Simple DIY grounding. Do-it-yourself grounding in a private house: step-by-step implementation and everything you need to know about the process. Correct grounding connection is the key to safety and long service life of equipment

Connection using TT method

The phase and the combined wire (neutral and protective), supplied to the house through the air, are mounted on separate busbars, isolated from the electrical panel.

The grounding of the house is routed to the third bus, which has a metal connection to the panel body.
Advantages of the TT grounding system:

Protection against accidental occurrence of potential voltage on the housings of household appliances. This happens if the combined wire burns out or voltage appears in the neutral wire due to an uneven load across the phases (sometimes up to 40 V). When a jumper is installed between the zero and ground buses, in case of an emergency, current flows to the ground bus.
Flaws:

Price. A voltage relay is also required.

What is important to remember when performing installation work

Before connecting them to the corresponding wire in the house, you must follow simple rules:

1. devices cannot be grounded in series;
2. connect several sockets to one mount on the ground wire;
3. Do not paint or place the main ground wire into the wall;
4. terminals or platforms for attaching grounding contacts, which are holes for M4 bolts, must be lubricated with grease to prevent corrosion;
5. The insulation of grounding wires should be yellow with a green stripe, and their cross-section should be at least 4 square meters. mm.

It is advisable to ground some household appliances not through an outlet, but by attaching the wire directly to the housing (to a special mount).

• a washing machine is a high-power device that can conduct current in a humid environment even if the insulation is fully intact;
• affects the fact that if there is weak contact with the socket, it can emit waves that are hazardous to health. Many manufacturers produce stoves with a special grounding screw on the housing;
• oven and hob - these appliances have high power consumption and an increased risk of insulation damage;
• a computer operating with an uninterruptible power supply also needs separate grounding. A leak from the power supply interferes with the operation of the computer and slows down the Internet speed. The computer system unit is grounded through any fastening screw on the case.

Installing grounding in a private house is a responsible task. Most owners can handle this task on their own. And those who have doubts can contact the appropriate services. Installation of a grounding loop by a commercial company and subsequent acceptance of the work by the energy supervision service is not a cheap pleasure. But it will be possible to demand compensation for damage in the event of an accident.

Which type of grounding device to choose in a private house is up to everyone to decide for themselves. The main thing is that everything is done with high quality and lasts for many years.

Installation of grounding in a private house on video

Content:

How to protect people living in a private home from electric shock? For this purpose, there is a safety measure in which the main electrical installation is connected to the ground through a conductor. Having basic skills, you can do the grounding of a private house with your own hands, significantly saving on the services of special organizations.

It is necessary to study in detail the rules for the construction of electrical installations (PUE), safety precautions when working with devices. The choice of equipment and tools should be approached carefully, giving preference to reliable manufacturers. Before starting work, you should examine the existing equipment and the actual wiring around the house. Initial data is needed for the correct calculation of the grounding device - the most important component of the entire system.

As a result, the optimal values ​​of the resistance value, the number of electrodes and the distance between them will be obtained. Then markings are made on the area near the building to determine the best design option. The methods of laying a trench and deepening the electrodes depend on the type of grounding device chosen. Installation of the installation is the most important stage; the skill of its execution determines whether the entire grounding system will work effectively.

Role of grounding

Let's ask ourselves a question. Why do you need grounding at all? The abundance of household appliances and other electrical appliances places strict demands on home safety. As in any building, grounding in a private house means establishing contact between the electrical installation housing and the soil. It provides human protection from the negative effects of current, and also performs a number of other important functions:

• optimization of electrical installations;
• preventing network problems;
• maintaining the functionality of equipment during overvoltage;
• reducing the power of high-frequency electromagnetic radiation.

Grounding principle

When a person comes into contact with a device on the surface of which voltage has arisen, the electric current is directed into the soil not through his body, but through a conductor. It's all about the difference in resistance values: for a person - 1 kOhm, for a conductor - 4 Ohms. Electric current takes the easiest and fastest path to the ground, which has a high electrical capacity. As a result, the residual current device (RCD) reacts to current leakage in the circuit and turns off the problem area.

Basic Concepts

The key element of the system is the grounding device, which can be factory-made or home-made. It includes:

1. Ground electrode - a metal structure in contact with the ground. It carries out the descent and dissipation of current. Kinds:

• natural (parts of building elements buried in the soil);
• artificial (specially made conductors. Used when the resistance of natural ones does not meet the standard).

