I don't see any indications that MLSD is making solar safer. It's increasing system cost and maintenance expense but the safety benefits haven't revealed themselves to me yet. Adding all the extra components increases the risk of failure in the system and increases the time our technicians have to spend on the roof. This extra time on the roof reduces overall safety for the installers. Also as per lussers' law, the system is only as reliable as the least reliable component times the reliability of all the other components in the system. By doubling the number of connections with MLSD we're increasing the likelyhood of system failure and exposing ourselves to a potential for increased downtime and lower productivity, this means a technician may have to spend more time on the roof dealing with maintenance issues and less time bringing more production online. Additionally, any potential safety benefit from MLSD hinges on the product performing properly, and if that product fails (which we see regularly) then it could create a false sense of safety for the people and firefighters that makes them less safe than they would be if the MLSD was not present at all. With that said, I recently became aware of a product called PVSTOP that looks like it may be a real solution to the concerns for firefighter safety in the event of a fire, that actually guarantees the panels are de-energized. Apparently it's been used in australia for some time now. It's fairly inexpensive and the cost will likely come down further as they continue to achieve economies of scale. https://www.pv-stop.com/
Your thoughts are appreciated, Sky Sims https://EcologicalSystems.org <https://ecologicalsystems.org> 732-462-3858 f)732-462-3962 "Just an old wrench" On Fri, Feb 5, 2021 at 11:55 AM jay <jay.pe...@gmail.com> wrote: > HI Andrew, > > I’ve been pondering your comments, and I hope you can elaborate on why you > don’t think MLPE has anything to do with firefighter safety? > And I guess I lump into the firefighter safety, homeowner safety as well. > > As to the code meeting. I have it on pretty good info that a very senior > member of the the NEC was pushing MLPE. It is true that the string > inverter OEM’s pushed back hard and that is why for the first time(?) a > code rule had a 2 year delay in implantation of the NEC 2017. > > Thanks > > jay > > peltz power > > > > On Feb 4, 2021, at 12:49 PM, Solar Energy Solutions < > solarenergysoluti...@yahoo.com> wrote: > > Dear All, > > I apologize for letting this conversation get a little stale before being > able to comment further. > > Before I reply, I would like to say I don't believe MLSD has anything to > do with firefighter safety. If being on dangerous roofs was really a > concern, steep roofs, slate roofs, metal roof, wet metal or shake roofs and > snow on roofs would get the same kind of scrutiny as solar on roofs. I can > only guess and think that some HUGE solar hating utility company devised > this whole firefighter safety thing. It is also my understanding none of > the string inverter folk turned up to the code development meetings where > MLSD was determined and you can guess who was. But much of this is only > rumor and the dark thoughts of a solar bozo. > > I HATE the hassle and maintenance issues of MLSD. I loved string > inverters and hated to see them go. So far as I can tell the US is the > only place on planet Earth to make String inverters all but illegal. This > said... a picture is worth a thousand words. All of the attached photos of > systems had the wire management done very well. If you look at the metal > roof photo you can see a small hole in it from the arc. I have many more > photos of different squirrel damaged systems. Ground Fault protection has > saved the inverters, but not the roofs. > > I don't really like the idea of squirrel guards. It seems like I may be > creating another problem down the road that I can't really imagine. Debris > build up could be an issue. Rainwater could back up from a damn and get > under shingles and into the cavity of the house. For me the easiest thing > that could be done is for some kind of a bittering agent to be part of the > wires so that one little lick would send a critter looking for a better > food source. > > Your