Re: [RE-wrenches] Attaching Array To or Through Ply
Chris, Jason, all; I really like the idea of double clamping in serious situations. I wish we had had this conversation about 2 months ago, before we installed 2 more systems in Puerto Rico. I definitely would have suggested the team try that. Save it for next time, and hopefully we get a bit better with new found idea on each install. Thanks again for great ideas Wrenches, Ray On 3/31/2023 2:15 PM, Jason Szumlanski wrote: Hi Ray, I'm happy to have some confirmation from another major storm's impact. My father has a home in Dominica, which was hit by Maria with 165 mph winds before it moved on to PR. He had a mixed bag of results with solar panels (forget about the pole mounts I installed there over 20 years ago!) I was just reminded by your email about something I plan to try. For panels that are pitched on flat roofs, I am going to double up and install BOTH IronRidge CAMO and UFOs. With proper planning, it would be pretty easy to install with UFOs first and then go back and snap in all of the CAMOs without much labor cost and an acceptable material cost for the added peace of mind. Jason Szumlanski Principal Solar Designer | Florida Solar Design Group NABCEP Certified Solar Professional (PVIP) Florida State Certified Solar Contractor CVC56956 On Thu, Mar 30, 2023 at 9:45 PM Ray Walters via RE-wrenches wrote: Hi Jason; I was like you: thinking good ol' bottom mounting with SS hardware was the best. All of us old wrenches were wrong. The top down mounting system is much stronger. I've only had a handful of failures over 25 years, and all were bottom mounted. The module completely ripped off the rack, leaving the stainless hardware, washers, etc with a thin sliver of module frame between. For repairs, I come back and install 1/2" SS angle on the inside of the module frame to spread the load more. ANDon new installs, no more bottom mounting. If you compare today's modules with old 12v models from 20 years ago, you'll see: much thinner metal on the bottom frames now. Meanwhile I saw several systems survive Hurricane Maria in Puerto Rico: all top down mounting. You are correct that the failures come from the modules themselves letting go, not the racking. Either the wind itself is so strong as to blow the glass, then the frame looses its structure, or flying debris breaks the glass. There were some MW PV fields that got tore up pretty bad. So no, ground mounts definitely can be destroyed. They had tornadoes moving inside of the hurricane, and you could see it in the damage, 50' wide strips of total carnage with undamaged modules a few feet away. Like you said, The storm has a mind of its own. As far as mid clamp T bolt failures, I can confirm that probably a majority are not installed correctly, especially Unirac, which are terrible to get the T lined up right. I've done numerous inspections world wide, and a signifcant % of racking I looked at was NOT installed correctly. 1) The Ts not squarely lined up with the rail, 2) massive over torqueing, to the point the bolt can't be reversed 3) under torqueing, to the point the modules had slipped down a little. Most of these problems come from installing with an impact driver. Impact drivers are a great tool (so is a hammer), but you got to know when and where to Not use them, too. They're great for installing the lags and L feet, but then get that tool off the roof. Use an electric screw driver, socket wrench, or *drill with a clutch* set low to snug up the clamps, and then final torque with a torque wrench. Period. Ray Walters Remote Solar Former NABCEP 2004-2016 On 3/30/2023 4:34 PM, Jason Szumlanski via RE-wrenches wrote: That would be great if it were possible! I'm not sure how you bottom mount a flush mount array. For a brief period many years ago, I was building solar trailers. I would bottom mount 4-6 panel arrays on rails in my warehouse and then hoist them up and through-bolt the whole array on the top of a trailer. I wasn't about to allow a trailer going 80 mph on the interstate to have panels mounted on the roof with mid-clamps! I had no idea what I was doing, but I had enough sense to know that would have been a bad idea! I did provide feedback to IronRidge regarding a handful of failures from Hurricane Ian, but most of the issues we saw were most likely related to catastrophic module failure. After all, they are only tested to 5600 Pa uplift for even the best options we have on the market and 2400 Pa for some (which I refuse to use). The mid-clamp T-bolts tearing out of the rail are slightly concerning, but this was pretty rare, and honestly it could be related to installation torque issues, misalignment, or coupled with module failure. There was no
Re: [RE-wrenches] Attaching Array To or Through Ply
