According to the EIC * (clause 1.7.32.): Potential equalization- this is the electrical connection of conductive parts * to achieve equality of their potentials.

Why do we need a potential equalization system? To figure it out, let's imagine the bathroom power supply scheme:

As you know, electric current flows from phase to zero. From the diagram above, it can be seen that the current, when turned on washing machine into the socket, passes through its electric motor and returns back to the network through the N-bus along the neutral wire. From the same N-bus, grounding (zeroing) of the washing machine case was made, this is necessary so that in the event of damage to the insulation in the washing machine and a short circuit to its case, the voltage is turned off by the protection device. But since the washing machine body is connected to the same N-bus through which current flows through the neutral wire, there is a danger of current flowing from the neutral wire through the N-bus to the washing machine body and the appearance of an electric potential on it.

As you know, voltage (denoted by the letter U) is the difference in potentials of two points (denoted by the letters φ 1 and φ 2):

U= φ 1 - φ 2

For example, in our case, the phase wire has a potential φ 1 \u003d 220 Volts, and the neutral wire has a potential φ 2 \u003d 0 Volts, then the voltage between the phase and neutral wires (mains voltage) will be equal to:

U=220 - 0=220 Volts

In addition to the neutral wire, all conductive structures of the building that have contact with the ground also have a zero potential, for example: a heating system, metal pipes for supplying hot and cold water, metal gas pipe, building fittings, etc.

Imagine the situation: on the body of the washing machine, as a result of the connection shown in the above connection diagram, an electric potential appeared, equal, for example, to 30 volts, at this time a person, having taken a bath, leaned on the washing machine, reached for a towel and touched the heated towel rail, which, through the system heating has a connection with the ground (i.e. its potential is zero), a person can get an electric shock, because. Current is known to flow along the path of least resistance:

The tension between the arms (i.e. between points "A" and "B") will be equal to:

U= φ 1 - φ 2 \u003d 30 - 0 \u003d 30 Volts

where: φ 1 - potential on the body of the washing machine; φ 2 - potential on the heated towel rail

The current will pass through the body of the washing machine, then along the hand-hand circuit to the heated towel rail and from it through the heating system to the ground, in addition, the current can also pass through the hand-foot circuit, because. the floor in the bathroom, as a rule, is also conductive.

In order to prevent such a development of events, a potential equalization system is used:

In this case, even if the above situation occurs with the appearance of an electric potential on the body of the washing machine, the potential of the same value will appear on all conductive structures and, therefore, the voltage between any points of the building will be equal to zero.

For example, a potential φ 1 \u003d 30 Volts appeared on the body of the washing machine, in this case, a potential of the same value φ 2 \u003d 30 Volts will appear on all conductive structures of the bathroom through the potential equalization system. The voltage in this case will be:

U \u003d φ 1 - φ 2 \u003d 30 - 30 \u003d 0 Volts

A video that clearly shows what happens in the absence of a potential equalization system in the house (potential difference between grounding and a gas pipe):

2. The device of the potential equalization system.

The potential equalization system (SUP) is divided into the main (OSUP) and additional (DSUP).

2.1 The device of the main potential equalization system.

It is carried out, as a rule, during new construction or reconstruction of a building and should provide for the connection to the main ground bus (PE bus) of the following conductive parts * (according to clause 1.7.82. PUE):

1) zero protective conductor of the supply line;

2) a grounding conductor connected to the re-grounding conductor at the entrance to the building (if there is a grounding conductor);

3) metal pipes of communications included in the building: hot and cold water supply, sewerage, heating, gas supply, etc.

If the gas supply pipeline has an insulating insert at the entrance to the building, only that part of the pipeline that is relative to the insulating insert from the side of the building is connected to the main potential equalization system;

4) metal parts of the building frame;

5) metal parts of centralized ventilation and air conditioning systems. In the presence of decentralized ventilation and air conditioning systems, metal air ducts should be connected to the bus RE power supply panels for fans and air conditioners;

6) grounding device of the lightning protection system of the 2nd and 3rd categories;

7) a grounding conductor of functional (working) grounding, if there is one and there are no restrictions on connecting the working grounding network to a protective grounding grounding device;

8) metal sheaths of telecommunication cables.