If you ground a private house with your own hands, PUE recommend the use of natural grounding electrodes:

• steel pipeline;
• street metal structures (pole, support);
• protective lead coating of power cable;
• a metal or reinforced concrete part of a building structure located in the ground (foundation, column).

2. Grounding conductor - an element connecting the ground electrode and the electrical installation. It consists of wire cores in yellow insulation, parts of external and internal circuits, and a busbar in the distribution panel.

How to calculate the resistance of a grounding device

The conductivity of the ground electrode directly affects the resistance of the entire system. As the electrode size increases, the resistance decreases and the amount of current received increases. According to the PUE, the maximum permissible resistance values ​​are as follows:

To properly carry out grounding in a private house, it is necessary to make preliminary calculations. An example of a formula for a single ground electrode with a circular cross-section:

The source data is located in specialized reference books. To check the functionality of the assembled equipment, measurements are carried out directly on site. If the value exceeds the norm, it is necessary to increase the number of grounding conductors or the depth of their location.

When using several electrodes, the calculation becomes more complicated. For each, an indicator is found using the formula indicated above, in order to then obtain their total value. Next, a utilization factor is used, showing the impact of the grounding conductors on each other. The most effective distance between the electrodes is equal to the length of their penetration multiplied by 2.

To calculate the number of electrodes, the following formula applies:

Grounding rules in a private house

Before you do grounding yourself in a private house, you need to familiarize yourself with the methods for doing it.

Zeroing

It works, but is not very reliable. A wire passes through the distribution board - zero potential, in contact with the housing by connecting with a bolt. To ground the new conductor, it must be secured under this bolt or a similar fixation nearby. However, in this case the wire is not protected from combustion at the input.

Ground loop

Grounding diagram in a private house. Photo

The safest way. How to implement it:

1. Next to the house, dig a hole two shovels deep. Mechanical drilling of a hole in the ground cannot be done, since such a circuit will not work;
2. hammer a metal corner (about 3 m long, 40 x 40 cm or 50 x 50 cm wide) into the bottom of the pit;
3. connect a flexible stranded wire PV-3 (with a cross-section of 6 mm2) to the corner and bring it to the switchboard.

In order for the grounding loop in a private house to give maximum effect, its design must have a metal bond: consist of 3-4 corners welded together with a metal strip of the same width.

In addition to direct grounding, at least one of the following conditions must be met during work:

• equalization of potential values;
• voltage reduction;
• installation of a device for automatic shutdown;
• use of double insulated wires;
• use of isolation transformers.

Specially designed and regularly updated PUEs are designed to help implement proper grounding in a private home. This regulation prohibits:

• ground electrical installations on any type of pipeline, including plastic;
• bring the grounding conductor out to connect to the bus on contact pads not protected from moisture.

What is required for the work

Steel corners, pipes, rods, and galvanized electrodes can be used as artificial grounding conductors. These elements cannot be painted to avoid reducing their conductivity. For anti-corrosion purposes they are treated with special compounds. Other quantities are no less important:

• minimum cross-section of electrodes: rectangular rolled metal - 48 mm2, ferrous metal rod - 10 mm, galvanized rod - 6 mm. Thickness of walls and shelves - 4 mm;
• minimum cross-section of materials for metal bonding: rod - 5 mm, rectangular steel - 24 mm2. The thickness of the walls and shelves is 2.5 mm. ​​

Also, grounding in a private house involves the use of busbars made of electrical bronze. You will need a sledgehammer to deepen the natural electrode or a jackhammer for artificial ones, a stepladder, arc welding for ferrous products.

When wiring rooms, you must:

• wire (minimum cross-section for uninsulated copper - 4 mm, insulated - 1.5 mm, uninsulated aluminum - 6 mm, insulated - 2.5 mm);
• socket with grounding contact;
• bracket, plinth or box for fixation and decoration.

Stages of installing a grounding device in a private house

1. Preparatory work.
2. Deepening the structure.
3. Collection of metal communications
4. Connection to distribution board.

Preparatory work. The location of grounding conductors is planned based on several conditions:

• the distance to the foundation is about a meter, the shape of the contour is any: line, triangle, circle, etc.;
• the optimal gap between the electrodes is 1.2 m;
• minimum parameters of the trench: for natural grounding 50 cm deep, 1 m wide in places of burial; for artificial ones - a pit 0.5 x 0.5 x 0.5 m.

