Safety Fencing

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  • Vandergraaff
    Member
    • Aug 2010
    • 44

    #1

    Safety Fencing

    I'm working on my township Solar Energy Ordinance and found to my surprise that there is no requirement to fence in a PV system. With voltages typically running 500VDC or more, I figured they should be secured (at least as well as a swimming pool) IMHO. Our local subcode official says that the 2011 NEC now requires fencing in ground mounted arrays. Can someone with a copy confirm this?

    New Jersey won't be adopting the 2011 code for a while (yes, we're slow back east) but if this is true, I can see putting it in the ordinance until we catch up.

    For that matter, does anyone have experience (or an oppinion) about fencing in home ground mounted systems?

    Thanks,
    Art
    Art
  • Sunking
    Solar Fanatic
    • Feb 2010
    • 23301

    #2
    Local jurisdictions can add any amendments they want. FWIW NJ is not slow to adopt the 2011 NEC. I do not know of any who have yeat. I know a lot of jurisdictions still operating on 1999 cycle.
    MSEE, PE

    Comment

    • jonson07
      Junior Member
      • Oct 2012
      • 6

      #3
      Hi dear i read this topic about fence and i want to say that electric fence is best for this purpose because An electric fence works by sending a signal to a specially designed collar, which will then issue a small static electrical discharge, similar to the kind you can get from walking along the carpet and touching a doorknob, but a little more painful. Without the collar, the "fence" does nothing.
      If you're referring to a metal fence that has an electrical wire along the top, or has electricity coursing through some part of it, it's possible that it could harm your cat, but the specifics are very dependent on how the fence is set up.
      Good old fashioned family Service

      Comment

      • Naptown
        Solar Fanatic
        • Feb 2011
        • 6880

        #4
        Originally posted by Sunking
        Local jurisdictions can add any amendments they want. FWIW NJ is not slow to adopt the 2011 NEC. I do not know of any who have yeat. I know a lot of jurisdictions still operating on 1999 cycle.
        The county I live in just adopted the 2011 Whey were on 2002 up until a month ago.
        NABCEP certified Technical Sales Professional

        [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

        [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

        [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

        Comment

        • Naptown
          Solar Fanatic
          • Feb 2011
          • 6880

          #5
          Originally posted by jonson07
          Hi dear i read this topic about fence and i want to say that electric fence is best for this purpose because An electric fence works by sending a signal to a specially designed collar, which will then issue a small static electrical discharge, similar to the kind you can get from walking along the carpet and touching a doorknob, but a little more painful. Without the collar, the "fence" does nothing.
          If you're referring to a metal fence that has an electrical wire along the top, or has electricity coursing through some part of it, it's possible that it could harm your cat, but the specifics are very dependent on how the fence is set up.
          Great Idea
          You could use the electricity from the solar to power an electric fence. Or set up an invisible fence and make all the residents buy and wear the collars. Buying the collars would be better as it will create revenue for the town in collar sales and fines for not wearing them
          NABCEP certified Technical Sales Professional

          [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

          [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

          [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

          Comment

          • peakbagger
            Solar Fanatic
            • Jun 2010
            • 1566

            #6
            You asked for an opinion so here is mine. I wouldnt force adoption of an ordinance specifically calling for a chain link or other fence around an array . It can make an installation quite ugly. If the NEC 2011 requires it than it wouldnt be a special requirements specific to a town. Special local requirements are why the cost of solar installations are high in the US compared to elsewhere. The unintended consequence of requiring a fence around the array is that the array is going to have to be mounted higher up in the air so that the panels do not not get shaded by the fence during the winter due to low sun angles. If its a 6 foot fence and the array is tilted seasonally, the actual high voltage wiring is going to be over 8 feet in the air and therefore wil not be "accessible" even without a fence.

            There are just as effective ways to isolate people from the high voltages in a solar array using raceway and or metal netting. A comparison with a swimming pool is a bad comparison, a pool without a fence is a attractive nuisance to a child, without a fence there is no barrier between the child and the hazard. With a solar array, all of the wiring within 8 feet of the ground has to be encased or enclosed in a way that it is inaccessible without the use of a tool. Unless the designer installed a ladder, a child is most likely going to have a tough time climbing up on the array which acts as an additional barrier. Probably the biggest hazard to a person is someone running into the array and getting a bruise or a cut. Choosing a fence versus a an inaccessbile barrier should be left up to the installer as long as it meets the NEC in effect in that jurisdiction.

