eli5 why every household needs to have their own ground system? they don’t provide a universal ground cable like live & neutral from the grid system.

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eli5 why every household needs to have their own ground system? they don’t provide a universal ground cable like live & neutral from the grid system.

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3 Answers

Anonymous 0 Comments

Because grounding simply involves sticking a metal rod into the ground, rather than laying kilometres upon kilometres of copper wire. You don’t need a centralised ground because it is everywhere.

Anonymous 0 Comments

Because the ground is there already, and is already connected to all houses and all power plants. If there was a really massive ground fault and current started flowing to ground somewhere, the electricity could indeed flow back to the power plant that way. In fact telegraph engineers back in the day initially set up their circuits with a return path, but then realized that the system worked just fine if they used the ground as a return path, and halved their installation costs. Of course, with modern systems, if there is a massive ground fault there’s hopefully equipment for detecting and interrupting that (breakers, for example) so nobody gets electrocuted.

Anonymous 0 Comments

Ground is not quite universal. There are differences in the ground potential over long distances. Especially in certain conditions like during a thunderstorm or a solar flair. It is therefore important to have a local connection to the ground so that the ground wire in your electrics have the same potential as for example your plumbing or the wet grass on your lawn. If instead you hook your ground wire to a post on the other side of the neighbourhood you could get a nasty surprise, or even regular sparks damaging your utilities or causing a fire.

Another issue is that when you get a static discharge you want it to go to the ground as soon as possible. Even electricity have a certain amount of speed and any wire will resist changes in current through it. The longer the wire the longer it takes for the electricity to get to the other side and the more it is going to resist the change in current. This may cause a much higher spike in voltage in your house grounding system then you want. And again it can cause sparks and other issues. Even worse if your ground system is hooked up to your neighbours house then the current may find an easier path to the ground through his house. You may end up burning down your neighbours house just because of the long wire across the neighbourhood to the ground post.