If rolled metal is used, then for better immersion into the soil its end can be sharpened using a grinder. Used material must be cleaned of any coatings. When installing a factory module, a pointed head is screwed onto the electrode, and the connection point is lubricated with paste.

Deepening the structure. Homemade metal pins are driven into the ground using a sledgehammer. When the metal is not very hard, it is advisable to put wooden spacers on it to seal it during impacts. The upper part of each ground electrode should protrude from the bottom of the trench by 15 - 20 cm.

A jackhammer with a cartridge with an impact power of 20 - 25 J is used to deepen the factory electrodes. The coupling and the next part of the ground electrode are screwed onto the first pin lowered to a depth of 1.5 m. Then hammering and attaching other parts continues until the design depth is reached.

Collection of metal communications. All electrodes can be connected using metal strips to form a ground loop in a private house - the final element of the design. Ferrous metal is joined by welding, non-oxidizing materials by bolted connections.

When the strip is ready, it is continued towards the house and attached to the foundation. An M8 bolt is welded to the end of the circuit to secure the conductor. In the factory installation, for this purpose, a clamp is hung on the final pin, which is then protected with waterproofing tape. The trench is buried with a dense fine-grained compound or excavated soil. A factory module with one electrode may have a plastic well.

Connection to distribution board. You can bring a conductor into the house using a plastic or metal sleeve pipe. Next, its end must be crimped with a bolted connection and connected to the grounding bus located on the housing according to the TT system (when the grounding loop is not connected to the neutral working conductor N). The yellow wires must also be clamped to the bus connectors. A multimeter is used to check the resistance of the grounding device.

Conclusion

It is very important to use high-quality materials and follow safety precautions. Having minimal electrical experience, good knowledge of the house in which you will be working and careful preparation of all stages is the key to successful grounding.

All household electrical appliances not only make our existence comfortable, but also pose a certain danger to human health. Therefore, in a network of any voltage class (220 V or 380 V), it is always necessary to provide for grounding in a private house; we will tell you how to do it further.

Why is grounding necessary?

Grounding in an electrical network is based on elementary physical laws and is a universal system for protecting people from electric shock, as well as a system for protecting electrical equipment for any purpose from insulation breakdown (grounding). Operation of electrical networks without grounding is potentially fire hazardous. Equipping a private home with a grounding loop is a prerequisite for the safe use of any electrical appliances and devices.

According to the rules for the construction of electrical installations (hereinafter referred to as PUE), which apply to all types of electrical installations, protective grounding must be provided.

1.7.56. To prevent electric shock if the insulation is damaged, the following protective measures in case of indirect contact should be applied separately or in combination:

Protective grounding (1.7.63, 1.7.65, 1.7.66);

Automatic power off (1.7.61, 1.7.63);

Potential equalization (1.7.78);

Equipment of class II or equivalent insulation (1.7.86, 1.7.87);

Protective electrical separation of circuits (1.7.86, 1.7.88);

Insulating (non-conductive) rooms, zones, areas (1.7.86, 1.7.89);

Ultra-low (low) voltage systems BSNN, ZSNN, FSNN (1.7.68–1.7.70);

Potential equalization (1.7.65, 1.7.66).

PUE-2009

For an objective understanding, you need to understand the following terms, according to the PUE:

• Direct touch- electrical contact of people or animals with live parts that are energized, or approaching them at a dangerous distance.
• Indirect touch- electrical contact of people or animals with an exposed conductive part that becomes energized as a result of insulation damage.
• Protection against direct contact- protection that prevents electric shock in the absence of damage to the insulation of conductors.
• Protection against indirect contact- protection that prevents electric shock in the event of a single fault.
• Ground electrode- a conductive part (conductor) or a set of interconnected conductive parts (conductors) that are in electrical contact with the ground directly or through an intermediate conductive medium, such as concrete.
• Grounding conductor- a conductor connecting the ground electrode to a specific point in the system or electrical installation or equipment.
• Grounding device- a set of electrically connected grounding conductors and grounding conductors, including elements of their connection.

Grounding- making an electrical connection between a specific point in a system or installation or equipment and the local ground.

Note. Connection to local ground may be intentional, unintentional, or accidental, and may be permanent or temporary.

Having convinced yourself of the need for grounding, you can begin to consider the issue of independently equipping a private house with a grounding loop.

What types are there

First of all, you need to understand for what purpose the grounding needs to be installed. The decisive factor in making a decision will be the voltage class in a private home (220 V or 380 V).

