Operation of modern household and computer equipment without grounding is fraught with its failure. In a significant part of our country, especially in rural areas, old-style power transmission systems. They have protective grounding not provided for or they are in such a condition that they simply do not meet electrical safety requirements. Therefore, owners have to do the grounding of a private house or cottage themselves.
What does it give
Protective grounding is necessary to ensure electrical safety in the home. If done correctly, when a leakage current appears, it leads to immediate tripping of the RCD (damage to electrical insulation or when live parts are touched). This is the main and main task of this system.
The second function of grounding is to provide normal operation electrical equipment. For some electrical appliances, having a protective wire in the socket (if any) is not enough. A direct connection to the ground bus is required. For this purpose there are usually special clamps on the case. If we talk about household appliances, these are a microwave oven, an oven and a washing machine.
The main task of grounding is to ensure the electrical safety of a private home.
Few people know, but a microwave without a direct connection to the “ground” can emit significant radiation during operation; the reception level of radiation can be life-threatening. In some models, you can see a special terminal on the back wall, although the instructions usually contain only one phrase: “grounding is required” without specifying exactly how it should be done.
When touched wet hands to the body washing machine A tingling sensation is often felt. It is not dangerous, but unpleasant. You can get rid of it by connecting the ground directly to the case. In the case of an oven, the situation is similar. Even if it does not “pinch”, a direct connection is safer, since the wiring inside the installation operates under very harsh conditions.
With computers the situation is even more interesting. By directly connecting the ground wire to the case, you can significantly increase the speed of the Internet and minimize the number of freezes. It’s that simple because of the direct connection to the ground bus.
Do you need grounding in a country house or in a wooden house?
In holiday villages, grounding is mandatory. Especially if the house is built of flammable material - wood or frame. It's about thunderstorms. At dachas there are a lot of elements that attract lightning. These are wells, boreholes, pipelines lying on the surface or buried to a minimum depth. All of these objects attract lightning.
If there is no lightning rod and grounding, a lightning strike is almost equivalent to a fire. There is no fire station nearby, so the fire will spread very quickly. Therefore, in combination with grounding, also make a lightning rod - at least a couple of meter-long rods attached to the ridge and connected to the ground using steel wire.
Grounding systems for a private house
There are six systems in total, but in individual developments, mainly only two are used: TN-S-C and TT. IN last years TN-S-C system is recommended. In this scheme, the neutral at the substation is solidly grounded, and the equipment has direct contact with the ground. The earth (PE) and neutral/zero (N) are connected to the consumer by one conductor (PEN), and at the entrance to the house they are again divided into two separate ones.
With such a system, a sufficient degree of protection is provided by automatic devices (RCDs are not required). The disadvantage is that if the PEN wire burns out or is damaged in the area between the house and the substation, phase voltage appears on the earth bus in the house, which cannot be turned off by anything. Therefore, the PUE imposes strict requirements on such a line: there must be mandatory mechanical protection PEN wires, as well as periodic backup grounding on poles every 200 m or 100 m.
However, many transmission lines in rural areas do not meet these conditions. In this case, the TT system is recommended for use. Also, this scheme should be used in free-standing open outbuildings with an earthen floor. There is a risk of touching the ground and ground at the same time, which can be dangerous with a TN-S-C system.
The difference is that the “ground” wire to the panel comes from the individual ground loop, and not from transformer substation, as in the previous diagram. Such a system is resistant to damage to the protective wire, but requires the mandatory installation of an RCD. Without them, there is no protection against electric shock. Therefore, the PUE defines it only as a backup if the existing line does not meet the requirements of the TN-S-C system.
Grounding device for a private house
Some older power lines have no protective ground at all. They all must change, but when this will happen is an open question. If this is your case, you need to make a separate circuit. There are two options - do the grounding in a private house or country house yourself, with your own hands, or entrust the implementation to a campaign. The company's services are expensive, but there is an important advantage: if problems arise during operation due to improper functioning of the grounding system, the company that carried out the installation will compensate for the damage (must be specified in the contract, read carefully). If you do it yourself, everything is on you.
The grounding system of a private house consists of:
- grounding pins,
- metal strips combining them into one system;
- lines from the ground loop to .
What to make grounding conductors from
A metal rod with a diameter of 16 mm or more can be used as pins. Moreover, you cannot take the reinforcement: its surface is hardened, which changes the distribution of current. Also, the hardened layer in the ground breaks down faster. Second option - metal corner with shelves 50 mm. These materials are good because they can be driven into soft soil with a sledgehammer. To make it easier to do this, one end is sharpened, and a platform is welded to the other, which is easier to hit.
