FYI DP&W has been shipping their TOP racks with lock nuts AND additional steel where the main pivot bolt goes thru the strongback for a while. IF the customer adjusted the rack & he didn't have to touch this bolt it would indicate to me that the nut was loose. Sounds like additional annual maintenance! On Apr 22, 2014, at 9:52 PM, john wrote:
> Dave, > I just had my first ever failure of a DPW TPM-8 with 8 SolarWorld 260's > on it. I installed it late last fall and the customer called last week to > say that it is on the ground. It turned out that the nut on the main pivot > bolt worked its way off, the bolt then worked its way out of one of the ears > and then the other ear bent 90 degrees and let the bolt slide out. The whole > rack then fell to the ground snapping the adjusting bar off. The rack landed > face down and the corner panel broke from hitting the ground first and two > more both hit the concrete base and broke. The other five panels were OK and > the rack parts are all OK except for the adjusting arm and the cap. The main > bolt holes in the strong-back are a little roughed up. We had torqued the > main bolt when we installed it and then the customer adjusted it to spring > angle a few weeks ago. He said he didn't touch the main bolt. The only > thing we noticed on these current racks was the appearance of never-seize on > the main bolt. I would suggest that everyone in windy areas should check the > bolt torque often. I have been told by notable mechanical engineers that the > only way to assure that the nut does not loosen is to use lock-tite. We used > nyloks on all the racks we built in 2009 - 2011. We started buying DPW racks > again when we discovered that shipping was cheaper than renting space for a > rack shop. > > PS Dave, Plan on coming to SolarFest 2014. It's the 20th anniversary > year and we are going to celebrate the good old days of solar. (as well as > the latest and greatest. I still remember when I was the Newbee. Any other > wrenches, I can get you free tickets (worth $75) contact me off-list. > > John Blittersdorf > Central Vermont Solar & Wind. > email cvso...@aol.com > > > -----Original Message----- > From: Dave Palumbo <d...@independentpowerllc.com> > To: 'RE-wrenches' <re-wrenches@lists.re-wrenches.org> > Sent: Mon, Apr 21, 2014 6:32 pm > Subject: Re: [RE-wrenches] Solar World shattered module > > Wrenches, > > I have a customer with one SW 230 poly V2.0 frame (top mount) module that has > shattered glass. It is on a DPW TPM10 pole mount. She noticed it the other > day and does not think that it was hit by anything. I agree that is unlikely > based on the site conditions. > > Other than by a falling tree, thrown rock, or twisted frame – is there > another way that glass shatters on a 65 degree tilted pole mount like this? > We installed the system 2 years ago. The module was on the lower corner of > the array. > · Is it likely that this modules frame was being pressured by the > module(s) above it? TPM has two rows of 5 modules in landscape, so this > bottom module has 4 modules mounted above it. Again it is a top mounted DPW > pole array. > · Or, is there another way that glass shatters on this type of module? > I have not visited the site yet, just received the phone call today. > > David Palumbo > Independent Power LLC > 462 Solar Way Drive > Hyde Park, VT 05655 > (802) 888-7194 > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > t...@swnl.net www.SWNL.net > Solarwinds Northernlights > Serving Mid Coast Maine & Northern California > 207-832-7574 Cl. 610-517-8401 > > Blair "TUMP" May > ******** MAINE'S CHARTER ******** > NABCEP "Certified PV Installer" > > ******** MAINE'S CHARTER ******** > Trace Xantrex "Certified" Dealer / Installer" >
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