What should be the ground pin. How to make grounding in the country: do-it-yourself grounding with metal parts. Device in a private house of the TN-C-S grounding system
One of the options for installing a ground loop in a private house is the installation of a pin ground. In this case, the operating time is significantly reduced, while the functionality of the ground electrode system 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 and what does such a system consist of? The device consists of steel one and a half meter pins, which are processed with copper and connected using couplings. Also included is a brass clamp that connects horizontal and vertical circuits. Below is the design diagram.
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 nozzle is necessary to transmit the force of the vibratory hammer. A steel tip is installed on the lower part of the structure. It simplifies driving the unit into the ground. There are several types of tips, the scope of which depends on the hardness of the soil.
In addition, a special electrically conductive liquid paste is attached to the kit, the purpose of which is to protect against corrosion and constantly maintain electrical resistance during operation. Electrically conductive paste is applied to all threaded connections designs. You can also use a special waterproof adhesive tape against corrosion. It is resistant to acids, salts and gases, does not allow moisture to pass through.
Installation steps
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 an electrically conductive paste against corrosion. On the other end we screw the coupling and also treat it with anti-corrosion paste. Then a landing pad is screwed onto the device to apply the forces of the vibratory hammer.
The modular pin grounding, which was assembled, is placed in a pre-prepared hole in the ground. You need to screw it as deep as possible into the ground with your own hands. Then you need to connect the vibrating hammer to the network and attach it to the platform of the rod. Thus, the pin is immersed in the ground for its entire length. You only need to leave 20 cm in order to connect another rod.
After that follows. To do this, remove the landing nozzle and connect to the place where it was located special device, ohmmeter, as in the photo below:
When the first rod is located in the ground for its entire length, the landing nozzle 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 up the installed device. And on the mounted structure, the coupling and the attachment for the vibratory hammer are again installed, after which the process is repeated.
The spreading resistance should be checked after the installation of each vertical rod. The pins are installed until the required resistance is set. 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 grounding conductor 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 a special adhesive tape. It provides additional protection against corrosion.
Advantages and disadvantages of the system
Modular pin grounding, like any system, has its pros and cons. Compared with the classic and standard circuit, pin grounding has the following advantages:
- ease and simplicity in installation;
- occupies a small area;
- installation is carried out by a minimum number of workers (1-2 people);
- installation takes place without welding, since all connections are made using couplings;
- thanks to the vibratory hammer, there is no heavy land work;
- modular pin grounding is resistant to corrosion, as it is treated with special lubricants and coatings, thanks to which they serve for several decades;
- regardless of the soil, the pin system is easily driven into the ground;
- structural elements are manufactured industrially, thanks to which they are of high quality and are ready for instant installation without additional preparatory work.
Modular pin grounding has one, but a significant disadvantage - this is its high cost. But, despite this drawback, the system is beneficial, given all its advantages.
The industry produces a wide variety of kits that combine such elements that are necessary for reliable and quality installation. Modular pin grounding has an important purpose - it is to protect the house from fire, and the people in the room from electric shock.
Grounding traditional
Prong ground
As you can already see in the figure, arranging the ground loop on your own is not particularly difficult. Today, there are two main methods of grounding device. The first, which has already become traditional, is when three or more metal pins are driven into the ground to a depth of up to 3 meters. And more modern method when one pin is driven into the ground to a depth of up to 30 m, i.e. to the maximum possible depth of the first aquifer.
1. Grounding by traditional method
Choose a place on the site as close as possible to the introductory cabinet (power shield). The optimal distance is not more than 10 m.
To install the ground loop, you will need a steel corner 50x50x5 mm in the amount of 9 m and a steel strip 4x40 mm in the amount of 9 m plus the distance from the ground loop to the power shield.
We dig a trench about 0.5 m wide and at least 0.8 m deep. The trench is dug in the form of an equilateral triangle (3 x 3 x 3 m) with a branch to the power cabinet.
Then, at the corners of the triangle, we drill 3 wells 3 meters deep and hammer in 3 corners 3 meters each. If the soil is stretch soft, you can try to drive it with a sledgehammer without drilling a well. The end of the corner should protrude slightly from the ground so that a metal strip can be welded to it.
