pls do fast
write a note on electrical earthing in about 200 words considering what is earthing by it is important for us what are the methods of providing earthing in a building ?
Answers
Answer:
In almost every electrical installation made, earthing is used. The earthing system, also known as the grounding system, is a circuit connecting parts of the electrical system to the ground. The earthing system thus regulates the conductors with respect to the earth’s conducting surface. Hence, the term, ‘earthing’ is also quite appropriate and indicative.
Why is an Earthing Necessary?
Earthing is an important component of electrical systems because of the following reasons:
It keeps people safe by preventing electric shocks
It prevents damage to electrical appliances and devices by preventing excessive current from running through the circuit
It prevents the risk of fire that could otherwise be caused by current leakage
Advantages of earthing
From a technical perspective, earthing has some excellent advantages, resulting it in becoming a mainstream practice in the electrical industry.
The electrical system is related to the potential of the general earth mass and cannot reach a different potential. The potential of the earth is zero volts and is known as the neutral of the electricity supply. This helps in keeping the balance.
Another advantage is that metal can be used in electrical installations without having to worry about conductivity. Though metal is a good conductor of electricity, proper earthing ensures that metal parts not meant to be used for current transfer can be included in the system. This is done by providing a separate path for this faulty current, enabling its immediate detection and stoppage.
In cases of surges in the voltage, high voltages can pass through the electricity circuit. These kinds of overload can lead to damaging of devices and danger to human life. When earthing is installed with the electrical installations, the current is routed through a different path and does not affect the electrical system.
An electrical circuit has to be connected together with a lot of attention to the kind of reactions each transformer may have in response to any action on the part of any other transformer. The earth is an ever-present conductive surface and helps configure these relationships between different electrical sources and makes them easier to handle.
Types of Earthing
Plate earthing
Plate earthing requires a copper or galvanised iron to be buried vertically into the earth in an earth pit, dug more than 10 feet into the ground. These earth pits are then filled with charcoal and salt in alternate layers.
Pipe earthing
For pipe earthing, a pipe of galvanised steel is placed in the soil instead of a plate. The pipe is drilled with holes for connecting the earthing wires. The length and diameter of the pipe depends on the type of soil and the type of electrical installation. In this method as well, the earth pits are filled with alternate layers of charcoal and salt for inducing reactivity. Pipe earthing is the most common type of earthing.
Rod earthing
Similar to pipe earthing, rod earthing requires the burying of a rod made of copper or galvanised iron. Electrodes are embedded in the soil and thus decrease the resistance of the earth as required.
Wire earthing
For wire earthing, several horizontal trenches are dug. Strip electrodes are buried inside these trenches. These electrodes are made of copper, or galvanised iron or steel. Sometimes, round conductors are also used in the ground.
Waterman method
The Waterman method calls for the use of Waterman or galvanised GI pipes. These pipes are buried in the earth and earthing clamps are used to reduce the resistance for the electrical connection.
Irrespective of which method is used for earthing, it is important to ensure that the size of the device, depth of its burial, and its connection to the electrical installations is done with great care and after in-depth calculations in order for it to be effective.
Factors Affecting Earthing Installations
Several factors can play a role in the earthing installations. These factors will have to be taken into consideration for any kind of calculations made about the type of earthing, the kind of circuits required, and so on.
The kind of soil is important for determining the effectiveness of the earthing. The earth’s resistance, moisture level in the soil, salts in the soil, etc. will play a significant role in determining the way the earthing is made. The soil composition is also another factor that needs to be taken into consideration. For e.g., rocky soil has to be treated very differently to wet soil.
Apart from the soil, the location of the earth pit is important to determine how the installation should be done. If there are underground obstructions in the form of rock beds, then they will affect the installations.
Answer:
Definition: The process of transferring the immediate discharge of the electrical energy directly to the earth by the help of the low resistance wire is known as the electrical earthing.
Explanation:
Mostly, the galvanised iron is used for the earthing. The earthing provides the simple path to the leakage current.
Types of Electrical Earthing
The electrical equipment mainly consists of two non-current carrying parts. These parts are neutral of the system or frame of the electrical equipment. From the earthing of these two non-current carrying parts of the electrical system earthing can be classified into two types.
1-Neutral Earthing
2-Equipment Earthing.
Neutral Earthing
In neutral earthing, the neutral of the system is directly connected to earth by the help of the GI wire. The neutral earthing is also called the system earthing. Such type of earthing is mostly provided to the system which has star winding. For example, the neutral earthing is provided in the generator, transformer, motor etc.
Equipment Earthing
Such type of earthing is provided to the electrical equipment. The non-current carrying part of the equipment like their metallic frame is connected to the earth by the help of the conducting wire. If any fault occurs in the apparatus, the short-circuit current to pass the earth by the help of wire. Thus, protect the system from damage.
Importance of Earthing
The earthing is essential because of the following reasons
The earthing protects the personnel from the shortcircuit current.
The earthing provides the easiest path to the flow of shortcircuit current even after the failure of the insulation.
The earthing protects the apparatus and personnel from the high voltage surges and lightning discharge.
Earthing can be done by electrically connecting the respective parts in the installation to some system of electrical conductors or electrodes placed near the soil or below the ground level.
The earthing mat or electrode under the ground level have flat iron riser through which all the non-current-carrying metallic parts of the equipment are connected .
When the fault occurs the fault current from the equipment flows through the earthing system to the earth and thereby protect the equipment from the fault current. At the time of the fault, the earth mat conductors rise to the voltage which is equal to the resistance of the earth mat multiplied by a ground fault.
The contacting assembly is called earthing. The metallic conductors connecting the parts of the installation with the earthing are called electrical connection. The earthing and the earthing connection together called the earthing system.