- Grounding rules
- “Grounding” and “neutralization”
- Ground loop
- What is required for wiring around the house
My bitter experience as an electrician allows me to assert: If your “grounding” is done as it should – that is, there is a place for connecting “grounding” conductors in the shield, and all plugs and sockets have “grounding” contacts – I envy you, and you have nothing worry.
What is the problem, why it is impossible to connect the ground wire to heating or water supply pipes?
In reality, in urban conditions, wandering currents and other interfering factors are so great that anything can be on the heating battery. However, the main problem is that the tripping current of the circuit breakers is large enough. Accordingly, one of the options for a possible accident is a short-circuit breakdown of a phase to the case with a leakage current just somewhere at the limit of the machine’s operation, that is, at best 16 amperes. Total, we divide 220v by 16A – we get 15 ohms. A total of some thirty meters of pipes, and you get 15 ohms. And the current flowed somewhere, towards the not sawn wood. But it doesn’t matter anymore. It is important that in the neighboring apartment (up to which 3 meters, not 30, the voltage on the tap is almost the same 220.), but on, say, a sewer pipe – a real zero, or so.
And now the question is – what will happen to the neighbor if he, while sitting in the bathroom (having connected to the sewer by opening the plug), touches the tap? Guess?
The prize is prison. Under the article on violation of electrical safety rules resulting in a victim.
Do not forget that you cannot imitate the “grounding” scheme by connecting the “zero working” and “zero protective” conductors in the European socket, as some “craftsmen” sometimes practice. Such a replacement is extremely dangerous. Cases of “working zero” burning out in the shield are not uncommon. After that, on the case of your refrigerator, computer, etc. 220V is very firmly placed. The consequences will be about the same as with the neighbor, with the difference that no one will be responsible for this, except for the one who made such a connection. And as practice shows, this is done by the owners themselves, tk. consider themselves skilled enough not to call an electrician.
“Grounding” and “neutralization”
One of the options for “grounding” is “grounding”. But not as in the case described above. The fact is that on the housing of the switchboard, on your floor, there is a zero potential, or more precisely, the zero wire passing through this same shield simply has contact with the housing of the switchboard through a bolted connection. Zero conductors from the apartments located on this floor also join the shield body. Let’s take a closer look at this point. What we see is that each of these ends is wound under its own bolt (in practice, however, it is often found that these ends are paired). This is where our newly-made conductor should be connected, which will later be called “grounding”.
This situation also has its own nuances. What prevents “zero” from burning out at the entrance to the house. Actually, nothing. We can only hope that there are fewer houses in the city than apartments, which means that the percentage of such a problem is much less. But this is again Russian “maybe”, which does not solve the problem.
The only correct decision in this situation. Take a metal corner 40×40 or 50×50, 3 meters long, hammer it into the ground so that they do not stumble over it, namely, we dig a hole into two bayonets of a shovel in depth and we hammer our corner there as much as possible, and from it draw a PV-3 wire (flexible , stranded), with a cross section of at least 6 mm. sq. before, your switchboard.
Ideally, the “ground loop” should consist of 3 – 4 corners, which are welded with a metal strip of the same width. The distance between the corners should be 2 m.
Just don’t drill a hole in the ground with a meter drill and lower the pin there. It is not right. And the efficiency of such grounding is close to zero.
But, as with any method, it has its drawbacks. You are, of course, lucky if you live in a private house, or at least on the ground floor. But what about those who live on the 7-8 floor? Stock up on a 30 meter wire?
So how do you find a way out of this situation? I am afraid that even the most experienced electricians will not give you an answer to this question..
What is required for wiring around the house
For wiring around the house, you will need a copper ground wire of the appropriate length and cross-section of at least 1.5 mm. sq. and, of course, a socket with a “grounding” contact. Box, plinth, bracket – a matter of aesthetics. The ideal option is when you are doing renovations. In this case, I recommend choosing a three-core double-insulated cable, preferably VVG. One end of the wire is inserted under the free bolt of the switchboard busbar connected to the switchboard frame, and the other end – on the “grounding” contact of the socket. If there is an RCD in the shield, the grounding conductor should not have contact with the N conductor anywhere on the line (otherwise the RCD will operate).
Do not also forget that the “ground” has no right to be torn apart by any switches.