To the three ground electrodes (corners) installed in the ground, we weld a steel strip around the perimeter. We lead one end of the strip from the ground loop to the power cabinet. Weld the strip to the cabinet body.
Before backfilling the trench, we check the resistance of the ground loop. To do this, you need to arm yourself with an ohmmeter, for example: brands ES 0212 or any other similar. The resistance should not be higher than 10 ohms (usually 4-6 ohms are obtained). This is very small, for comparison - the resistance of the human body is on average 7000 ohms. If the loop resistance is above 10 ohms, drive another pin into the ground and weld it to the loop. Natural ground electrodes (metal fence posts, supports, etc.) will help to reduce the resistance of the ground loop if they are connected to the loop. Do not forget - all connections are made by welding.
The trench is buried with a homogeneous soil that does not contain crushed stone and construction debris.
A correctly made ground loop will allow you to equip lightning protection in the future, i.e. lightning protection.
2. Grounding with one pin
The procedure for the installation of grounding
- Preparation of the first pin.
Treat the inside of the starting tip with an anti-corrosion conductive lubricant and then put it on the pin.Treat the inner part of the coupling with anti-corrosion conductive grease and screw it up to the stop on the other side of the pin.
Screw the guide head for the jackhammer until it stops into the coupling screwed onto the earthing pin.
Please note that it is necessary to screw in the guide head until it makes full contact with the pin. This is necessary so that during installation, the impact energy of the jackhammer is transmitted through the head directly to the pin, and not through the coupling. Otherwise, the coupling may be destroyed.
- Immerse the pin into the ground with a jackhammer (impact energy 20-25 J) to a level convenient for subsequent operations.
- Unscrew the guide head (without the coupling - it must remain on the pin).
- Once again, treat the remaining coupling screwed to the pin with anti-corrosion conductive paste.
- Screw the next pin into it (coupling from item 4) until it stops.
- Take a new clutch and process it inner part anti-corrosion conductive grease.
- Screw the guide head for the jackhammer into this coupling (from item 6) as far as it will go.
- Screw the sleeve with the mounted head onto the pin connected to the already mounted pin (from point 5).
- Consistently repeat steps 2 through 9 until a ground electrode of the required depth is obtained.
Please note that when installing the last pin, it is necessary to leave on the surface the section of this pin that is necessary for connecting to the ground conductor. - A clamp for connecting a grounding conductor is installed on top of the mounted electrode.
- A grounding conductor (round wire or strip) is connected to the clamp.
- The junction (clamp) is tightly wrapped with waterproofing tape.
Andinformation about accessories modular grounding(on a separate page).
Conductor routing depth
P The surface layer of soil is exposed to seasonal and weather influences. high humidity, freezing / thawing of the soil in this layer negatively affects both the grounding conductor and the grounding / connecting conductors located in it.
Moreover, the probability mechanically damage to the conductors in the surface layer during housekeeping creates inconvenience and increases the likelihood of creating a dangerous situation associated with an emergency grounding condition.
Hand in most of the Russian Federation and CIS countries, the depth of the surface layer of soil, which is subjected to the above types of impact, is 0.5 - 0.7 meters.
Therefore, grounding and connecting conductors in the ground must be laid at this depth (0.5 - 0.7 meters) in a pre-prepared channel.
Hand vertical ground electrodes are buried at the same depth.
Connecting earth electrodes
FROM the grounding electrodes are connected to each other and the grounding electrode to the object is made with a steel or copper conductor (wire or strip).
M The minimum cross-sectional area of the grounding conductor depends on the tasks performed by the grounding conductor.
Pthe conductor is laid at a depth of 0.5 - 0.7 meters in a previously prepared channel (in which the electrodes are also installed).
DTo connect the ground electrode to the conductor, a special clamp is used, which is included in the kit. modular grounding ZandZ.
