In this guide, we will learn about some of the common procedures that are used by the electricians, electrical contractors and maintenance workers of the power utilities. By reading this guide, one will get a simple idea given by the users and it is intended to be educational. These procedures might vary depending on the task and only a qualified person must perform these procedures. This guide is not a substitute for the National, international or local standard, and that one should consult an expert if there is a doubt.
What Is Earthing/Grounding?
The top layer or the surface of Earth is covered with rocks and soil. This topmost layer is generally used for agricultural use and also for excavations as the foundation for construction work.
For modern day installations in industrial plants and utilities, one important thing is conductivity. This is crucial for a variety of reasons. Earth is relatively a poor conductor of electricity when compared to other conductors like aluminium or copper cables. Keeping in mind the mass of the Earth, which is huge, it offers a large surface area for the current to flow and therefore the resistance of the current is quite low with the result that the earth can be considered as a good electricity conductor.
This is why the whole planet is said to be an infinite conductor that has zero potential. In the USA it is referred to as “ground” and in Europe, it is referred to as “earth". We, humans, are always in contact with the earth, therefore, if we touch a charged object that has different potential compared to earth, the resulting potential differences across the person will cause an electric shock.
In the process of Earthing, all the objects which may have become charged due to the mass of earth, are connected. This helps to create a path for the fault current and also to form an equipotential on all the objects that are closed to the earth’s potential.
In short, the process of Earthing is important if you want to prevent a potential difference between the objects that are earthed and the earth. This reduces the risk of getting electrical shocks and also creates a flow path resistance to the fault current and ensures that the circuit protective system can work efficiently.
Therefore Earthing/Grounding is an indispensable part of the electrical system to make sure that it has integrity and also safety.
There are professionals in the market today who offer you Earthing services. You can choose to take their help or hire Earth Pit Test Services in Dubai to check the situation and whether Earthing is enough.
How Can Earthing Prevent Electrical Faults And Shocks?
The metal chassis of the electrical object and the internal live parts are insulated to protect against electrical shocks when people come in direct contact with the object. In some cases when the insulation fails, the metal chassis of the equipment becomes potential that of the voltage supply and therefore there is a potential difference concerning the ground that is created. Therefore if the equipment is not earthed properly, when anyone touches it, the current will pass the human body and will cause an electric shock.
If the metal case is earthed, the fault current flow is entirely divided. Therefore, the majority of the fault current flows through the protective conductor of the earth and then into the ground as the earth path resistance is designed to be lesser than the resistance of the human body. Therefore only a small amount of harmless current will flow through the body.
When there are chances of harmful physiological damage to a human, the power supply is disconnected automatically. This way the person is saved from the dangerous voltage that may have transferred from the equipment to the human body. Right coordination and design of the earth system along with the protective devices such as MCB, Fuse and RCD will make sure that the power is disconnected automatically.
What Is Earth Resistance?
Mainly three combined elements compose the resistance of the earth. They are:
• Resistance to the earth electrode and earth wire
• The contact resistance between the ground and the earth electrode
• Better earth resistivity and ground resistance interested as the characteristic of the earth
Following is an analysis of the three elements:
• This is generally very small and it can be ignored but of the element
• It varies depending on the type of the material, shape and also depth of the installed electrode.
• The value of the element generally has the greatest effect on the resistance value of the earth
Things like moisture content, temperature and soil composition impact the resistivity of the earth. As a general rule, it is suggested that the electrode of the earth should be placed deep inside the ground to reduce the resistance of the earth to a minimum.
The earth Pit Test Services in UAE will be effective for you to learn more about Earthing. These services are provided by the experts to the customers.
