Many of us are constantly faced with the problem of discrepancy between the requirements (recommendations) of manufacturers of various household appliances (especially high-powered ones) and the local conditions of its operation. One of the problems is the lack of a grounding conductor in the apartment, if a two-wire line (phase + zero) of power supply is connected to it.

This applies to almost all houses of old construction, of which we have the majority. What can be done in this case, what to do? All answers to questions regarding the organization of grounding in an apartment are in this article.

From the author's point of view, this is where the conversation should start. Not everyone, unfortunately, understands that the concept of "private property" has its limits. In relation to one, separately taken apartment, these are its walls (floors, ceilings) and the front door. Everything outside is community property.

It is forbidden to use a heating circuit, cold water (DHW) as grounding elements, and even more so - gas pipes. You can often hear that since they still go into the ground outside the house, they can be used to connect the conductor.

What can this lead to?

• In the case of gas - to an explosion.
• To the defeat of one of the residents of the house (apartment) by electric current.
• To increased metal corrosion and, as a result, cracks in pipes and leaks.
• Connect (independently) to the contact in the access shield, on which the so-called PEN-conductor is wound up.

What can be done

As noted, most apartments are “powered” according to an outdated two-wire scheme. At the same time, a cable is brought into the house itself, designed for 3-phase power, which is supplied from a local substation. Each apartment is connected to one of the phases, the second wire entering it is zero. Grounding in such a scheme is not provided in principle.

Therefore, it will have to be looked for in the access shield, into which it starts power cable. There are also some nuances here.

In some houses, 4 wires enter the shield, in others - 5. In the latter case, we can say that there are no problems. Fifth - this is the grounding conductor. It is easy to identify by the color of the braid. He looks like this.

Many electrical panels have a terminal block, to which you can attach "your" wire and stretch it into the apartment.

If the cable is 4-core, then this means one thing - 3 phase wires + 1 protective (PEN). In fact, this is a combined zero and earth (). But you don't need to join it on your own. Why?

Firstly, you will have to “pass” along it along the entire riser and make sure that the conductor cross section is unchanged throughout the route. Who and how builds houses - no one needs to explain. Is there a guarantee that the electricians of the developer company didn’t mess anything up anywhere (violated, cheated, saved)?

Secondly, theoretically, connection to the PEN conductor is possible if its cross section corresponds to the norm (16 "squares" for aluminum and at least 10 for copper). But you will have to mount something and additionally - an RCD and, preferably, a voltage control relay.

What to consider

For those who are not convinced by the above arguments:

• If there are several devices in the apartment that need to be grounded, then you need to know that you cannot connect more than 2 wires to 1 bolt (screw). Therefore, the block will have to be fixed.
• It does not make sense to involve a third-party specialist in the work, at least as a consultant. Even if he is a "pro" of the highest qualification, from a legal point of view, all his advice has no value. The only possible option in such a situation is to contact the chief engineer of your management company. Only those who know the project of the house, in particular, its grounding scheme, will be able to give qualified advice. If the problem is solvable, Ch. the engineer will send a company specialist who will show on the spot how and what needs to be mounted. Then in the future no one will have any claims against the owner of the apartment.
• When carrying out repairs in the apartment, the old electric wiring should be replaced by laying a cable with 3 cores instead. It will come in handy in the future.

For a good and thinking owner of information is enough. Well, how exactly to proceed, at your discretion, dear reader.

The importance of arranging grounding in old city apartments is beyond doubt, but only a very few imagine the way in which this possibility can be realized. In order to make effective grounding in Khrushchev, for example, a separate ground electrode is needed, which is brought outside the residential building. Moreover, such a design should be calculated for the entire entrance, that is, for those apartments whose residents really want to protect themselves from electric shock.

Ways to organize

In the simplest case, in old houses it is allowed to replace the grounding in the apartment with a high-speed differential device (RCD), however, it provides only instantaneous protection and must work in conjunction with the ground electrode. And the option of implementing grounding in an apartment connected to heating or water supply pipes is absolutely not suitable. The danger of this method of protection against electric shock lies in the fact that the quality of the contact of pipes with the ground is not always satisfactory, which worsens the conditions for current flow to the ground. As a result, the potential at the ground point can be quite high.

In addition, if mains voltage hits the body of an electric kettle, for example, it will immediately appear through an illiterately organized PE core on the pipe lines of this riser (and in all apartments connected to it). Responsibility for the consequences of electric shock to any of the residents of the entrance, of course, will be borne by the person who has such a "grounding".