Hi Ray, I'm happy to have some confirmation from another major storm's impact. My father has a home in Dominica, which was hit by Maria with 165 mph winds before it moved on to PR. He had a mixed bag of results with solar panels (forget about the pole mounts I installed there over 20 years ago!) I was just reminded by your email about something I plan to try. For panels that are pitched on flat roofs, I am going to double up and install BOTH IronRidge CAMO and UFOs. With proper planning, it would be pretty easy to install with UFOs first and then go back and snap in all of the CAMOs without much labor cost and an acceptable material cost for the added peace of mind. Jason Szumlanski Principal Solar Designer | Florida Solar Design Group NABCEP Certified Solar Professional (PVIP) Florida State Certified Solar Contractor CVC56956 On Thu, Mar 30, 2023 at 9:45 PM Ray Walters via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > Hi Jason; > > I was like you: thinking good ol' bottom mounting with SS hardware was the > best. All of us old wrenches were wrong. > > The top down mounting system is much stronger. I've only had a handful of > failures over 25 years, and all were bottom mounted. The module completely > ripped off the rack, leaving the stainless hardware, washers, etc with a > thin sliver of module frame between. For repairs, I come back and install > 1/2" SS angle on the inside of the module frame to spread the load more. > ANDon new installs, no more bottom mounting. If you compare today's > modules with old 12v models from 20 years ago, you'll see: much thinner > metal on the bottom frames now. > > Meanwhile I saw several systems survive Hurricane Maria in Puerto Rico: > all top down mounting. You are correct that the failures come from the > modules themselves letting go, not the racking. Either the wind itself is > so strong as to blow the glass, then the frame looses its structure, or > flying debris breaks the glass. There were some MW PV fields that got tore > up pretty bad. So no, ground mounts definitely can be destroyed. They had > tornadoes moving inside of the hurricane, and you could see it in the > damage, 50' wide strips of total carnage with undamaged modules a few feet > away. Like you said, The storm has a mind of its own. > > As far as mid clamp T bolt failures, I can confirm that probably a > majority are not installed correctly, especially Unirac, which are terrible > to get the T lined up right. I've done numerous inspections world wide, > and a signifcant % of racking I looked at was NOT installed correctly. > 1) The Ts not squarely lined up with the rail, > 2) massive over torqueing, to the point the bolt can't be reversed > 3) under torqueing, to the point the modules had slipped down a little. > > Most of these problems come from installing with an impact driver. Impact > drivers are a great tool (so is a hammer), but you got to know when and > where to Not use them, too. They're great for installing the lags and L > feet, but then get that tool off the roof. > > Use an electric screw driver, socket wrench, or *drill with a clutch* set > low to snug up the clamps, and then final torque with a torque wrench. > Period. > > Ray Walters > Remote Solar > Former NABCEP 2004-2016 > > > On 3/30/2023 4:34 PM, Jason Szumlanski via RE-wrenches wrote: > > That would be great if it were possible! I'm not sure how you bottom mount > a flush mount array. For a brief period many years ago, I was building > solar trailers. I would bottom mount 4-6 panel arrays on rails in my > warehouse and then hoist them up and through-bolt the whole array on the > top of a trailer. I wasn't about to allow a trailer going 80 mph on the > interstate to have panels mounted on the roof with mid-clamps! I had no > idea what I was doing, but I had enough sense to know that would have been > a bad idea! > > I did provide feedback to IronRidge regarding a handful of failures from > Hurricane Ian, but most of the issues we saw were most likely related to > catastrophic module failure. After all, they are only tested to 5600 Pa > uplift for even the best options we have on the market and 2400 Pa for some > (which I refuse to use). The mid-clamp T-bolts tearing out of the rail are > slightly concerning, but this was pretty rare, and honestly it could be > related to installation torque issues, misalignment, or coupled with module > failure. There was no widespread or definitive reason for rail failures at > the clamp locations. > > I would suggest that FEMA's recommendation is overkill and not based on > much science, but conclusions based on anecdotal information without > statistical data. It should be scrutinized. I think it would be a good idea > to consider bottom mount for ground racks and tilt mounts that allow it, > but it's just not practical or possible in the vast majority of residential > installation cases. On that note, I am not aware of any ground mount > failures around