According to its purpose, there are two types of grounding: protective and working.

Working- is performed to prevent a sudden increase in voltage in household electrical appliances. This can happen as a result of a violation of the insulation of the transformer windings. This type of grounding also protects electrical appliances from lightning striking the building structure. In this case, the entire charge goes into the ground.

Protective grounding- is carried out due to the forced connection of the housing of the electrical appliance to the ground through a conductor.

The following household appliances must be provided with protective grounding:

• washing machine- its body has a relatively large electrical capacity due to operation in conditions of high humidity.
• microwave- the main working element of the furnace is the magnetron. It has great power. If the contact with ground in the outlet is poor, then an increase in the level of magnetic radiation may occur. Many manufacturers of microwave ovens equip a grounding terminal on the back of the oven.

For contact between the grounding conductor in the network and the electrical appliance, modern sockets are equipped with grounding contacts.

Grounding in a household electrical network

There are six grounding systems to provide grounding. In individual building structures, in particular residential buildings, two main grounding systems are used.

TN-S-C system- recommended for implementation in recent years. The following scheme was made with a solidly grounded neutral at the substation. The equipment in this case has direct contact with the ground. The earth (PE) and neutral/zero (N) are connected to the consumer itself by one conductor (PEN). At the entrance to the electrical network of a private house, such a conductor is divided into two independent conductors.

Such a system does not require the installation of a residual current device (RCD). Protection is provided by automatic switches.

The disadvantage of such a system is that if the PEN conductor is damaged or burned out along the substation/house section, phase voltage appears on the grounding bus of the house. This voltage cannot be turned off by anything. Based on this, the PUE regulates strict requirements for such a line: the PEN conductor must be provided with mechanical protection, and periodic local grounding must also be equipped on the power line supports.

Many power lines, especially in rural areas, do not meet the above conditions. For such a case, another grounding system is recommended - the TT system.

Schematic diagram

This grounding system is implemented through a separate wire from the grounding loop to the input panel of the building, and not from the transformer substation. This system is more resistant to damage to the protective conductor, but requires the installation of an RCD. Without equipping the system with such devices, there is no protection against electric shock. In this regard, the PUE recommends such a system only as an addition to the TN-S-C system. (If the line does not meet the requirements of the TN-S-C system).

General form

Differences in grounding for 220V and 380V networks

The differences in the grounding systems of private houses with an operating voltage of 220 V or 380 V are insignificant. In both cases, a grounding loop is constructed. The difference lies in the way the circuit is connected to the home electrical network.

In the 220V network - single-phase voltage. In this case, a three-wire conductor and sockets with three contacts (phase, neutral, grounding) are used.

For 220 V network

The network is 380 V - three-phase voltage. In this case, a five-wire conductor and sockets with five contacts are used (phase - 3 pcs., neutral, ground electrode).

For 380 V network

Kinds

The main purpose of the ground electrode is direct electrical contact with the ground. The grounding device (grounding loop) includes a ground electrode and a set of all conductors connected to it. Including elements of their connections.

There are two types of ground electrodes:

• natural - metal structures located at a sufficient depth in the ground or reinforced concrete foundation of the building;
• artificial - a metal structure installed independently in the ground for direct use;

Artificial grounding conductors are distinguished by their design features.

The combined installation scheme of the grounding device (circuit) is the most effective. When installation is carried out in compliance with the necessary rules, such a circuit will be reliable and durable.

How to make a ground loop for a private house with your own hands

The most popular protective circuit design today is the triangle circuit. It is made by connecting three pins buried in the ground with a metal strip. This scheme is characterized by increased reliability. If the steel connecting strip is broken or damaged on one side, the circuit will continue to function due to contact on the other side.

Triangle pattern

To manufacture and install the ground loop, you will need the following materials and tools:

Materials:

• steel corner 50–70mm, h=4mm, 3 pcs. the length of one corner is at least 2 meters;
• steel strip 50–70 mm, h=4mm, 4 m for connecting pins from the corner;
• steel strip 30 mm, h=4mm. for electrical connection of the grounding loop and the building's input panel. Length depends on local conditions;
• electrodes 3mm.

Tool:

• shovel, crowbar, earth-moving drill for making holes in the ground;
• grinder for cutting metal blanks;
• metalworking tools (hammer, sledgehammer, file, screwdriver, clamp) for processing and installing workpieces;
• welding machine;
• measuring tool (tape measure, square) for marking workpieces;

The connection points of the ground loop workpieces should be made exclusively by welding. This is regulated by the requirements of the PUE. This type of connection provides the most effective electrical contact and is most resistant to corrosion.

