Corrosivity of Earthing Electrode (Galvanized Tape) in Various Soil Locations for TNBR Transmission Tower

Tenaga Nasional Berhad (TNB) transmission towers carrying electrical lines are earthed by earthing electrodes. They are at risk of corrosion due to being fully submerged in soil for long periods and periodical maintenance of these towers can be a challenge as some of the sites of these towers are hard to access. Previous research on galvanized tape as earthing electrodes was limited to certain locations, and subsequently, only focused on certain types of soils. Moreover, there is no prediction of the lifespan of earthing electrodes using galvanized tape, which is crucial information for industry. Hence, the objective of this study is to determine the corrosion rate of galvanized tape in various soil types in Malaysia by the Weight Loss Method (ASTM G1-03). Soils from four locations from Ulu Bernam, Teluk Kalong, Merlimau, and Gelang Patah are analyzed to identify the soil types and compositions, followed by a corrosion lab-based experiment for 14 days. The mass reductions of the corroded galvanized tapes were measured to determine the corrosion rate with pH values monitored daily. Results revealed that the soil type and area influence the corrosion of the galvanized tape with the average lifespan of galvanized tape in Malaysian peat soil being 7.2 years.