Earth Mat Design Ppt

Use of e mix a conductive earthing compound with earth mats will always improve the earth resistance.

Earth mat design ppt.

So we have to effectively use conductor and down rod to minimize the step and touch potential within mat zone and beyond of. Introduction to substation earthing grid. Chemical electrolytic ground electrodes provide a low grounding resistance in areas of high soil resistivity and low. Standard crowfoot earth 25mm x 3mm copper tape x 5m long joined to a 70mm2 bcew tail 2m long.

Increase in no of mesh in mat reduces the touch potential but beyond certain limit the mat is said to be saturated. While designing an earth mat the following step is taken. In high and medium voltage air insulated substations ais the electromagnetic field which causes are the static charges of bare cable and conductors and by the atmospheric conditions surges induce voltages at no live parts of the installation that create potential differences between metallic parts and ground and also between different points of. The wenner and schlumberger test methods are both recommended with testing and interpretation.

Earthing mat is mostly used in a placed where the large fault current is to be experienced. Earthing mat is made by joining the number of rods through copper conductors. It reduced the overall grounding resistance. Earthing mat design for hv ehv substations.

The grounding system in substation is very important. Could u please explain me how to do the earth mat design for 220 132 33 kv outdoor gss which have 5 steps 135m 138m 141m 144m 147m. Introduction earthing is essential wherever electricity is generated transmitted and distributed or user to ensure safety and proper operation of the electrical system. Auxiliary rectangular wire mats.

Such type of system helps in limiting the ground potential. Design procedure of earth mat increase in horizontal conductor length actually reduces touch potential. Earth mat design for 132kv substation in rivers state using etap pdf. Driven chemical electrolytic ground rod.

As earthing systems are installed near the surface of the earth the top soil layers being subject to higher current densities are the most significant and require the most accurate modelling. It is well that the earthing systems are intended to protect equipment and personnel in and around the substation from the dangerous over voltage. Content uploaded by omeje crescent onyebuchi. In this design these additional rods or mats are made to bond with the existing main ground mat and thereby assist in achieving the desired results.

Read about design of substation earthing system here. The substation earthing system comprises of a grid earth mat formed by a horizontal buried conductors.