Friendly Neighborhood Solar Man, > > https://www.dropbox.com/s/3g5c57nqke9x7b2/Fire%201.JPG?dl=0 > Fire 2.JPG <https://www.dropbox.com/s/ksd5yhfsammybdz/Fire%202.JPG?dl=0> > > Fire 2.JPG > Shared with Dropbox > <https://www.dropbox.com/s/ksd5yhfsammybdz/Fire%202.JPG?dl=0> > https://www.dropbox.com/s/3g5c57nqke9x7b2/Fire%201.JPG?dl=0 > Fire 3.JPG <https://www.dropbox.com/s/vtehaht4rlcrco7/Fire%203.JPG?dl=0> > > Fire 3.JPG > Shared with Dropbox > <https://www.dropbox.com/s/vtehaht4rlcrco7/Fire%203.JPG?dl=0> > Fire 4.JPG <https://www.dropbox.com/s/bjm01bkquds1b31/Fire%204.JPG?dl=0> > > Fire 4.JPG > Shared with Dropbox > <https://www.dropbox.com/s/bjm01bkquds1b31/Fire%204.JPG?dl=0> > Fire 5 Voltair the culprit.jpg > <https://www.dropbox.com/s/vv6f7je8asgx3ih/Fire%205%20%20Voltair%20the%20culprit.jpg?dl=0> > > Fire 5 Voltair the culprit.jpg > Shared with Dropbox > > <https://www.dropbox.com/s/vv6f7je8asgx3ih/Fire%205%20%20Voltair%20the%20culprit.jpg?dl=0> > Metal Roof Squirrel damage.JPG > <https://www.dropbox.com/s/u4fryj0hleusphd/Metal%20Roof%20Squirrel%20damage.JPG?dl=0> > > Metal Roof Squirrel damage.JPG > Shared with Dropbox > > <https://www.dropbox.com/s/u4fryj0hleusphd/Metal%20Roof%20Squirrel%20damage.JPG?dl=0> > Shadow of scorched squirrel on metal roof.JPG > <https://www.dropbox.com/s/3bnrgmqzkryu3w5/Shadow%20of%20scorched%20squirrel%20on%20metal%20roof.JPG?dl=0> > > Shadow of scorched squirrel on metal roof.JPG > Shared with Dropbox > > <https://www.dropbox.com/s/3bnrgmqzkryu3w5/Shadow%20of%20scorched%20squirrel%20on%20metal%20roof.JPG?dl=0> > > > *Andrew Koyaanisqatsi* > *President* > > > *Solar Energy Solutions, Inc.The BRIGHT CHOICE* > *Since 1987,* > * helping you and your Portland neighborsmove** towards an > environmentally sustainable future.* > > *503-238-4502www.SolarEnergyOregon.com <http://www.solarenergyoregon.com/> > * > > > On Friday, January 29, 2021, 8:15:28 PM PST, Ray <r...@solarray.com> > wrote: > > > I totally agree; where else does the NEC allow loose single conductor > cables to run unprotected? outdoors? All because the module manus and > industry in general has made no effort, zero, to accommodate any type of > electrical industry standard K/Os for conduit, or TEK 90 (great stuff > BTW). If we hadn't gone this wacky direction, starting about 15 years > ago, we probably wouldn't be having this conversation, because there would > be much less reason for MLSD. > > I could see whips of TEK 90 that plugged into polarized 2 pole quick > connects mounted integrally to a J box on the back of each module. > > [image: Teck 90 Armoured Power & Control Cable 600V CSA FT4 HL ...][image: > Llt M10 Bayonet Lock Molding Waterproof Cable 2 Pole ...] > > Ray Walters > Remote Solar > 303 505-8760 > > On 1/29/21 8:10 PM, Hilton Dier wrote: > > There’s a buried-in-plain-sight issue here that has bugged me for years. > > In the bad old days we had to hard wire into J-boxes on the backs of modules. > A pain, but it meant that, if necessary, we could install conduit from the > module to the combiner box. Now we have convenient pigtails. > > However, we are stuck with #10 PV wire hanging under the module from the box > to the nearest attachment point. There are all sorts of trays and wire > management systems, but there’s always that one loop of wire hanging in the > open. > > I know that the module industry has near zero margins as a commodity market. > Perhaps one manufacturer could differentiate themselves by making a module > with either 1) armored pigtails, or 2) provision for some kind of conduit > starting at the J box. > > I’m thinking of all the various back covers installers have to improvise on > ground mounts. I’m thinking of squirrels and ice dams. > > Why can’t there be a module with the equivalent of Teck 90 cable on it? > > Maybe I’m just being naive. > > Hilton > > Hilton Dier III > Renewable Energy Design > Missisquoi River Hydro LLC > > _______________________________________________ > 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 > > 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 > > 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 > > 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 > > --
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