Connect equipment with a separate ground wire. Grounding at home with your own hands

The grounding is called the connection of the low-profile parts of electrical equipment to the earthing. This ensures the presence of the potential of the Earth on the electrical appliances housings. This is necessary to prevent electrical shock as a result of touches of housings and other structural parts of damaged equipment. Connecting to the ground bus is performed using a wire or cable. In this article we will tell what should be the wire for grounding so that you can choose the brand, cross section and other parameters.

Briefly about the terms

So that the article was understandable even for those who far from electrical engineering, we led to the explanation to the terms that will be used in it.

The ground is called the base of the grounding system. It usually represents metal pins, vanned to the ground at an equal distance from each other, forming a figure like a triangle.

A grounding tire or is called the metal strip, laid around the perimeter of the room or near the protected devices, which connects all grounding conductors of electrical appliances with a ground.

A ground wire or residential is called that conductor, which provides the grounding of the grounding with GZSH.

Metal communication is a concept that characterizes the contact between the metal parts of the electrical equipment, including the doors of electrical shields or cabinets with their enclosures.

Grounding wire section

To ensure reliable protection against lesion and operation of protective switching devices, the grounding wire is selected depending on the phase cross section. It is necessary in order for in the event of an accident, it has grown high currents and has not burned down. If this happens - the defense does not work, and the dangerous potential will be on the electrical appliance body.

The cross section of the grounding wire must be:

• If the phase is used in cross section to 16 square meters. mm - grounding conductor must be similar.
• If the cross-sectional area of \u200b\u200bthe phase from 16 to 35 square meters. mm, then "land" it should be 16 square meters. mm.
• When the phase section is more than 35 square meters. MM - the minimum cross section of the grounding wire should be at least half the phase cross section.

Let us give two examples to answer the question which section should be grounding the instrument:

1. You connect the electric stove with a cable with a cross section for 4 square meters. mm. So the cross section of the protective wire should be the same.
2. An inlet cable with 50 kV cores is connected to the electrical cabinet. mm. In this case, the ground cross section should be at least 25 square meters. mm. You can more.

Brand and requirements for conductors

Conducting grounding wire or cable can be single-core and multi-moist - it depends only on where it will apply. For example, for grounding the doors in the electrical protection, it is necessary to ensure its mobility. The hard lived from the permanent openings of the door and its bending will be broken. Therefore, the veins should have a corresponding class of flexibility that does not prevent discovery, for example 3 and higher.

At the same time, for connecting, for example, the housing of the pumping station's electric motor to the GZSH does not need to provide mobility, since this type of electrical equipment refers to stationary mounted. Therefore, you can use hard veins.

Core grounding can be:

• isolated;
• uninsulated;
• is located as part of the cable;
• be a separate single-core wire;
• aluminum;
• copper.

From here it follows the question: so what wire to use to connect the Earth?

In stores for sale cable products with different quantities lived: 2, 3, 4, 5. This is necessary for assembling certain schemes for turning the devices and connect electrical equipment to networks with different phases.

To connect the grounding in sockets and other electrical equipment of a single-phase network, it is convenient to use triple cables, such as 3x2.5 VG. And for connecting three-phase equipment to the network and grounding, four-core cables are intended, such as AVVG 4x32. At the same time, in thick cables, the ground conductor usually has a cross section of less than the phase lived. We give examples.

If you got a cable with a color marking that does not correspond to the GOST, you can designate the ground, phase and zero with a healer or a shrink tube. In addition to color labeling, there is an alphabetic or digital:

• L - Line or phase.
• N - Neutral or neutral, zero.
• Pen or PE - protective conductor or earth.

Earth and zero tires are often used to connect to the introductory and distribution panel (and other places). This is a rail with a set of holes and screw clamps where the wires are connected. To connect the wire of land with a multi-breed residential, it is necessary to be necessary or clipped with a pin tip of the type and the like. This rule concerns and connect to machine terminals and other screw connections of any flexible conductors.

To connect the wire with a grounding tire, it is necessary to use round closers, nvi or other types of cable lugs with terminals in the form of a ring.

It may be necessary when laying ground from the contour to the shield. Usually they are two types:

• Crimp. In order to secure them on the cable, they are crimped with a special tool. There should be no passports to this, because you will not achieve a reliable crimping. The best compression provides press clamps (another name - crimp) with hexagonal (hex) clamps.
• With disruptive screws - for their tightening, the screw is simply tightened to the breakdown of his head.

