Arvīds Kanbergs

The causes of the changes of soil resistivity and the substantiation of prospective experiments

This scientific paper presents a survey of soil resistivity changes and the results of grounding resistance measurements. Adequate grounding systems for telecommunications, electronic and electrical equipment, power lines and lightning arresters of steel towers and high buildings are of extreme importance. Good grounding systems safeguard personnel and equipment during fault conditions. They are also frequently necessary in minimizing electrical noise and for normal, reliable operation of electrical and electronic equipment. The resistance of any grounding system should be periodically checked to ensure that it is within limits. We are reporting the results of grounding measurements using a 3-point method with digital ground tester MEGGER DET3TD. The measurements were conducted on April 15 2010 in Balozhi, Latvia.

The Causes of the Parameters Changes of Soil Resistivity

The Causes of the Parameters Changes of Soil Resistivity The grounding of electrical installations is primarily concerned with safety; in particular, the prevention of electrical shock risks of human life. As such, a grounding system must be designed, tested and maintained to satisfy this primary aim. This scientific paper presents a survey of soil resistivity and how its value varies from geological and meteorological factors. Soil resistivity is not only a useful measurable that reflects subsurface structure, but also a basic parameter to the design of effective grounding and lightening prevention / protection system. The most significant variations occur from such parameters of soil resistivity as moisture content, chemical composition, porosity, conductivity, temperature, vertical thickness and divisions, etc. Knowledge of soil resistivity at the intended site provides a valuable insight into how the desired ground resistance value can be achieved and maintained over the life of the installation with the minimum cost and effort.

Correlation analysis between grounding resistance and seasonal variations of upper soil resistivity of two-year period in Balozhi, Latvia

This scientific paper presents a correlation analysis between grounding resistance and temperature, humidity, pressure, precipitation, snow cover, solar flux by using program STATISTICA 6. We are reporting the results of grounding resistance measurements of two-year period using a 3-point method. The measurements were conducted during selected periods: from March 1 to March 31 in 2010; from July 1 and July 31 in 2010; from October 1 and October 31 in 2010; from January 1 to January 31 in 2011; from March 1 to March 31 in 2011; from July 1 to July 31 in 2011; from October 1 to October 31 in 2011; from January 1 to January 31 in 2012, in Balozhi, Latvia using the 3-point method with ground resistivity tester type M416. The grounding resistance values are considerably unequal during the different season; the results of the measurements of two-year period and experiments that have been done in the laboratory are the evidence of that. The resistance of any grounding system should be periodically checked to ensure that it is within limits. From our point of view the verification process of the grounding system should be carried out more frequently than once a year, but at least four times throughout the year - in winter, spring, summer and autumn time.