Operational Reliability of Earthing System as Significant Factor Determining the Power Quality, EMC and Lightning Protection
Palabras clave:
earth electrodes, earth conductors, test requirements, standards and requirements, laboratory and field corrosion tests (es)
One of the main requirements for earthing system is to provide its reliable service for long time (20 - 30 years). The earthing system components embedded in soil: earth electrodes, earth conductors , joints and clamps are usually exposed to much more severe environmental factors than those installed in open air area. Main phenomenon influencing their reliable performance is the corrosion affecting earthing system components. The extensive list of different requirements for design and dimensioning of earthing system elements of LPS is given in new series of IEC 62305 on lightning protection as well in the EN standards related to the specific test requirements for lightning protection system earth electrodes and conductors. Some of these requirements are characterized in the paper.
In 2003 started in Poland the long-term project of field corrosion tests of earth rods. The aim of these investigations was to compare the corrosion rate of two commonly used protective coating materials of steel earth electrodes: hot-dip zinc coatings and electrodeposited copper coatings. Preliminary results of earth rods field corrosion tests after 2 and 4 years exposure in different soil types are discussed in the paper.