[RE-wrenches] Solar World Wind Damage

Wed Jan 11 10:26:02 PST 2017

Bill;

Great point,  I have had the exact same trouble not being able to torque 
that center bolt down.  I went back on a DP&W rack that was rocking E-W 
as you described, and brought a big socket (1-1/16"?) and my new 
Milwaukee 1/2" impact driver.  It only took a 1/4 turn more, but what a 
difference: completely tight.  I don't know what the torque spec on that 
bolt is, but its obviously more than I can do with regular wrenches. My 
Pocket Ref shows 257 ft-lbs for a 3/4" bolt.  I'm suspecting that might 
be part of the trouble on the rack that I just reported module failure 
on.  If that rack can start rocking back and forth in high wind, it can 
really cause damage.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 1/11/2017 8:20 AM, frenergy wrote:
> William,
>
>             Looking closely at your picture of the rack failure with 
> the tower in the background, it looks like there is some 
> discoloration/staining/rust? at the main spar center bolt.  I went 
> back to some of my older installs to discover this happening and on a 
> couple of them was able to rock the rack E-W more than I should have 
> been able to.  I think this was discussed on the list a ways back, you 
> may be aware of it that that center bolt needs to be reefed on to 
> prevent any movement.  If the hole in that main spar was compromised 
> and the rack was able to shift back and forth...not sure if that would 
> contribute to failure of the kind you experienced.
>
> Bill
>
> Feather River Solar Electric
> Bill Battagin, Owner
> 4291 Nelson St.
> Taylorsville, CA 95983
> 530.284.7849
> CA Lic 874049
> www.frenergy.net
>
> On 1/10/2017 5:26 PM, William Miller wrote:
>> Ray:
>>
>> I can't say I have a solution to your problem, but I can share some 
>> photos
>> of two similar failures in case you can glean any information from them.
>> See:
>> http://www.millersolar.com/MillerSolar/case_studies/Wind_damage/_wind_dama 
>>
>> ge.html
>>
>> The first failure is a Zomeworks.  On the same exact spot we tried a DPW
>> TOP.  Neither could withstand a funnel effect provided by the 
>> topography.
>>
>> At the same location we installed a roof mount as well that has never
>> failed (to my knowledge, we don't service that customer anymore).
>>
>> I think if you have terrain that is tilted in the correct direction a
>> mount that hugs the ground is best.  That is a lay opinion, however.
>>
>> William
>>
>>
>>
>> Lic 773985
>> millersolar.com
>> 805-438-5600
>>
>> -----Original Message-----
>> From: RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] On
>> Behalf Of Ray Walters
>> Sent: Tuesday, January 10, 2017 2:31 PM
>> To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
>> Subject: [RE-wrenches] Solar World Wind Damage
>>
>> Greetings All;
>>
>> I just had the dreaded call from one of my higher profile commercial
>> clients: a remote radio repeater station had modules ripped off the 
>> frame
>> by high winds.
>> Two  SW285s were damaged.  The wind was strong enough to rip right 
>> through
>> the aluminum side rails.  We had used the proper stainless 1/4"
>> bolt hardware with washers on the inside, etc.  All the hardware was 
>> still
>> tight, it just tore the aluminum past the washers.  This is not a top 
>> down
>> clamp system, but uses bolts through the mounting holes on the back 
>> of the
>> module.  This was all on a DP&W rack with high wind option.
>> In 20 years in business, I've never seen that happen.  Is there a 
>> contact
>> at Solar World?  I'm not getting through on the tech support line I 
>> have.
>> First, I need to know what the wind rating is on the modules blowing 
>> from
>> the back side, and Second, a suggested fix for the remaining modules.
>> One module was completely ripped from the frame and thrown 30 yds (total
>> destruction), a 2nd one has cracks in the Aluminum, but has not let go
>> yet.  I was thinking of adding some angle aluminum on the inside to beef
>> it up.  IMHO, the frames are pretty thin aluminum compared to older
>> modules.  I'll share some pics when available.
>>
>> As always thanks in advance for your comments,
>>
>> -- 
>> R.Ray Walters
>> CTO, Solarray, Inc
>> Nabcep Certified PV Installer,
>> Licensed Master Electrician
>> Solar Design Engineer
>> 303 505-8760
>>
>
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