Improvement of Electrical Grounding System Using Bentonite

Abstract

Abstract Low grounding resistance ensure the proper operation of lightning protection system. The lower Rg value, the easier current flow through the earth without any obstacles. Lightning protection system can easily have mechanical and electrical damage. Mechanical correction can be done by cleaning the junction from corrosion, repairing the loose junction, or creating a new junction. On the other hand, electrical correction can be done by deepen the electrode and widen the area for lowering the grounding resistance. In this case the most influential in determining the value of Rg is ρ factor. Value of ρ affected by soil conditions, the more humid the soil gets smaller ρ. One of the ways to increase the soil moisture by adding bentonite to the soil. Bentonite is a natural clay containing the mineral montmorillonites; this consists of octahedral coordinated aluminium atoms sandwiched between tetrahedral coordinated silicon atoms. Consideration of using bentonite to improve the value of Rg because bentonite has various good properties including: very low and stable resistivity; abilities to absorb and retain large quantities of water; can swell up to 13 times its dry volume; low cost; it will not gradually leach out because it is part of the clay itself. The result show that the decrement of grounding resistance is around 16% - 48% (average 32%) with deviation standard is 8%.