Analysis a mixtures of bentonite, palm kernel shell charcoal and magnesium sulfate (MgSO4) for reducing grounding resistance using rod-type electrodes at varying soil depths

Abstract

A grounding system is an essential electrical safety mechanism designed to protect humans and equipment from disturbances such as lightning-induced surge currents or short circuits. It operates by channeling excess current into the ground through grounding electrodes, thereby reducing the risk of damage and hazards. High grounding resistance can compromise the dissipation of fault currents and overvoltages, leading to safety risks. This study focuses on reducing grounding resistance through chemical soil treatment using bentonite combined with a mixture of magnesium sulfate (MgSO₄) and palm shell charcoal. The optimal composition consists of 10% bentonite, 10% native soil, and 80% of the material mixture. Experiments were conducted at electrode depths of 30 cm, 60 cm, 90 cm, and 110 cm. Results showed that the initial resistance of 312.5 Ω at 30 cm depth decreased to 86.1 Ω, and at 110 cm depth, resistance decreased from 186.5 Ω to 53.0 Ω. The average reduction reached 77.4%, indicating that this material combination is highly effective in lowering grounding resistance and improving system performance.