Thirdly measure the individual resistances of the ground system using the selective test of the earth ground tester see fig.
Earth mat testing procedure.
Earth electrode conductive part which may be embedded in the soil or in a specific conductive medium e g.
It reduced the overall grounding resistance.
Concrete or coke in electrical contact with the earth.
Various governments and agencies have developed stringent requirements for electrical products that are sold world wide.
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.
Electrical safety testing is essential to ensure safe operating standards for any product that uses electricity.
Bureau of standards now nist developed.
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.
Suitable test techniques must be used for large systems to ensure valid readings are obtained.
Earthing mat is mostly used in a placed where the large fault current is to be experienced.
This method is derived from the 4 point method which is used for soil resistivity measurements.
An earth electrode and earth electrode resistance are defined in bs 7671 as.
Measure the resistance of the mgn.
The substation earthing system comprises of a grid earth mat formed by a horizontal buried conductors.
Such type of system helps in limiting the ground potential.
This is unlike a small single electrode for example a lightning.
Frank wenner of the u s.
Read about design of substation earthing system here.
Earth electrode resistance the resistance of an earth electrode to earth.
The measuring procedure described here uses the wenner method and uses the formula.
One among that is earth test.
The grounding system in substation is very important.
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.
The value is the resistance of that particular leg of the mgb.
Several tests are conducted to check the safety of products.
In a tt system where a connection to earth is not provided by the.
Application guide for equipotential earth mat installation on substation structure mounted switches version.
While designing an earth mat the following step is taken.