Sometimes used metal pipes, one edge of which is flattened (welded) into a cone. Holes are drilled in their lower part (about half a meter from the edge). When the soil dries out, the distribution of the leakage current deteriorates significantly, and a saline solution can be poured into such rods, restoring the functioning of the grounding. The disadvantage of this method is that you have to dig/drill holes under each rod—it won’t be possible to hammer them in with a sledgehammer to the required depth.
Pin driving depth
The grounding pins should go into the ground below the freezing depth by at least 60-100 cm. In regions with dry summers, it is desirable that the pins be at least partially in moist soil. Therefore, corners or rods 2-3 m long are mainly used. Such dimensions provide a sufficient area of contact with the ground, creating normal conditions to dissipate leakage currents.
What not to do
The job of protective earthing is to dissipate large area leakage currents. This happens due to the close contact of metal grounding conductors - pins and strips - with the ground. That's why Grounding elements are never painted. This greatly reduces the current conductivity between the metal and the ground, making the protection ineffective. Corrosion in welding areas can be prevented with anti-corrosion compounds, but not with paint.
The second important point: grounding must have low resistance, and for this good contact is very important. It is provided by welding. All joints are welded, and the quality of the seam must be high, without cracks, cavities and other defects. Please note again: Grounding in a private house cannot be done on threaded connections. Over time, the metal oxidizes, breaks down, the resistance increases many times, the protection deteriorates or does not work at all.
It is very unwise to use pipelines or other metal structures located in the ground as a grounding conductor. For some time, such grounding works in a private house. But over time, the pipe joints become oxidized and destroyed due to electrochemical corrosion, activated by leakage currents, and the grounding becomes inoperative, as does the pipeline. Therefore, it is better not to use these types of grounding conductors.
How to do it right
First, let's look at the shape of the ground electrode. The most popular is in the form of an equilateral triangle with pins hammered into the vertices. There is also a linear arrangement (the same three pieces, only in a line) and in the form of a contour - the pins are driven around the house in increments of about 1 meter (for houses with an area of more than 100 sq. m). The pins are connected to each other by metal strips - metal bonding.
Procedure
From the edge of the house to the installation site, the pin must be at least 1.5 meters. In the selected area, they dig a trench in the form of an equilateral triangle with a side of 3 m. The depth of the trench is 70 cm, the width is 50-60 cm - so that it is convenient to cook. One of the peaks, usually located closer to the house, is connected to the house by a trench with a depth of at least 50 cm.
At the vertices of the triangle, pins are hammered (a round rod or corner 3 m long). About 10 cm is left above the bottom of the pit. Please note that the ground electrode is not brought to the surface of the earth. It is located 50-60 cm below ground level.
A metal bond is welded to the protruding parts of the rods/corners - a strip of 40 * 4 mm. The created ground electrode is connected to the house with a metal strip (40*4 mm) or a round conductor (cross section 10-16 mm2). The strip with the created metal triangle is also welded. When everything is ready, the welding areas are cleaned of slag and coated with an anti-corrosion compound (not paint).
After checking the grounding resistance (in general, it should not exceed 4 Ohms), the trenches are covered with earth. There should be no large stones or construction waste, the earth is compacted layer by layer.
At the entrance to the house, a bolt is welded to the metal strip from the ground electrode, to which a copper conductor in insulation is attached (traditionally the color of the ground wires is yellow with a green stripe) with a core cross-section of at least 4 mm 2.
Grounding outlet near the wall of the house with a bolt welded at the end
In the electrical panel, the grounding is connected to a special bus. Moreover, only on a special platform, polished to a shine and lubricated with grease. From this bus, the “ground” is connected to each line that is distributed throughout the house. Moreover, wiring the “ground” with a separate conductor according to the PUE is unacceptable - only as part of a common cable. This means that if you have two-wire wiring, you will have to completely change it.
Why you can’t make separate groundings
Rewiring the entire house is, of course, time-consuming and expensive, but if you want to operate modern electrical appliances without problems and household appliances, it's necessary. Separately grounding certain outlets is ineffective and even dangerous. And that's why. The presence of two or more such devices sooner or later leads to the output of the equipment plugged into these sockets. The thing is that the resistance of the circuits depends on the condition of the soil in each specific place. In some situation, a potential difference occurs between two grounding devices, which leads to equipment failure or electrical injury.
Modular pin system
All the previously described devices - made from hammered corners, pipes and rods - are called traditional. Their disadvantage is the large volume of excavation work and the large area that is required when installing a ground electrode. This is because a certain area of contact between the pins and the ground is required, sufficient to ensure normal “spreading” of the current. The need for welding can also cause difficulty - there is no other way to connect the grounding elements. But the advantage of this system is relatively low costs. If you do traditional grounding in a private house with your own hands, it will cost a maximum of $100. This is if you buy all the metal and pay for welding, and do the rest of the work yourself
Modular pin (pin) systems emerged a few years ago. This is a set of pins that are driven to a depth of up to 40 m. That is, you get a very long grounding rod that goes to a depth. The pin fragments are connected to each other using special clamps, which not only fix them, but also provide a high-quality electrical connection.
