What is the type of earthing system TN-C
The most important part of a robust wiring is correctly implemented grounding system. To date, there are several types of grounding: TN-C, TN-C-S, TN-S, TT, IT. In this article I will tell you about the earthing system TN-C, which is in the new buildings are not used, but still very common in the old housing stock.
What does the acronym TN-C
This abbreviation stands as follows:
"T" – Terre - literally translated as the land is grounded.
"N" – Neuter - the literal translation of the neutral. It means that the compound has a connection to the neutral source.
"C" – Combined - the literal translation pooled. In an aligned conductor and the neutral ground conductor on the entire length and across the grid.
Earthing type TN-C
This type of ground is sometimes called a relic of the Soviet Union and even now it is forbidden, but almost half of the housing sector and Khrushchev so far, the system is used. And it is implemented as follows:
Work zero circuit connected to grounding directly at the substation and from a substation has come to the consumer a single wire, wherein the combined function of the working and protective conductor.
In this case, the wiring in the house is done:
If a single-phase, the two wires, where one of them is a phase, and second working zero.
If four three-phase power cables, where there are phases: A, B, C and working zero (PEN).
The positive side of the system
The advantage of this system is the only ground saving and ease of installation. After all, here you need a two-core cable, and nothing more.
Similarly to the positive moments can be attributed the fact that this system can be used without additional modernization of the rest of the network (old stock).
Important. If you live in a private home and hired specialist offers new wiring run on this system, you should refuse the services of such a master.
The negative side of the system
The problem here is one, but it is significant. In this system, the highest risk of electric shock to persons.
In fairness, we want to say that with proper control of the neutral conductor, this system works pretty well. Moreover, in most of the old buildings in general, there is no ground. After all of the requirements of the same TN-C system, all metal parts of the electrical equipment, which can be touched must be neutral earthing.
What to do with TN-C earthing system
If you have a private house you can make the transition to TN-C earthing system - S.
And if you have a flat, then it is possible to perform the modernization of your system, but do not connect the PEN conductor as long as your management company does not comply with the transition MCR on TN-C-S system.
Thank you for your attention.