Background: A 4 decade old leading manufacturer of sheet metal components of electrical machines with sophisticated automatically operated CNC machines and robot machines wanted us to suggest the suitable surge protection devices for their factory and to study the existing earth pits on their factory premises aimed at protecting their assets. Key Issues: Frequent failure […]
Earthing is a process of giving dedicated path for the flow of high current during an abnormal condition to the ground by using earthing electrode. In order to achieve the efficiency, the earthing material should have high current carrying capacity and less corrosive.
As specified by IS3043 – Code of Practice for Earthing, the conduction in an earth electrode is not ohmic but electrolytic in nature. Hence the performance of an earth electrode mainly depends on the resistivity of the soil (electrolyte) surrounding the earth electrode. The philosophy of Earthing is that “Lower the Resistivity of Soil, Better […]
The Earth electrodes should be designed to withstand the fault current without any physical damages. The fault current carrying capacity of a material mainly depends on cross sectional area of that particular material. In this article, we shall discuss about the current carrying capacity of pipes and strips of different dimensions and different materials as […]
The earth resistivity extremely varies between 1 to 10,000-ohm meters and in most situations, the soil resistivity is found to be non-uniform. Variation of the soil resistivity in depths is more predominant as compared to the variation with same in the horizontal distance and this happens due to stratification of earth layer. Measurement of earth […]
The Earthing Resistance of any electrode is made up of the following factors: • Resistance of the (metal) electrode, • Contact resistance range between the electrode and the soil • Resistance of the soil from the electrode surface outward in the geometry (which is set up for the flow of current outward from the electrode) […]