Re: [RE-wrenches] Attaching Array To or Through Ply
I had worked in USVI after those two hurricanes and I don't think FEMA is overkill. Their design manual is very thorough. It considers the factors mentioned here. Having done a fair amount of high wind compliance engineering for structures, the FEMA approach is just something you have to organize to install. Yes it will take longer. Chris On 3/30/2023 6:34 PM, Jason Szumlanski via RE-wrenches wrote: That would be great if it were possible! I'm not sure how you bottom mount a flush mount array. For a brief period many years ago, I was building solar trailers. I would bottom mount 4-6 panel arrays on rails in my warehouse and then hoist them up and through-bolt the whole array on the top of a trailer. I wasn't about to allow a trailer going 80 mph on the interstate to have panels mounted on the roof with mid-clamps! I had no idea what I was doing, but I had enough sense to know that would have been a bad idea! I did provide feedback to IronRidge regarding a handful of failures from Hurricane Ian, but most of the issues we saw were most likely related to catastrophic module failure. After all, they are only tested to 5600 Pa uplift for even the best options we have on the market and 2400 Pa for some (which I refuse to use). The mid-clamp T-bolts tearing out of the rail are slightly concerning, but this was pretty rare, and honestly it could be related to installation torque issues, misalignment, or coupled with module failure. There was no widespread or definitive reason for rail failures at the clamp locations. I would suggest that FEMA's recommendation is overkill and not based on much science, but conclusions based on anecdotal information without statistical data. It should be scrutinized. I think it would be a good idea to consider bottom mount for ground racks and tilt mounts that allow it, but it's just not practical or possible in the vast majority of residential installation cases. On that note, I am not aware of any ground mount failures around here from Hurricane Ian except for submerged arrays that were washed away from storm surge (Yikes!). And the handful of failures that we observed were a drop in the bucket relative to the installed numbers here. One other thing. Wind direction, upwind obstructions/windbreaks, and luck have a huge amount to do with failures (of both PV and roofs themselves). These storms pick winners and losers. You will have ten houses in a row with pool enclosures mangled, and one in the middle that is unscathed. It's crazy to see. We have lots of gated communities with houses close together. When wind accelerates between houses, it can topple air conditioning units and pool equipment. If you look hard enough at where the wind was coming from and the surrounding area, you can really see how there are so many factors that come into play. Jason Szumlanski Principal Solar Designer | Florida Solar Design Group NABCEP Certified Solar Professional (PVIP) Florida State Certified Solar Contractor CVC56956 On Thu, Mar 30, 2023 at 7:35 AM Christopher Warfel via RE-wrenches wrote: If you look at FEMA's design guide for solar installations in FL and the Caribbean, the recommended module to rail attachment method is back to using the attachment holes in the solar module. Chris On 3/30/2023 5:56 AM, Jason Szumlanski via RE-wrenches wrote: This thread has morphed into more than it started as, and for good reason. I want to provide some practical/anecdotal information, having just gone through arguably the most catastrophic wind event in Florida's history (Ian) since the boom in solar energy started, and another major wind event (Irrma) just 5 years ago. First, Aside from the Sunmodo and Quickbolt decking-only products, I would check out IronRidge's new entrant into the market, the IronRidge HUG. If you can't find info on it, ask your distributor or IronRidge sales rep. They have data on truss attachments and also missed truss installation procedures. It's a unique approach to a dual-purpose product, and they did a stellar job on the engineering documentation in my opinion. Ok, now let's get to my most important point. Due to Hurricane Ian, the number of roofing PV attachments that I have witnessed that failed due to fastener pull-out (mine or competitors): ZERO The only building where we had any mounts fail was on a flat roof with pitched panels and Anchor Products mounts on TPO membrane, but the mounts themselves did not cause the failure. The roofing system itself failed, causing a small section of the PV system to fail. But even in that case, the following applies... The weak point in a well-designed and installed system is not the fastener or flashing system. The module to rail connection is where we saw failures. These failures fell into a few categories: * Windborne debris struck panel, panel frame