Conductive parts entering the building from the outside should be connected as close as possible to their point of entry into the building.

The connection of the conductive parts of the main potential equalization system must be carried out in a radial pattern, i.e. Each conductive part must have a separate ground conductor from the PE busbar.

Cross-section of conductors of the main potential equalization system there must be at least half of the largest cross section of the protective conductor of the electrical installation, if the cross section of the potential equalization conductor does not exceed 25 mm 2 for copper or equivalent from other materials. Larger conductors are generally not required. The cross section of the conductors of the main potential equalization system in any case should be at least: copper - 6 mm 2, aluminum - 16 mm 2, steel - 50 mm 2. (clause 1.7.137 of the PUE)

As can be seen in the diagram above, all conductive parts that make up the main potential equalization system are connected to separate conductors, and the GZSH itself must be grounded by connecting it to.

Inside the introductory switchboards in accordance with clause 1.7.119. PE bus should be used as PUE as GZSH. We will analyze how it looks on the example of connecting a gas pipe of a private residential building to the OSUP:

To connect the conductors of the potential equalization system to the pipes, special clamps are used:

2.2 Device for an additional potential equalization system.

Additional potential equalization system (DSUP) must interconnect all simultaneously accessible to touch open conductive parts of stationary electrical equipment and third-party conductive parts, including touchable metal parts of the building structures of the building, as well as zero protective conductors in and protective grounding conductors in systems and, including protective conductors of plug sockets. (clause 1.7.83. PUE)

Therefore, DSUP is mandatory for human injury electric shock, in which it is possible for a person to simultaneously touch open conductive parts of stationary electrical equipment on the one hand and a third-party conductive part on the other.

For bathrooms and shower rooms, an additional potential equalization system is mandatory and should include, among other things, the connection of third-party conductive parts that extend outside the premises. If there is no electrical equipment with zero protective conductors connected to the potential equalization system, then the potential equalization system should be connected to the PE bus (clamp) at the input. Heating elements embedded in the floor must be covered with a grounded metal mesh or a grounded metal sheath connected to the equalization system potentials. As additional protection for heating elements, it is recommended to use for a current of up to 30 mA (clause 7.1.88. PUE).

IMPORTANT!: It is not allowed to use local potential equalization systems for saunas, bathrooms and shower rooms. (clause 7.1.88. PUE).

Thus, the additional potential equalization system is designed to complement the main potential equalization system and should not be performed in its absence.

The connection of the conductive parts of the additional potential equalization system can be carried out both according to the radial circuit, and by a loop according to the main circuit, ensuring the continuity of the connecting conductor. In this case, the connection is usually made through the PMC - a potential equalization box.

PMC is designed to connect to one conductor of the potential equalization system of several conductive parts. The CUP has the following form:

An example of an additional potential equalization system (in this case, the geyser is connected to the mains, i.e. we conditionally assume that it is a stationary electrical appliance):

Connection of DSUP conductors:

For the system of additional potential equalization, separate specially provided conductors can be used.

Cross-section of conductors of the additional potential equalization system(clause 1.7.138 PUE):

• when connecting two open conductive parts * - the section of the smaller of protective conductors connected to these parts;
• when connecting an open conductive part and a third-party conductive * part - half the cross section of the protective conductor connected to the open conductive part.

At the same time, in accordance with paragraph 1.7.126. PUE smallest cross-sectional area protective conductors must match the following values:

NOTE: The cross-sectional areas of protective conductors are given for the case when the protective conductors are made of the same material as the phase conductors. The cross sections of protective conductors made of other materials must be equivalent in conductivity to those given.

The minimum cross-sections of copper conductors for additional potential equalization, which are not part of the cable, should be as follows (clause 1.7.127 of the PUE):

• 2.5 mm 2 - in the presence of mechanical protection;
• 4 mm 2 - in the absence of mechanical protection.

