Grounding connection provides protection in the event of faults on the line. These faults can occur at various times and damage electrical devices and equipment. They can create potential differences, which are very dangerous for people.
The presence of a neutral ground on an overhead line is therefore essential. It must be carried out correctly to be as effective as possible.
The Components of a Grounding System
Essential Equipment
The grounding system is made up of various components that work together to allow fault currents to flow into the ground.
The essential components of the system are:
- An aerial connector to divert the neutral,
- A copper conductor running down the pole to connect the aerial connector to the ground rod,
- A protective sheath securing the conductor running down the pole,
- A neutral disconnection device to open the circuit and allow earth resistance measurements,
- A junction accessory to connect the copper grounding conductor to the ground rod,
- A ground electrode, usually a ground rod, to create a contact zone in the soil and enable the fault to flow deep into the earth.
Accessories
In addition to the above components, MICHAUD recommends using accessories that help with cable protection, system installation, and operation.
Since the grounding connection is made along the pole, it is particularly useful to use certain accessories, such as:
- Cable saddle: guides the conductor along the pole during the cable descent,
- TPC sheath: protects the conductor in semi-buried technology up to the ground rod.
Additionally, the grounding system is exposed to weather, environmental, and operational constraints, which may justify the use of specialized equipment:
- Grounding inspection box: provides a dry environment for the connection of the conductor to the ground rod and makes maintenance easier by providing better access to the grounding system,
- Protection tip and driving cap: facilitate the installation of the ground rod and prevent damage to the material during installation. These are placed at both ends of the ground rod.
An Effective Grounding Connection
The Importance of Deep Grounding
The surface of the soil has resistivity that changes with the seasons, a phenomenon that decreases with depth. At greater depths, the soil tends to be more moist. The more water present in the soil, the better it will conduct and dissipate fault currents efficiently.
The ground rod provides the necessary stability to ensure the effectiveness of the grounding system. Typically between 1 and 2 meters in length, the ground rod can be extended using sleeves. Threaded sleeves are used for rods with threads, and conical compression sleeves are used for smooth rods.
How to Ensure the Grounding Connection is Effective?
Using measuring tools such as a tellurometer ensures that the installation meets the required standard for earth resistance. If the target value is not reached, the grounding system must be improved by connecting additional ground electrodes or increasing the depth.
A grounding connection is a critical element of electrical safety, ensuring the protection of equipment and individuals against electrical faults. A well-designed grounding system, including quality equipment and an effective connection, is essential to prevent dangers associated with potential differences. The use of suitable accessories and the implementation of technical solutions, such as the depth of the ground rod and the use of measurement devices, optimize the performance of the system and ensure its compliance with standards. In short, a well-maintained and regularly checked grounding connection ensures lasting and effective safety for any electrical installation.