You should work with power tools using the necessary protective equipment: glasses, overalls. Job safety comes first.

When working on preparing a corner, it is better to cut one end at an acute angle. Such a corner will be easier to drive into the ground.

Ground loop pins

Let's consider the process of installing a ground loop in stages.

This completes the installation of the ground loop. Next follows the process of connecting it to the power supply network of a private home.

After connecting the circuit to the PE conductor of the electrical network, the circuit's performance should be tested. For this purpose, special electrical measuring instruments are used. Such equipment is quite expensive. Therefore, they use a more simplified version of checking the performance of the circuit.

This method is carried out by connecting an incandescent lamp (100 W) to the network as follows: the phase wire is placed on the phase contact of the socket, and the neutral wire is placed directly on the circuit structure. In this case, you need to pay attention to the intensity of the lamp. A bright light indicates proper operation of the circuit. Dull, indicating poor-quality contact at the junction of metal circuit elements. In this case, the connections should be strengthened with an additional weld.

Using an incandescent lamp

When determining the value of the protective grounding resistance of a circuit using a special device, you must remember that the value of grounding should not exceed 4 Ohms. If its value is greater, then this may indicate poor contact of the circuit with the ground. To eliminate this problem, you can fill the ground with water in the place where the pins are driven in. This will compact the soil and increase the contact area.

Calculation of the grounding device

The grounding device is also calculated based on the condition of the maximum resistance value of the protective grounding loop. Which should not exceed 4 ohms. The best option would be a resistance value of an artificial ground electrode not exceeding 1 ohm.

It is almost impossible to carry out a thorough calculation of the grounding system at home, without special knowledge and technical literature. Since it provides for the experimental determination of soil resistivity, taking into account correction factors that take into account drying and freezing of the soil. Determination of the spreading resistance value. Element-by-element calculation of circuit resistance based on its geometric dimensions, burial depth and soil moisture. Usage factor of vertical grounding conductors. Availability of natural ground electrodes. And other.

It is better for specialized organizations to do this and issue a protocol on the suitability of the grounding loop and the compliance of its characteristics with regulatory documents.

There is a simplified method.

Simplified calculation of the ground electrode:

For a vertical grounding electrode (single), the following formula is used:

R1=0.84*p/L Where:

R1 - grounding resistance, Ohm;

p - soil resistivity, Ohm*m;

L - length (depth) of the ground electrode;

For multiple vertical ground pins (electrodes):

R=R1/0.9*n Where:

R - resistance of one electrode, Ohm;

n is the number of electrodes in the ground loop;

Thus, if the soil resistivity (p) is known, then the resistance of one electrode (R1) is calculated using the first formula. The resulting value is substituted into the second formula and the number of electrodes (n) is determined at the specified length (L).

In the case where the specific resistance of the soil is not known, you can use the reference table:

Values ​​for common soils

If in practice it was not possible to find or measure the value of the soil resistivity in the area for installation of the circuit, use the method of test immersion of the electrode. The method consists of periodically measuring the resistance of the electrode as it is immersed in the ground. You can stop plugging the electrode when the resistance readings have stopped decreasing. This means that the electrode has reached a depth at which the soil resistivity becomes constant. In the future, this electrode must be connected with a metal strip to other elements of the circuit.

Choosing a location for installation

Its efficient and safe operation largely depends on the correct location of the circuit arrangement. There are several recommendations on this matter:

• Do not place the ground loop in a place where people or animals are constantly or frequently present. When the insulation breaks down and voltage is discharged into the ground, a person or animal in the immediate vicinity may be harmed. It is better to take measures to fence such an area.
• Some experts recommend placing the contour on the north side of the building. This is explained by the more humid, damp conditions in such an area.
• If the soil is too wet and there is a high probability of corrosion of the metal of the circuit, then it is better to make it from large-section steel. The circuit structure can also be coated with special conductive materials that will protect against corrosion, but will not impair electrical contact with the ground.
• You should not place the grounding loop close to heat communications. Over-dried soil has a negative effect on the circuit resistance indicator.
• It is prohibited to place the circuit in close proximity to a gas pipeline running in the ground.
• The depth of the circuit must be below the freezing level of the soil, but not less than 0.5 m.

