Earth Mat Testing Procedure

Concrete or coke in electrical contact with the earth.

Earth mat testing procedure.

While designing an earth mat the following step is taken. The grounding system in substation is very important. Suitable test techniques must be used for large systems to ensure valid readings are obtained. One among that is earth test.

Earthing mat is mostly used in a placed where the large fault current is to be experienced. Earth electrode resistance the resistance of an earth electrode to earth. Application guide for equipotential earth mat installation on substation structure mounted switches version. Several tests are conducted to check the safety of products.

Various governments and agencies have developed stringent requirements for electrical products that are sold world wide. Bureau of standards now nist developed. Such type of system helps in limiting the ground potential. The 3 point method called the fall of potential method comprises the earth electrode to be measured and two other electrically independent test electrodes usually labelled p potential and c current these test electrodes can be of lesser quality higher earth resistance but must.

The substation earthing system comprises of a grid earth mat formed by a horizontal buried conductors. In a tt system where a connection to earth is not provided by the. Thirdly measure the individual resistances of the ground system using the selective test of the earth ground tester see fig. Read about design of substation earthing system here.

The value is the resistance of that particular leg of the mgb. An earth electrode and earth electrode resistance are defined in bs 7671 as. Electrical safety testing is essential to ensure safe operating standards for any product that uses electricity. 2 oct 2005 5 of 11 testing procedure before installation of gratings lv rubber gloves must be worn at all times when test leads are connected to the substation earths.

This is unlike a small single electrode for example a lightning. It reduced the overall grounding resistance. The measuring procedure described here uses the wenner method and uses the formula. Testing large earth systems.

This method is derived from the 4 point method which is used for soil resistivity measurements. In order to obtain a low enough value of earth resistance earth systems may consist of an earth mat covering a large area or many interconnected rods. Measure the resistance of the mgn. Earth electrode conductive part which may be embedded in the soil or in a specific conductive medium e g.