Thus, the only acceptable way, using which you can equip the grounding in the apartment with your own hands, is to make an external grounding structure (ground electrode).

Important! All of the above does not apply to modern residential buildings, in which power supply is organized using a 5-core cable, which has a full-fledged grounding bus in its composition. (The presence of a grounding contour of apartments is provided for in such houses by the general development plan).

Why ground

It is known that in houses of old buildings, the supply of risers is organized using. The specified scheme is implemented in such a way that a cable consisting of only 4 cores, namely: three-phase L1, L2, L3 and a combined PEN conductor, is suitable from the substation to the input device. Moreover, if there is no ground loop in the house, then electrical panels apartments are without local (re) grounding.

The only way in which the "earth" can get to the consumer in the apartments is from the substation through the PEN conductor (see the figure on the right)
Some electricians mistakenly believe that in order to equip grounding in this situation, it is enough to connect a PE protective wire combined with working N to the body of the input shield. However, such a connection in the apartment not only does not solve the problem, but is also extremely dangerous!

If the PEN wire is damaged or burnt out (which happens quite often) phase voltage through the load circuit it gets to all neutral wires N. And if these latter are electrically connected on the shield body with protective conductor, then on all the cases of devices connected to them in the apartment, a voltage of 220 volts will appear. That's why you should think carefully before following the advice of short-sighted electricians.

The only right solution in this situation is to equip your own separate ground loop. For many residents of panel houses from ground floor apartments, this option is quite affordable and is quite often implemented in practice. Under the windows, several metal rods are hammered into the ground, which are then tied along the contour and connected by a copper bus to the PE conductor laid through the apartment together with two others (phase and zero).

Conditions for a quality connection

To equip a high-quality ground loop in an apartment in a city house, first of all, it is necessary to completely replace the old wiring with a three-core cable, in which the phase and zero working cores are supplemented with a PE ground bus. Only if such a separate wire is available, it will be possible to organize a circuit for draining the emergency current from the body of the damaged device through the ground loop into the ground.

When replacing wiring in an apartment, do not try to save on consumable and choose a high-quality copper three-core cable of the desired section (NUM or VVG brands, for example).

Next, you should assemble a team of interested residents of the entrance who want to connect apartments to a collective ground electrode system and, if necessary, obtain permission from the housing and communal services for the arrangement of grounding. It is best to position the contour from the back of the house (not from its front part). For distributing the grounding conductor in apartments and connecting it on the consumer side, a copper bus with a cross section of at least that of the PEN conductor, which is part of the cable supplied to the house, is used.

In the figure above, you can see how grounding is organized by connecting the PE conductor of the electrical wiring to the grounding elements, which in this situation performs the function of re-grounding.

The procedure for constructing a protective circuit

Arrange grounding in apartment building You can use the standard method for manufacturing a ground loop and connecting a PE conductor to it.

According to this technique, the preparation of the ground loop for apartments is carried out as follows.

First, not far from the entrance, at a distance of at least 1.5 meters from the blind area, to a depth of about 0.6 meters, several trenches are dug in the form of a triangle with a side length of 1.2 meters.

Note! The width of the trenches is selected based on the convenience of welding.

Then, a separate trench (about half a meter deep) is dug towards the blind area of ​​the house, which is necessary for connecting the ground line to the access distribution cabinet.

After that, at the corners of the formed triangle, metal corners or pipes of small diameter with a length of at least 2.5 meters are driven into the ground.

Upon completion of the main excavation work, the tops of the blanks hammered into the ground are connected for welding into a solid grounding structure. This will require pre-cut steel strips 40x4 mm of the appropriate length, called a metal bond.

In order to lay a ground line from a welded steel structure to a distribution cabinet located on one of the floors, the following operations must be performed:

It is worth noting that after the line is stretched to a common distribution cabinet located on the driveway in a residential building, each of the residents will be able to forward their own ground bus to the apartment to the GZSH. The rules for its laying and fastening are regulated by the relevant sections of the PUE.

How to conduct grounding in the apartment. technology, whether it is feasible in all premises - the answers to these questions are presented in this article.

Before starting work, you need to find out which system is used in your home. According to the rules that were adopted back in 2003, each building must be equipped with a riser of five wires, in which the 5th wire is just the grounding conductor. If everything is exactly like this in your house, then you just have to spread the ground wire around the apartment (the third core in the cable), then put special sockets with grounding everywhere, and arrange a DSUP in the bathroom.

