I know that electricity doesn’t just dissolve in the ground, it must return to the power source. But once the electricity is in the grounding device, how does it find its way back to the substation if it can be relatively far away?
Edit: I know ground isn’t used in normal working mode and where I live there’s no grounding in sockets.
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It does, with lightning and radio signals.
I think the loose terminology in this thread is causing a lot of misunderstanding.
The term “ground” refers to the ground state of an atom. This is how you say an atom is uncharged. Ground conductors are current carrying conductors that are held in this ground state by being connected to a current sink that dissipates any charge. By charge I mean voltage or “electrical pressure”.
The dirt outside can be used as both a current sink and current carrying conductor. In most AC power systems we bury a rod in the dirt called the “grounding electrode”. This establishes a zero volt reference that is the same voltage as the human standing on the dirt. This makes sure that there is no electrical pressure difference between the human and the dirt. It also redirects any lightning strike that hits the electrical system to it’s target, the dirt.
This rod is attached to “grounding conductors” that distribute this reference to all the stuff humans touch. These conductors also make sure that if a wire comes lose inside any metal box that is connected to the system the box doesn’t become charged. Also, since there is a low resistance path back to the source of voltage, current can flow unimpeded in this “fault condition” and the circuit breaker will trip and prevent the building from burning down.
The third and final part of the earth grounding system is the “bonding location”. This is where a lot of understanding goes sideways. The bonding location serves 2 purposes. It attaches one of the conductors coming from the power transformer supplying power to the dirt physically close to where the electricity will be used. This creates a return path to the transformer that is “0 volts” called the neutral. It also creates a return path from the earth grounding system to the source of power allowing for that low resistance path mentioned earlier.
This means that if a human grabs a live conductor there is a return path through the dirt they are standing on. The current doesn’t just dissipate in the dirt because the nearby ground rod is applying an electrical pressure to the dirt that is the exact force to counter the pressure applied by the charge traveling through the human because the bonding location is connecting them together. This means the lowest effort place for the current to go is towards the ground rod.
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