Wandering currents: characteristics, essence, protection

Wandering currents are a kind of directed motion of charged particles that occurs in the earth 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 when several metallic parts (with the metals necessarily must be dissimilar), between which contact exists, are placed in some electrolytic liquid. The liquid of this can be absolutely everything except distilled water. With increasing temperature, the conductivity of the electrolyte will only increase, as, for example, it happens with ships that move from the northern seas to tropical countries.

Wandering currents can occur under the influence of both internal and external sources, such as, for example, a short circuit in the electrical network, improper connection of elements, poor insulation of the electrical wiring. With regard to large building structures, which can be safely attributed to any apartment building, then in them the wandering current is formed due to the fact that between the grounding elements in different parts of the building a potential difference is formed.

As is known, any metal structure must be closed to a neutral conductor in the input-distribution device. Such a system is called a system of equipotential bonding, it is necessary to ensure that there is no directional electric current between the grounding elements.

Also, an important reason for the formation of stray currents and, as a consequence, electrochemical corrosion, is the widespread replacement of metal pipes with plastic ones in apartments. The thing is that in this case the metal connection is broken between the main risers, which are grounded through the system of potential equalization, and additional pipes that lead, for example, to the heated towel rail. In this case a difference of potentials is formed between the riser and the auxiliary pipes, and if a conductor appears between them, for example, running water, then an electric current arises.

Protection from stray currents is the equalization of potentials between metal structures. For this it is sufficient to connect the main riser and auxiliary pipes, after which the possibility for the appearance of an electric current will disappear.

Another danger is connected with the fact that the water moving along the pipes, which, as already mentioned above, is an excellent conductor, constantly comes into contact with the tubes themselves - dielectrics. This friction creates an electric current, 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 arising stray currents will have more power. This must be taken into account.

Thus, wandering currents are a fairly common phenomenon in a person's daily life. To avoid their unpleasant effects, it is necessary to carefully approach the grounding of all metal structures in the house, especially considering that some of the pipes are now replaced with metal-plastic ones.