What is the Necessity of earthing in computer?

Answer 1

Earthing is a vital safety feature in domestic and business power supplies. Most equipment such as refrigerators or convection heaters has a separate earth wire along with the live and neutral wires which carry the current. This connects the external surfaces of all such equpiment together, independently of the supply, so that the voltage between all surfaces which might be touched is zero and therefore safe even if some types of common fault occur. The earth wire is also connected physically to the gas and water pipes and to the ground in all properties. Certain portable low-power items with double insulation and no metal exterior surfaces do not require an earth lead.

<<>> Earthing or Grounding (depending on where you live) is a practice of connecting one terminal of the generator to the Earth's ground, and then doing the same at the load (user end).

This gives us two main benefits.

1. Most importantly, if the hot wire comes in contact with the earthed frame, then a very high fault current will flow, which will cause the protective device to operate, and shut down the supply before harm or fire can occur.

2. As already stated above, It limits the touch voltage on the frame of the device to a safe level, so that persons contacting the frame are not likely to come in contact with a hazardous voltage.

This type of protection is bets achieved when the neutral wire is connected to the earthing system at multiple locations, This is called an MEN (multiple Earth Neutral) System or in IEC speak a TN (Terra Neutral) system. The more earths in the systems, the more effective earth bonding of appliances is.

Below gets a littl heavy for this question, but it's valid.

If you could have an ideal ungrounded system, the generator could be ungrounded, then a person could touch one live wire without a path for current to flow through his body. Ideal is the key word here. Nothing is ideal. There are capacitive and inductive currents between the transmission lines and ground, so that even an ungrounded generator would actually have a return path for current. Also note that both wires will be 'hot' in an ungrounded system, rather than just one (there is no neutral wire).

Think about this. A capacitor is two plates separated by a dielectric. But if you have miles of transmission line even 100 feet in the air will act like a capacitor. Since the current is alternating, the transmission lines act sort of like a broadcast antenna for electromagnetic waves (very low frequency - 60 Hz - though), but some current could be induced into metal objects that are touching the ground, like thousands of tiny receiving antennas.

Therefore, you want to ground one of the generator terminals, and then ground the corresponding terminal at the load (the user end). Now you have created a path to ground which has much less impedance to current flow than the sum of these inductances and capacitances created by the transmission line. By having the 'neutral' wire grounded, you can also connect any metal parts in your appliance to ground, so that if there is a short to an exposed metal part, the breaker will trip rather than just energizing the entire device.

Imagine you are on an ungrounded system and your entire toaster were hooked to the 'hot' side, rather than the neutral side, for example.

Note that you could experience this situation if you are running a portable generator, which is not electrically connected to Earth's ground.

Answer 2

Most of the internal components (ie: cpu, ram, motherboard etc) are sensitive to and damaged by even small amounts of static electricity and need to be earthed to discharge any build up as do we when we touch any of those internal parts.

Answer 3

Earthing or grounding is done for safety of equipment and human beings (including all animals and plants).

Equipment Safety:

The outer housing of an electrical equipment is earthed by directly connecting it to a earth grid or earth electrode, thereby providing a low resistance path to ground. In case of a fault involving earth the live part of the equipment gets connected with the low resistance earth path. This produces high earth fault current and the protective devices in the circuit disconnects the circuit from the power source thereby reducing further damage to the equipment.

Neutral of electrical equipment are also earthed for equipment safety. Like, neutral of generators in power plants are earthed through Neutral Grounding Resistor to limit the earth fault current. Three phase transformer's neutral are earthed to provide neutral point to supply single phase loads like lighting and small appliances.

Human Safety:

If a person touches an appliance which has an earth fault in it he will not get an electric shock as his body (standing on the earth) and the equipment's body are at the same potential provided the equipment is earthed properly. Thus proper earthing protects a person from getting electric shock.

Answer 4

You could get an electric shock, If there is a fault in electrical installation, if you touch a live metal part. Because the electricity may use your body as a path from the live part to the earth part.

Earthing protects you from an electric shock. By providing a path for a fault current to flow to earth.

Answer 5

earthing is very important as it protects from short circuit and getting shock. earthing may also be considered as a circuit breaker and this circuit breaker trips to prevent us from getting electrocuted in cases of electrical leakage. the electrical leakages can be detected through this earthing. and in any circuital system in order to prevent shock we do earthing. one wire in the circuit has to be neutral and this earthing may also help to drain all the charge to ground and protect from short circuit.

Answer 6

All of these