1. So, in new (post-Soviet) houses, this is, as a rule, a modern TN-C-S system (it has zero both working and protective conductors, which are usually connected in the main shield of the building; then they are disconnected everywhere). In this system, 3 phases L are suitable for the access risers, as well as a separated N (working zero) and PE (protective conductor). The connection process is much simpler, since the floor shield already has separate buses designed to connect zero, phase and ground. And the ground bus has metallic bond with electrical box.

Electricity supply of the apartment TN-C-S

It is not difficult to determine whether your house is connected by (TN - C - S). Just look at the cable that goes to the riser (introductory). It should have 5 wires:

• 3 phases such as L1, L2, L3;
• protective zero PE;
• working zero N.

The connection is made as follows:

• the phase wire from the apartment is connected to the same bus where the previous old wire was;
• the working neutral N wire is connected to the bus that has neutral wires;
• grounding PE wire (zero protective) is connected to the shield body.

Important! It is impossible to connect all ground wires (which are in the shield) to 1 bolt (clamp)! It is necessary to use different bolted connections. It is better to use a busbar: screw it to the shield, then connect the PE.

An example of separation by household appliances: lighting devices, power supplies, large household appliances are grounded separately

It is also important to consider the following:

• with a 3-phase input, absolutely all conductors must have the same cross-sections (for copper up to 16 mm2);
• under 1 terminal of the machine, you can clamp up to 2 conductors of the 1st section;
• in order to obtain a uniform load, a 3-phase connection to the hob is preferable;
• all metal parts in the bathroom (pipes, underfloor heating screen, bathtub, etc.) and the grounding conductor of the socket (of course, if there is one in the bathroom) must be connected to the DSUP (or PMC) bus, which should be located there. In this case, the socket is powered by a 3-wire circuit;
• all PE conductors in the presence of mechanical. protection should be a cross section of 2.5 mm2, if it is not - 4 mm2. The conductor from the DSUP bus to the bus of the PE shield (better than the storey one) must have a cross section of 6 mm2;
• it is preferable to separate lighting circuits and power (socket). However, mixed power supply is allowed. And the lines to all power plants (stove, oven, SM) should be separate.

2. In some new type apartment buildings (since 1997) TN-S is used throughout the disconnected). This grounding is the most reliable. When connecting a house, the ground wire is laid separately, together with the phase, neutral wires from the substation to the electrical panels of the house. The work is carried out in the same way as in TN - C - S.

How to conduct grounding in an old house?

In old houses, the TN-C system is usually found, in which, throughout its entire length, the neutral conductors (working and protective) are combined into one neutral conductor (PEN). The electrical equipment case (electrical appliance, shield or assembly case) is connected to the PEN conductor. Such protection is called zeroing. The zeroing circuit is installed at the substation that feeds the house. 3 phases L are suitable for access risers, as well as a combined PEN conductor. All floor shields in such a system are zeroed, and grounding is not provided for in them.

Wiring in the case of a single-phase power supply to the living space is carried out with 2-core cables (phase, PEN). Or 4-core cables (A, B, C, PEN) with 3-phase power supply of the apartment. There are no protective earth contacts in the sockets.

This is the oldest and most common system. It existed in the USSR for a very long time and, unfortunately, still continues to exist in many homes. When used, there is a serious risk of injury electric shock. Circuit breakers(protective switching devices) installed with the TN-C system protect el. circuits (groups, lines) only from currents short circuit. But protection against electric shock is completely absent.

Important! If an electrician recommends doing an electrical installation using TN-C, do not hesitate to refuse! It is completely incapable of protecting against electric shock! The operation of electrical appliances with such a system creates a potential threat to life! In addition, the PUE (clause 1.7.80) prohibits the installation of an RCD in this grounding system as the main protection.

According to the new standards adopted in 2003, in all old houses, the TN-C system must be transferred to either the TN-C-S or TN-S system by upgrading the power supply circuits (installing a potential equalization system). However, poor funding does not yet allow this to be implemented in all homes. In most cases, power supply organizations proceed as follows: at the input to an apartment building, they install a re-grounding of the neutral wire. Then separate the PEN conductor into 2 separate wires:

• zero (N) working conductor;
• protective (PE) conductor.

Important! In the case of a TN-C system, nothing can be done independently regarding grounding, unfortunately! You can not build your own personal memory! Since it will be located outside the SES of the house and can cause stray currents. Therefore, you can only use the existing common house system.

