Articles: Earthing Design

Modelling earthing rods surrounded with bentonite

Using bentonite to reduce resistance Sometimes it is not possible to achieve the desired reduction in ground resistance by adding more grid conductors or ground rods. An alternate solution is to effectively increase the diameter of the electrode by modifying the soil surrounding.

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Testing of Earthing Systems

Testing of earthing systems enables confirmation of the design values and safe operation in the case of a fault condition according to the applicable safety standards and criteria.

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Fundamentals of Earthing Design

This tutorial introduces key concepts used in the design of substation earthing/grounding systems. Important terminology is discussed including Grid Potential Rise, touch and step voltages and current distribution.

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Earthing Software Benchmark Study

The Annex H in IEEE Standard 80-2013 contains benchmark case results for comparing and evaluating software tools and methodologies used for the analysis of substation earthing.

The results compare the simple equations from IEEE Std 80 with the results given by some of the commercially available software such as CDEGS, ETAP, SGW, SDWorkstation and WinIGS.

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Safety Limit Calculations to IEEE and IEC Standards

A safe earthing system design has two objectives; to provide a means to carry normal and fault current without exceeding equipment limits or adversely affect continuity of service and to reduce the risk of a person in the vicinity of an earthed facility being exposed to the danger of a critical electric shock.

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Earthing modelling of concrete slabs

Switchgear in substations is installed on top of concrete slabs containing substantial quantities of steel reinforcement. Often the embedded steel reinforcement is bonded to the main earthing system and used to cost-effectively improve earthing electrical performance and safety.

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Use of Rods to Improve Grid Safety

To show how and when earthing rods can be used to improve the safety of earthing grids by reducing the grid resistance and potential rise (GPR) as well as surface, step and touch potentials.

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