Definition of Electrical Earthing
The process of transferring the discharge of electrical energy directly to the ground using low resistance wires is known as electrical grounding. Earthing is carried out by connecting the non-current or neutral part of the equipment from the power supply system to the ground.
Galvanized iron is mainly used for earthing. Earthing provides a simple path for leakage current. The equipment short-circuits current flows to the ground which has zero potential. Thus, protecting systems and equipment from damage.
Types of Electrical Earthing
Electrical equipment is mainly composed of two non-current bearing parts. These parts are neutral to the electrical equipment system or chassis. From the ground of the two parts of the non-current conductor, the electrical system’s grounding can be classified into two types.
- Neutral Earthing
- Equipment Earthing.
In neutral earth, the system neutral is directly connected to earth via GI cable. Neutral earth is also called system earth. This type of earthing is mostly intended for star winding systems. For example, neutral grounding is provided in generators, transformers, motors etc.
This type of Electrical Earthing System is intended for electrical equipment. Parts of equipment that do not conduct current such as metal frames are grounded with the help of conducting wires. If a fault occurs in the equipment, a short-circuit current flows to the ground with the help of a wire. Therefore, protect your 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 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 has a 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, thereby protecting 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 connections. The earthing and the earthing connection together called the earthing system.