Earthing system for HV / EHV substations, Telecommunication installations, Signaling installations
Building with electronic installations need either foundation earth or ring earth for the reliable operation of the installation as strongly recommended in IEC 62305-3.Such an earthing system provides equipotentialisation and hence the effects of transients are reduced.the belief of concrete encased foundation earth is often viewed with suspicion, due to the myth that “concrete is an insulator”.Concrete used for the foundations of buildings has certain conductivity and generally a large contact area with the soil.Therefore bare metal electrodes completely embedded in concrete can be used for earthing purposes, unless the concrete is insulated from the soil by using insulating material against ingress of water.Due to chemical and physical effects, bare or hot-dip galvanised steel and other metals embedded in concrete with a cover depth of more than 50 mm are highly protected against corrosion, normally for the whole life-time of the building.
Creation of a concrete-embedded foundation earth electrode during the erection of the building is an economical solution to obtain a good earth electrode with long life
- it does not necessitate additional excavation works,
- it is erected at a depth which is normally free from negative influences resulting from seasonal weather conditions,
- it provides a good contact with the soil,
- it extends over practically all of the building’s foundation surface and results in the minimum earth electrode impedance which can be obtained with this surface,
- it provides an optimal earthing arrangement for lightning protection system purposes, and
- from the beginning of the erection of the building, it can be used as an earth electrode for the electrical installation of the construction site.
In addition, the concrete-embedded foundation earth electrode provides a good basis for the main protective bonding.Several customers find LPCI’s expertise in this field as rare and precious.