The advantage of modular grounding is the small area and less work required. A small pit with sides 60*60 cm and a depth of 70 cm, a trench connecting the ground electrode to the house is required. The pins are long and thin; driving them into suitable soil is easy. This is where we come to the main disadvantage: the depth is great, and if you encounter, for example, a stone on the way, you will have to start over. But removing the rods is a problem. They are not welded, but whether the clamp will hold up or not is a question.
Second minus - high price. Together with installation, such grounding will cost you $300-500. Self-installation problematic, since driving these rods with a sledgehammer will not work. We need a special pneumatic tool, which we have learned to replace with a hammer drill with impact mode. It is also necessary to check the resistance after each driven rod. But if you don't want to mess with welding and land works, modular pin grounding is a good option.
One of the options for installing a grounding loop in a private house is to install a pin grounding. In this case, the operating time is significantly reduced, while the functionality of the ground electrode is not inferior to similar system options (linear, electrolytic, etc.). In this article we will tell you how to make modular-pin grounding with your own hands and what are the advantages of such a system.
Design features
What is such a system and what does it consist of? The device consists of one and a half meter steel pins, which are treated with copper and connected using couplings. The kit also includes a brass clamp that connects the horizontal and vertical contours. Below is a diagram of the design.
The modular pin grounding system is installed as follows: a landing pad (nozzle) is mounted on the top of the pin, which in turn is connected to the coupling. The attachment is necessary to transmit the force of the vibrating hammer. A steel tip is installed on the lower part of the structure. It makes it easier to drive the unit into the ground. There are several types of tips, the scope of which depends on the hardness of the soil.
In addition, the kit comes with a special electrically conductive liquid paste, the purpose of which is to protect against corrosion and constantly maintain electrical resistance during operation. Electrically conductive paste is applied to everything threaded connections designs. You can also use a special waterproof anti-corrosion duct tape. It is resistant to acids, salts and gases, and does not allow moisture to pass through.
Installation stages
Modular-pin grounding is installed according to a simple principle. First of all, the tip is put on the first pin. But before installation, it should be treated with electrically conductive paste against corrosion. We screw the coupling onto the other end and also treat it with anti-corrosion paste. The landing pad is then screwed onto the device to apply the vibratory hammer forces.
We place the assembled modular-pin grounding in a pre-prepared hole in the ground. You need to screw it into the ground as deeply as possible with your own hands. Then you need to connect the vibrating hammer to the network and place it on the rod site. Thus, the pin is immersed in the ground along its entire length. You only need to leave 20 cm in order to connect another rod.
This is followed by . To do this, you need to remove the landing nozzle and connect a special device, an ohmmeter, to the place where it was located:
When the first rod is located in the ground along its entire length, the landing attachment for the vibratory hammer is removed and another pin is mounted through the coupling. A special clamp that holds the pin in a vertical position rises along installed device up. And the connecting coupling and attachment for the vibrating hammer are again installed on the mounted structure, after which the process is repeated.
Spread resistance should be checked after installing each vertical rod. The pins are installed until the required resistance is established. The figure below shows a diagram of the change in resistance depending on the length:
Next, you need to connect the horizontal ground electrode and the vertical conductor. To do this, a brass clamp is attached to the end of the rod that protrudes from the ground and a horizontal ground electrode is connected to it. A special plate is placed between the pin and the horizontal cable, which protects against corrosion when dissimilar metals come into contact. After the system has been connected, the connection points are treated with special adhesive tape. She serves additional protection from corrosion.
Advantages and disadvantages of the system
Modular-pin grounding, like any system, has its pros and cons. Compared to the classic and standard circuit, pin grounding has the following advantages:
- ease and simplicity of installation;
- occupies a small area;
- installation is carried out by a minimum number of workers (1–2 people);
- installation occurs without welding work, since all connections are made using couplings;
- thanks to the vibratory hammer, there is no heavy earthwork;
- modular-pin grounding is resistant to corrosion, as it is treated with special lubricants and coatings, thanks to which they last for several decades;
- regardless of the ground, the pin system is easily driven into the ground;
- structural elements are produced industrially, due to which they have high quality and are ready for immediate installation without additional preparatory work.
Modular-pin grounding has one, but significant drawback - it high price. But, despite this drawback, the system is beneficial if you take into account all its advantages.
The industry produces a wide variety of kits that combine the elements necessary for reliable and high-quality installation. Modular-pin grounding has an important purpose - it protects the house from fire, and people in the room from electric shock.