In other words, you need to either completely re-equip all the wiring in the house to new standards, or use electrical appliances with a non-conductive housing. It is also recommended to install an RCD on circuits that feed household appliances. Especially important - in the bathroom. RCD is not able to protect against electric shock, but it will save from fatal injury.

Reasons for excluding grounding installation

1. If grounding is not connected to water pipes, batteries, fittings and other conductive parts of the apartment, dangerous voltage will appear between the equipment connected to such wiring and these parts. But even if you connect and the grounding turns out to be good, then from these structures the equalizing grounding current will go through the entire apartment. Such currents can be very high, so if the PEN (primary earth electrode) is violated, there will be a fire hazard due to overcurrents. But that's not all. In the event of a voltage on the body of electrical appliances, grounded by means of a battery or a water pipe, all pipes and batteries will be energized, including those in neighboring apartments. As a result, a neighbor who decided to pour water from the tap can be electrocuted to death! The prohibition of the use of pipes is written in the PUE 1.7.110.
2. It is also impossible to simulate a circuit through a connection in a “zero worker” euro socket with a “zero protective” conductor. This is extremely dangerous. It is not uncommon for the “zero working” conductor to burn out in the shield. And this leads to the fact that on the computer case, refrigerator, etc. placed 220 V.
3. The only exception is grounding "to zero", which is done in houses specially equipped for electric stoves. However, this should be done only after carefully studying the neutral conductor for the cross section (at least 16 squares for aluminum), as well as continuity (according to PUE 7, clause 1.7.131). This must be done by a qualified electrician.

Thus, we see that in some cases it is not easy to draw a circuit in an apartment. If this is a TN - C - S or TN - S system, then you can ground yourself (that is, run wires around the apartment). If this is an outdated TN - C, then even an experienced electrician will not help in the case of a single apartment. It needs to be changed throughout the house.

Recently, there has been a huge increase in public interest in the term grounding. The word seems to be simple and seemingly understandable, but as a rule, in fact, no one really knows anything about its definition and meaning. Something connected with the earth and certainly necessary. Let's figure out what it is grounding and what it is for.

First of all s grounding protects a person from electric shock, when it appears on separate parts of electrical equipment, which in normal operation should not be energized. A little confusing, but then we will analyze this issue, for full understanding, using a specific example.

We have all heard about the fact that washing machines must be grounded in residential premises. Why do you need to do this, is there such a need and need in reality?

The fact is that the body of the washing machine is usually made of two components, plastic and metal. Such execution of its design is connected, basically, with safety of the consumer. The washing machine drum spins at a very high speed, from 400 to 1200 rpm, which in itself is a very serious danger. The drum is driven by an electric motor, which poses an even greater danger to human life and health, both mechanical and electrical.

When the washing machine is running, the electric motor performs various operations specified by the washing program. It rotates, accelerates, brakes, waits, switches to reverse. At certain moments, during the normal course of the washing cycle, small current leaks occur in the engine, which, due to the design of the machine, one way or another fall on its body. Of course, this is not dangerous on plastic elements, but on metal ones, there will be a voltage of small values. This voltage is considered safe for human life, but sufficient for a slight shaking, the significance of which is determined by the individual characteristics of each person. One person can be lightly pinched, and another decently shy away. The resistance of the human body ranges from 0 to 1000 ohms and depends on many factors of human life and health. All these processes take place during each wash, in the normal mode of operation of the machine, but the electric motor may fail and then the voltage on the case will be equal to the voltage in the outlet, 220 volts. And this is a serious stress, which is considered fatal.

Grounding removes voltage from the body of the machine to the ground, preventing electric shock to a person. For this, a grounding contact is provided on the plug, which is connected to the grounding contact in the socket, unless, of course, grounding was provided in your house when designing its electrical part.

So, we have determined the main purpose of grounding.

Now, let's look at where the ground comes from in the outlet.

Grounding itself is a few driven into the ground metal corners connected to each other by a metal strip. According to the PUE, power distribution cabinets and shields should be grounded both in industrial and residential buildings.

At the input of each house there is a power electrical cabinet, it usually has a metal case. Not far from it, a grounding structure is being carried out. The cabinet is connected to the structure with a metal tape, by welding. Inside the cabinet there are special grounding contacts for connecting wires outgoing to consumers. They reach for the floor shields and from there they are distributed among the apartments. Thus, three wires phase, zero and earth enter the apartment.

