Announcement

Collapse
No announcement yet.

Worry about reverse tilt setup?

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Worry about reverse tilt setup?

    I just have my first solar panel project installed on my roof. Now I am worry about it.
    My installer worked with his solar designer and proposed reverse tilt to improve efficiency of north side panels by making them 10 degree south facing reverse tilt.
    I love the idea but when installed I am concern about wind might up lift these panels and blow them away.
    Some say the installation is ugly, I am not too concern about cosmetic but safely.
    My roof is pitched with around 20 degree, my house is middle of three connected house.

    I am thinking about hiring a structure engineer to ensure it can survive wind speed of 118MPH.
    My solar design paperwork says this setup can hold:
    WIND 118 MPH
    SNOW 20
    PSF - 4.0
    The building is in NYC.
    Iron ridge X100 with longest rail span 6 feet.

    Please see 5 pictures attached, I am open to any feedback.

    Thank you all
    Tomato
    Attached Files

  • #2
    The installer and your city building code should have demanded wind and roof load calcs BEFORE starting the install.
    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister

    Comment


    • #3
      Originally posted by Mike90250 View Post
      The installer and your city building code should have demanded wind and roof load calcs BEFORE starting the install.
      Right, The installer should have an engineer on staff who did the required calculations. I would ask them for some documentation.

      Comment


      • #4
        I'm unsure of NYC building codes and I don't like sounding like a bureaucrat, but If it's been signed off by the city, and the permits are genuine, complete and in order, its good to go. However, after seeing the pictures, I'd sure have my doubts about it.

        If I was the OP, I'd root around in the permits and paperwork and see if any review was done for wind and seismic for the arrays and the roof, look for the calcs and drawings and/or look for exemptions/variances that may have been granted by the city.

        There's always the possibility, and I'm sure not saying that's what happened, and however slight, that some of the docs are less than genuine in the sense that some engineer may have sold out or a stamp/seal forged, expired or stolen. Wouldn't be the first time that ever happened. If the OP is in doubt, which I can empathize with, take the whole package to a P.E who claims proficiency in such matters and have a chat. Just know you might be opening up Pandora's Box.

        Comment


        • #5
          Knowing a little about the electric codes in NYC I am very surprised the AHJ approved that installation. But then again who knows what the relationship is between the contractor and code department.

          Comment


          • #6
            Originally posted by SunEagle View Post
            But then again who knows what the relationship is between the contractor and code department.
            Indeed !

            Comment


            • #7
              Originally posted by tomatoUSA

              I do have the design paperwork. It says:
              WIND 118 MPH
              SNOW 20
              PSF - 4.0

              But nothing on:
              What size of rail to use*
              How far rail span should be
              Distance from lower leg to upper leg

              My contract with the installer says Iron ridge X100 but when comes the installation date they gave me half X10 and half X100.
              They claim X10 is good enough for shingle mount (non tilt) and X100 for reverse tilt mount.
              The owner of the company said X10 is good enough so I back down even I should be getting X100 for the whole project.

              I am not too concern about the designer calculation but I am worry about the if installation is done right?
              I was up on the roof with them 4 days. The installer was not given detail info on the reverse tilt setup.
              It seem like the installer technician never had done reverse tilt.
              The installer technician basically work with the material he had at the time and setup best he can.
              At one point we both agree tilt leg is too short for panels to be mounted correctly.
              But Iron ridge don't make longer tilt leg. In fact, iron ridge don't even support reverse tilt setup.
              So to make it work, we had to move the tilt leg closer to middle of panels.
              Which according to LG that is not the ideal placement for rail.

              I am thinking design is only good if installation is done right. Otherwise, my solar structure will withstand 118MPH wind on paper but not on roof.
              I have attached part of the design paperwork.

              Thanks
              If you and the installer are the only ones on the roof during and/or after install, that is, no AHJ inspections, IMO, you may have a set of problems. Anyone besides you and the installer been up there?

              I also don't see any stamps or signatures on anything you've attached. Do you have a signoff for the work from the building dept. or whoever/whatever agency in city gov. that's the responsible authority, or any documentation that indicates any proper authority has even seen the design much less reviewed and approved it ?

              Comment


              • #8
                Originally posted by J.P.M. View Post

                If you and the installer are the only ones on the roof during and/or after install, that is, no AHJ inspections, IMO, you may have a set of problems. Anyone besides you and the installer been up there?

                I also don't see any stamps or signatures on anything you've attached. Do you have a signoff for the work from the building dept. or whoever/whatever agency in city gov. that's the responsible authority, or any documentation that indicates any proper authority has even seen the design much less reviewed and approved it ?
                I assume my installer has signed and stamped version.
                From what I heard, city inspector don't go up to the roof to check.

                So basically you think if city inspector see it and don't complaint then it is safe?
                You don't think I should hire a structure engineer to check it out?

                Thanks

                Comment


                • #9
                  Originally posted by tomatoUSA View Post

                  I assume my installer has signed and stamped version.
                  From what I heard, city inspector don't go up to the roof to check.

                  So basically you think if city inspector see it and don't complaint then it is safe?
                  You don't think I should hire a structure engineer to check it out?

                  Thanks
                  I think you should do whatever you think is safe and what you believe keeps you out of trouble. If the inspector didn't go up and actually inspect the job, I'm not sure what the use is in paying for permits other than notifying the city/county that there's a reason to raise an assessment.

                  Look: Anyone looking at the photos you supplied that has more than one eye and one butthole can probably quickly come the opinion that you got screwed on a crappy install that you probably paid too much for. And the docs you supplied here don't appear to have been signed off or maybe not even reviewed by the AHJ.

                  How it usually works goes something like this: You sign a contract for a PV system. The vendor then does a design based on what you want. The vendor then takes the design, including calcs, drawings and other docs/related stuff as required by the AHJ and submits all of it for review and approval and then changes the design as the AHJ and applicable codes dictate as found by their review. After design approval - not before - construction can begin with any hold points or intermediate inspections done by the AHJ as called out in the approval. Then, after construction is complete, a final inspection usually takes place. If all's well, the approval is given. All that is somewhat separate from any approvals or paperwork required by your utility. The utility often works with/requires AHJ approval but may have additional hoops to make you jump through.

                  At this time you've heard, but apparently don't know for sure if any AHJ even set foot on the jobsite and from what anyone here has seen, you have no signed off docs to show the design was reviewed or approved.

                  Do what you think is best, but if I was in your shoes, I'd think my butt was hanging out a mile and I'd start with whatever authority was supposed to review/approve/inspect the job and find out what they know about it and what they think is the state of any review/approval/inspections on the job.

                  Just my $ 0.02.

                  Comment

                  Working...
                  X