An earthing system is a network of metal rods, plates, or wires buried in the ground that are used to dissipate the static electricity build-up or to provide a safe path for electrical current to flow into the ground. The system’s primary purpose is public safety.
A well-designed and installed earthing system will provide a low impedance path to dissipate the static electricity or the stray current so that it will not present a shock hazard or cause damage to equipment.
The second purpose for an earthing system is to provide a safe path for the flow of current in the event of a system fault. When a system fault occurs, the current will flow through the earthing system to the ground instead of through people or equipment.
The last purpose for an earthing system is to provide a reference point for the voltage in the system. The earthing system is connected to the earth, which has a very low impedance, so it provides a good reference point for the voltage in the system.
There are several different types of earthing systems, but the most common are rod earthing systems and plate earthing systems.
Rod earthing systems consist of metal rods that are driven into the ground.