The general potential equalization scheme of the building will look like this:

M- open conductive part; C1- metal water pipes entering the building; C2- metal sewer pipes entering the building; C3- metal gas supply pipes with an insulating insert at the inlet, entering the building; C4- ventilation and air conditioning ducts; C5– heating system; C6- metal water pipes in the bathroom; C7- metal bath; C8- third-party conductive part within reach of exposed conductive parts; C9- reinforcement of reinforced concrete structures; GZSH - main ground bus; T1- natural grounding; T2- lightning protection ground electrode (if any); 1 - zero protective conductor; 2 - conductor of the main potential equalization system; 3 - conductor of an additional potential equalization system; 4 - down conductor of the lightning protection system; 5 - contour (main) of working grounding in the room of information computing equipment; 6 - conductor of working (functional) grounding; 7 - potential equalization conductor in the working (functional) grounding system; 8 - ground conductor

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PUE - Rules for the installation of electrical installations

Conductive part- a part that can conduct electricity. (According to clause 1.7.7. PUE)

exposed conductive part- a conductive part of an electrical installation accessible to the touch, not normally energized, but which may become energized if the basic insulation is damaged. (According to clause 1.7.9. EIC)

When in the bathroom there is electric current from metal pipes, then this problem can be solved by installing special protection for metal objects, which is called a potential equalization system.

Usually in new buildings they plan and implement such protective systems against electric shock. But in old houses, this option does not always work. Let's figure out what the potential equalization system is (its abbreviated abbreviation SUP), its types, and how you can do it yourself.

Purpose

Find out if a potential equalization system is necessary in ordinary apartment. All objects made of metal conduct electricity. We know this from school lessons in physics. In our apartments, dangerous places are heating pipes, as well as water pipes, a downpipe, plumbing, a heated towel rail in the bathroom, and ventilation ducts.

All metal communications in the house are connected to each other. If a potential difference occurs between some metal objects, such as a bathtub and a heating radiator, a person touching these two objects at once can lead to electric shock. This is because the body acts as a jumper between the battery and the bath, so the current flows through the human body from the object with the highest potential to the object with the lowest potential value.

A similar case of danger is the appearance of a potential difference on sewer and water pipes. If there is a leakage of current on the water pipes when a person is washing in the bathroom, there will be a high probability of electric shock when touching the turned on faucet. Water conducts current from the water supply to the sewer, and you complete this circuit with your body.

To eliminate the presence of such a danger, it is necessary to equalize potentials using a special system installed in the apartment.

Kinds

There are two types of potential equalization systems:

1. Main (OSUP).
2. Additional (DSUP).

OSUP

This is the main potential equalization system, which is a circuit that combines the following elements of this system:

• Grounding.
• GZSH - the main ground bus. It is located at the entrance to the building.
• Metal parts of the fittings of a residential building.
• Ventilation system box.
• Metal water pipes (hot and cold water supply).
• Lightning protection.

In early times, when all these parts were combined, there was no danger of a potential difference. But today the situation has changed radically, as the owners of many apartments are replacing rotten metal pipes with plastic or polypropylene pipes that do not conduct electricity. plastic pipes break the circuit, resulting in a potential difference between different metal parts in the bathroom.

The main type of system has a significant problem, which is that over a significant length of pipes, for example, in a 12-story building, the electrical potential of the same pipe on the first and last floor will have a large difference. This leads to a dangerous situation. Therefore, an auxiliary system is needed, which we will discuss below.

DSUP

This system is optional and is located in the bathroom. It includes the following elements:

• Shower enclosure or bathtub.
• Towel dryer.
• Pipes: gas, water supply, heating.
• Sewer system.
• Ventilation system box.

Each element of this system is connected by a separate wire to a copper core. The second end of this wire is brought out into a special box (KUP).

There are certain requirements for the creation of a DSUP according to the rules of the PUE:

• You can not connect the components of the DCS with a loop.
• It is forbidden to carry out DSUP, provided that the ground loop is not installed in the apartment.
• The additional system should not be torn along its length from the PMC box to the apartment shield. Switching devices must not be installed in the circuit.

If you don't have this protective circuit, as potential equalization, we will describe below how it can be done on your own.

Installation of a potential equalization system

Installing an auxiliary potential equalization system is not very difficult. It is called the local system. But such work is best done when carrying out repairs in the apartment, since it is necessary to conduct a wire to the shield from the PMC box under the floor, and this is due to a violation of the floor covering, and related repairs.

To start the installation, prepare some materials according to the following list:

• Terminal box complete with copper busbar (SHDUP).
• Copper wires, consisting of one core. The cross-sectional area of ​​the wires should be from 2.5 to 6 mm 2, brand PV-1.
• Fasteners: bolts, clamps, fixing petals. They are required to connect the wires of the entire equalization system to pipes and metal parts.