The sequence of work during the installation of grounding at the facility
- Dig a channel with a depth of 0.5 - 0.7 meters at the place where the connecting conductor is laid
- Carry out the installation of grounding electrodes in the prepared channel. As an instruction for the installation of grounding electrodes, it is necessary to use the list of operations "Procedure for the installation of grounding"
- Lay the connecting conductor in the channel
- Connect the ground electrodes to the conductor using the clamps included in the ZandZ kits
- Connect the resulting ground electrode to the electrical panel
- Fill the canal with soil
Modular pin grounding provides minimal ground resistance to propagation in it electric current. This method of grounding is widely used in industrial, administrative buildings, private houses. We will tell you how to make it yourself, what rules you need to know when working with the device.
What does the system include?
The system is sold as a kit, but if necessary, you can purchase its components separately.
The set includes:
- Vertical metal one and a half meter threaded rods treated with copper.
- Brass threaded sockets serving as connecting elements between the pins.
| Coupling MS-58-11
|
- Brass clips connect the metal pin to the metal strip.
| Brass clips universal MS-58-11 |
- Tips put on a rod that is inserted vertically into the ground. There are several types of tips designed for normal and very hard soil, making it much easier to dive due to the sharp lower end.
| Tip 58-11″UNC
|
- Landing pad with impact propeller used to transfer force from the vibratory hammer.
| The landing pad serves to transfer forces from the jackhammer to the rod. Landing pad 5/8”-11 UNC
|
- To protect against corrosion, all connecting elements on the thread are coated with the supplied anti-corrosion graphite paste. It does not spread even with strong heating and serves to maintain electrical resistance.
- Plastic, moisture-resistant, resistant to aggressive solutions, anti-corrosion tape serves to protect all metal grounding elements from destruction.
To service the system, an inspection hatch is required.
| 1. Landing pad with impact propeller. 2. Installation coupling. 3. Clamp holding the rod in a vertical position. 4. Coupling. 5. Grounding rod. 5. Metal tip. |
Benefits of a modular earthing system
The modular pin grounding system has the following advantages:
- Ease of installation - installation requires one or two people, a minimum of tools. Read also the article: → "".
- A large amount of excavation and welding work is excluded, all connections are made through couplings. Installation can be done in 3-4 hours.
- Occupies less than 1 sq. meters of area. It can be installed even in the basement or near the walls of the building.
- The service life is more than 30 years.
- It is not subject to corrosion, as all elements are covered with anti-corrosion lubricants.
- All parts of the system are manufactured in the factory, respectively, are of high quality.
- Almost any type of soil is suitable for installation.
Disadvantages of the modular-pin system
Modular pin systems also have some disadvantages:
- The high cost of a modular grounding system.
- Impossibility of installation on rocky ground.
- Commissioning involves the execution of an act of hidden work, the preparation of a resistance measurement protocol, as well as the development of a technical passport with a grounding diagram. Documents must be kept for the entire period of use. Read also the article: → "".
Do-it-yourself system installation
Installation can be done with the involvement of specialists or on your own. To complete the work you will need:
- a jackhammer or puncher, which greatly simplifies the installation of the device;
- resistance meter.
System installation steps:
- We calculate the required depth of occurrence, determine the required number of rods and the amount of their immersion in the ground.
- Stepping back 1.5 m from the wall of the building, we dig a hole with a width, length and depth of 20 cm, stepping back one and a half meters from the wall.
- Close to the venue installation work we install a resistance meter, at a distance of 10 and 25 meters from it we drive measuring electrodes into the ground, connect the device.
Council number 1. If it is not possible to measure the resistance after installing each pin, you can bury the system to a lower level from 15 to 30 meters, and call laboratory representatives who will make all the necessary measurements and draw up documentation.
The layout of the electrodes with a modular-bayonet system - We prepare the device. We process the threads on both sides with graphite paste (or a similar composition). We put the tip on the thread, install the coupling on the second end. We wind the landing shock nozzle, which will be in contact with the vibrating hammer. A special clamp will hold the rod in a vertical position.
- We insert the prepared rod into the hole with the tip down. Using a jackhammer, we drive the rod into the ground, leaving 20 cm above the surface for docking with the second rod. We remove the landing shock nozzle.
- We measure the resistance by connecting the meter to the rod.
- We process the coupling with conductive anti-corrosion paste and screw the next rod into it, and again the coupling treated with paste on it. We install the nozzle and drive it into the ground in the same way using a hammer. We measure the resistance. We build up the rod again, repeating this action until the resistance reaches 4 ohms.
