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Thread: Ground rods

  1. #51
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    Re: Ground rods

    Quote Originally Posted by Insaneride View Post
    I think IBM learned that without a resistor a wrist band can electricute a person also. No?
    Bingo!!!! quite a few people have been 'enlightened' by doing that... heh heh heh

  2. #52
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    Re: Ground rods

    Quote Originally Posted by Insaneride View Post
    I think IBM learned that without a resistor a wrist band can electricute a person also. No?
    Never heard that, kinda defeats the purpose of "the path of least resistance"... My strap is always grounded.
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  3. #53
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    Re: Ground rods

    I think of cow barns. A traditional cow barn the cow is tethered to the stantions. Her water bowl is supplied by iron pipe. Vacuum, milk lines touch her. She stands on a urine soaked concrete floor. Behind her is a barn cleaner. All of these conductive surfaces is connected to a power supply. The definition separating earth grounding from bonding is a bit fuzzy. All of these machines are always wet with electrolyte. Any can contribute voltage.

    If the current passes through a cow she suffers.

    By connecting earth electrodes to concrete reinforcing steel to electrical neutral, along with bonding all conductive items in contact with the cow, current flows through these wires, instead of the cow.

    Earth electrodes are notoriously high resistance. Still they provide a path of less resistance than a human being. Without them there would always be some small potential from center tap to ground.
    An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.

  4. #54
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    Re: Ground rods

    Quote Originally Posted by Willie B View Post
    I think of cow barns. A traditional cow barn the cow is tethered to the stantions. Her water bowl is supplied by iron pipe. Vacuum, milk lines touch her. She stands on a urine soaked concrete floor. Behind her is a barn cleaner. All of these conductive surfaces is connected to a power supply. The definition separating earth grounding from bonding is a bit fuzzy. All of these machines are always wet with electrolyte. Any can contribute voltage.

    If the current passes through a cow she suffers.

    By connecting earth electrodes to concrete reinforcing steel to electrical neutral, along with bonding all conductive items in contact with the cow, current flows through these wires, instead of the cow.

    Earth electrodes are notoriously high resistance. Still they provide a path of less resistance than a human being. Without them there would always be some small potential from center tap to ground.

    Excellent point. Sometimes it's easier to put everything at the same potential rather than trying to insulate one from another. Ever notice inside a large electrical substation yard at the base of a manual disconnecting switch. There is a metal pad that is bonded to the support structure that the switch is mounted on. The operator of the switch stands on the metal pad effectively placing his body at the same potential as the switch. In the case of a short of the switch and the structure becomes energized, the operator is at the same potential so no current flows through his body and he is safe.
    Owner of Fast Leroy's Bar and Grill
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  5. #55
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    Re: Ground rods

    Quote Originally Posted by Fast Leroy View Post
    Excellent point. Sometimes it's easier to put everything at the same potential rather than trying to insulate one from another. Ever notice inside a large electrical substation yard at the base of a manual disconnecting switch. There is a metal pad that is bonded to the support structure that the switch is mounted on. The operator of the switch stands on the metal pad effectively placing his body at the same potential as the switch. In the case of a short of the switch and the structure becomes energized, the operator is at the same potential so no current flows through his body and he is safe.
    10-4!!
    An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.

  6. #56
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    Re: Ground rods

    Quote Originally Posted by Insaneride View Post
    Electrons don't feel..
    Electrons absolutely are subject to an electric field and the Lorentz force. Covered in any good physics class on classical electromagnetism.
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  7. #57
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    Re: Ground rods

    Quote Originally Posted by Oscar View Post
    Electrons must travel to open valence shells in atoms or molecules which do not have closed/complete valence shells. However which way the electrons "feel" the electric field and ultimately subject to the Lorentz force is what will determine the ultimate path they end up taking, until they end up occupying incomplete valence shells in atoms/molecules at their destination.
    Ok but, your starting to sound like WackyMaC.

  8. #58
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    Re: Ground rods

    A static wrist band is for protecting Integrated Circuits IC's. The resistor is for protecting the wearer from being the least resistance to ground. If zapped while wearing a wrist band on opposite wrist, an undischarged capacitor could travel thru your heart.

  9. #59
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    Re: Ground rods

    Well..... I doubt the capacitor would travel that way unless you really had some huge electo magnetic pulse going on!!!! but you'd sure get a giga-jolt of electrons traveling around the chest area

  10. #60
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    Re: Ground rods

    Quote Originally Posted by ronsii View Post
    Well..... I doubt the capacitor would travel that way unless you really had some huge electo magnetic pulse going on!!!! but you'd sure get a giga-jolt of electrons traveling around the chest area
    Well I'm not going try and find out I've felt electrons from capicitor's and one thing I can tell you is, they don't completely discharge after getting zapped. Although it's only theory, I've been bitten by a coil. The caps were discharged. It would seem that the coil held a magnetic field and got me good. I used an led and resistor to bleed one side of the coil to continue.

  11. #61
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    Re: Ground rods

    Always look for the bleed resistor on big caps... for each tap!!! if you don't see em' then you really need to manually discharge them yourself... and to be safe I have a bunch of 6 inch alligator end jumpers for tech work and I'll clip them on any caps on the device I am working on


    Oh, btw I was trying to make a joke about the physical cap going through you... I never was good at telling jokes...

  12. #62
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    Re: Ground rods

    Quote Originally Posted by Insaneride View Post
    Ok but, your starting to sound like WackyMaC.
    Well, I mean, this is where the truth leads to. It's called science. It's gotten us this far, so I'll believe it.
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  13. #63
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    Re: Ground rods

    Quote Originally Posted by Oscar View Post
    Well, I mean, this is where the truth leads to. It's called science. It's gotten us this far, so I'll believe it.
    I was joking because it seemed like you were saying electrons can feel and have a mind of their own. I never heard an explanation like yours saying the electrons felt like going to holes in valence bands except when dealing with semiconductors like Germanium and Silicon. In fact , it was a lot like a semiconductor approximation class I took years ago but Lorentz was a totally different class.

  14. #64
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    Re: Ground rods

    Quote Originally Posted by Insaneride View Post
    I was joking because it seemed like you were saying electrons can feel and have a mind of their own. I never heard an explanation like yours saying the electrons felt like going to holes in valence bands except when dealing with semiconductors like Germanium and Silicon. In fact , it was a lot like a semiconductor approximation class I took years ago but Lorentz was a totally different class.
    I know when electrons 'feel' pizzed they bite. Piss off enough of them and you get bit bad.
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