Excavation and construction assembly

Excavation work must be carried out carefully. Beforehand, you should consider the perimeter of the work, taking into account the possible occurrence of communications for various purposes in the ground: pipelines, telephone lines, cable power lines. It is better to place the circuit away from such objects.

Earthworks are carried out using standard tools: shovels, crowbars, drills.

Installation of the ground loop

When constructing trenches, they must be made wide enough. This is necessary for the convenience of welding work. After all, the efficiency of the protective grounding system largely depends on the quality of welding joints.

A bolted connection may only be used at the point where the steel strip is brought out directly to the house and connected to the input panel of the electrical network.

Some factory-made ground electrodes use bolted connections, but high-quality contact in these cases is achieved through pressure plates and copper-plated electrode surfaces.

Connecting copper-plated circuit elements with pressure plates

Welding joints must be continuous, the length of the weld seam must be at least 100 mm.

For clarity, here is a video that shows the process of installing a protective grounding loop in a private house.

The video was taken from the Internet resource Youtube, is used for informational purposes and is not advertising.

Video: DIY installation of a ground loop

Constantly using a 220-volt household power supply, we do not think about the dangers of high voltage. Long-term trouble-free operation of electrical installations dulls the sense of self-preservation.

Do-it-yourself grounding at home photo

And only in the event of an electric shock or fire due to faulty electrical wiring, the search for the cause of the trouble begins.

In the vast majority of cases, home grounding will correct the situation. The “earth” will not save you from an electrical wiring fire, although this is possible if the switching devices are correctly connected. But saving your health, or even life, is a feasible task.

Is it necessary to do grounding in a private house?

If you answer the question in one word: absolutely – Yes! To understand the process, consider the principle of operation of the “earth”.

Soil, regardless of its origin, is a good conductor of electric current. Different materials resist electricity differently, and soil moisture plays a big role. But in any case, there is always a potential difference between the phase wire and the ground (in the literal sense of the word).

Why do you still need grounding in the house?

There are many electrical appliances in your home that have a metal body.
PC system unit, refrigerator, electric oven, water boiler, iron, and many other devices. A common breakdown of household appliances is the so-called penetration of electric current into the body. In other words, the external panels of the device become a phase contact.

If you touch a body that has voltage, an electrical current will flow through you to physical ground. Depending on the humidity, your shoes and floor covering, the current strength will be different. But the danger of electric shock is very high. It is enough to touch a water tap or a heating radiator, and an electric shock can be fatal.

If there is grounding in a private house, and your electrical appliances are connected to it, electric current will flow through the grounding wire.

Why? Now you will understand. Ohm's law states that current is directly proportional to voltage and inversely proportional to conductor resistance. The body of the electrical appliance is grounded. The conductor resistance is 2-5 Ohms.

Your body's resistance is measured in kiloohms, which is thousands of times greater. Even if you are standing barefoot on a wet concrete floor, there will be little, if any, electrical current flowing through your body.

Important! All of the above is true only for electrical appliances that are correctly connected to the ground loop.

Let's assume that the supply wire is frayed and touches the exposed core of the metal body.

Sparking and overheating may occur, resulting in a fire. Or the circuit inside the electrical appliance will fail.

If the device body is normally connected to the ground wire, a short circuit will occur. At the same moment, the machine at the entrance to the house will open the electrical circuit, and the danger will be removed.

Grounding a private home is necessary not only to ensure safety.
All modern electrical equipment is a powerful generator of radio waves, read – interference. Noise during a telephone conversation, ripples on the TV screen, decreased WiFi Internet speed, crackling in the speakers when listening to music.

All this is the result of uncontrolled filling of your home with electric fields. They are also, to put it mildly, unhealthy.
You probably noticed that the power plug of a computer monitor, TV or music center has a third terminal - for connecting the ground.

It would seem, why? After all, they have plastic cases, electric shock is excluded.

Important! The efficiency of grounding (in terms of safety) can be increased if residual current devices (RCDs) are installed on the input circuits. The machines react to current leakage and instantly de-energize the dangerous area.

We figured out the need to organize grounding in the house. Now let's talk about its presence in an already built home. If you are just designing a country house, the electrical wiring will comply with the standards of PUE, SNiP and GOST.

Probably every person has heard the term “grounding” at least several times in their life. However, few people have any idea what it is and why it serves. In this article we will try to fully reveal the essence of grounding, its functional purpose and how to do it yourself.