That's all that we wanted to tell you in this article. Now you know what section and stamps should be a ground wire. Finally, we recommend viewing a useful video.

General requirements

Grounding is one of the main measures of protection against electric shock.

This article provides a detailed, step-by-step instruction on how to make a ground in a private house with your own hands.

To begin with, we will define What is grounding?

According to Pue. Ground - This is a deliberate electrical connection of any point of the network, electrical installation or equipment with a grounding device. (paragraph 1.7.28.)

As a grounding device usedmetal rods or corners that are driven vertically to the ground (so typical vertical grounding) and metal rods or metal strips which by means of welding combine vertical entries (so typical horizontal entrancers).

Vertical and horizontal entrancers together form earth coneThis circuit may be closed (Figure 1) or linear (Figure 2):

The grounding circuit must be attached to the main grounding tire in the introductory electrical panel of the house with ground conductoras a rule, the same metal strip or rod is used as a horizontal earthing.

Private grounding of a private house will have the following general view:

In turn, the totality of the grounding circuit and the grounding conductor is called grounding device.

A closed earth circuit is usually performed in the form of a triangle with the sides of 2 to 3 meters (depending on the length of the vertical grounding agents) it is important that the distance between the vertical grounds was no less than their length (see Fig. 1). A closed circuit can also be performed in other forms, such as oval, square, etc. In turn, the linear circuit is a series of vertical earthingers in the amount of 3-4 pieces built into the line, while in the same way as in the case of a closed circuit, the distance between them in the linear circuit should be no less than their length, i.e. From 2 to 3 meters (see Fig. 2).

Note:The closed earth loop is considered more reliable, because Even in case of damage to one of the horizontal earthingers, this circuit retains its performance.

Horizontal and vertical grounders must be performed from black or galvanized steel either of copper (paragraph 1.7.111. Pue). In view of its high-cost copper entrancers, as a rule, do not apply. Same do not perform earthing motors from fittings -the outer layer of reinforcement reinforcement due to which the current distribution is disturbed by its cross section, in addition, it is stronger than corrosion.

Vertical earthingers are performed from:

• round steel rods with a diameter of at least 16mm (recommended: 20-22mm)
• steel corners with minimum 4x40x40 (recommended: 5x50x50)

Length of vertical entrancers must be 2-3 meters(recommended at least 2.5 m)

Horizontal earthingers are performed from:

• round steel rods with a diameter of at least 10 mm (recommended: 16-20mm)
• steel stripes with dimensions 4x40

Ground conductor perform from:

• round Steel Rod with a diameter of at least 10mm
• steel stripes with dimensions at least 4x25 (2x40 recommended)

2. Procedure for mounting grounding:

STEP 1 - choose a place for mounting

The place for mounting is selected as close as possible to the main electrical panel (input shield) of the house in which the main grounding bus is located (GZSH), it is a PE tire.

If the introductory electrical stopper is inside the house or on its outer wall, the grounding circuit is mounted near the wall on which electrical stoppers are located at a distance of about 1-2 meters from the foundation of the house. If the electrical shield is on the power line support of the power line or on the remote rack of the ground circuit can be mounted directly below it.

At the same time, it should not be positioned (use) earthingers in places where the land is dry under the influence of heat pipelines, etc. (p. 1.7.112 Pue)

Step 2. - Excavation

They dig a trench in the form of a triangle - for mounting a closed earth conserve, or a straight line for linear:

Tranche depthmust be 0.8 - 1 meter

Trench widthmust be 0.5 - 0.7 meters(For the convenience of welding work in the future)

Length of trench- depending on the selected number of vertical earthing and distances between them. (For a triangle, 3 vertical earthing is used for a linear circuit, as a rule, 3 or 4 vertical earthing).

Step 3. - Installation of vertical grounding

We set up vertical entries in the trench at the required distance from each other (1.5-2 meters) after which they score them to the ground using a perforator with a special nozzle or ordinary sledgehammer:

Previous ends of the grounding agents must be focused for easier entering the ground:

As already written above, the length of the vertical entrancers should be about 2-3 meters (it is recommended to at least 2.5 meters), while it is necessary to drive them into the ground for the whole length, so that the upper part of the earthing is 20-25 cm above the bottom of the trench :

When all vertical entries are clogged into the ground, you can move to the next step.

