The ground is an electrical conductor which is used to carry fault currents, signals, and radio waves.
An earthing involves an uninsulated electrically conductive element of a grounding system which is located as a line-shaped electrical contact surface below the earth’s surface. The earth should have a good electrical connection to the ground to divert electrical currents there. The International Electrotechnical Dictionary defines the Earth as “a conductive part embedded in the soil or into another specific conductive medium, such as concrete or coke, which is in electrical contact with the earth.”
Since earthing is laid in the ground and is subject to certain self-corrosion, the electrode is made of corrosion-resistant materials. Sufficiently corrosion-resistant earth ensure reliable grounding for at least ten years. Hot-dip galvanized steel is suitable for embedding in concrete as well as in almost all types of flooring. Most earth electrodes are made of hot-dip galvanized steel. The zinc coating is at least 70 microns.
In the case of copper-plated steel, the minimum proportion of the copper coating is 20% of the steel weight. Copper is very resistant in the soil and is used as earth material for the earth in high current plants. In addition to earthing made of pure copper, those with galvanic covers of tin, zinc or lead are also used.
Stainless steel earth is increasingly used, but especially in larger cities near subways and trams with direct current propulsion, as they cause corrosion due to earth currents. The steel should contain at least 16% chromium, 5% nickel and 2% molybdenum. The geometric dimensions of the earth material are determined in networks with a rated voltage above 1 kV with low-impedance star point grounding by the required current carrying capacity of the earth.
There are several methods to reduce propagation resistance:
- Use of special filler materials
- Use of mineral or chemical soil electrodes
- Use of several parallel switched earth
- In soils with variable soil moisture, i.e. rocky or sandy soils, a special filling material is used to improve contact, which is used to improve the contact of the earth with the soil. The earths are embedded in the filling material and then covered with soil.
Special soil electrodes are used to improve soil conductivity, which is filled with a salt mixture. The grounding electrodes are provided with several holes through which the saline solution can migrate into the ground.
By the parallel connection of several earths, the contact surface with the ground is increased and thus the propagation resistance is reduced. To prevent the earths from influencing each other, they are laid at a distance of two earth lengths.
To further improve the grounding effect, so-called chain conductors are connected, i.e. metal jackets for cables or earth ropes for overhead lines. In larger construction plants (industrial plants), the earthing systems are often connected to achieve a meshed grounding plant. The connection of the individual grounding systems reduces the potential differences between the earths and, on the other hand, reduces the grounding resistance of the entire system.
How to Make a Good Electrical Earthing for Home?
There are a lot of things for which earth is dug to place metal rod or pipe. All of these can work as electrodes.
Probably the best grounding system is connecting to the common cold water pipe (when the city’s supply is via metal pipes, not PVC pipes). The common cold water pipe is many times more effective than any metallic components placed in the ground to earth. There are clamps available for earthing purpose, attaching them does the job.
The second way is to connect the grounding wire to the pipe of the hand pumps are used to extract water. Electrical shock is the major risk when the clamp connecting to the pipe is not tight enough.
The conventional way for earthing is to purchase a “grounding kit” for three different methods – rod earthing, plate earthing and pipe earthing. In all cases, the site requires watering during the summer for good conductivity.
At least 8 feet long pipe of 35-75 mm in diameter is buried in the dig out pit along with sand and charcoal. The pipe is provided with several perforations to maintain dampness to maintain the conductivity. The earth wire is tied and clamped near the neck. Water should be poured into it during summers. A pre-cast concrete inspection pit is suitable for any type of installations.Tagged With earthing on concrete , Steel Made Grounding Materials