With this set of elements, you can begin the installation of DSUP. First, a wiring diagram is drawn up in order to perform the correct potential equalization. The diagram also shows the places where the wire passes from the PMC box to the ground bus in the apartment panel. The figure shows one example project.

Further, the communications themselves are preparing for connection, that is, the place of contact of the clamp with the pipe is cleaned, until a metallic sheen appears. This is necessary for the reliability of the connection. In a dangerous situation, potential equalization will work as expected.

Then wires are connected to each element of the system. If you are sure that the wire will not be damaged, then a wire cross section of 2.5 mm 2 is sufficient. But if there is any doubt about this, then it is better to use a 4 mm 2 wire. All conductors are carried into the box and perform reliable connection with tire.

The bathroom terminal box must have a degree of protection of at least IP54. a wire with a cross section of 6 mm 2 should be led from the box bus to the apartment shield. There is a requirement here that this wire should not have intersections with other cables of different lines.

At the end of the work, the wire is connected to the ground bus of the shield. On this installation can be considered complete. For peace of mind, you can call a qualified electrician to check the operation of the system using instruments, as well as visual inspection.

EMS Installation Limitations

It is recommended to install the EMS during the construction of the building. But there are some restrictions on its use in already built houses, in which grounding is carried out according to the TN-C system, with a combined PEN conductor. In such houses it is forbidden to carry out potential equalization. Otherwise, during a break in the neutral wire, there is a risk of electric shock to residents of other apartments in which there is no DSUP. Most often, such a restriction applies to multi-storey buildings of the old fund.

This problem is solved by switching to grounding according to the TN-C-S system. For this in switchboard at home on the main ground bus, the PEN conductor is disconnected into PE and N wires, the ground loop is connected and connected to the main ground bus with a copper conductor.

Currently, there is a tendency to replace metal pipes with plastic ones, which do not require their connection to the EMS. If you already have additional potential equalization of metal pipes, and you decide to replace the pipes with plastic ones, this will lead to a break in the electrical connection with the ground bus of the remaining elements made of metal. This will make them dangerous to humans when touching several parts at the same time.

New building rules and regulations are aimed at maintaining the correct installation of potential equalization. This system is subjected to inspection, checked according to the project before handing over the house. Electrical safety is created by making electrical connections of all metal parts accessible to human contact with the main ground bus using PE wires.

The main system is complemented by local equalization systems in places with a high risk of electric shock. We must not forget that when installing the EMS, a reliable connection between the elements of the system that are connected in a radial pattern must be ensured. In this case, the wire cross-section must be at least the recommended value.

Potential equalization of lightning protection system

When a lightning strike occurs, a large current strength and its rate of increase occur. Because of this, a potential difference appears greater than from current leakage in the network. Therefore, to create protection against lightning, it is necessary to equalize the potentials.

In order to avoid uncontrolled short circuits during a lightning strike, it is necessary to directly connect electrical devices, metal elements, grounding, lightning protection system with protection devices. The conductors of the entire system are connected to an equalizing bus, which must be accessible for testing purposes, it is connected to an earth loop. Large buildings usually have several of these tires. At the same time, they are all connected to each other.

The lightning protection potential equalization system is carried out at the entrance to the building, and in places where it is impossible to maintain safe distances, for example, at ground level or in the basement.

In a concrete building, either with a metal frame or with lightning protection of a separate design, lightning protection equalization is performed only at ground level. In tall buildings above 30 meters, lightning protection potentials are equalized for every 20 meters.

Lightning-conducting parts are located at a safe distance from the ECS, in order to avoid impulse flashovers. If such a distance cannot be provided, then auxiliary connections are created between the lightning rod, the lightning rod and the EMS. At the same time, the factor that auxiliary connections make it possible for high potential to enter the building is taken into account.

1. It is forbidden to connect DSUP elements with a loop.
2. It is strictly forbidden to create an additional EMS if the apartment does not have a ground loop (grounding is done according to the system).
3. DSUP must be inseparable along the entire length from the terminal box in the bathroom to the apartment shield. The inclusion of any switching equipment in the circuit is prohibited.

