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What's the purpose of earth ground?

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Earth ground

Hi, iamsand!
I'd like you to tell me why lightening sometimes strikes the earth. Is the earth negative or not?
This may explain what you want to know.
 

Re: Earth ground

edbo1 said:
Hi, iamsand!
I'd like you to tell me why lightening sometimes strikes the earth. Is the earth negative or not?
This may explain what you want to know.

Hum.... Negative or positive is relative to a reference...

The negative potential mean there are more free electrons
There are 3 types of lightening...

Lightning from cloud to ground ( the most common type). cloud is negative and eartpositive.
Lightening from cloud to cloud ( the 2nd most common type). one cloud is positive and the other is negative
lightening from earth to cloud (quite unusual, but it could happens). Earth is negative and cloud is positive...
When hot cloud meet cold cloud, there is friction, and some electron are grabbed from one cloud to the other (same with wool pull over). Thus, there are positive potential on one cloud, and negative potential in the other. When the diffenrence between the potential reach the dielectriv breakdown voltage (about 30kV/cm for air, I think) There is a lightning (electron flow from negative to positive...)
 

Earth ground

Please try and seperate the idea that "Earth" is used for the "return current".

Surely this is what the "Nuetral" conductor is for.

Putting it simply...

The electric companies (for a charge) lend us some electricity along the "live" wire, we use it and then because it has not been all used up we send it back to the electricity companies along the neutral wire.

Then they send it to someone else to use, who also pays for the same electricity, they are very clever at this and make lots of money doing it. :)

From them to us in the live wire.
From us back to them in the neutral wire.

This completes the circuit.
You only actually need these 2 wires to allow an electrical circuit to work.

The Earth wire is used for safety, not all countries have an Earth wire.

Generally, if a fault develops then the earth wire is used to take the current that is being passed along the wires and dump it to Earth.
 

Earth ground

@grittinjames : cyberrat has almost answered your question, but I would like to add that groundfaults might occur too.

So if the voltage was ground referenced, after a ground fault, the live wire would be floating !
 

Re: Earth ground

This simple idea of cyberrat is something...I can't name it in english!

How power via power lines go "back"? This is not the 1st grade to analyze electrical circuits like this! A substation or a full power station ( 115KV or more in my country) is distributing power through the power lines in a parallel network of loads ( houses, offices, industries). Nothing is "going back" to the factory! The thing is that the power factory can regulate the production depending on the load demand its time.

D.
 

Re: Earth ground

dkace said:
This simple idea of cyberrat is something...I can't name it in english!
D.

I'll name it in English for you then.

Sarcasm, joke, humour, fun.

Using a similar theory to the ""darcksucker bulb" theory. as there is a return line then something must go back to them & they obviously dont use it at the power station so they must send it out to someone else, who gets billed for it. :D:D
 

Re: Earth ground

iamsand said:
I am trying to understand the purpose for earth ground. Imagine a world where the power company never attached the neutral conductor to ground, anywhere, not at the generation source, not along the transmission route and not at the destination. The neutral would be isolated from the earth, the same as the hot conductors are now. In that world, if either a neutral, or hot conductor were to come in contact with a metal equipment case and a person were standing in water with bare feet and touched it, they would not get shocked would they, since there would be no path back to either the neutral or hot side through the earth? How is earthing the neutral making things safer? Seems like we would have been better off if they never would have done it.

hi iamsand, i think i find out the answer to your very first question. why did the electric companies connected one side of the electrical wiring (the neutral) to earth (literally, the soil) in the first place. please read this interesting article.

http://amasci.com/amateur/whygnd.html

i find this article a bit humorous (at least for me). i'm not sure if the author is a real physicist, but i checked his claims from a physics book and other internet sites and somehow they agree. the site is very interesting and i hope you can read more of his articles. i have lots of question that's boggling me but he makes them clear after browsing his articles. have fun!:D
 

Earth ground

hi every boddy
how i can make less than 0.5 volt b/w earth n neutral
 

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