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Thread: Purpose of Grounding Electrode System

  1. #11
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    Quote Originally Posted by daytonajim00 View Post
    If the neutral on the utility failed open, I would guess an electrician is on the way because no single phase circuit using a neutral would be working.
    In the presence of a water pipe grounding electrode, where the water pipe is from a municipal system, and where neighbors are also connected to the same Power Company transformer secondary, the loss of YOUR service grounded conductor will only shift unbalance currents into your neighbor's service connections.

    However, if there is no local connection to a grounding electrode system that includes a municipal water pipe so connected, the open service grounded conductor results in the neutral on the load side of the Service Disconnect having a voltage derived from the balanced, or unbalanced, load impedances.
    Another Al in Minnesota

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    Quote Originally Posted by daytonajim00 View Post
    Or Mike Holt. They wrote an article titled"Ground Rod Does Not Assist in Clearing a Fault"


    https://www.mikeholt.com/technical-g...(01-25-2K).php

    And before the thread gets off topic- which is cool too- I would just like to bring it back to my original point. Why do we bond our electrical systems to earth?

    Is it for lightning, static, and other foreign surges like I thought or is there something I'm missing?
    I think the main reason is it is all but impossible to maintain an ungrounded/unearthed system, so it's best to go ahead and get something earthed. You mentioned OR rooms. Look at the work that has to be done to make that happen. Also, there are problems with ungrounded systems, capacitive coupling shocks and voltage spikes.

    Norway tried to go with a totally unearthed system and it didn't work. There was a post on this forum a couple of years ago about how bad it worked out. I tried tried to find it but failed. Maybe someone with better google skills can find it.
    If you don't think too good, don't think too much.

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    I would like to read that article Actiondave. I know a lot of work and money goes into ungrounded systems- where the neutral is left floating. It may be a bad anecdote to include that leads to a distraction. At any rate it leads back to my question: why do we bond our systems to earth? Why do we set up a GES? I thought it was for lightning, static, and other foreign voltages. So according to this thread, the main purpose of setting up a GES is as follows:

    1.) Clearing faults
    2.) Safe guarding against from electrical shock

    Is this correct?

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    Quote Originally Posted by daytonajim00 View Post
    If the neutral on the utility failed open, I would guess an electrician is on the way because no single phase circuit using a neutral would be working. In the event that a fault on a piece of metal happened directly after said neutral failure, I can see a hazard laying await. Whether you had a GES apart of that building or not would not matter, the hazard would be the same: there would not be enough conductivity through the earth to clear the fault.
    You need to read up on what happens when you have an open neutral, because it isn't nearly as simple as that. It's also not a 'fault' in the typical sense. The danger I described is there if you don't have a GES, and essentially not there if you do. That makes it a lot safer both for the homeowner who should turn off all his breakers right away, and the electrician who needs to check it out after getting the call. Both of those persons probably have to touch some metal housings to do that, and it's good if those metal housings don't have too many electrons trying to get out with nowhere to go besides those persons.

    This is why, to my understanding, the GES has nothing to do with clearing faults. I could be misunderstanding something but what you explained is a doomsday scenario. It's also the reason why every electrician should know the theory behind all of this. When going on a call never assume anything. I would use an amp probe on the GEC even if everything seems to be working fine. Voltage is easy to see. Current is the invisible killer.
    Here you are basically correct, but you talking around the subject of what the GES does.


    Quote Originally Posted by daytonajim00 View Post
    ...

    And before the thread gets off topic- which is cool too- I would just like to bring it back to my original point. Why do we bond our electrical systems to earth?

    Is it for lightning, static, and other foreign surges like I thought or is there something I'm missing?
    It is all those things, and then some. (An NEC-compliant GES is not a lightning protection system, though; that is something else.) Dave's point about ungrounded systems becoming unintentionally grounded is an important one. So, once we have grounded systems, it's fairly important that they are consistently grounded. Each premises GES plays a role in that.