Or a country house always involves a large volume electrical work. In this range of tasks, along with supplying power to the house, installing distribution and protective equipment, laying internal lines, a well-planned and executed grounding system is no less important. Unfortunately, when carrying out “self-construction”, inexperienced owners quite often forget about this point or even deliberately ignore it, trying to achieve some kind of false savings in money and labor costs.
Meanwhile, the grounding system is of extreme importance - it can prevent many troubles that can lead to very sad or even tragic consequences. According to existing rules, electrical network specialists will not connect a house to a power line if this system is not in the house or if it does not respond necessary requirements. And the owner, one way or another, will have to decide the question of how to make grounding at the dacha.
In modern urban buildings, a grounding loop is necessarily provided at the design stage of the building and its internal communications. The owner of a private home will have to decide this issue himself - invite specialists or try to do everything himself. There is no need to be afraid - all this is a completely doable task.
Why is a ground loop needed?
In order to understand the importance of grounding, basic concepts from a school physics course are enough.
The vast majority of private houses are powered from a single-phase network alternating current 220 volt . The electrical circuit necessary for the operation of all devices or installations is provided by the presence of two conductors - actually, a phase and a neutral wire.
The design of all electrical appliances, tools, household and other appliances includes elements of insulation and protective devices, which should prevent voltage from entering conductive housings or casings. However, the possibility of such a phenomenon can never be excluded - the insulation may be discharged, burn out from unreliable, sparking contacts in wire connections, circuit elements may fail, etc. In this case, phase voltage may get to the device body, touching which becomes extremely dangerous for humans.
Situations are especially dangerous if there are people near such a faulty device. metal objects, having so-called natural grounding - heating risers, water or gas pipes, open reinforcement elements of building structures and etc.. At the slightest touch to them the chain can close and be fatal dangerous current will pass through the human body towards a lower potential. Similar situations are no less dangerous if a person is standing barefoot or in wet shoes on a wet floor or ground - there are also all the prerequisites for shorting the alternating current circuit from the device body.
One of the expressed properties of electric current is that it will definitely choose a conductor with minimal resistance. This means that it is necessary to create in advance a line with minimal resistance and zero potential, along which, in the event of a breakdown on the housing, the voltage will be safely discharged.
The resistance of the human body is a variable quantity, depending on individual characteristics, and even from the temporary state of a person. In electrical engineering practice, this value is usually taken as 1000 Ohm (1 kOhm). Therefore, the resistance of the ground loop should be many times lower. Exists a complex system calculations, but usually operate with values of 30 Ohms for the household electrical network of a private house and 10 Ohms if the grounding is also used as lightning protection.
It may be objected that all problems can be completely solved by installing special protective devices(RCD). But for correct operation, grounding is also necessary. If even the slightest current leak occurs, the circuit will close almost instantly and the device will operate, turning off the dangerous section of the home electrical network.
Some owners are prejudiced that for grounding it is enough to use water supply or heating pipes. This is extremely dangerous and absolutely unreliable. Firstly, it is impossible to guarantee effective voltage removal - the pipes may be heavily oxidized and may not have good enough contact with the ground, and in addition, they often have plastic areas. Electric shock cannot be ruled out if someone touches them in the event of a breakdown of the power supply to the housing, and neighbors may also be exposed to such a danger.
Most modern electrical appliances are immediately equipped with a power cable with a three-pin plug. Appropriate sockets must also be installed when installing wiring in the house. (Some older model electrical appliances have a contact terminal on the body for a ground connection instead.)
There is a strictly defined color “pinout” of the wires: the blue wire is definitely “zero”, the phase can have different colors, from white to black, and the ground wire is always yellow-green.
And so, knowing this, some “wise” owners, wanting to save on updating the wiring and organizing full grounding, simply make jumpers in the sockets between the neutral contact and the grounding. However, this does not solve the problem, but rather aggravates it. Under certain conditions, for example, in the event of a burnout or poor contact of the working zero in some part of the circuit, or in the event of an accidental phase change, a phase potential will appear on the device body, and this can happen in the very unexpected place Houses. The danger of electric shock increases many times in such a situation.
Grounding is reliable protection from many troubles The conclusion from all that has been said is that grounding is mandatory. structural element home electrical network. It immediately performs the following functions:
- Effectively removes voltage leakage from conductive parts, touching which can cause electric shock.
- Equalization of potentials in all objects in the house, for example, grounded appliances and heating pipes, water supply, gas supply.
- Ensuring the correct operation of all installed systems and safety devices - fuses, .
- Grounding is also important in preventing the accumulation of static charge on the housings of household appliances.
- It is of particular importance for modern electronics, especially computer technology. For example, the operation of switching power supplies for computers is very often accompanied by the induction of voltage onto the housing of the system units. Any discharge can lead to failure electronic elements, malfunctions, loss of information.
