What are the 2 major types of earthing?

Earthing, also known as grounding, is an essential aspect of electrical systems. It involves providing a safe path for electricity to flow into the ground in case of a fault. There are two major types of earthing - plate earthing and pipe earthing. In this article, we will explore these two types and understand their differences.

Plate Earthing

Plate earthing is one of the most common types of earthing used in residential, commercial, and industrial buildings. It involves burying a copper or galvanized iron plate in the ground, which acts as an electrode. The plate is buried vertically, keeping its top surface at a minimum depth of 3 meters from the ground level. The size of the plate varies depending on factors such as soil resistivity and the maximum fault current. Typically, a plate with dimensions of 600mm x 600mm x 3.15mm is used.

To ensure effective plate earthing, the plate needs to be surrounded by a mixture of charcoal, salt, and sand, which helps in maintaining low resistance. The plate is connected to the electrical system's neutral point using a copper strip or wire. This connection helps in diverting fault currents safely to the ground. Additionally, periodic maintenance is required to ensure that the earthing system remains intact and free from corrosion or damage.

Pipe Earthing

Pipe earthing, also known as rod earthing, is another commonly used method for earthing. In this type, a perforated galvanized iron (GI) pipe, usually of 40mm diameter and 2.5 meters length, is vertically inserted into the ground. The top end of the pipe is exposed above the ground level, and the lower end is connected to a metallic plate or strip buried deep in the ground. The plate acts as an electrode, similar to plate earthing.

The pipe is filled with alternate layers of charcoal and salt, ensuring good conductivity and low resistance. The top exposed end of the pipe is protected with a cap to prevent moisture and corrosion. The GI pipe provides better protection against corrosion compared to copper rods, making it suitable for areas with high soil resistivity. Periodic checks and maintenance are necessary to keep the integrity of the pipe earthing system intact.

Conclusion

In conclusion, plate earthing and pipe earthing are the two major types of earthing systems used in electrical installations. While plate earthing involves burying a metal plate vertically, pipe earthing utilizes a perforated GI pipe inserted into the ground. Both methods ensure a safe path for fault currents to flow into the ground, preventing electrical hazards. The choice between the two depends on factors such as soil resistivity, installation location, and maximum fault current. Regular maintenance and periodic checks are crucial to ensure the effectiveness of the earthing systems.