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Thread: Trying to understand the physics of bonding

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    Trying to understand the physics of bonding

    Is the reason we bond neutral at source with ground to keep a potential difference and always keep flow of electrons biased to flowing back through the return side to the neutral on transformer? Is it because if there is neutral to line fault on feed it will go to ground or is it just simply so that the fault has low enough resistance that the breaker trips in a safe manner? Sorry can't sleep and these kinds of things keep me up when I don't fully understand them.

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    https://youtu.be/3vvvv5QVZoA

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    Quote Originally Posted by LouisianaApprentice View Post
    Is the reason we bond neutral at source with ground to keep a potential difference and always keep flow of electrons biased to flowing back through the return side to the neutral on transformer? Is it because if there is neutral to line fault on feed it will go to ground or is it just simply so that the fault has low enough resistance that the breaker trips in a safe manner? Sorry can't sleep and these kinds of things keep me up when I don't fully understand them.
    Neutral is bonded to ground at the panel primarily because that is where the EGC lands. A ground fault in the residence travels along the EGC and lands on the ground bar in the panel. In order to complete the low impedance path back to the transformer (to trip the breaker), a connection must be made from the neutral to the ground bar. Without this connection, the path would be via the ground which is usually not enough to trip the breaker.

    The transformer neutral is connected to ground because that is how POCO grounds its systems. Mike Holt has some good videos explaining why we do it this way.

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    Quote Originally Posted by LouisianaApprentice View Post
    Is it because if there is neutral to line fault on feed it will go to ground or is it just simply so that the fault has low enough resistance that the breaker trips in a safe manner?
    Our goal is to send the electricity back to the source, not ground. This can get confusing because of what the previous poster said about the POCO grounding their neutral at the transformer.

    The NEC wants all faults to have a low impedance path back to the source, not the ground. That's why we bond our grounding conductor to the neutral. So a ground fault will effectively have path back to the source via the neutral. The reason we only bond the ground and neutral at the first disconnect is to eliminate a parallel path for the neutrals current to flow on.

    This concept is tricky for those learning because of the different, but similar terms. For example - grounded and grounding conductor. Take the time to understand the NEC definitions, and it will help out a lot

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    Quote Originally Posted by WarrMann View Post
    Our goal is to send the electricity back to the source, not ground. This can get confusing because of what the previous poster said about the POCO grounding their neutral at the transformer.

    The NEC wants all faults to have a low impedance path back to the source, not the ground. That's why we bond our grounding conductor to the neutral. So a ground fault will effectively have path back to the source via the neutral. The reason we only bond the ground and neutral at the first disconnect is to eliminate a parallel path for the neutrals current to flow on.

    This concept is tricky for those learning because of the different, but similar terms. For example - grounded and grounding conductor. Take the time to understand the NEC definitions, and it will help out a lot

    Sent from my SM-G950U using Tapatalk
    Ok thank you I understand it better now .

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