So we examined what the main and additional potential equalization system consists of. If you do not have a local protective circuit in your apartment, then we will tell you how to make a DSUP with your own hands.

We carry out installation

Installation of an additional EMS (it is also called local) is easy to perform. It is advisable to do such work at the stage of overhaul, because. the wire from the box (KUP) to the shield must be led in the floor screed. So, first you need to prepare the following materials:

1. Terminal box with a special copper bus - ShDUP, as in the photo below.
2. Single-core copper wire, cross section 2.5; 4 and 6 mm 2 . It is recommended to use and .
3. Mounting systems - clamps, bolts, contact petals. Needed to connect the conductors of the potential equalization system to pipes and metal cases.

Having prepared such a small set of DCS, you can proceed to installation. First of all, it is recommended to draw up a potential equalization scheme, according to which you will connect all the elements. You can also draw on the diagram where the wire will run from the terminal box to the ground bus in the shield. You can see examples of projects for an apartment on the plans below:

After that, you must prepare communications for connection - clean a small area under the clamp on the pipes to a metallic sheen. This is necessary so that the contact is reliable, and the potential equalization system works in a dangerous situation.

Next, you need to connect each element with a separate wire. If there is no possibility of mechanical damage to the wire in the sections, you can use a conductor with a cross section of 2.5 mm 2 for equalization. When there is a probability of damage, albeit insignificant, it is better to play it safe and use a wire with a cross section of 4 squares. All wires are brought into the PMC and securely fixed on the bus. By the way, terminal box for installation in the bathroom, it is recommended to choose from 54 or higher. A wire with a cross section of 6 mm 2 is output from the bus, which must be laid to the apartment shield. There is also a specific requirement here - this conductor should not cross other cable lines, for example, if you decide.

Finally, the wire is connected to the ground bus in the shield, on which the installation of an additional potential equalization system is completed. We recommend playing it safe and calling an electrician to check the system's performance with a tester and visual inspection!

I am sure that many of you have heard about the potential equalization system (abbreviated as EMS), but few people understand what it is and why it is needed. This article aims to clear up this misunderstanding.

What is a potential equalization system?

SUP is designed to equalize the potential of all conductive parts of the building:

• building elements;
• building structures;
• engineering networks and communications;
• lightning protection systems.

The connection of all conductive parts of the building is carried out by protective conductors PE, which are laid separately, or may be part of the power supply lines. These conductors form the so-called "grid" in the building and must connect all of its above-mentioned parts to the grounding device and grounding conductors.

In case of damage in the electrical installation and potential (voltage) on the conductive parts of the building, a current occurs short circuit, or high leakage currents, which lead to disconnection of the damaged section of the circuit from the power source, by tripping circuit breakers or RCD.

In previous articles, we talked about TN-C-S, TN-S grounding systems, where, according to the requirements of PUE-7, electrical wiring of residential, domestic and administrative buildings is prohibited without the use of protective conductors, i.e. PE conductors. This primarily has a positive effect on electrical safety.

The potential equalization system (SES) is of 2 types:

• main potential equalization system (OSUP);
• additional potential equalization system (DSUP).

Main system (OSUP)

Comprises:

• ground loop (grounding device);
• main ground bus (GZSH);
• "grids" of protective conductors PE;

The main ground bus (GZSH), it is also a PE bus, is installed in the introductory switchgear(VRU) buildings. A steel strip is connected to the GZSH, coming from the ground loop (grounding device).

Connected to the same main bus:

• PEN-conductor of the input line (cable) in the TN-C-S grounding system;
• PE conductor of the input line (cable) in the TN-S earthing system.

1. It is forbidden to arrange a potential equalization system in houses with a TN-C grounding system.
2. It is forbidden to connect protective PE conductors with zero working N-conductors starting from the main ground bus (GZSH).
3. The scheme of connection to grounded structures, elements and engineering networks of the building must be radial. The radial scheme is performed as follows: each grounded part of the building has its own potential equalization conductor. It is strictly forbidden to connect the potential equalization PE conductors with a loop!
4. It is forbidden to install various protective switching devices in the circuits of protective PE conductors. The continuity of protective conductors is the most important and basic requirement.

