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Do small generators require a ground rod?

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  • Do small generators require a ground rod?

    I'm being told that small generators like the Honda EU3000i never require a ground rod driven to be legal to use for stage power. Does anybody have a link to a code that says different?

    "We Have Met the Enemy and He is Us" - Walt Kelly​

  • #2
    Thats not quite true..from the nec:

    250.34 Generators-Portable and Vehicle-Mounted
    (A) Portable Generators. The frame of a portable generator is not be required to be grounded to the earth if:
    (1) The generator only supplies equipment or cord-and-plug-connected equipment through receptacles mounted on the generator, or both, and
    (2) The metal parts of generator and the grounding terminals of the receptacles are bonded to the generator frame.

    (B) Vehicle-Mounted Generators. The frame of a portable generator is not required to be grounded to the earth if:
    (1) The generator frame is bonded to the vehicle frame.
    (2) The generator only supplies equipment or cord-and-plug-connected equipment through receptacles mounted on the generator, or both, and
    (3) The metal parts of generator and the grounding terminals of the receptacles are bonded to the generator frame.

    I interpret this to mean that if a distro is used, the genset must be grounded.
    <div class="signaturecontainer">My Rig:<br />
    <br />
    EAW LA325's (2)<br />
    EAW LA400's (4)<br />
    QSC PLX 3402 (2)<br />
    QSC PL1.8<br />
    QSC RMX 2450<br />
    Ashly ProTea 3.24c<br />
    Ashly ProTea 4.24G<br />
    EAW LA212 Monitors<br />
    JBL PRX-512M Monitors<br />
    Whole Lotta Cables <img src="http://img3.harmony-central.com/acapella/ubb/smile.gif" border="0" alt="" title="Smilie" class="inlineimg" /></div>

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    • #3
      I interpret this to mean that if a distro is used, the genset must be grounded.
      The question there is "what is a distro?". Does a range plug distro need one but a breaker protected power strip not? Is there any real difference between them legally? Does every single piece of equipment have to be plugged into the generator's outlets separately to get away without a ground rod?


      "We Have Met the Enemy and He is Us" - Walt Kelly​

      Comment


      • #4
        The question there is "what is a distro?".

        Let's put it to the test:


        (1) The generator only supplies equipment or cord-and-plug-connected equipment through receptacles mounted on the generator, or both, and
        (2) The metal parts of generator and the grounding terminals of the receptacles are bonded to the generator frame.


        If I'm reading this right, it seems like a power strip or a distro would require a generator earth ground.
        Kickin' it in the sticks...

        Comment


        • #5
          Hmm... Looks like AH hasn't been around for a few days - I'm looking forward to his opinion. Gotta say that handing a mic to a singer standing barefoot on the grass that's tied to the genny frame via the cable shield with no ground rod seems like a bad idea to me?

          Oh, and do yous guys call digsafe before you drive a rod?

          "We Have Met the Enemy and He is Us" - Walt Kelly​

          Comment


          • #6
            Hmm... Looks like AH hasn't been around for a few days - I'm looking forward to his opinion. Gotta say that handing a mic to a singer standing barefoot on the grass that's tied to the genny frame via the cable shield with no ground rod seems like a bad idea to me?

            Oh, and do yous guys call digsafe before you drive a rod?


            Almost all my events that I use a genny for are pretty remote & outside city limits, so I don't.

            I basically always would err on driving a rod, and keep some large auger type rill bits in order to get the hole started.
            <div class="signaturecontainer">My Rig:<br />
            <br />
            EAW LA325's (2)<br />
            EAW LA400's (4)<br />
            QSC PLX 3402 (2)<br />
            QSC PL1.8<br />
            QSC RMX 2450<br />
            Ashly ProTea 3.24c<br />
            Ashly ProTea 4.24G<br />
            EAW LA212 Monitors<br />
            JBL PRX-512M Monitors<br />
            Whole Lotta Cables <img src="http://img3.harmony-central.com/acapella/ubb/smile.gif" border="0" alt="" title="Smilie" class="inlineimg" /></div>

            Comment


            • #7
              Hmm... Looks like AH hasn't been around for a few days - I'm looking forward to his opinion. Gotta say that handing a mic to a singer standing barefoot on the grass that's tied to the genny frame via the cable shield with no ground rod seems like a bad idea to me?

              Oh, and do yous guys call digsafe before you drive a rod?


              Andy is at the state fair. He has setups at the livestock areas plus he's putting on a horse show. I will try to scan and put up a link to a article about him. It's a busy couple of weeks for him.

              Comment


              • #8
                I can already see the shoes being thrown at me, but.....

                The ground rod is simply to bring your separately derived system to the same potential as the earth, so you don't have potential between the earth and ground. It is not designed to make a breaker trip, nor is it designed to allow fault current to travel to ground in sufficient quantity to make it trip. You must have at least 25 ohms to ground per NEC, or you are required to drive a second. If you don't get your 25 ohms after that, the code basically says, "oh well, you tried".

                If the ground rod is 25 ohms to ground of the ground rod, and you apply 120 volts to it, ohms law says you are only gonna get 4.8 amps on that bad boy, not enough to make a breaker trip.

                So should you drive one. Absolutely. 8 feet into the ground, and leave it there, otherwise it's useless, gotta hit wet soil. Would I on a Eu 3000? Depends on a few things I guess.