In Soviet times, only introductory power cabinets were grounded, there were no groundings inside the apartments, this was due to saving construction funds. In addition, in those days there was not yet such a quantity of various household electrical equipment and such capacities consumed by them.

How to determine if your apartment has grounding?

First, you need to see if the outlets you have installed have an additional grounding contact.

This photo shows a socket with grounding contacts. They are two metal mustaches located above and below the socket, to which a suitable ground wire is connected using a screw connection.

Secondly, the socket should have three wires - phase, zero, and the third - ground.

You can only check the performance of the ground wire using a multimeter or voltmeter. With this device you need to make simple measurements. We find the phase wire and then measure the voltage relative to it. First phase zero, then phase earth. If the readings are different, then the ground is working, if the same, then most likely the ground wire is connected to zero somewhere. Instead of grounding, grounding is performed, which is very dangerous, especially in case of overvoltage.

So, in this article, we have analyzed in detail what grounding is, where it comes from and how to determine its presence in the outlet.

Are you familiar with such a situation that you need to make grounding in the apartment, but there is no corresponding “ground” terminal on the floor panel? Typically, the absence of a ground loop is observed in panel houses old building - Khrushchev. Many electricians solve this problem in their own way: who connects the RCD, who makes an individual circuit, and who generally connects the ground wire to the battery or plumbing system. Next, we will tell you how to properly make grounding in an apartment with your own hands, if it is not there, and which protection option to mount is strictly prohibited!

Right Decisions

Method number 1 - Connecting an RCD

If there is no grounding in the apartment (not provided by the developer), and you still want to protect yourself from electric shock, then it is best for a while (pictured below). Of course, this device will not solve the whole problem, but nevertheless, in case of current leakage, it will instantly turn off the power of the serviced device - a washing machine, water heater or a group of sockets.

In addition, we recommend that you use a new one yourself - with a three-core wire. In the future, when it comes time to make grounding in your entrance, you will already be prepared, and all that remains is to run and connect the PE wire to the corresponding bus of the floor panel.

Method number 2 - Mounting your own circuit

Recently, there have been cases when residents of panel houses decide to independently make grounding in Khrushchev, for which they organize an individual ground loop. This idea lies in the fact that a single-core PE wire is pulled from the apartment to the basement along the risers. Near the house, at least three metal corners or electrodes are driven in, interconnected by a metal plate. A wire drawn from the floor is connected to the finished protective triangle (provided in the diagram below), the other end of which is fixed on the shield body. All that remains is to connect the grounding of the apartment to the shield and, as you understand, the leakage protection is ready!

We draw your attention to the fact that you can do such grounding with your own hands only after agreeing this event with the management company. Spontaneous adoption of this decision can lead to many problems, because. No matter how you interfere with the approved project, and if some kind of accident occurs, it is possible that you will be the last one.

I would also like to add that if you still decide to make your own ground loop in the apartment, then the PE wire must be copper, with a cross section of at least 4 mm2. This method of protection is suitable not only for the residents of the first floor, but also for everyone else - the 4th or even the 5th.

Video review of the protective system:

Wiring Grounding Technology

Dangerous defense option

Some unfortunate electricians decide to make grounding in the apartment by simply connecting the third wire to the plumbing or heating system that runs through the room. In no case do not use this version of the ground loop, because. in this case the picture is as follows:

• there is a breakdown of the current on the body of the electrical appliance (boiler or washing machine In bathroom);
• dangerous current passes to batteries and hot / cold water risers not only of your apartment, but also of all neighbors, because. the system is unified.
• anyone who at the moment decides to drink tap water or simply touch metal pipes can become a victim.

By the way, this moment is stipulated by the rules of the PUE and is also strictly prohibited, according to PUE 1.7.110.

In addition to this method of grounding an apartment, the following are also considered unsafe:

1. Connection in a zero socket with a ground conductor (the so-called). If it suddenly happens in the network, a dangerous voltage will pass to the case of all electrical appliances connected to the grounding of the apartment - a computer, a water heater, a refrigerator, etc.
2. Serial grounding of electrical appliances (through each other). If you decide to make such a ground loop, be aware that in the event of an accident, electromagnetic incompatibility may occur. As a result, electrical installations will create interference and there is a high probability that the ground loop will not prevent electric shock.
3. Connection to one terminal of the PE bus of several wires. It is allowed to connect one conductor to each contact pad. It is strictly forbidden to neglect this rule.