ground mount racking

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  • 1oldmf
    Junior Member
    • Nov 2017
    • 5

    ground mount racking

    searching "engineered" plans, or approved system.
    or help on getting my mounts plans "PE" stamped.
    plans are for 3 strings, 12 panels ea string (240w) ground mounted.
    anyone ever get their plans engineered?
    or know of someone REASONABLE.
    one local engineer said $1800 for stamped plans.

    in AZ, where the sun (almost) always shines!
  • J.P.M.
    Solar Fanatic
    • Aug 2013
    • 14920

    #2
    Originally posted by 1oldmf
    searching "engineered" plans, or approved system.
    or help on getting my mounts plans "PE" stamped.
    plans are for 3 strings, 12 panels ea string (240w) ground mounted.
    anyone ever get their plans engineered?
    or know of someone REASONABLE.
    one local engineer said $1800 for stamped plans.

    in AZ, where the sun (almost) always shines!
    Many jurisdictions require P.E. design/review/stamping for the mechanical portion of a design, particularly for ground mounting that's not a mostly "standard " roof mount.

    Depending on the M.E.'s experience level w/PV racking/ground mounting, you may do a bit better by shopping around. Rates for P.E. services vary a fair amount. Don't know where you are but rates of, maybe, ~ $150/~ 250/hr. or so in CA are pretty common, often with a min. hr. charge and up front retainer. Depending on the location and particulars, that may be a reasonable number, but shop around.

    Also, electrical design services (if required) and mechanical design services may or may not be available from one source.

    Comment

    • Mike90250
      Moderator
      • May 2009
      • 16020

      #3
      Even buying certified racks from Ironridge or Tamarack, you will still need local soil engineer to certify the anchorage of the rack.
      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

      • Syberdog
        Junior Member
        • Sep 2017
        • 65

        #4
        IMO... Might depend on where your located.
        Out here in the boonies, my AZ county didn't require any of that however I highly suggest taking wind load as you primary concern if you don't have to submit calcs. I was able to build my own ground mount but I looked at several factory certified units while designing it. Having some engineering background, and knowing how over-engineered most structures are, I ran various calcs to make sure I was within 'good enough' of course my nearest neighbor is 8 acres away. I decided to go with a modified ballast block/pier setup because most piers were 8-10'deep and I didn't have means to drill 2'dia hole that far. So I went with 3' surrounded by 24"x18"x 8' concrete ballast in grade blocks. This was arrived at by analyzing 7 different of-the-shelf racks of similar size to determine weight required to keep it from tipping in high winds. Also look at what gauge metal is used, the max spacing, the size of the bolts etc. Read the engineering letters they all provide and you will see a lot of similarities- follow those guidelines and put together your package... then if you are still uncertain, take that plan to an engineer and have him review it and it should be a lot cheaper in the long run.

        Comment

        • 1oldmf
          Junior Member
          • Nov 2017
          • 5

          #5
          I'm 15 mi out of town, and on 7ac, county said MUST have PE stamped plans, doing grid tie, so have to co operate with power co, ( which requires permit,)
          the $$ I saved on buying panels, and inverter, will be shot with added cost for engineering. anyone know of an engineer who does this type of stuff?
          thanks

          Comment

          • J.P.M.
            Solar Fanatic
            • Aug 2013
            • 14920

            #6
            Originally posted by 1oldmf
            I'm 15 mi out of town, and on 7ac, county said MUST have PE stamped plans, doing grid tie, so have to co operate with power co, ( which requires permit,)
            the $$ I saved on buying panels, and inverter, will be shot with added cost for engineering. anyone know of an engineer who does this type of stuff?
            thanks
            I'd call SEIA (Solar Energy Industries ASSN.) in AZ. Bet they know of some folks.

            If you are still considering doing the project, other members in AZ may know of some engineering resources.

            Comment

            • Syberdog
              Junior Member
              • Sep 2017
              • 65

              #7
              What county you in? I'm in Cochise. They have a little known "self-installer-no inspection required" permit that covers all kinds of property owner installed improvements. You do have to ask for it as the counter person may not offer it up front. All they inspect is the setback. I used it for my 1000sf Rastra addition in 05 and again for the solar this past year.

              Comment

              • 1oldmf
                Junior Member
                • Nov 2017
                • 5

                #8
                Mohave County doesn't have a "eazy" way, so.... checked SEIA, nothing obvious, so am back to seeking a PE, that can do the engineering.
                I looked at unirac, as they provide "frame work engineering" but no sub structure engineering. frustrating to say the least.

                Comment

                • J.P.M.
                  Solar Fanatic
                  • Aug 2013
                  • 14920

                  #9
                  Originally posted by 1oldmf
                  Mohave County doesn't have a "eazy" way, so.... checked SEIA, nothing obvious, so am back to seeking a PE, that can do the engineering.
                  I looked at unirac, as they provide "frame work engineering" but no sub structure engineering. frustrating to say the least.
                  Sounds like you looked at a web site but haven't called SEIA yet. I'm not necessarily a supporter of SEIA, but I'd give them a call before giving up on them. What have you got to lose by a phone call ?

                  As for Unirac or the other racking/support vendors, they can't provide foundation design or details because they do not know, nor can they know the actual site soil or foundation conditions with much certainty. Also, they may not deal with foundations or soil details at all. Roof fixations, while not absolute and quite variable, are still generally more predictable than soil or ground conditions, and in any case are much more common.

                  There is also the phone book or a web search for solar designers.

                  Comment

                  • Syberdog
                    Junior Member
                    • Sep 2017
                    • 65

                    #10
                    What about just buying a pre-made rack system, like a Patriot, AET Rayport or even Schletter (if you can source one)
                    I looked at 25 different manufacturers and the cost in the ground (conc, sch-40 poles etc) before building my own. You'd be surprised how expensive those unirac-ironridge DIY kits become after adding your own pipe and conc. It's often cheaper to buy a complete system like the Patriot. But even then your looking a 3k in the ground.I think I still have a spreadsheet of my research showing all the details of most racks - if you want a copy just PM me & I'll see if it is available.

                    Comment

                    • J.P.M.
                      Solar Fanatic
                      • Aug 2013
                      • 14920

                      #11
                      Originally posted by Syberdog
                      What about just buying a pre-made rack system, like a Patriot, AET Rayport or even Schletter (if you can source one)
                      I looked at 25 different manufacturers and the cost in the ground (conc, sch-40 poles etc) before building my own. You'd be surprised how expensive those unirac-ironridge DIY kits become after adding your own pipe and conc. It's often cheaper to buy a complete system like the Patriot. But even then your looking a 3k in the ground.I think I still have a spreadsheet of my research showing all the details of most racks - if you want a copy just PM me & I'll see if it is available.
                      Design the foundation and also do the structural proofing for shear and uplift for the entire structure.

                      BTW, there are no PM's with this forum.

                      Comment

                      • 1oldmf
                        Junior Member
                        • Nov 2017
                        • 5

                        #12

                        thanks for the help, Syberdog, I'd like any info you can offer, .
                        email is cruzn57@yahoo.com
                        I spoke with a (ground) engineer, he can help with pier/ concrete spec's
                        I did go to "Patriot" site, and submitted an inquiry,
                        in looking at what is commercially available, my sketches were over kill, ( larger metal, thicker metal)
                        oh what fun! LOL

                        Comment

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