EVALUATION OF ELECTRICAL SUBSTATION EARTHING PROTECTION: EVIDENCE FROM ILE-OLUJI POLYTECHNIC, ONDO STATE

Earthing protection systems are a critical component of electrical substations, providing essential safety for both electrical equipment and human operators by ensuring the safe dissipation of fault currents into the ground. The effectiveness of earthing systems directly influences system stability, equipment protection, and the overall reliability of power networks. With the increasing complexity of modern power systems, driven by technological advancements, fluctuating load demands, and the integration of renewable energy sources, conventional earthing designs are increasingly challenged. Environmental factors such as soil resistivity, fault current magnitude, electrode configuration, and seasonal variations further affect the performance of grounding systems, making regular evaluation and maintenance imperative.
In higher education institutions, where electrical substations support academic, research, and administrative activities, a reliable earthing protection system is essential to minimize electrical hazards, prevent equipment damage, and maintain uninterrupted power supply. This study evaluates the performance of earthing protection systems across selected distribution substations at Federal Polytechnic, Ile-Oluji, Ondo State, Nigeria. The institution is connected to the national grid through the Ile-Oluji 33 kV feeder and operates seven distribution substations across its campus.
An earth resistance megger was employed to measure the grounding resistance of each substation, enabling a comparative assessment of their earthing effectiveness. The measured resistance values were analyzed to identify substations with the strongest and weakest earthing systems based on acceptable electrical safety standards. The results reveal variations in earthing performance attributable to differences in soil conditions, grounding configurations, and installation practices. Substations exhibiting lower earth resistance values demonstrated improved fault current dissipation and enhanced safety, while higher resistance values indicated potential operational and safety risks.
The findings underscore the importance of routine testing, proper design, and continuous maintenance of earthing systems in institutional power networks. This study provides practical insights for electrical engineers, facility managers, and policymakers aimed at improving grounding system reliability, enhancing safety standards, and supporting informed decision-making for earthing system optimization in higher education environments