Now that the importance of the grounding system has been explained, we can move on to the question of how to make it yourself in a private home.
Prices for protective automation
Protective automation
What are the types of grounding systems in private homes?
So, a well-executed grounding system should provide reliable contact with zero ground potential and with the minimum possible resistance of the created circuit. However, grunt —gruntat discord - its different types are seriously different from each other resistivity:
| Soil type | soil resistivity (Ohm × m) |
|---|---|
| Sand (at level groundwater below 5 m) | 1000 |
| Sand (at groundwater level above 5 m) | 500 |
| Fertile soil (chernozem) | 200 |
| Wet sandy loam | 150 |
| Semi-solid or forest-like loam | 100 |
| Chalk layer or semi-hard clay | 60 |
| Graphite shales, clayey marl | 50 |
| Plastic loam | 30 |
| Plastic clay or peat | 20 |
| Underground aquifers | from 5 to 50 |
It is obvious that those layers that have the lowest resistivity are, as a rule, located at a considerable depth. But even when the electrode is deepened, the results obtained may not be enough. This problem can be solved in several ways - from increasing the installation depth of pin electrodes, to increasing their number, the distance between them, or total area contact with the ground. In practice, several basic schemes are most often used:
- Scheme “a” - installation of recessed metal closed loop around the perimeter of the house. As an option - shallowly driven pins connected in a ring by a bus.
IN dacha construction it is used infrequently due to its large volume earthworks or due to the peculiarities of the location of buildings on the site.
- Scheme “b” is perhaps the most popular among owners of suburban housing. Three or more moderately recessed pin electrodes connected by one busbar - this design is easy to make yourself, even in a limited space.
- Diagram “c” shows grounding with one electrode installed at a greater depth. Sometimes such a system is even installed in the basement of a building. The scheme is convenient, but not always feasible - it is almost impossible to implement it on rocky soils. In addition, for such a grounding system, you need to use special electrodes - we will talk about it below.
- Scheme “d” is quite convenient, but only if it was thought out at the stage of designing the house, and executed during the pouring of the foundation. Bring it to life on finished building will be extremely unprofitable.
So, the easiest way to implement it is with minimal costs schemes “b” or, if possible, “c”.
Grounding using homemade metal parts
To make a grounding system of this type, you will need metal profiles, welding machine, tools for excavation work, sledgehammer. In some cases, with complex dense soils, a hand drill may be needed.
Schematically, this system looks like this:
Location buried electrodes are selected so that it is as convenient as possible to bring the grounding bus to switchboard. The optimal distance from the house is 3-6 meters. Acceptable limits are no closer than one meter and no further than ten.
The dimensions indicated in the diagram are by no means some kind of dogma. So, the side of the triangle can be up to three meters in length, and the depth of driving the pin can be slightly smaller - 2.0 ÷ 2.5 m. The number of electrodes can also change - if the soil is dense and it is not possible to drive the pins to a greater depth, you can increase their number.
A good idea is to contact your local utility company in advance for recommendations on how to install a ground loop. These specialists probably have well-thought-out schemes that have been tested in this region. In addition, they will be able to help calculate the dimensions based on the planned load of the home electrical network - this also matters.
What can serve as electrodes? For these purposes, a steel corner with a shelf of 50 × 50 mm and a thickness of at least 4 ÷ 5 mm is most often used. Pipes can be used, preferably galvanized ones with a wall thickness of at least 3.5 mm. You can take a steel strip with an area cross section about 48 mm² (12 × 4), but it is more difficult to drive vertically into the ground. If you decide to use a steel rod, then that It’s better to take galvanized one with a diameter of at least 10 mm.
To tie the pins into one circuit, use a 40 × 4 mm strip or 12 - 14 mm wire rod. The same material is suitable for laying a grounding bus to the point of its entry into the house.
- So, initially markings are made at the selected location.
- Then it is advisable to dig a small pit of the intended shape to a depth of 1 meter. Minimum depth– 0.5 m. At the same time, a trench is dug to the same depth - a grounding bus will go along it from the contour to the base of the house.
- The task can be somewhat simplified by digging not a solid pit, but only trenches along the perimeter of the contour being created. The main thing is that their width allows free driving of electrodes and welding work.
- Electrodes of the required length are prepared. The edge with which they will be driven into the ground must be sharpened with a grinder, cutting it at an angle. The metal must be clean and unpainted.
- At the designated locations, the electrodes are driven into the ground using a sledgehammer or electric hammer. They are buried so that in the pit (trench) they protrude above the surface level by about 200 mm.
