Wandering currents are a type of directionalmovement of charged particles, which occurs in the ground when using the latter as a conductor. The main danger of this phenomenon is the development of corrosion of those metal objects that are underground or at least partially in contact with it.
Wandering currents occur whenseveral metal parts (in this case, the metals must necessarily be heterogeneous), between which there is contact, are placed in some kind of electrolytic liquid. This liquid can be absolutely everything, except distilled water. At the same time, as the temperature rises, the conductivity of the electrolyte will only increase, as is the case, for example, with ships moving from the northern seas to tropical countries.
Wandering currents may occur under the influence ofand internal and external sources, such as, for example, a short circuit in the electrical network, incorrect connection of elements, poor insulation of electrical wiring. As for large building structures, to which any apartment building can safely be attributed, the stray current is formed in them due to the fact that a potential difference is formed between grounding elements in different parts of the building.
As is known, any metal constructionmust close to the neutral conductor in the input-distribution device. Such a system bears the name of a potential equalization system; it is necessary so that a directed electric current does not occur between grounding elements.
Also an important reason for the formation of wanderingcurrents and, as a consequence, electrochemical corrosion, is a widespread replacement in the apartments of metal pipes for plastic. The thing is that in this case the metal connection is broken between the main risers, which are grounded through the potential equalization system, and additional pipes that lead, for example, to a heated towel rail. In this case, a potential difference forms between the riser and the auxiliary pipes, and if a conductor, for example, flowing water, appears between them, an electric current arises.
Protection against stray currents consists in levelingpotentials between metal structures. To do this, it is enough to connect the main riser and auxiliary pipes, after which the possibility for the appearance of electric current will disappear.
Another danger is that the movingpiped water, which, as already mentioned above, is an excellent conductor, is constantly in contact with the pipes themselves - dielectrics. An electric current arises from this friction, which, in accordance with the basic physical laws, will accumulate at the ends of the metal structures. The resulting static charge will play an important role in the fact that the emerging stray currents will have more power. This must be taken into account.
Thus, the stray currents arequite common in everyday life. To avoid their unpleasant effects, it is necessary to carefully approach the grounding of all metal structures in the house, especially given the fact that some of the pipes are being replaced with metal ones.