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    Quote Originally Posted by daytonajim00 View Post
    I would like to read that article Actiondave. I know a lot of work and money goes into ungrounded systems- where the neutral is left floating. It may be a bad anecdote to include that leads to a distraction. At any rate it leads back to my question: why do we bond our systems to earth? Why do we set up a GES? I thought it was for lightning, static, and other foreign voltages. So according to this thread, the main purpose of setting up a GES is as follows:

    1.) Clearing faults
    2.) Safe guarding against from electrical shock

    Is this correct?
    We connect to earth because earth is the ship we are on and it is too hard to maintain a system that is unearthed. You are correct that it has nothing to do with clearing a fault, don't let anybody try and talk you out of that.
    If you don't think too good, don't think too much.

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    Quote Originally Posted by ActionDave View Post
    We connect to earth because earth is the ship we are on and it is too hard to maintain a system that is unearthed. You are correct that it has nothing to do with clearing a fault, don't let anybody try and talk you out of that.
    Thanks ActionDave. I only ever had these discussions with those as interested as me with the topic. Electrical theory is VERY interesting.

    Earth is the ship we are on and the voltages that come along with that ship must be addressed (lightning, static). That is the point of the GES. No? We create man made voltages (high voltage from utility) that aren't apart of our systems because our systems are stepped down in voltage through induction, so those higher voltages need to be addressed as well should they find a way on our stepped down systems. That is the point of the GES too. Is that what that means? That's how I currently understand it.

    Could you take an AC system, complete from generator to outlet, and have it function properly floating on a blimp, not connected to the earth?

    Also, can a small generator on wheels that we get at the local hardware store supply clean AC power without needing to be grounded to earth?

    If so, what makes our common systems different? Why would we include the GE system. I think it's because we can sacrifice a small generator to a lightning strike. What we don't want is a lightning strike jumping on a whole service and then some. I would imagine the utility provider grounds their systems for the same reason.
    Last edited by daytonajim00; 09-22-18 at 08:01 PM.

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    Quote Originally Posted by ActionDave View Post
    ...Norway tried to go with a totally unearthed system and it didn't work. There was a post on this forum a couple of years ago about how bad it worked out. I tried tried to find it but failed. Maybe someone with better google skills can find it.
    This has a 2004 copyright at the bottom. Does this address what you are thinking?

    https://www.mikeholt.com/mojonewsarc...h~20040602.php

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    Quote Originally Posted by MAC702 View Post
    This has a 2004 copyright at the bottom. Does this address what you are thinking?

    https://www.mikeholt.com/mojonewsarc...h~20040602.php
    That's not what I was talking about but that is a great link.
    If you don't think too good, don't think too much.

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    Lets no forget the reason why utilities use grounding electrodes... I think that is the force behind the grounding electrodes.
    I'm in over my head...

  10. #20
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    Quote Originally Posted by daytonajim00 View Post
    Thanks ActionDave. I only ever had these discussions with those as interested as me with the topic. Electrical theory is VERY interesting.

    Earth is the ship we are on and the voltages that come along with that ship must be addressed (lightning, static). That is the point of the GES. No? We create man made voltages (high voltage from utility) that aren't apart of our systems because our systems are stepped down in voltage through induction, so those higher voltages need to be addressed as well should they find a way on our stepped down systems. That is the point of the GES too. Is that what that means? That's how I currently understand it.
    It's a common point and is easy to find and connect to.

    Could you take an AC system, complete from generator to outlet, and have it function properly floating on a blimp, not connected to the earth?
    Yes.

    Also, can a small generator on wheels that we get at the local hardware store supply clean AC power without needing to be grounded to earth?
    Yes.

    If so, what makes our common systems different? Why would we include the GE system. I think it's because we can sacrifice a small generator to a lightning strike. What we don't want is a lightning strike jumping on a whole service and then some. I would imagine the utility provider grounds their systems for the same reason.
    If there were a better way it would have been implemented. We've been solidly grounded for almost a century now. More than that if you go back to the telegraph days.
    If you don't think too good, don't think too much.

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