Electrical earthing or ground is the process of making a path of least resistance to ground in the event of a fault current. This is because electricity usually flows from path of least resistance to the lower potential.
Free Google Image
The standard electrical connection comprises three wires. They are the live, neutral and earth.
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| Single phase cable: Earth is the yellow-green stripped cable,live is reddish-brown and neutral is blue | A typical UK standard three-pin 13A plug showing the three wire connection. 1=Cable clamp,2=Neutral, 3=Earth, 4=Live, 5=Fuse |
In a single phase system involving three wires, the earth or protective ground cable is usually color-coded to be either green or green with yellow stripe depending on the country or region.
Live: carries the current to the electric equipment.
Neutral: completes the circuit by forming a path back to the mains. It is usually at zero volts.
Earth is the very low resistance wire connected to the metal casing of devices and connected to the earth in case the appliance becomes "live" (energized).
How Does Earthing Prevent Electric Shock?
Source: Free Google Image showing an electric washing machine connection showing earth connection
First a look at how electrocution works. Electrocution is when a person comes in contact with a live wire and electricity flows through the person. But how do birds manage to perch on live wires and not get electrocuted? It is simply due to the principle of how electricity works, you need to close (complete) a circuit. The birds only perch on the one wire, that wire alone cannot electrocute them. But while flying away, if their wings inadvertently touch a grounded pole or wire while the feet are still on the wire, the circuit is then complete and the bird would be electrocuted.
Electricity also flows through the part of least resistance and basically, the earth connected to the metal part of an electrical device provides that path. So when the live wire insulation fails, the equipment is now live and could electrocute anyone that touches it. But when someone touches it, instead of the electricity to flow through him, it follows the part of low resistance which is via earth wire to the earth. This current (fault current) now moves and trips the circuit breaker thereby making the equipment safe and the person touching it not to be electrocuted.
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If there was no earthing in location and fault current would see the person touching the equipment as the part of least resistance and would flow through the person resulting in electrocution.
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Advantages of Earthing
Prevents damage, injury, and death. It protects the user from electric shock by its provision of the path of least resistance for fault current.
It protects the equipment in the event of surges, lightning or any abnormality that may damage our electrical equipment. If your electrical system is grounded, all of that excess electricity will go into the earth rather than fry everything connected to your system.
It makes for easier distribution of electric power, by ensuring circuits are not overloaded. It is a common reference point for many voltage sources in an electrical system
From my little observation, I noticed most houses in Nigeria are not earthed. Most technicians also do not take earthing serious. A case in point, watch whenever most electricians are changing the plugs of devices such as electric pressing iron, what they do first is cut off the earth cable! If you ask, they would tell you it is not useful!
Most home builders do not run earthing connection in like 40% ( this is a conservative estimate) of buildings.
Here is an earth cable terminated to the earth rod.
Free Google Image showing an earth cable connected to an earth rod which was driven into the earth
Check if your house has an earth connection if in doubt invite an experienced electrician to run a check. Earth also fails after some time. Some house has an earth connected but not functional.
Be safe. Take all the precaution possible.
Ok
This is the most informative post I have read ever since I joined the platform.
Firstly I now know why those pigeons never gets electrocuted
And secondly I now know the use of the earthen wire, although I have asked my physics teacher once about this question while on secondary school but he said its just to prevent electric shock and did not explain anything
That's the beauty of steemit, though I already know this, I had to do a refresher "course" on it while writing the article. Be awesome. Keep steeming.
Beautiful. Unfortunately most nigerians only learn being a victim of circumstances.
That is rightly so!
There are some scenarios where lightening would power the sockets in the building. Is this also as a result of a faulty earthing wire?
You'd need a lightening arrestor to combat that of lightning. A lighting arrestor needs an earth rod. Some do them separately, other use a central earth system.
But with a good earth system, the whole surge goes directly to the earth. The earth is large enough to take any surge.
Well explained bro...
This is true because I once worked as an apprentice under an electrician. The earth wire is just seen mainly as a waste. Sometimes we just connect it in the socket although there is earth rod fixed in the house.I think if more people see this post and get to know the benefits it has they may be willing to use it. I'm doing my part of letting more people to see it by resteeming..
Thanks a lot for the resteem, I just hope people would take earthing more serious here. It'd help with all those fried electronic components due to surges and other anomalies in the electric system.
Very incisive post @greenrun.
You are quite right, about the importance of earthing. Most electricians who like to cut corners on a job, fail to factor it into their services, leading to various forms of electric shocks and damages.
One of my Aunt's house was one nasty example of terrible electric wiring. Imagine a house were the toilet "flush", emits electric charges. The toilet flush o!
Then in the bathroom, the shower handle give's any and everyone a dose of shockwaves, when the bathroom light is switched on. So, in order to avoid the shock, don't bath with the bathroom light switched on.
Very terrible scenarios. But i'm a witness (Not Steem's.....Lolz)
The house has got some serious electric leakage that I doubt an earth could even fix. They need to redo the house wiring as the cables must've been old with many points where electrical insulation must have failed.
Thanks my broda, we all need to be reminded of these things we take for granted. Keep running with the Steem!
We really take safety for granted here. Growing up I have always thought the yellow wire is redundant as I see all electrician cut it off. As a budding DIY engineer wannabe, I started cutting off mine too during my connections :) A connection that may get me a life sentence if IEEE is to come within 100m of it!
Thanks for the kind comments.Bravo.
@greenrun, you wouldn't know how many lives you have potentially saved by writing this article.
I have always wondered why birds do not seem to get electrocuted. Now I know the reason why. In Nigeria, we take too many things for granted and as a result **many lives are lost. ** When we were living on campus (before my parents retired), our flat then (Flat C6, campus 2, beside Abraka post office, DELSU) was earthed. Besides, my father wouldn't buy any appliance that does not have earth wire. He is very safety conscious . Maybe because of his training abroad. I need to ask my mum if our family house is earthed.
One quick question. Please, how does wearing bathroom slippers (made from rubber) prevent one from not being electrocuted? Thanks a lot!
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@maryfavour & @redfishpillar.
The bathroom slippers reduce the severance of the electric shock. It is also dependent on the current in play. If it's minute, the bathroom slippers act as an insulator from allowing the current flow through you to earth.
It is the same principle that insulation mat is used by technicians and engineers while working at high voltage installation
Insulation mats are made of rubber. ... Rubber is a natural dielectric material and will, therefore, inhibit the flow of electric charge as a result of its molecular structure preventing the free flow of electrons.
Also, your body's conductivity increases if you are wet. This is because water is a conductor of electricity. That is why if you are wet and barefoot and touch the refrigerator which has some leakage current in a house that is not earthed, you'd get some shock. But if you are dry and wearing thick rubber shoes (one of the reasons electric engineers/technicians wear safety shoes with thick rubber soles while working) you'd open the same refrigerator and feel no shock.
wow.......I wish I could write like this too, this is really informative well done bro
You already write so well. I think you could write even much better.
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