Grounding of Older Building Installations: A Common Problem

The grounding system of every electrical installation is one of the key safety measures that ensure its proper and safe use by users.

This is particularly important in installations in the Attica region that utilize a TT supply system, where the flow of electrical current in the event of a fault depends solely on the condition of the installation's grounding system. Today, the only accepted grounding system is the foundational grounding, which is implemented during the construction of the building. However, this became mandatory only in 2006.

In older installations, grounding may have been achieved through grounding triangles, simple electrodes, or even through water supply pipes. However, these grounding methods may deteriorate over time and fail to provide the necessary protection. Particularly, when grounding has been done using water supply pipes (a practice that is now prohibited), a complete interruption of the grounding system is often observed after the replacement of metal pipes with plastic ones.

Considering that the majority of buildings in Greece were constructed in the 1970s and 1980s, it is clear that many of these structures lack an appropriate grounding system.

Based on the above, it is understandable how important the role of re-checks of electrical installations is for the issuance of an Electrician’s Certificate. The grounding resistance must be measured by the installing electrician, and its effectiveness should be evaluated. Any additional measures to improve the grounding system should be carefully considered and implemented in accordance with current legislation and the corresponding international and national technical guidelines.

Finally, it is important to note that the installation of a grounding system with grounding triangles or electrodes in the ground, particularly in existing building installations in densely populated areas of Attica, may face practical difficulties. In such cases, electricians should offer appropriate technical solutions after careful study and ensure their understanding and acceptance by the respective owners or users.

In any case, professional electricians, whether constructing or inspecting existing installations, should ensure the effective functioning of grounding systems so that users can safely enjoy the benefits of electricity.