Similar to what William mentions, PV Racking makes a clamp-free rail that would support the frame along the entire length of the module. I’m not sure if their solution is engineered for higher wind speeds than a bottom mount or clamp based system, but it might be worth looking into. They are also now listed to UL 2703, which is helpful.
https://www.pvracking.com/ground-mounting-systems/overview/ Garrison Garrison Riegel PV Manager | Solar Service Inc<http://www.solarserviceinc.com/> [p] 847-677-0950 | garri...@solarserviceinc.com<mailto:garri...@solarserviceinc.com> NABCEP Certified PV Installation Professional™ From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of William Miller Sent: Thursday, January 12, 2017 9:11 PM To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Subject: Re: [RE-wrenches] Solar World Wind Damage Ray: Great thread. Thanks for starting it. An idea crossed my mind (and there was plenty of room in there): If one could find a sturdy aluminum channel that happened to fit firmly over your module frame, one could use it along the long access, or maybe even the short access, of the module frame to reinforce it. Bottom mounted, the fasteners would go through a hole in the module frame and the aluminum channel. The outside channel could stiffen up a module pretty significantly. Now the above idea may not be practical, especially if you can’t find the right channel, but I would not be surprised if this idea maybe someone else on the list come up with a related idea that might be better. William [Gradient Cap_mini] Lic 773985 millersolar.com<http://www.millersolar.com/> 805-438-5600 From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org<mailto:re-wrenches-boun...@lists.re-wrenches.org>] On Behalf Of Ray Walters Sent: Thursday, January 12, 2017 6:40 PM To: RE-wrenches <re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>> Subject: Re: [RE-wrenches] Solar World Wind Damage Yep, the old modules were heavier, had a thicker frame, and most importantly: much less total surface area. The old 75 w modules were less than 7 sq ft, compared to almost 18 sq ft of a new 60 cell module. 2-1/2 times the forces on even thinner metal. Not that I want to go back to the good ol' days, but I think the industry got a little too thin on the frame, or at the least, we need a beefier hardware solution for bottom mounted arrays on open frames in high wind locations. I'll send a pic of our fix, once we try it. R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 1/12/2017 6:01 PM, Dana wrote: Bottom side bolt up. But they were 1995 Solarex remember the weight of those frames! ---------------------------------------------------------------------------- Dana Orzel - Great Solar Works, Inc - C - 208.721.7003 NABCEP # 051112-136 : Idaho PV Licence # 028374 E - d...@solarwork.com<mailto:d...@solarwork.com> - Web - www.solarwork.biz<http://www.solarwork.biz> "Responsible Technologies for Responsible People since 1988" P Please consider the environment before printing this email. From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ray Walters Sent: Thursday, January 12, 2017 5:22 PM To: RE-wrenches Subject: Re: [RE-wrenches] Solar World Wind Damage Chris & Dana; Our site is a mountain in Wyoming and does have some focusing effects, so maybe 170 mph is possible. Are your arrays using top down clamps? I think that is apparently stronger, also possibly the 2011 Sanyos look to have beefier frames. However, I looked at their spec sheet and they're only rated at 60 PSF (less than the SWs). From my measurements here of Solar World 4.0 frames, I'm seeing a flange thickness of approx 1.3 mm, while an old Siemens SP 75 has 1.8 mm thick metal. I'm coming up with a fix for the Solar Worlds: 3/4 x 3/4 Stainless steel Angle fits just inside the lip of the module, and will distribute the forces more evenly. The question then is, are we just going to lose the glass next? Anyone have a currently available module that is beefier? I may recommend we swap the whole array out, if we are indeed exceeding the design of the Solar Worlds. Thanks, R.Ray Walters CTO, Solarray, Inc Nabcep Certified PV Installer, Licensed Master Electrician Solar Design Engineer 303 505-8760 On 1/12/2017 2:39 PM, Chris @ The Oasis wrote: Wrenches: We have a ~70KW ground mounted array on the Rocky Mountain front near Choteau, MT. Springs winds are not unusual with 150 to 175 MPH gusts. The system was installed in 2011 (with Sanyo 215W modules). No problems yet; we certainly over-engineered the racks, knowing what high winds there are! Chris Daum Oasis Montana Inc. 406-777-4309 406-777-0830 fax www.oasismontana.com<http://www.oasismontana.com> ________________________________ From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ray Walters Sent: Thursday, January 12, 2017 2:16 PM To: RE-wrenches Cc: Sefchick, Steve Subject: Re: [RE-wrenches] Solar World Wind Damage Hi Bill; Solar World customer support did come through yesterday with flying colors. They got hit by a big storm in the North West. Right now though, they are saying that we exceeded the 64 PSF rated loading to the back of the module. I've pointed out that that would correspond to over 170 mph winds, so I'm not quite ready to concede the warranty. Their engineering team is reviewing my information. As always, the Wrench list experience is invaluable. Are 170 mph winds possible, outside of a tornado or hurricane? Whether or not Solar World stands by their product in this extreme situation, I definitely stand by my installations. I'm taking a snow cat up to replace and reinforce the modules next week, then hopefully get a little help from my supply chain after. My repair costs will be many times the cost of one replacement module anyway. Yes, the 33 mm vs 31 mm refers to the module thickness. I don't have a version 2.5 frame to check the flange metal thickness, and it is conspicuously absent from the specs. I have a good micrometer, and I will compare metal thicknesses of several module brands, because with all the cost cutting, many module manus seems to be using thinner metal lately. As Jay pointed out, we're bolting much bigger modules down with much weaker flanges, and the same hardware we used on a 75 w module, so its not entirely surprising to start seeing high wind failures. R.Ray Walters _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto: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<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org>
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