- After all the electrodes are clogged, they are connected with a common busbar (horizontal grounding conductor) made of a 40 × 4 mm metal strip. Only welding is applicable here, although you can find recommendations to use a bolted connection. No, to ensure reliable and durable grounding, this harness must be welded - a threaded contact placed underground will quickly oxidize, and the circuit resistance will increase sharply.
- Now you can lay a bus from the same strip to the foundation of the house. The tire is welded into one of the clogged electrodes and placed in a trench, then it goes onto the base of the building.
- The busbar is attached to the base. Not shown in the figure, but it is advisable to provide a slight bend in front of the attachment point, so-called"compensation hump" to compensate for linear expansion of the metal during temperature changes. A bolt with M10 thread is welded at the end of the strip. A copper terminal with a grounding wire will be attached to it, which will go to the distribution panel.
- To pass the wire through the wall or through the base, a hole is drilled and a plastic sleeve is inserted into it. The wire used is copper, with a cross-section of 16 or 25 mm² (it is better to check this parameter with specialists in advance). It is also better to use copper nuts and washers for connections.
- Sometimes they do it differently - a long steel pin is welded to the tire, so that it passes right through the wall of the house, also through the sleeve. In this case, the terminal part will be indoors and will be less susceptible to oxidation under the influence of high air humidity.
Bronze Distribution Plate for Ground Wires - The grounding wire is connected to the electrical distribution panel. For further “distribution”, it is best to use a special plate made of electrical bronze - all the grounding wires going to the points of consumption will be attached to it.
You should not rush to immediately fill the mounted circuit with soil.
— It is recommended, firstly, to capture it in a photograph with reference to surrounding stationary ground objects - this may be required to make changes to project documentation, as well as for carrying out control and verification activities in the future.
— Secondly, it is necessary to check the resistance of the resulting circuit. For these purposes, it is better to invite specialists from the energy supply organization, especially since their call, one way or another, will be necessary to obtain permits.
If the test results show that the resistance is high, it will be necessary to add one more or even more vertical electrodes. Sometimes, before checking, they resort to tricks by generously watering the areas around the corners hammered into the ground with a saturated solution of ordinary table salt. This will certainly improve the performance, however, do not forget that salt activates metal corrosion.
By the way, if it is not possible to hammer in the corners, then they resort to drilling wells to the required depth. After installing the electrodes, they are filled with clay soil as densely as possible, which is also mixed with salt.
After the performance of the ground loop has been checked, it is necessary to process welds anti-corrosion composition. The same can be done with the bus going to the building. Then, after the mastic has dried, the pit and trenches are filled with soil. It must be homogeneous, not littered and free of crushed stone inclusions. Then the backfill area is carefully compacted.
Video: installation of a grounding loop using a metal corner
Using ready-made factory kits
Very convenient for organizing grounding in the country ready-made kits factory made. They are a set of pins with couplings that allow you to increase the depth of immersion into the ground as you drive.
This grounding system provides for the installation of one pin electrode, but to a greater depth, from 6 and even up to 15 meters.
The kit usually includes:
- Steel pins 1500 mm long with a galvanized or copper-plated surface, or made of stainless steel. The diameter of the pieces may differ in different sets - from 14 to 18 mm.
- To connect them, they are equipped with threaded couplings, and for ease of penetration through the ground, a steel tip is included in the kit.
In some kits, the couplings are not threaded, but press-fit. In this case, one end of the ground rod is tapered by forging and has a ribbed surface. When impacted, a strong connection occurs and reliable electrical contact is achieved between the rods.
- To transmit the impact, a special attachment (dowel) made of high-strength steel is provided, which will not be deformed by the impact of the hammer.
Dowel - a nozzle that will transmit the impact force from the hammer - Some kits include a special adapter that allows you to use a powerful hammer drill as a driving tool.
To install such a grounding system, it is also advisable to dig a small pit up to a meter deep and the same in diameter, although some even prefer outdoor placement.
The pins are driven in sequentially and incrementally to the required depth.
Then on left on the surface section (about 200 mm) a brass contact clamp is put on.
Either a conductive busbar made of a metal strip is inserted into it, or a grounding cable with a cross-section of 25 square meters is inserted. mm. For connection to the steel strip, a special gasket is provided, which does not allow for electrochemical contact between the ground of the rod and the steel (zinc). Subsequently, the bus or cable is brought into the house and connected to the distribution panel in exactly the same way as described above.
Video: manually driving pin electrodes
Prices for components for lightning protection and grounding
Components for lightning protection and grounding
What type of rod coating should I choose – galvanized or copper-plated?
- From a cost-effective point of view, galvanizing with thin layer(from 5 to 30 microns) is more profitable. These pins are not afraid mechanical damage during installation, even left deep scratches do not affect the degree of protection of iron. However, zinc is a fairly reactive metal, and while protecting the iron, it oxidizes itself. Over time, when the entire zinc layer has reacted, the iron remains unprotected and is quickly “eaten up” by corrosion. The service life of such elements usually does not exceed 15 years. And making the zinc coating thicker costs a lot of money.
