can't see us having any luck in removing 690.12 > requirements, except perhaps to replace the inside the array boundary > voltage limit with only option as 3741 listing). So please keep asking > manufacturers (inverter/rack) to pay attention to UL3741 and design > products to meet the standard. > > > > Best > > Rebekah > > Licensed Electrical Contractor > NABCEP Certified Solar PV Installation Professional™ 091209-85 > > Tel: 336.266.8800 > > > > > > On Mon, Feb 17, 2025 at 10:59 AM Amos Post via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > Seems like there has been talk of rescinding RSD requirements before on > this forum. It also seems that it might gain some traction if a dedicated > group of installers spoke up to the right people (Code Making Panel for > instance) and put some time into it. I agree that at the very least we > need reliable RSD equipment, and my preference would be less vs more. > > > > Does anybody know if any sort of RSD is being required in Europe (not that > we follow their electrical codes/ideas…just curious)??? > > > > > > > > Amos Post > Integrity Energy > W 802.763.7023 > C 802.291.2188 > ienergyVT.com <http://www.ienergyvt.com> > > Facebook <https://www.facebook.com/integrityenergyllp?ref=hl> > > > > On Feb 17, 2025, at 12:30 PM, david quattro via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > > > It seems anecdotal until it happens to you. > > My mention of civil disobedience has been answered clearly with a “No” > in this forum, and I'm fine to hear that. > > I'll clarify a few points as to why I honestly think RSD has been a > huge and costly mistake. I genuinely think RSD requirements should be > terminated immediately. If the technology were more robust and if it worked > consistently I wouldn't protest. But *all* the products I've tried have > been trouble. > > William, respectfully your analogy to seat belts is not an appropriate > comparison to Rapid Shutdown. Seat-belts were required in all new cars > starting in 1968 because there was statistical evidence supporting their > tremendous efficacy in saving human life. Currently seat belts save about > 15,000 lives per year. > > Contrasting to RSD: was implemented because of the following paranoid > fairytale scenario - “A firefighter is on a burning solar roof in the > daytime, and wearing a metal axe at their hip. the poor guy/gal falls into > live solar glass, and shatters it. The fall is so forceful that the > heavy-duty fireman’s suit is punctured. Electricity conducts through the > axe blade, through the suit, contacts the skin, and a DC circuit is > completed through their body.” > > As far as I know, this has never happened once anywhere on earth. Let’s > be honest - this scenario has an incredibly low chance of ever happening in > all the future of humanity. So considering that RSD has never helped anyone > yet, and probably never will... How many fires can be attributed to RSD? > How much property damage has occurred because of these fires? > > The best path to safety for firefighters is by preventing fire > disasters in the first place. Fires spread. Any fire that happens > endangers property owners, tenants, business owners, neighbors, shoppers, > bystanders, nearby forests, etc. RSD manufacturers aren't doing a good job > right now, so we are seeing low quality unreliable electronics on the roof. > I will stick my neck out and admit that installers are not always perfect. > Humans make mistakes - sometimes in initial construction, and sometimes > during repair and maintenance (i.e. when hunting down failed RSD's which > happens far more than it should). > > At this time, these devices are not being designed to withstand > reality. When problems happen, manufacturers are quibbling. They ignore you > until you go away, or until you sue them. > > This level of "safety" is not important, and in fact RSD is causing > fires every year. > > > > > > > > > > > > On Sat, Feb 15, 2025 at 11:38 AM William Miller <will...@millersolar.com> > wrote: > > David, Ray: > > > > I have not had any problems with the Tigo RSS equipment I have installed > and I have had minimal problems with optimizers and micro-inverters (which > are also RSS equipment). Apparently others have had failures. We don’t > know statically how serious this problem is—the posts here are purely > anecdotal. > > > > We also have not heard from the other side of the debate: the fire > fighters. > > > > Based on lack of verifiable information I can not personally conclude that > RSS is all problem and no benefit. > > > > To declare that the concept is flawed because the equipment available is > not reliable is like saying we should not be required to install airbags > because a bad batch of them was manufactured. We are seeing problems with > the equipment needed to implement a safety requirement. That observation > does not logically conclude the safety requirement is not valuable. > > > > I hesitate to dismiss any safety requirement out of hand. Safety systems > are designed to save lives and protect from injury, and most of them do. I > am glad to have anti-lock brakes, smoke detectors and air bags. I have > also found it quite handy to initiate RSS to allow me to work more safely > on solar circuits. > > > > Does anyone on this installers forum have contacts in the fire-response > community that can comment on the their side of the issue? If RSD is > really necessary for safety, then I will do my best to install good > equipment properly and hold manufacturers accountable for shoddy > solutions. If RSD is not that effective we need to discuss undoing the > code requirements. > > > > Sincerely, > > > > William Miller > > > > Miller Solar > > 17395 Oak Road, Atascadero, CA 93422 > > 805-438-5600 > > www.millersolar.com > > CA Lic. 773985 > > > > > > *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On > Behalf Of *david quattro via RE-wrenches > *Sent:* Saturday, February 15, 2025 6:05 AM > *To:* RE-wrenches > *Cc:* david quattro > *Subject:* Re: [RE-wrenches] Tigo inverter experience > > > > RSD is the worst thing to happen to solar. Has anyone considered civil > disobedience? > > I wonder what would happen if all the installers banded together and > refused, as a united industry ‘brotherhood.’ WE are the ones stuck with the > bullshit in the aftermath. > > I’m not being snarky here , this a genuine question to the group: > Does anyone have *good* experience with RSD? i.e. you’re really glad > RSD was there, and you genuinely feel safer? you’re glad and happy to > comply with this code and you look forward to continuing to use RSD for the > rest of your career? > > > > > > > > > > On Fri, Feb 14, 2025 at 3:40 PM Ray Walters via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > it seems silly that we are required to install these extra pieces of > equipment for added "safety", that are actually a fire hazard on the roof. > Just to survey again: how many homes have been saved by RSD? How many fire > fighters have actually actuated the RSD system, so that they could hack > through the array to vent the roof? > > I think it should only be required if you have covered so much of the roof > with PV, that the fire dept can't access uncovered roof to do their > venting. The whole premise of RSD is flawed. IMHO, its just another > effort to block the wider adoption of solar. > > When it comes to off grid, RSD causes such a decrease in reliability to > amount to a decrease in safety, due to possible loss of communications, > water, and heat. Add the fire hazard and RSD is really not making our > customers' lives better. > > Ray Walters > Remote Solar > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > 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 > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > > > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > 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 > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > 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 > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > >
_______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org 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 There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
