Corrosion and Grounding Systems

Corrosion that occurs in the presence of dissimilar metals in the same electrolyte, or same metal in different electrolytes, or in different concentrations of the same electrolyte, has caused numerous problems in operating electric systems. This corrosion is the result of a potential difference existing between two surfaces which forces an electric current to flow. This effect is often ignored or overlooked in electrical grounding design, with the premise that electrical system protection will be hampered by the incorporation of corrosion protection. By careful design, however, both sets of requirements can be met. Some of the principles that determine corrosion and how these conditions exist in underground systems of cement plants are reviewed. The principles of grounding design are analyzed and suggestions to improve the design to minimize corrosion are discussed.