- We drive the last pin to such a depth that the coupling can be unscrewed from it, and leave about 10 cm above the ground.
Ready-made modular pin grounding - Next, we connect the vertical grounding conductor to the horizontal grounding conductor. The clamp consists of three plates, has four bolt fastenings. It has connectors for ground rod, cable and steel strip. We screw the clamp onto the outer end of the pin - with the side that is intended for the rod. On the other side of the clamp, we screw a cable or a metal strip with a bolt, laying a plate between them that protects the contacting elements from corrosion. We process all bolted connections with a plastic moisture-resistant tape.
- We install an inspection hatch.
Council number 2. Instead of a ready-made inspection hatch, which has enough big sizes, you can use a sewer coupling. From below, a plywood plug with a hole for the rod is attached to the coupling.
If the ground allows, then the pins can be deepened up to 40 meters. If it is impossible to immerse the rods into the ground to the required depth, it is necessary to install conventional ground electrodes. Their number will depend on the resistance of the soil.
With the modular system, you can different kinds grounding: single point, focal, comb, multipoint. The installation method is selected depending on the type of soil and the area of \u200b\u200bthe site for installation.
Modular grounding refers to technologically advanced ways of electrically connecting a conductive material to the ground. Another name for the technology is the modular pin system.
This article will discuss the advantages and options for installing this type of grounding. Attention will also be paid to the issue of control over the loop resistance.
Modular Pin Grounding System
This system consists of vertical steel rods and couplings (shown in Figures No. 1 and No. 2). The length of each rod covered with a copper layer is 1.5 meters. Brass couplings are used to fasten the rods to each other.
ground rod Technical specifications:
- part length - 1500 millimeters;
- rod diameter - 14.2 mm;
- thread: 5/8” (double-sided, copper-plated);
- thread length - 30 millimeters;
- weight - 1.85 kilograms.
Technical specifications:
- material - brass L63 (bronze can be used);
- length - 70 millimeters;
- diameter - 22 mm;
- internal thread - 5/8";
- thread length - 60 millimeters;
- weight - 114 grams.
The package includes a brass clamp, which is used to fasten the elements of the ground loop arranged vertically and horizontally. A steel rod acts as a vertical element, and a steel rod acts as a horizontal element. copper wire from a switchboard or a strip of steel.
As can be seen from Figure 4, there are two types of steel tips in the equipment kit. They are wound on a rod that is installed vertically in the ground. Tips are designed for different types soils: for especially hard soils and for ordinary soils.
Technical specifications:
- tip length - 42 mm;
- steel tip diameter - 20 millimeters;
- internal thread - 5/8";
- thread length - 20 millimeters;
- weight - 45 grams.
In addition to the main device, a landing pad is supplied (shown in Figure No. 5), as well as special nozzle(Figure No. 6). These devices will be needed to apply and transmit the movements of the vibratory hammer.
Technical details:
- length - 53 mm;
- diameter - 23.6 mm;
- external thread - 5/8";
- thread length - 35 millimeters;
- weight - 110 grams.
impact nozzle - length - 265 millimeters;
- diameter of the main part - 18 millimeters;
- diameter of the working part - 11.7 millimeters;
- the length of the working part is 14.5 millimeters.
In addition, an anti-corrosion conductive liquid paste is attached to the main kit (Figure No. 7). It is designed to prevent corrosion. The package also includes a protective tape (Figure No. 8), which is used for clamping the system elements vertically and horizontally.
Anti-corrosion conductive grease Graphite-based conductive paste allows you to achieve a permanent electrical circuit of the vertical ground electrode. This pasty composition can be used regardless of the seasonal factor. The threads of all used connections are treated with grease.
The anti-corrosion paste has good adhesion and high temperature resistance. In other words: the paste does not flow when heated. The use of lubricant can reduce the resistance of the joint by 9-10%.
The tape is used to prevent corrosion on pipes (regardless of their location), as well as on any other metal structural elements. The anti-corrosion tape is characterized by plasticity even at high temperatures, as well as acid resistance, resistance to alkaline and salty environments. The tape is not afraid of harmful microorganisms and moisture.
