2007-02-15 07:31:18 · 11 answers · asked by Richard H 1 in Science & Mathematics ➔ Engineering
If a live wire touched a metal part it would become live and would give a potentially lethal shock. By connecting the metal part to earth, as soon as the live wire touched it a large current would flow to earth and blow a fuse or trip a circuit breaker making it safe.
2007-02-15 07:41:35 · answer #1 · answered by Anonymous · 1⤊ 0⤋
the earthing system is there as a safety ring around the installation. electricity is usually 240 volts in uk (+/- 6%) and 110 volts in usa. if a person touches a live point, the electricity flows through them, taking the lowest resistance path to earth. if an rcd is in the circuit it will detect the imballance and cut off the supply very quickly. everything is done in the house to allow the electricity an easy path to earth and many ways out of the building. the incomming water pipe, gas pipe and mains cable are all joined together by the earth wire so that a high current could not create a spark and ignite the gas or lately, water pipe has become plastic rather than copper or lead and this may hinder the fault path to a current which, if not dispersed, may cause death to anyone who touched it. kitchens, bathrooms and all metalwork related to the installation must be at earth potential to ensure that safety is ensured.
2007-02-15 09:00:46 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Purpose Of Earthing System
2016-12-18 07:01:33 · answer #3 · answered by ? 4 · 0⤊ 0⤋
As already stated the main reason for earthing is for safety . However some systems use it to simplify wiring such as cars which utilise the metal chassis as an earth return. Also when screening from electrical interference Faraday cages and the like are connected to earth.Incidentally the earth we are talking about is actually a spike in the ground somewhere either at your house or the electrical substation
2007-02-15 23:28:14 · answer #4 · answered by Anonymous · 0⤊ 0⤋
I assume you mean in a normal house installation. The function of this system is to divert any electrical currents away from exposed parts on the units in an installation in case of earth fault. Earth fault can occur if the mains lead somehow get in contact with the casing or piping connected to a unit. Or you have a short circuit in an appliance. In simple terms, a spear is rammed into the ground somewhere on the premises outdoors. The lenght of this spear is determined by the electric condictivity of the soil its rammed into, and typically varies between 4 and 8 feet. This spear is connected up to a "current operated circuit breaker" on one side, and your water pipe, and/or any other metal and electric installations is connected up to the other side of the breaker. The green/yellow wire in your electric installation is also connected up to this breaker. If a fault occurs on any unit connected to the breaker, the latter will trip, rather than having mains power applied to the casing or other exposed conductors. The current it takes to trip this unit is typically 30milliAmps. This is less than the current it takes to stop your heart if the current runs straight through it. Thus it saves lives. If any appliance, such as your hairdrier, have the "double insulated" sign on it, it need not be earthed. Please note that electric installations should always be performed by a qualified electrician. Rules in your area may apply.
2016-03-18 02:22:55 · answer #5 · answered by ? 4 · 0⤊ 0⤋
Earthing System, or Unified grounding.
To eliminate grounding differentials.
If the potential rises at one end, the entire grounding grid rises.
It also provides a life safety, if it were not there the difference in potential can be lethal.
2007-02-15 14:09:47 · answer #6 · answered by John P 2 · 0⤊ 0⤋
main purpose of earthing system is To provide a low resistance pathway of earthing conductors in order to dissipate the current to the general mass of the earth via deep driven earth rods
2015-04-07 08:32:01 · answer #7 · answered by Muhammad Abdul 1 · 0⤊ 0⤋
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depends upon the application, in electronics, earthing or grounding system is used to eliminate some signals on a circuit which is not needed on the next stage of the signal processing operations. on antennas, it is used to make the antenna more smaller. on electricals, some application used this to divert lightning directly to ground to avoid its effect to the application
2016-04-03 03:20:50 · answer #8 · answered by Josephine 4 · 0⤊ 0⤋
In relation to what? It is is of no use asking a question such as this without explaning what it is relative too. If you feel the need to ask such a question then you should have some knowledge, which it seems you are withholding.
2007-02-19 07:12:39 · answer #9 · answered by Spanner 6 · 0⤊ 0⤋
I agree with what Iain said
2007-02-15 08:46:19 · answer #10 · answered by sarah w 1 · 0⤊ 0⤋