Earthing of an Electrical Installation

Earthing is suppose to have the most important and requirement of a healthy electrical installation. And also is one of the most confusing and complicated engineering aspect. In this blog we will discuss the basics of Earthing system. Earthing is required to address the following problems faced frequently in an electrical system:

1. Earth Faults occurred to an electrical system. Failure of equipments, conductor snapping etc.
2. Lighting surges
3. Induced EMF to structures and equipments
The design of earthing system depends on various aspects of site and system. The site parameters and system details must be carefully studied before designing and earthing system. Here are the major factors that affect an electrical Earthing system for a large installation.
1. Resistivity of the soil
2. The magnitude of earth fault
3. The maximum grid current
4. The geometry and size of the station area
5. Fault clearance time
Now let us see what the main objectives of an Earthing system are. The first and most important aspect of an Earthing system is safety and then comes reliability and economy. The key aspects can be summarized as follows.
1. To avoid shock accidents
2. To protect equipments
3. Proper functioning of the relay/protection system.