Step 4. - Installation of horizontal earthing and grounding conductor:

At this stage, it is necessary to combine all vertical grounding machines using horizontal earthing and to the resulting grounding contour to weld the grounding conductor that will exit the ground to the surface and is designed to connect the grounding circuit with the main grounding electrical circuit tire.

Horizontal and vertical earthingers are connected to each other by welding, while the connection location must be designed from all sides for better contact.

IMPORTANT! It is not allowed to use bolted connections! Vertical and horizontal earthing machines forming the grounding contour, as well as the grounding conductor at the site of its attachment to the grounding circuit must be connected by welding.

Welded seams need to be protected from corrosion, for which the welding location can be treated with bitumen mastic.

IMPORTANT!Self the grounding contour should not be painted! (clause 1.7.111. Pue)

As a result, it should be approximately the following:

Step 5. - I fall asleep the trench.

Here, everything is simple, we fall asleep the trench with the mounted grounding contour of the earth, so that there would be no less than 50 cm of the soil over the contour, as already mentioned above.

However, there are subtleties here:

IMPORTANT! Trenches for horizontal entrancers should be filled with homogeneous soil that do not contain rubble and construction waste (paragraph 1.7.112. Pue).

Step 6. - Connecting a grounding conductor to the GZSH of the introductory switch (input device).

Finally, we approached the final stage - grounding the electrical panel of the house, for this we carry out the following works:

We supply the grounding conductor to the electric tailor, so that it would be up to the electric booster about 1 meter, if the introductory shield is in the house, it is desirable to start a grounding conductor into the building. At the same time, the input places of grounding conductors in the building should provide the following identification mark (p.1.7.118. Pue):

The grounding conductor itself above the surface of the Earth must be painted, it must have a color designation by alternating longitudinal or transverse stripes of the same width (from 15 to 100 mm) of yellow and green colors. (Clause 1.1.29. Pue).

By the end of the grounding conductor from the gear side, we weld the bolt to which by connecting the flexible copper wire with a cross section of at least 10 mm 2, which should also have a yellow-green color. The second end of this wire is connected to the main grounding bus, which inside the introductory device (input electrical panel at home) should be used Re (clause 1.7.119. Pue).

IMPORTANT! The main grounding tire must usually be copper. It is allowed to use the main grounding tire of steel. The use of aluminum tires is not allowed. (clause 1.7.119. Pue).

As a result, the grounding circuit of the house's panel must have the following form:

Comfort and comfort in a private house or apartment is difficult to imagine without an established power supply system. Electricity consumption is constantly increasing, so the protection of people and domestic animals from electric shock is complicated. Eliminate risks, minimize the effects of injuries using a grounding system connecting the point of an electrical network or an energy consumer with a grounding structure.

Construction and purpose of grounding devices

Such structures are divided into working and protective devices.

1. Work is used to organize the safety of industrial aggregates. Also distributed in private farms.
2. Mandatory for power grids in the residential sector.

Installing a grounding device (memory) is required in accordance with the rules of the electrical installation and the rules of the electrical installation of consumers.

The touch of people to the current-carrying parts, open as a result of the improper operation of electrical equipment, structural defects, coming into disrepair of isolation and other reasons, is often found. The poor-quality design of the memory and its installation can entail heavy consequences for people: electric shock, burns, violation of the heart and other human bodies. Defection of the current often leads to amputations of limbs, disability and even fatal outcomes.

The grounding system consists of outer and inner parts that are joined in an electric shield. The outer grounding device consists of a complex of metal electrodes and conductors, reducing emergency current from electrical equipment to the ground in secure places for people. Electrodes are called earthing. Electric veins are pins with a length of 1.5 m, a diameter of 1 mm.

Manufactured by industry from copper or steel covered with copper. Their main advantage is an increased conductivity of the current. Drive into the ground with hammers or sledgehammes to a depth of 50 cm, contact with the ground should be as strong as possible, otherwise the ability of the structure to divert current.

Simple design is made from one electrode. Applied in lightning lifters or to protect remote objects and equipment. In individual farms, preference is given to multielectroda devices. Placed in one row and are called linear profiles of the memory. Standard chain length - 6 meters. Between themselves are connected by brass clutches, the mounting threaded, welding is not recommended. Ground conductors are installed through the terminals. Twisting, soldering lived excluded.

Such a device as a ground loop (closed version) is still distributed. Constructed at a distance no closer than 1 meter and no further than 10 meters from the house. It is placed in the trench in the form of an equilateral triangle. The length of the side is 3 m, the depth is 50 cm, the width is 40 cm. Earthings are driven in the corners. The same operation is done with other vertical electrodes (not over five units). Grounders in the lower support part are welded with horizontal products.

