[RE-wrenches] S-5 clamps on the standing seam roof

[North Texas Renewable Energy Inc]

Paul
I bid a 21' x 16'  PV array on a 1.5:12 standing seam roof using the S-5 PV kits. http://www.s-5.com/clamps/index_686.cfm The seams were 1-1/2" high with a half inch folded lip on top. It seemed like a good idea to mount the modules using the 4-point method you suggest. 
After clamping a sample S5 to a random rib, I realized the seam, and the attached S5 were not sitting level. After trying several more ribs I realized that all the ribs were leaning slightly. It's not a problem for shedding water but it meant the plane of the module mounting surface was way uneven. 
I ordered Unirac Lite rails and end clamps, and ate that cost. 
Once the 16' N-S rails were attached and torqued, three of us grabbed the one piece rail near the ends and in the middle and after several heave-ho's managed to bend the ribs to align pretty close to flat across the rail tops. We checked with a carpenters level across each pair of rails to be sure. The were close enough that tightening the module clamps didn't have to pull the rails into a proper alignment. 
We then went back and re-torqued all the clamping screws and retightened the hex bolts on the assumption that they probably loosened while being man handled.
Using the S5's alone would have been a huge chore trying to straighten the steel ribs, was the lesson learned. It was also easier to adjust and level the height of the rails using the L-foot slots as opposed to the jam nuts on each individual S5. 
The MetlSpan ribs seem to be the same style and are mechanically crimped during installation. I suspect they will have the same issues.
Jim Duncan
North Texas Renewable Energy Inc
817.917.0527
ntrei at earthlink.net
www.ntrei.com  

  ----- Original Message ----- 
  From: Paul Lyons 
  To: re-wrenches at lists.re-wrenches.org 
  Sent: Wednesday, August 26, 2009 5:32 PM
  Subject: [RE-wrenches] S-5 clamps on the standing seam roof


  Hello RE-Wrenches -

   

  We are working on the design details for S-5 clamps on a standing seam roof with the PV modules mounted directly on the clamps at four points (i.e. no horizontal rails).  The roof is made by Metl Span of Lewisville, Texas.  The building is in New England and the roof has a slope of 0.5:12 

   

  Have any of you had experience with these clamps and/or this particular roof manufacturer?  

   

  Paul Lyons, P.E.

  Zapotec Energy Inc.

  675 Massachusetts Ave

  Cambridge, MA 02139-3309

  Tel: 617-547-5900  ext.201

  Fax: 617-547-5901

  Mobile: 617-285-0634

  Email: Lyons at ZapotecEnergy.com

   

   



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