Maadoituselektroodi

Maadoituselektroodi, also known as a grounding electrode, is a device that provides an electrical path from a building, structure, or electrical system to the earth. Its primary purpose is to dissipate unwanted electrical energy, such as fault currents, lightning strikes, or static charges, into the ground, thereby protecting people, equipment and the electrical system from damage.

The most common form of a maadoituselektroodi is a bare copper or steel rod driven into the soil. Other types include fire-hedges, concrete-encased electrodes, plate electrodes, and multiple-electrode systems that combine rods and plates. Each type is chosen based on soil resistivity, the expected fault current, and local building codes. Soil resistivity is a key factor: higher resistivity requires longer or more parallel electrodes to achieve the desired impedance.

Grounding electrodes are specified by standards such as IEC 62305 for lightning protection, IEC 60364 for electrical installations, and local electrical codes. Those standards provide guidelines for electrode depth, spacing, material, and the acceptable maximum impedance to earth, which is usually set at 2 Ω for residential and 5 Ω for industrial installations.

Installation of a maadoituselektroodi involves driving or installing the electrode at a site with minimal soil disturbance, ensuring good contact with the surrounding soil, and soldering or bolting the connection to the main grounding bus. After installation, the free resistance of the earth connection can be measured using an earth resistance tester to confirm compliance with the specified impedance.

Periodic inspection and maintenance are important because corrosion, soil movement, or mechanical damage can increase resistance over time. Replacing or adding electrodes, cleaning corroded contacts, and retesting are common practices to keep the grounding system effective.

In summary, a maadoituselektroodi is an essential component of any electrical or lightning protection system, providing a low‑impedance path to dissipate dangerous currents safely into the ground.