Assembly work is more convenient to carry out using a vibrating hammer (Figure No. 9). Spreading resistance is controlled by a resistance measurement device (Figure #10).
Resistance measuring instrument Installation work
Do-it-yourself installation consists of several successive stages, which will be discussed below.
Installing the Meter
We put a device for measuring resistance near the place where the ground loop will be installed. As a place, we choose a pit with a height, width and depth of 200 millimeters for each parameter. The pit should be located one and a half meters from the wall of the building, where the horizontal element of the ground loop is located. As an element, a copper wire or a strip of steel can be used.
To carry out measurements, you will need measuring electrodes, which are installed with an indent of 25 and 10 meters on opposite sides of the device. We drive the electrodes into the ground and connect them to the measuring device.
Electrode mounting scheme
Installing the first module pin
- Screw the tip onto one side of the rod. Before winding, the tip must be treated with anti-corrosion grease.
- On the other rod end we screw the coupling. We also treat it with an anti-corrosion compound.
- We install the landing head designed to apply the pressure of the vibrohammer.
- The assembled rod (with the tip down) is installed as deep as possible into the ground in the pit.
- We turn on the vibratory hammer, direct it to the platform of the rod and drive the rod into the ground in about 15-20 seconds. At the same time, we leave 20 centimeters on the surface so that the rods can be connected to each other.
Intermediate resistance measurement
We remove landing pad and measure the resistance. To achieve the required resistance, it is necessary to deepen the vertical pins by placing grounding sections on top of each other.
Installation of other vertical pins
- After processing the coupling with grease, we screw another copper rod into it.
- We put on another sleeve on the rod and put the landing head again.
- We repeat the operation with a vibrating hammer.
- We check the resistance to spreading.
We increase the rods until the resistance drops below 4 ohms.
Installation of a horizontal earthing switch
- We begin to connect the vertical and horizontal conductive grounding elements. To connect a steel tape or copper wire to the rod, we use a brass clamp. One side of the clamp is adapted for a pin, the other for copper wire or steel strips.
- We fix the clamp with bolts on the rod.
- We fasten the horizontal part of the ground to the clamp. The horizontal component is separated from the pin by a separation plate, which avoids bimetallic corrosion.
- We apply anti-corrosion tape to all bolted connections (Figure No. 12).
Deep modular pin grounding system The grounding loop, manufactured according to the standard of the modular-pin system, can be made both in single-point and multi-point versions. The specific choice depends on the task at hand - the required resistance of the ground electrodes.
Advantages of modular pin grounding
Figure #13 shows the relationship between spreading resistance and earth rod depth. The commissioned grounding system made it possible to achieve a spreading resistance of approximately 4 ohms in less than an hour.
Graph of grounding resistance versus the depth at which the rod is located.
Let's figure out what conditions are needed installed system. To install the ground loop using the pin method, you need:
- vibratory hammer, which will facilitate the installation process for the installer;
- measuring device;
- another installer who will act as an assistant holding the rod during the operation of the vibratory hammer.
The following are the advantages that modular grounding has over the most commonly used standard ground loop:
- The area on which the modular-pin system was located occupied no more than one square meter, which indicates the possibility of a compact installation.
- No need for labor intensive earthworks thanks to the use of a vibrohammer.
- No welding work is required, since all connections in the modular-pin system are carried out using couplings.
- Long service life of the system (over 30 years) due to coatings resistant to corrosion processes (indicates resistance to corrosion of soil and electrolytic origin).
- The use of a deep modular pin design removes the dependence on the characteristics of the soil.
- The design lacks any complex elements, even a not very trained person can assemble it.
Another issue worth mentioning is the cost of the system. In general, the costs are approximately equivalent to 500 US dollars. The installation cost will add another $120 to the cost. At the same time, a classic grounding system will cost about $ 240, including installation work. However, despite the loss in terms of price, the advantages of the modular-pin system listed above unequivocally testify in its favor.
When the ground loop is installed, you will need to draw up appropriate documentation for it, including a measurement protocol, a grounding passport (with a diagram included in it) and an act of hidden work. Documents must be kept throughout the life of the system.