Additional system (DSUP)

We figured out the main potential equalization system (OSUP). Now let's look at what an additional potential equalization system is. DSUP is necessary to provide additional electrical safety in rooms with heightened danger e.g. bathroom or shower room.

It consists of:

• potential equalization boxes, abbreviated KUP;
• potential equalization conductors.

How is DSUP mounted?

1. First of all, it is necessary to determine the installation location of the potential equalization box (PEC).
2. Next, you need to connect the PE bus of the input electrical panel(apartments, cottages) with a PE bus located in a potential equalization box (PEC). It's done copper wire section 6 sq. mm.
3. The third step, according to, will be the connection of all the metal structures of the bathroom:
   • heating;
   • cold plumbing;
   • hot plumbing;
   • bathtub or shower.
4. Protective potential equalization conductors from grounded structures are laid and connected to the PE bus in the potential equalization box (PUE). Fastening of protective conductors of potential equalization to pipes can be done using metal clamps.
5. Also, all sockets installed in the bathroom are subject to additional grounding.

Quality control

The cross section of the potential equalization protective conductors is carried out with a copper wire with a cross section of 2.5 - 6 square meters. mm.

After the electrical installation of the potential equalization system, it is necessary to invite specialists from the electrical laboratory to carry out the following electrical measurements:

• ground resistance measurement;
• checking the presence of a circuit between the grounded structures and the PE grounding bar in the box (KUP).

This was introductory information about the potential equalization system. If you have any clarifying questions, ask them in the comments.

Over time, buildings acquire an ever wider and more sophisticated system of electrical equipment. Thus, consumers with low voltage can suffer more damage from surges caused by thunderstorms and arising from the effects of electrical impulses and the reduction of the separating dangerous space between electrical objects and the lightning rod. A volumetric system of electrically conductive networks is organized by information supply, antenna structures, centralized heating communications, water supply, gas and power systems. The only lightning protection under the influence of an electromagnetic pulse is not able to prevent damage to rather weak equipment. Therefore, a general lightning protection network should be formed, and first of all, the main potential equalization system.

What is it used for

Potential equalization is used to ensure equalization in all interconnected metal parts of a building, i.e. to form an equipotential surface. In this case, when an increased potential enters the house on all metal structures, it increases synchronously, due to which a dangerous voltage difference does not develop and sparking and the passage of dangerous currents do not form.

Connecting elements

An important protective measure is the creation of the main potential equalization system. It connects the grounding main bus, the main grounding line, the protective main line and conductive elements, which include:

• reinforcing parts of structures with a reinforced concrete base;
• building elements made of metal, climate systems, centralized heating;
• steel pipelines for system power supply.

Most often, the potential equalization system has only one output method. In the distribution element room, the main busbar is mounted as close as possible to the injection point.

Lightning protection system

Due to the rapid rise of the current and its high strength, a lightning strike creates a huge potential difference, much greater than that which occurs due to current leakage. Therefore, potential equalization is required to protect against the influence of lightning currents.

To prevent an uncontrolled short circuit, a lightning protection structure, grounding system, metal equipment, electrical installations with protective mechanisms should be side-by-side or directly combined.

The potential equalization bus with open access for testing work must be connected to the equalizing system. The bus also has a ground connection. In large buildings, there may be several if they have a connection to each other.

Potential equalization in the lightning protection system is carried out at the point where the conductors enter the room and where the safe distances are violated, at the level of the soil or in the basement.

A house built with a steel frame or reinforced concrete base, or with separate room for external lightning protection, must have potential equalization at ground level. In houses with a height of more than 30 m, it is performed every 20 m.

Lightning conductive parts are installed at a safe distance to prevent the occurrence of impulse reactions. If it is impossible to maintain a safe distance of the potential equalization system, the lightning diversion device and the receiver form complementary connections between themselves. It is worth noting that they can lead to the entry of increased potential into the structure.

Complementary device

An additional potential equalization system is being created, the PUE of which determines the form and application, at the locations of electrical equipment where the existing conditions can be dangerous, and if the standards indicate the need for it. It forms a connection between all parts of the existing equipment and third-party conductors that are next to them.

Typical premises and objects in which additional security measures should be used are antenna equipment, lightning protection facilities, remote communication facilities, areas with a high explosion hazard, hospitals, fountains, water parks, bathrooms. The company that performs the installation work must carry it out in accordance with the instructions of PUE-7.