What is grounding in a private house?

This is a connection of metal network elements, equipment or mechanisms with a grounding device (grounding loop), due to which, when leakage currents occur (insulation breakdown), the entire potential is completely transferred to the ground.

If we consider this issue at the “user” level, then grounding protects you from electric shock if the insulation in the electrical wiring is damaged.

Is it necessary to ground a private house or cottage?

Very often people ask the question: “is grounding necessary at the dacha?” According to the requirements of the PUE (Chapter 1.7. Grounding and protective electrical safety measures), all modern equipment and electrical networks must be grounded.

Grounded systems are designated TN-S and are installed at the design stage during reconstruction or capital construction.

If your dacha or private house was built a very long time ago, then it is highly recommended to do the grounding yourself, since the power supply organization may stop supplying electricity, arguing its decision for violating the rules of the PUE, GOST, PTB and PTEEP.

Main functional units of the grounding system

A complete grounding system consists of:

1. Ground loop.
2. Strip metal.
3. Copper grounding conductors.

Let's take a closer look at each of the elements and their functional purpose.

This is a group of interconnected conductors or electrodes (in most cases, stainless or ordinary steel) that are located vertically in the ground and located near the object being protected.

Depending on the characteristics of the protected object, 50x50x5 mm corners (grounding for a gas boiler in a private house) or round steel (ᴓ16–18) are used to construct a grounding loop, which are driven into the ground to a depth of 3 m. After which these electrodes are welded together with using a strip (4x40 mm) and bring the above strip to the connection point of the general grounding system of the house.

Ground loop diagram for a private house or cottage

Today there are 2 main types of ground loop:

1. Closed in the form of an equilateral triangle.
2. Linear.

Since the linear grounding loop has a significant drawback - if the connector between the electrodes is severely corroded, part of the loop will simply not be able to remove potential from the electrical equipment and thus the main functional purpose of the loop will not be fulfilled. For this reason, the installation of this circuit will not be discussed in this article.

Structurally, the ground loop is made with your own hands in the form of an equilateral triangle with a long side of 3 m. The optimal distance from the ground loop to the foundation is 1 m.

As mentioned earlier, the vertices of this triangle are either a 50x50x5 corner or round reinforcement with a cross-section of 16–18 mm (hereinafter referred to as “electrodes”). Before driving the electrodes into the ground using a sledgehammer or any other tool, you must first sharpen them, since otherwise you will not be able to drive it to a depth of 3 m.

After driving the electrodes to the required depth, along the contour of the resulting triangle, it is necessary to remove a layer of soil of 30–50 cm. This is necessary in order to simplify the welding of the electrodes to each other in the future. Welding of grounding conductors to each other is carried out using a regular 40x4 mm strip.

After welding the electrodes, a 40x4 strip with a welded M12 or M14 bolt with nuts and washers is placed on the foundation of the building in one or several places, to which a grounding conductor (in most cases yellow-green) is then connected, which is one core of the VVGng (PVSng) input cable ) 3x6, VVGng (PVSng) 3x10.

If the house has a 3-phase power supply system, then the input cable can be (PVSng) 5x6, VVGng (PVSng) 5x10, in which 3 lived - these are phases “A”, “B”, “C”, the zero wire is blue colored “N” and the grounding conductor “G” yellow-green.

Important! After welding the grounding conductors together using a strip, it is strictly forbidden to paint metal structures, as this will lead to a deterioration in the conductivity of the grounding loop.

Tricks when installing a ground loop

When putting an object into operation, very often cases arise when, when checking the resulting ground loop by a specialized electrical laboratory, the resistance value is higher than 4 Ohms. This may be caused by high soil resistance or failure to comply with the designed grounding requirements.

In this case, you can dilute 2-3 packs of salt in a bucket of water and pour the resulting solution into the places where the electrodes are located. Thanks to this simple manipulation, you can reduce the value of the ground loop resistance to 1–3 ohms.

After familiarizing yourself with the theory, let's consider a practical answer to the question: “how to make grounding in a private house with your own hands”?

DIY grounding device: step-by-step instructions

If you are asking the question: “how to make grounding at the dacha?”, then to complete this process you will need the following tool:

• a welding machine or inverter for welding rolled metal and bringing the circuit to the foundation of the building;
• an angle grinder (grinder) for cutting metal into specified pieces;
• wrenches for bolts with M12 or M14 nuts;
• bayonet and pick-up shovels for digging and burying trenches;
• a sledgehammer for driving electrodes into the ground;
• a hammer drill for breaking up rocks that may be encountered when digging trenches.