                What is it serving? For a small park gig, I probably wouldn't if it was just a few extension cords. If it was anything bigger, I'd probably have a gen set that required camlok tails, so I would most def drive one. But thats a whole nother beast.

                Then again, if it was a barefoot singer on the wet grass in the park, I probably wouldn't wanna own the liability with or without ground rods.

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                • #9
                  Then again, if it was a barefoot singer on the wet grass in the park, I probably wouldn't wanna own the liability with or without ground rods.
                  Good point. I do carry GFCI's for outdoor shows and I think they provide better protection in a situation like this than a ground rod would . My biggest system is only 5.5kw into FOH so I'll never be needing camlocks .

                  "We Have Met the Enemy and He is Us" - Walt Kelly​

                  Comment


                  • #10
                    I'd probably just wear shoes.
                    <div class="signaturecontainer"><font size="1">How about a mother****************ing crocodile pit instead of those titty ****************s !</font><br />
                    <br />
                    <br />
                    <font size="1"><i>Last edited by Jazz Ad on 06-20-2004 at 098 PM</i></font></div>

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                    • #11
                      I'd probably just wear shoes.
                      Well, me too - but I don't want to rely on them keeping folks alive.

                      "We Have Met the Enemy and He is Us" - Walt Kelly​

                      Comment


                      • #12
                        You must have at least 25 ohms to ground per NEC, or you are required to drive a second. If you don't get your 25 ohms after that, the code basically says, "oh well, you tried".

                        If the ground rod is 25 ohms to ground of the ground rod, and you apply 120 volts to it, ohms law says you are only gonna get 4.8 amps on that bad boy, not enough to make a breaker trip.


                        Hang on a sec. Your wording is a bit off. NEC [250.56] states that resistance after driving a rod should be no MORE than 25 ohms, not at least 25 ohms. You want as little resistance as possible, and the second rod is intended to lower resistance to ground.

                        Having said that, only a qualified electrician is going to have the proper metering gear to do a ground resistance test, as you can't simply stick your meter probe into the dirt and get an accurate read. Even the AHJ's I've encountered have no metering setup, and simply look at the installation, assume the rod is 8 feet long, and sign off or not based on how you look.

                        Oh, and this is a good time to mention the old trick for driving a rod easily, in case you do so. Simply get a disposable cup, dig out a little cupsized hole, and put it in the hole. Fill with water, and drive the rod through the bottom. Keep filling the cup as you drive. Unless you hit rocks, of course, it'll go in way easier. As always, lubrication is the key
                        Write something...

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                        • #13
                          Andy is at the state fair. He has setups at the livestock areas plus he's putting on a horse show. I will try to scan and put up a link to a article about him. It's a busy couple of weeks for him.


                          Hahaha, Andy is at the State Fair? That cracks me up. Such a small world it is. I'm sure my girlfriend has ooooh'd and aaaaah'd at his horses then.

                          I heard the Crest is up for sale? Is that the same Crest that Andy works at?
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                          <img src="images/misc/quote_icon.png" alt="Quote" /> Originally Posted by <strong>Player99</strong>
                          <a href="showthread.php?p=46425922#post46425922" rel="nofollow"><img class="inlineimg" src="images/buttons/viewpost-right.png" alt="View Post" /></a>
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                          <div class="message">No it is not repairable. You need to send the forum to me, and I will throw it away and sell you a new forum at full retail plus shipping. That is your only option.</div>

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                          <img src="images/misc/quote_icon.png" alt="Quote" /> Originally Posted by <strong>eco1</strong>
                          <a href="showthread.php?p=46441330#post46441330" rel="nofollow"><img class="inlineimg" src="images/buttons/viewpost-right.png" alt="View Post" /></a>
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                          <div class="message">i just got fed up with my ****************ing neighbor and shot him a few minutes ago.</div>

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                          • #14
                            Hahaha, Andy is at the State Fair? That cracks me up. Such a small world it is. I'm sure my girlfriend has ooooh'd and aaaaah'd at his horses then.

                            I heard the Crest is up for sale? Is that the same Crest that Andy works at?


                            If it's the Crest in Sacramento, then I'd say "yes".

                            Probably not worth the amount of time/money it takes to keep such a place going. But geez, it sure do look perty.
                            Write something...

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                            • #15
                              Well I think there might be The Crest, which is a movie place... and then The Crest which is more like a playhouse or opera or whatever? I don't know my own city.
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                              <img src="images/misc/quote_icon.png" alt="Quote" /> Originally Posted by <strong>Player99</strong>
                              <a href="showthread.php?p=46425922#post46425922" rel="nofollow"><img class="inlineimg" src="images/buttons/viewpost-right.png" alt="View Post" /></a>
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                              <div class="message">No it is not repairable. You need to send the forum to me, and I will throw it away and sell you a new forum at full retail plus shipping. That is your only option.</div>

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                              <div class="bbcode_postedby">
                              <img src="images/misc/quote_icon.png" alt="Quote" /> Originally Posted by <strong>eco1</strong>
                              <a href="showthread.php?p=46441330#post46441330" rel="nofollow"><img class="inlineimg" src="images/buttons/viewpost-right.png" alt="View Post" /></a>
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                              <div class="message">i just got fed up with my ****************ing neighbor and shot him a few minutes ago.</div>

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