- Copper, on the contrary, without reacting, protects the iron it covers, which is more active from a chemical point of view. Such electrodes can serve for a very long time without compromising efficiency; for example, the manufacturer guarantees their safety in loamy soil for up to 100 years. But during installation, care should be taken - in places where the copper plating layer is damaged, a corrosion area will likely appear. To reduce the likelihood of this, the copper plating layer is made quite thick, up to 200 microns, so such pins are much more expensive than conventional galvanized ones.
What are the general advantages of such a set of grounding systems with one deeply placed electrode:
- Installation is not particularly difficult. No extensive excavation work required, no welding machine needed - everything is done ordinary tool, which is in every home.
- The system is very compact; it can be placed on a tiny “patch” or even in the basement of the house.
- If copper-plated electrodes are used, then the service life of such grounding will be several tens of years.
- Thanks to good contact with the ground, minimal electrical resistance. In addition, the efficiency of the system is practically not affected seasonal conditions. The level of soil freezing accounts for no more than 10% of the length of the electrode, and winter temperatures cannot in any way negatively affect the conductivity.
There are, of course, some disadvantages:
- This type of grounding cannot be implemented on rocky soils - most likely, it will not be possible to drive the electrodes to the required depth.
- Perhaps some will be put off by the price of the kit. However, this is a question With with porn, as high-quality rolled metal for conventional scheme Grounding is also not cheap. If we also add the duration of operation, simplicity and speed of installation, and the absence of the need for specialized tools, then it is quite possible that this approach to solving the grounding problem may seem even more promising from an economical point of view.
Video: how to ground your home using a modular pin system
The device of the so-called buried grounding loop externally consists of electrodes - metal rods that are driven into the ground and connected to each other. The most effective design is considered to be one in which the electrodes are arranged in one line. However, under favorable conditions, a design in which the rods are arranged in a triangle will also work quite well.
Grounding device if the pins are located in one line
Grounding device in case of pin arrangement in the form of a triangle
The arrangement in a triangle is somewhat worse, since the electrodes shield each other much more, which means that the material consumption when organizing such a design, all other things being equal, will be greater. On the other hand, at a short distance, the triangular arrangement significantly reduces the number of excavations, and it is much more convenient to connect the pins with the busbar to each other in a triangular-shaped pit than in a narrow trench. 
Design of a deep grounding loop using an angle: 1. Angle made of steel 50 by 50 by 5 millimeters, 2. connecting strip of steel 50 by 5 millimeters, 3. Steel grounding bus 50 by 5 millimeters.
The distance of the ground loop from the house walls must be at least 1 meter.
Grounding electrodes should be buried to a sufficient depth for possible soil freezing. The thing is that, when frozen, the soil conducts very poorly. electricity. In particular, when the topmost soil layer half a meter high freezes, its resistance increases approximately ten times, and at a depth of about a meter - three times. In summer, the surface layers of the soil (up to about a meter deep) dry out noticeably, which quite sharply increases its resistance. That is why it is necessary to bury the electrodes deeper into the so-called stable soil layers, which lie at a depth of 1-2 meters. At this depth, soil parameters remain almost unchanged throughout the year.
Of course, it is quite possible to take longer metal electrodes, but this will increase material consumption. The calculation of the grounding loop is given in the article entitled “Grounding Calculation” on our resource. In addition, it is worth noting that manually driving grounding rods over 2.5 meters long into the ground can be quite problematic.
Table 1 Coefficients for using 3 electrodes placed in a row 
Construction fittings are not suitable for grounding rods
Table 1 shows how the distance between the 3 rods affects the coefficient of their use. The distance ratio between the rods is the ratio of the rod length used to the distance between them. For example, if you take a pair of electrodes 2.5 meters long, completely buried in the ground to the required freezing depth (their entire length is used) and place them at a distance of two and a half meters from each other, then their ratio will be 1 = 2.5 /2.5.
Looking at the table, we can conclude that the most optimal distance between the ground loop rods is usually equal to their length. With an increased distance, the increase in efficiency will be small given the fairly large amount of work on the ground and the consumption of material for connecting the rods with a tire.
For the production of depth electrodes, you can use any materials having the minimum dimensions indicated in Table 2.
It should be noted that Table 2 does not contain reinforcement with the so-called periodic profile, which is usually used for concrete reinforcement. Rods of this kind of reinforcement are completely unsuitable for deep grounding, since when driven into the ground, they loosen it near them, which leads to an increase in resistance.