Lightning protection potentials and accessories

A lightning protection system and equipment parts must be connected, which includes air ducts for climatic and ventilation devices, crane frames, elevator guide elements, pipelines of such systems as fire extinguishing, heat supply, gas and water supply. If possible, each metal structure is connected to equalization busbars. Electrically conductive pipes can act as connecting lines (with the exception of a gas pipeline).

If there is an isolated section on the water and gas pipeline, the conductors of the potential equalization system are used for shunting. A special connection to a lightning protection device is not needed for buried metal pipelines close to ground. The same goes for railroad tracks. If unification is unavoidable, then it must first be agreed with the operating company.

grounding

The grounding repeater works with the help of two vertical electrodes with a length of at least 5 m, they are fastened together by a horizontal ground electrode. A steel strip acts as the latter; it is also used to form a conductor connecting the GZSH and an additional ground electrode. The strip must be at least 4 mm thick with a cross-sectional area of ​​75 mm 2 . There is no rationing of the resistance of the repeated ground electrode.

The cross section of the supply cable affects the selection of the potential equalization conductor; it should not be less than half the cable cross section. The most widespread wiring is PV1 and steel strip, a single-core cable is also used. Special clamps are often used when branching the line with a wire.

Technical equipment and lightning protection

In accordance with the theses of PUE-7 and subject to the cross-sectional boundaries of the conductors, all connections are made to equalize the potentials of lightning protection structures. Direct connections and connections made through spark separating gaps should be separated.

The lightning protection system can be directly combined with the following devices:

• grounding elements of the protection system against high voltage security structures;
• antenna devices;
• ground lines located underground at a distance from communication and overvoltage protection systems;
• grounding of power structures, the power of which exceeds 1 kW, while there should be no possibility of entering high potential into the grounding conductors;
• safety connections in TT networks for protection against electric shock during indirect contacts.

When carried out in metal pipes or screening of information or lines of force an additional potential equalization system is not needed.

spark gaps

Routine tests shall be carried out when gaining access to the spark-disconnecting spaces. Due to the correct design and installation of the internal lightning protection mechanism, damage caused by potential differences and overvoltage impulses is minimized.

Connection via spark intermediate separations is carried out for the following elements:

• grounding of measuring systems subject to separate design;
• installations protected from current leakage and having anti-corrosion cathodic protection;
• traction element return wire direct current, as well as a variable in the absence of the possibility of performing a direct combination for signal-technical arguments;
• auxiliary grounding parts protective shutdown, which operates at dangerous voltage.

Installation

During the construction of the building, the installation of the EMS should be carried out, as there are some difficulties when used in finished buildings. An additional potential equalization box is prohibited for use in buildings with grounding of the TN-C type. If this rule is not observed during a break in the neutral wire, there is a possibility of electric shock to residents who did not install DSUP. This restriction applies mainly to the old multi-storey housing stock.

Another type of grounding system gets rid of this problem: for this, a ground loop is made and connected with copper wiring to the pinching main bus.

plastic pipes

Today, there is a sufficient distribution of communications using plastic pipes, which do not need to be combined with an equalization system. At the same time, if metal pipes in the existing DSUP are replaced with plastic pipes that differ in conductive properties, there will be a violation of the connection between the metal parts in the room (towel dryer, batteries) and the ground bus, due to which they become dangerous when touched at the same time.

When creating communications using plastic pipes, the connection with the equalization system is carried out using metal combs, cranes and check valves to secure conductors. If there are dielectric inserts in metal pipes, they are added to the main system after the inserts inside the building.

What you need to know

In accordance with building rules and regulations, today increased attention is paid to the competent installation of a potential equalization system. First of all, when the building is put into operation, inspection and verification for compliance with the project are carried out. The creation of an electrical union of all conductive elements accessible to touch, using special conductors, ensures proper electrical safety. As an addition, there is a potential equalization box in places with a high possibility of electric shock.

It should be borne in mind that DSUP can only be created in buildings that have a grounding system with separate laying of N- and PE-type conductors.

A metal strong connection must be established between the parts of the ECS if they are connected in accordance with the radial scheme and the required cross-section of the protective conductor.