ANALYZING EARTHING PROTECTION IN ELECTRICAL SUBSTATIONS: EVIDENCE FROM ILE-OLUJI POLYTECHNIC, ONDO STATE

Abstract

This research evaluates the earthing protection systems across various electrical substation networks within Federal Polytechnic, Ile-Oluji, Ondo State, Nigeria. The assessment focused on measuring ground resistance values to determine the performance and reliability of earthing systems critical for equipment protection and personnel safety using earth resistance tester. Findings revealed that the Hostel Building, Engineering Substation, and Mega Substation (serving transformers and feeders) demonstrated low resistance values, indicating efficient earthing performance. Conversely, the Administrative Building exhibited significantly high resistance, suggesting issues such as poor soil conductivity and inadequate grounding design. Additionally, lightning arresters across substations consistently showed elevated resistance levels, likely due to isolated grounding configurations for surge protection. Recommendations include enhancing the Administrative Building’s earthing system through the addition of grounding rods, soil treatment, or complete redesign, inspecting lightning arrester grounds in the School of Agriculture and Mega Substations for improvements, and implementing routine testing and maintenance to ensure longterm system effectiveness. This evaluation underscores the importance of continuous monitoring and upgrades to maintain optimal grounding conditions in substation networks