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    #16
    [QUOTE=mbrooke;2000646]
    Got this- can't help but want to call them up. Count the number of incorrect statements:
    /QUOTE]

    i'm not even going to deal with the subtle linguistics until after you get the solid copper
    ground rod driven 8' into the ground. then we can talk linguistics.

    i'll wait.

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    ~New signature under construction.~
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      #17
      Originally posted by Fulthrotl View Post

      i'm not even going to deal with the subtle linguistics until after you get the solid copper
      ground rod driven 8' into the ground. then we can talk linguistics.

      i'll wait.

      [ATTACH=CONFIG]23071[/ATTACH]
      Good catch.

      Comment


        #18
        [QUOTE=Fulthrotl;2000889]
        Originally posted by mbrooke View Post
        Got this- can't help but want to call them up. Count the number of incorrect statements:
        /QUOTE]

        i'm not even going to deal with the subtle linguistics until after you get the solid copper
        ground rod driven 8' into the ground. then we can talk linguistics.

        i'll wait.

        [ATTACH=CONFIG]23071[/ATTACH]
        Ok got it driven (please don't look in the bushes, nothing to see there......)
        Ethan Brush - East West Electric. NY, WA. MA

        "You can't generalize"

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          #19
          Originally posted by romex jockey View Post
          This forum explains it every other day, but your advice is duly noted....so following i would probably dwell on the difference betwixt earthing and that which provides equopotential via bonding pieces/parts

          That said the long winded version may end up going down the noodle rathole, because our lovely NEC's grounding /grounded matrix often will disguise what is in reality a return path cloaked in the guise of a GEC.

          This is where even a tenured spark such as myself am often at a loss ,and refer to other systems for the sake of enlightened comparatives to 'think outta the nec box'....

          ~RJ~
          Because, if you ask me, at one point the NEC truly thought the earth had major functions in equal potential, shock reduction and assistance in fault clearing. Now its simply doing damage control basically trying to say 'but we knew it all along, you just don't understand our select choice of words'


          Further compounded by the fact in half the world the soil of the actual EGC...

          Comment


            #20
            [QUOTE=Fulthrotl;2000889]
            Originally posted by mbrooke View Post
            Got this- can't help but want to call them up. Count the number of incorrect statements:
            /QUOTE]

            i'm not even going to deal with the subtle linguistics until after you get the solid copper
            ground rod driven 8' into the ground. then we can talk linguistics.

            i'll wait.

            [ATTACH=CONFIG]23071[/ATTACH]



            For a portable generator? Show me the code section which requires it

            Comment


              #21
              Originally posted by mbrooke View Post
              Further compounded by the fact in half the world the soil of the actual EGC...
              And at higher system voltages and lower current breakers, it actually works there, even without obsessing on getting low contact resistance.

              Comment


                #22
                Originally posted by GoldDigger View Post
                And at higher system voltages and lower current breakers, it actually works there, even without obsessing on getting low contact resistance.
                Yes, when you get to 69kv and above. Below that its still hit or miss.


                Here is a miss example, the swing set is in the earth at 4 points:



                https://youtu.be/28Xq3JulV1o?t=38


                Here is a hit example, though reclosing keeps energizing it:


                https://www.youtube.com/watch?v=dqrqn9fqgqU

                Comment


                  #23
                  I was thinking more of 240V circuits with a 10A breaker as opposed to 120A circuits with a 20A breaker. And UK and EU seem to have fairly tight maximum resistance requirement for earth electrodes, while the NEC has none.
                  Of course in consumer environments, UK and EU tend to require Residual Current detectors which will also allow a non-metallic earth fault to trip a breaker fairly easily.

                  Comment


                    #24
                    Originally posted by GoldDigger View Post
                    I was thinking more of 240V circuits with a 10A breaker as opposed to 120A circuits with a 20A breaker. And UK and EU seem to have fairly tight maximum resistance requirement for earth electrodes, while the NEC has none.
                    Of course in consumer environments, UK and EU tend to require Residual Current detectors which will also allow a non-metallic earth fault to trip a breaker fairly easily.
                    With an RCD of course. The tight requirements are for a TT supply, where the earth resistance must be low and supplemented with RCD (GFCI) protection.


                    A 1 ohm ground rod may measure such at installation, but in reality it will fluctuate up and down from that value as the moisture in soil varies.

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                      #25
                      or PH....or proximity to a substation.....~RJ~

                      Comment


                        #26
                        Originally posted by romex jockey View Post
                        or PH....or proximity to a substation.....~RJ~
                        In theory proximity to a substation should not have any effect on the contact resistance of a ground electrode, nor of the earth resistance to from the electrode to the substation ground system.
                        In practice, high earth currents near a substation because of faulty neutrals might result in ground electrode voltage being different from remote earth voltage, with interesting consequences.

                        Comment


                          #27
                          Originally posted by GoldDigger View Post
                          In theory proximity to a substation should not have any effect on the contact resistance of a ground electrode, nor of the earth resistance to from the electrode to the substation ground system.
                          In practice, high earth currents near a substation because of faulty neutrals might result in ground electrode voltage being different from remote earth voltage, with interesting consequences.
                          But keep in mind, a 12kv uni grounded system will start to act line an LRG, MRG, HRG and then ungrounded as you move further from the substation.

                          Comment


                            #28
                            Originally posted by romex jockey View Post
                            or PH....or proximity to a substation.....~RJ~
                            That too.

                            Comment


                              #29
                              Originally posted by GoldDigger View Post
                              In theory proximity to a substation should not have any effect on the contact resistance of a ground electrode, nor of the earth resistance to from the electrode to the substation ground system.
                              In practice, high earth currents near a substation because of faulty neutrals might result in ground electrode voltage being different from remote earth voltage, with interesting consequences.
                              ergo , the nec 'disconnect' Gold one

                              thx

                              ~RJ~

                              Comment


                                #30
                                Originally posted by mbrooke View Post
                                But keep in mind, a 12kv uni grounded system will start to act like an LRG, MRG, HRG and then ungrounded as you move further from the substation.
                                Actually, a very firm NO to that.
                                In both theory and practice, the movement of current through a near infinite three dimensional solid is such that once you correctly subtract the interface resistance of the ground electrodes at both ends, the additional resistance of the path through the earth itself, regardless of distance, is so close to zero as to be negligible. Cross country telegraph circuits proved this quite well. Higher resistance over long distances was entirely the result of the metal line impedance. Modeled as a transmission line with resistance, capacitance and inductance but with a perfect return conductor (except for electrode interface resistance.)

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