08/12/2024
There are several types of grounding systems in electrical networks, and each system differs from the other based on the way it is connected and used. The most prominent of these types are:
1. Direct Grounding (TN System):
The system is connected directly to the ground without any resistors or transformers. There are subtypes of this system depending on how the elements are connected, such as:
TN-S: Where the Neutral line and the Earth line are separated along the network.
TN-C: Where the neutral and grounding lines are combined into one wire, it is known as PEN.
TN-C-S: This system combines the two previous methods, where the partner is involved in one part of the system and separated in another part.
2. Indirect earthing (TT system):
In this system, the grounding line is completely separate from the electrical supply network, and can be grounded elsewhere (usually by the user rather than by the regulator). Choose this simple and less expensive system, usually in small homes and small buildings.
3. Insulated grounding or resistance grounding (IT System):
This system depends on connecting the phase line with a small resistance to the ground, or not connecting it to the ground completely, so that in this case the grounding is isolated or the current is limited. This system is used in locations that require special protection against loss of power, such as hospitals and industrial sites with sensitive equipment.
4. Resistance Grounding:
In this system, a medium or large resistance is added between the neutral point and the ground. This system helps reduce current during ground faults and is used in industries that require additional protection against ground faults to reduce their impact on the network and equipment.
The difference between the systems:
The TN system is more common in cities and modern facilities because it provides high protection and quick response to faults.
The TT system is suitable for rural or remote locations where it is difficult to provide a central earthing system.
The IT system is best used in environments where frequent power outages due to grounding faults cannot be tolerated.
Each grounding system has its advantages and disadvantages, and choosing the most appropriate system depends on the type of building, the type of devices used, and security requirements.
