What is the main function of the grounding rod and how to achieve ground potential equalization?

The basic role of ground rods in electrical systems
The ground rod is an indispensable and important part of the electrical grounding system. It is mainly used to safely guide the current of electrical equipment or power systems to the earth. Its core function is to provide a low-resistance path so that the current can be quickly discharged to the ground in the event of a short circuit, lightning strike, voltage mutation or system failure, thereby avoiding harm to personnel, equipment or buildings.
The ground rod is buried deep underground and forms good contact with the soil, thereby establishing a reference point close to the earth's potential. Whether it is used for working grounding, protective grounding of the power system, or lightning protection grounding for lightning protection, the ground rod can play a basic supporting role in the entire system. It forms a continuous conductive path with the soil through metal materials to achieve the evacuation and balance of abnormal electrical energy.

The concept and significance of ground potential equalization
Ground potential equalization refers to the use of reasonable grounding connections in an electrical system to make all metal casings, structures, conductors and related electrical equipment have approximately the same potential to avoid arcing or electric shock caused by voltage differences. This is of great significance for ensuring personal safety, preventing equipment damage and signal interference.
In large-scale power, communication or industrial automation systems, there are often multi-point grounding or distributed grounding structures between devices. If there is no good ground potential balance, when the current changes or lightning strikes interfere, there may be a potential difference of tens of volts or even higher between the devices, which will directly affect the signal transmission or the stability of electronic components, and in severe cases may cause system crashes or fires.

The role of ground rods in achieving ground potential balance
The core role of ground rods in ground potential balance is to build a reliable low-impedance grounding path, thereby helping to maintain consistent or approximately consistent potential values between each device and the grounding conductor. By standardizing the arrangement and connection of ground rods, multiple nodes in the system can be effectively connected to form a ground grid with a uniform potential.
Usually, multiple ground rods are interconnected through copper strips, flat irons or grounding wires, and connected to electrical parts such as the metal casing of the equipment and the cable shielding layer to form a complete grounding system. The lower the contact resistance between the ground rod and the soil, the stronger the ground potential balance capability of the entire system. At the same time, a reasonable grounding layout can also suppress the propagation of high-frequency stray currents or interference waves and improve system stability.

The influence of ground rod material and performance on ground potential equalization
Ground rods of different materials have different conductivity, corrosion resistance and grounding efficiency, which will also have a certain impact on the ground potential equalization effect. Common ground rod materials include pure copper, copper-clad steel, hot-dip galvanized steel, stainless steel, etc. Among them, copper-clad steel ground rods are widely used because of their good conductivity and corrosion resistance.
The stability of the material determines whether the ground rod can maintain a low resistance state for a long time. Once the ground rod corrodes or the resistance increases, the ground potential equalization ability will decrease, and potential potential differences and interference risks will easily occur. Therefore, when selecting, not only the conductivity should be considered, but also the factors such as the pH, humidity and resistivity of the on-site soil should be evaluated to select the appropriate material combination and coating treatment method.

The influence of ground rod installation and layout on the equalization effect
The installation method and layout structure are the key factors affecting the ground rod's equalization effect. Standard practice usually requires that the ground rod be driven vertically into the ground with a length of not less than 1.5 meters, and whether to increase the number or use auxiliary conductive materials (such as grounding enhancers) should be determined according to soil conditions.
In the electrical system, multiple grounding rods should be laid out at equal intervals and interconnected in a ring through low-resistance conductors to form a closed ground network. Especially in communication equipment, computer rooms, substations and other occasions, multiple grounding points must be established and a voltage-equalizing loop must be formed through the grounding busbar to prevent the voltage difference from being concentrated at a certain node. In addition, the mixing of grounding rods and high-voltage line grounding should be avoided to reduce interference coupling.

Common configuration table in practical application of ground potential equalization
The following table summarizes the common grounding rod configuration methods and their ground potential equalization characteristics in different scenarios:

Common Ground Rod Configurations and Ground Potential Equalization Effects

The comprehensive value of grounding rods in system safety
In addition to achieving ground potential equalization, grounding rods also play multiple protective roles in the entire electrical system. The first is to reduce the voltage of the equipment casing to prevent leakage and injury; the second is to provide a drainage channel in the event of lightning strikes or induced overvoltage to avoid the accumulation of electrical energy; the third is to provide a low-noise, stable grounding reference point for various sensitive electronic equipment to improve signal stability.
The reasonable coordination of grounding rods and grounding systems is the basis for the long-term safe operation of the system. Ignoring ground potential equalization will not only affect equipment performance, but may also cause electrical accidents. Therefore, the installation quality, material selection, and connection arrangement of ground rods should be important considerations when designing or maintaining an electrical system.