Table 2 Minimum dimensions of grounding electrodes from the point of view of mechanical and corrosion resistance
Material | Surface | Minimum size |
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Diameter, mm | Sectional area, mm 2 | Thickness, mm | Coating thickness, microns |
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Black 1 metal without anti-corrosion coating | Rectangular 2 | |||||
Hot-dip galvanized 5 or stainless steel 5,6 | Rectangular | |||||
Round rods for recessed electrodes 3 | ||||||
Round wire for surface electrodes 4 | ||||||
Copper sheathed | Round rods for recessed electrodes 3 | |||||
Electroplated copper plated | Round rods for recessed electrodes 3 | |||||
Uncoated 5 | Rectangular | |||||
Round wire For surface electrodes 4 | ||||||
each wire | ||||||
Tinned | each wire | |||||
Galvanized | Rectangular 9 | |||||
1 Service life 25-30 years at a corrosion rate in normal soils of 0.06 mm/year. 2 Rolled or cut strip with rounded edges. 3 Ground electrodes are considered to be buried when they are installed at a depth of more than 0.5 m. 4 Grounding electrodes are considered to be surface electrodes when they are installed at a depth of no more than 0.5 m. 5 Can also be used for electrodes laid (embedded) in concrete. 6 Used without coating. 7 In the case of using wire manufactured by continuous hot-dip galvanizing, a coating thickness of 50 microns is adopted in accordance with current technical capabilities. 8 If it is experimentally proven that the likelihood of damage from corrosion and mechanical stress is low, then a section of 16 mm 2 can be used. 9 Sliced strip with rounded edges. |
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Galvanized clamps for fastening grounding conductors
Connecting a galvanized rod to a galvanized strip using a bolted clamp
In order to connect contour rods to the grounding bus and connectors, two methods are used:
In the case of using galvanized steel, a connection can be used without welding, using crimp threaded clamps. Moreover, the connection point must be protected from corrosion using an anti-corrosion bandage or coating with hot bitumen;
When using rolled black steel without any coatings, it is connected using electric arc welding.
Carrying out anti-corrosion treatment of connections on clamps
Regarding the wire (the so-called protective conductor), which is connected directly to the grounding structure (that is, to the grounding bus), it is best to use a copper wire. The size of the minimum cross-section of the grounding wire should be selected according to Table 3. For example, if you simply connect a copper wire to a steel busbar using a galvanized threaded connection, and the connection is located in a plastic distribution box, the wire itself is hidden in a plastic corrugation, then this type of connection is necessary be considered poorly protected from corrosive effects, since it is in direct contact with air. However, the connection between a ground loop of this kind and a conductor is mechanically protected, which means the minimum possible cross-section of a copper wire will be 10 millimeters2. Details on arranging protective home grounding yourself are given in the article entitled “Installing a grounding loop yourself.”
Modular grounding- this is a project created specifically for the installation of grounding conductors on residential properties, for example, such as private country houses, country houses, as well as for industrial and administrative facilities.
Practice of installing a modular grounding loop.
A modular ground electrode is a prefabricated structure consisting of steel pins specially treated with copper, each 1.5 meters long. These pins are combined into a single grounding circuit for grounding the object.
The length of the prefabricated grounding rod can reach a depth of about 30 - 40 meters. The 1.5 meter grounding pins have threads at the ends, through which and connecting couplings between them, it becomes possible, as the assembled grounding pin moves deeper, to extend it with the next pin, etc.
Installation of a vertical grounding pin in depth is done as follows. The first pin is equipped with a steel tip at the bottom, and a mounting sleeve with an attachment for a vibrating hammer is screwed onto its upper part. A hammer or hammer drill is used to strike the nozzle, and a special clamp is used to hold the pin in a vertical position.
When the first pin enters the ground to a length of approximately 1.3 - 1.4 meters, the mounting coupling with the attachment for the vibrating hammer is removed, and instead of them, the second pin is screwed through the coupling. A special clamp to hold the pin in a vertical position moves up the newly mounted structure, and its top is again equipped with a mounting sleeve and a hammer attachment, and the process of driving in the grounding pin continues.
The circuit of the modular grounding pin is shown in the diagram below, where:
1. Attachment for a hammer or vibratory hammer.
2. Mounting coupling.
3. Clamp to hold the ground rod in a vertical position.
4. Coupling coupling.
5. Ground rod.
6. Steel tip.
Several such modular grounding conductors are installed for the grounding loop (according to the design), and then they are connected to each other, by means of a copper strip or wire using clamps, into a single grounding loop. When installing clamps, these places are pre-treated with conductive paste, and after complete installation of the entire grounding loop, it is subjected to anti-corrosion painting.
Measuring the resistance of a mounted vertical pin is possible at the installation stage of each newly screwed 1.5 meter pin, and the service life of such a modular grounding loop is approximately 30 years.
Advantages of modular grounding.