In order to correctly and in accordance with regulatory requirements perform a grounding loop in a private house, we will need the following materials:

Once all the necessary materials and tools are available, you can proceed directly to the installation work, which is described in detail in the following chapters.

Selecting a location for installing the ground loop

Such measures are necessary so that if the insulation in the electrical wiring is damaged, the potential will flow to the ground loop and a step voltage may arise, which can lead to electrical injury.

After a location has been chosen, markings have been made (for a triangle with sides of 3 m), and the location for the strip with bolts to be laid out on the foundation of the building has been determined, you can begin excavation work.

To do this, it is necessary to remove a 30–50 cm layer of earth around the perimeter of a marked triangle with sides of 3 m using a bayonet shovel. This is necessary in order to later weld the strip metal to the ground electrodes without any special difficulties.

It is also worth additionally digging a trench of the same depth to bring the strip to the building and bring it to the facade.

After preparing the trench, you can begin installing the ground loop electrodes. To do this, you must first sharpen the edges of a 50x50x5 corner or round steel with a diameter of 16 (18) mm² using a grinder.

Next, place them at the vertices of the resulting triangle and, using a sledgehammer, drive them into the ground to a depth of 3 m. It is also important that the upper parts of the ground electrodes (electrodes) are at the level of the dug trench so that the strip can be welded to them.

After the electrodes are driven to the required depth using a 40x4 mm steel strip, it is necessary to weld the grounding conductors together and bring this strip to the foundation of the building where the grounding conductor of the house, cottage or cottage will be connected.

Where the strip will reach the foundation at a height of 0.3–1 moth of earth, it is necessary to weld an M12 (M14) bolt to which the grounding of the house will be connected in the future.

After all welding work has been completed, the resulting trench can be backfilled. However, before this, it is recommended to fill the trench with saline solution in the proportion of 2-3 packs of salt per bucket of water.

Afterwards, the resulting soil must be compacted well.

After completing all the installation work, the question arises: “how to check the grounding in a private house?” Of course, a regular multimeter will not be suitable for these purposes, since it has a very large error.

To perform this activity, the F4103-M1 devices, Fluke 1630, 1620 ER clamps, and so on are suitable.

However, these devices are very expensive, and if you do the grounding at your dacha with your own hands, then to check the circuit, an ordinary 150-200 W light bulb will be enough for you. For this test, you need to connect one terminal of the lamp socket to the phase wire (usually brown) and the second to the ground loop.

If the light bulb shines brightly, everything is fine and the grounding circuit is fully functioning, but if the light bulb shines dimly or does not emit a luminous flux at all, then the circuit is mounted incorrectly and you need to either check the welded joints or install additional electrodes (which happens when the electrical conductivity of the soil is low).

Basic requirements for ground loop resistance

If you do not know how to properly make grounding in a private house and what technical characteristics it should have, we recommend that you familiarize yourself with the PUE in which Chapter 1.7. entitled “Grounding and protective electrical safety measures” regulates the main technical characteristics of the grounding loop for equipment up to 1000 V.

According to this regulatory document The ground loop resistance must be:

1. No more than 4 Ohms for electrical installations up to 1000 V (this class of electrical installations includes the electrical equipment of a country house, house or cottage).
2. No more than 10 Ohms if the total power of generators or transformers is less than 100 kVA.
3. No more than 0.5 Ohm for electrical installations above 1000 V with large ground fault currents (over 500 A).
4. No more than 10 Ohms for electrical installations over 1000 V with low ground fault current.

In what cases is it necessary to check the ground loop?

If you are installing a grounding device in a private house or country house, then the test can be performed with a regular test light (as described above), but if you need to put the facility into operation, legalize a change in the power supply scheme, or enter into a power supply agreement with a specialized organization , then you will need a ground loop test report.

This document can only be issued by a certified laboratory that will take measurements. In this case, the contractor that installed the grounding loop is obliged to provide you with a passport for the grounding loop with certificates for hidden work.

conclusions

Do-it-yourself 220 V grounding in a private house will allow you to protect yourself and your family members from electric shock. In addition, grounding a private house is necessary for concluding contracts with an electrical supply organization or when putting an object into operation during new construction, reconstruction or major repairs.

To perform grounding with your own hands, it will be enough to read this information article and have some skills in electrical engineering.

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