            Comment

            • inetdog
              Super Moderator
              • May 2012
              • 9909

              #7
              Originally posted by peakbagger
              You asked for an opinion so here is mine. I wouldnt force adoption of an ordinance specifically calling for a chain link or other fence around an array . It can make an installation quite ugly. If the NEC 2011 requires it than it wouldnt be a special requirements specific to a town.

              There are just as effective ways to isolate people from the high voltages in a solar array using raceway and or metal netting. A comparison with a swimming pool is a bad comparison, a pool without a fence is a attractive nuisance to a child, without a fence there is no barrier between the child and the hazard. With a solar array, all of the wiring within 8 feet of the ground has to be encased or enclosed in a way that it is inaccessible without the use of a tool. Unless the designer installed a ladder, a child is most likely going to have a tough time climbing up on the array which acts as an additional barrier. Probably the biggest hazard to a person is someone running into the array and getting a bruise or a cut. Choosing a fence versus a an inaccessbile barrier should be left up to the installer as long as it meets the NEC in effect in that jurisdiction.
              IMHO, the other risk is to someone who deliberately enters the area with the intent of stealing the panels or the associated wiring. They will not be deterred by an 8 foot height or a cloth covering.
              SunnyBoy 3000 US, 18 BP Solar 175B panels.

              Comment

              • russ
                Solar Fanatic
                • Jul 2009
                • 10360

                #8
                A fence serves the purpose to deter kids and tourists - thieves either will not care or will steal the fence as well.

                A fence should be mandatory in my opinion.
                [SIGPIC][/SIGPIC]

                Comment

                • peakbagger
                  Solar Fanatic
                  • Jun 2010
                  • 1566

                  #9
                  Using that rational, house meters and every exterior electric item should be protected by a chain link fence to keep children and tourists from accessing them?

                  Comment

                  • russ
                    Solar Fanatic
                    • Jul 2009
                    • 10360

                    #10
                    Originally posted by peakbagger
                    Using that rational, house meters and every exterior electric item should be protected by a chain link fence to keep children and tourists from accessing them?
                    Please - that is not logic. Meters are generally in a reasonably safe place and voltages from the panels to the inverter can be well out of the ""safe" range - hardly like a receptacle for a lawn mower plug.
                    [SIGPIC][/SIGPIC]

                    Comment

                    • peakbagger
                      Solar Fanatic
                      • Jun 2010
                      • 1566

                      #11
                      There is enough juice in a electric receptacle to kill someone just as effectively as PV wiring with the even higher voltage with a household meter. Of course far more people get zapped by an aluminum ladder across the incoming overhead lines running to the meter so I guess they should be protected by a fence.

                      It goes back to the qualifier in my original post that the NEC is the rational group that calls the shots, if they have come to the conclusion that a fence is required, they have studied the issue and come to a conclusion that I am not going to change. I dont have access to the NEC 2011 so I cannot determine if they have changed their prior requirements which basically required inaccesible wiring within 8 feet of the ground, which is far more reasonable. If an installer wants to do a fence and leave his wiring in the open, its his perogative or if he wants to enclose the wiring under the panels, that also should be his option. Both serve the intended purpose of isolating the public from the wiring. IMHO, I just feel that the fence is an extra cost that leads to a higher and potentially more ugly installation.

                      Comment

                      • NorthwestPV
                        Junior Member
                        • Jun 2012
                        • 14

                        #12
                        The 2011 NEC does not require a fence. All the code says is in 690.31(A):

                        "Where photovoltaic source and output circuits operating at maximum system voltage greater than 30 volts are installed in readily accessible locations, circuit conductors shall be installed in a raceway"

                        To not be readily accessible, we have been installing netting to the back of the array where the wiring is located. We turn the modules so all the power ends of the modules are together in the same rail cavity. We then run conduit between the rail cavities.

                        Comment

                        • peakbagger
                          Solar Fanatic
                          • Jun 2010
                          • 1566

                          #13
                          Thanks for the clarification from the 2011 NEC. I sure like the "netting" better than a fence. To many folks a chain link fence make the installation far more hazardous than it is.

                          Comment

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