Grounding electrodes constitute the basic safety components of electrical systems as conductive parts buried under the ground. They have a variety of applications ranging from superficial grounders placed at a depth of 0.5 to 1 meter to deep grounders positioned deeper than 1 meter. For a safe earthing system, it must have the highest integrity and robust structure.
What are Grounding Electrodes?
Grounding electrodes are large surface conductive parts buried in the ground in electrical installations and providing a conductive connection with the earth or embedded in concrete. They are the basic component of the system that ensures electrical safety by establishing a conductive connection between the designated touch points of devices and machines and the earth.
Electrodes are generally manufactured in the form of piles, rods, plates and cages. Since they are in constant contact with the soil, they must be made of materials resistant to corrosion. These materials should not only be resistant to chemical and biological effects, oxidation and electrolysis, but also to mechanical stresses that may occur during installation. The materials used in the attachments of earthing electrodes must have the same mechanical strength as the electrodes and must be resistant to mechanical impacts during fastening.
Two different types of grounders are used according to their location. Superficial grounders are usually placed at a depth of 0.5-1 meter. Deep grounders are buried vertically more than 1 meter deep.
Deep earthing devices: Deep earth grounders are driven into the soil and should not be less than the length of the rod between each other. Rod earthing rods should be driven as perpendicular to the ground as possible.
Superficial (strip) grounding: Grounders made of strip, round conductor or braided conductor and generally not deeply buried. They can be laid longitudinally or they can be arranged in the form of star, ring, eye grounders or a combination of some of them.
Attachment of earthing devices: Splices are used to connect the conductive parts of the earthing network within the earthing network. The splices must be dimensioned in such a way that the electrical conduction, mechanical and thermal strength equivalents of the earthing earthing conductors are provided.
What Do Grounding Electrodes Do?
Grounding electrodes play a critical role in electrical systems for life safety and equipment protection. It eliminates the risk of electric shock by ensuring that leakage currents are safely transmitted to earth. It also protects electrical devices from excessive current and voltage, reducing the risk of malfunction and fire. It protects both human life and system safety by ensuring that high currents pass through a safe path, especially in short circuit situations.
Grounding electrodes, which also provide protection against lightning effects, reduce the risk of side jumps by safely distributing high voltages. It improves the performance of electronic devices by reducing electrical interference. In areas where people and animals are present, the transition resistance of grounding systems should be a maximum of 10 ohms. To reduce this resistance, electrodes are buried deep and soil with high conductivity is preferred.
Types and Properties of Grounding Electrodes
There are grounding electrodes with different properties suitable for various grounding needs. These electrodes offer certain advantages according to the material used and construction technique.
Earthing Networks
Grounding networks are used to ensure safety in electrical installations. They are connected systems created with conductive materials. These networks, usually made of copper conductors, are designed to be laid horizontally underground and designed to contact most of the soil.
Galvanized Sheets
Galvanized sheets are produced in sizes of 100x50 cm. Thicknesses are between 1 mm and 3 mm. Public Works Poz No. 30.1 EARTHING SHEET, 5 M. GALVANIZED STRIP AND BURIAL OF THESE
Galvanized Piles
Galvanized piles are long metal rods, usually made of steel, protected against corrosion by a zinc coating. They are used in electrical systems to connect the neutral line to the earth. These piles are preferred due to their durability and long-lasting structure. It is generally produced between 1 m, 1.5 m and 2 m. Public Works Poz No. 30.4.2 2 mt LENGTH GALVANIZED 65X65X7 GALVANIZED EARTH ELECTRODE AND BURIED
Galvanized Bars (Pointed Type)
Galvanized rod grounding electrodes are zinc plated by hot dip galvanizing technique. These electrodes are specially processed to be resistant to corrosion. They are generally produced in lengths of 1, 1.5 and 2 meters and thicknesses ranging from 16 mm to 20 mm. Although its cost is low, its underground life is shorter than copper electrode.
Copper Sheets
Copper plates used in earthing systems are produced in 70x70 cm - 100x100 cm dimensions and 1 mm - 5 mm thickness. The minimum thickness for copper plates should be 1.5 mm. Surface areas are designed as at least 0.5 m².
Copper Clad Stainless Bars
Copper Coated Stainless Steel Bars stand out with their non-magnetic properties. It is produced by copper plating on stainless steel. It is especially preferred in environments with sensitive electronic equipment and minimizes electromagnetic interaction. It is produced in 1000 mm to 3000 mm length and 1 mm - 3 mm copper thickness.
Copper Clad Steel Bars
Electrolytic copper with 99.95% purity is coated on high-strength steel with the help of a metallurgical bond. Copper plated steel bars are usually plated at a thickness of 250 microns. The cost is lower than solid copper and the underground life is much longer than steel. While 20 micron thick coatings crack in case of bending, there is no cracking in 250 micron coating. It is produced in accordance with IEC 61561-2 standard.
Copper Rods (Pointed Type)
Pointed copper rods made of solid copper are produced in diameters of 12 mm - 20 mm and lengths of 1 meter - 3 meters. For example, a 1-meter rod with a diameter of 16 mm weighs approximately 1.79 kg. The 3-meter model with the same diameter weighs 5.35 kg. It has superior corrosion resistance.
Copper Rods (Threaded Type)
Threaded type copper earthing electrodes provide easy connection with other electrodes or system components. They are generally produced in diameters of 14 mm, 16 mm, 18 mm and 20 mm. Thread sizes can be M.8, M.10 or M.12 depending on the diameter. Their lengths vary between 1 meter and 3 meters. Thanks to their attachable structure, they can be connected to each other to form longer electrodes.
Public Works Poz No. 35.750.4002 Earth electrode (rod) electrolytic copper (in accordance with TS 435/T1 and TS EN IEC 62561-2 standards)