They are made of copper covered with copper or zinc steel corner (5 mm shelf, strip 40 mm), a standard corner of stainless steel of any profile is often used. The products are not stained, since in this case the electrical properties will deteriorate due to the weakening of contact with the Earth.

The design of the contour is simple, it can be made with your own hands. But the work is simplified when using ready-made grounding devices presented in the market, in a set with which there is. Financial losses will pay off due to the use of quality materials, resistant to corrosion and with a long service life.

Connecting the outer part to the shield

To determine exact to the shield requires knowledge of the method of applying neutral. It happens isolated and grounded. Isolated lived in networks with increased voltage values \u200b\u200bof 3-35 square meters. When powering 380 V and 220, both options work effectively. However, the new PUE rules require neutral grounding. The contours must be erected to 1000 V.

Popular grounding systems TN-C, TN-S, TN-C-S. Two-phase TN-C is outdated, but still applied in buildings that have a long service life. Their replacement is related to the difficulties of technical and financial nature. In this scheme, zero lived as a protective grounding wire. From a practical point of view, for residents of apartments and houses Cable and wiring products with 4 residents are beneficial: its cost below, installation works are easier.

Interest is the question of how to connect ground in a multi-storey building. Conductors are connected to the total tire of the memory. Then the tire is displayed on the electrical panel body on the floor. Similar to the TN-C translation process on TN-C-S in the home player. The essence is to connect zero protective conductors to a single bus, followed by a jumper with a zero tire.

The main disadvantage is associated with the danger of damage to the zero wire. Then the grounding design will be unusable. The regulatory documents were prohibited by the use of TN-C in new buildings. But for complete replacement of the system will require decades.

The principle of operation TN-S is based on the fact that the zero working and protective lines are summed up to the consumer with individual veins from the transformer substation. In the Russian Federation and the CIS countries, the intermediate version of TN-C-S is common, in which the separation of conductors is carried out directly when entering the house. In both variants, the security feature performs a protective shutdown device (UZO).

However, for a complete warning and localization of the effects of electrical shocks, the protective means must also include circuit breakers in the panels, the grounding bus to connect zero conductors and the ground circuit.

The latter provides conditions for the uninterrupted operation of electrical equipment. In addition, it reduces the level of radiation of electrical units, cables and wires, localizes noise phenomena in the power grid.

In the following order (TN-C-S system). Two feed wires consisting of phase and combined working zero and protective (REN) are divided into three separate veins. To connect the phase and working core, use the grounding bus isolated from the shield. Each tire (N and Re) must have its own marking and color: zero - blue, earth - yellow. Vehicle n is fixed on an electric shield using insulators. Re is installed on the housing. Between themselves are connected by a jumper from the conductive material.

In the future, these should be isolated from each other to avoid short circuit.

Many users prefer the option when REN cables retain their integrity and connect to the N bus, playing the role of zero protective conductors. The advantage of this scheme is that consumers of electrical energy are closed on the free tire Ree. When the Ren line is bravely, all current collectors continue to maintain grounding contacts.

Errors when installing the memory

Typical disadvantages often occurring in practice include:

1. Use of metal fences or masts as the contour. The current resistance is not taken into account and the danger of severely damage to the current of people in the event of an accident in the system is created.
2. Connecting the contour directly to the electrical appliances housing, bypassing the grounding tires in the shield.
3. Installing individual switches in a zero conductor. When the device is output, the electrical appliances may be substituted. Sometimes the contact of the zero wire is not durable. The consequences are the same.
4. Use for earthing products of smaller sections or thickness. Such electrodes under the influence of corrosion quickly fail.
5. Using as an earthing of a working "zero". The likelihood is increasing that the system will be under voltage.
6. The location of horizontal earthingers on the ground surface. With an accident, the lesion zone will increase.
7. Connecting grounding to heating pipe. It is impossible to say what direction will the wandering currents, since the situation is unknown in the next apartment. The likelihood of damage to foreign people increases.

Upon completion of the installation work, the system is checked. Attention is drawn by the amount of current scattering. To carry out this work, it is desirable to attract a specialist with the appropriate equipment.

My bitter electrician experience allows me to say: if you have "grounding" done as it is necessary - that is, there is a place to join the "grounding" conductors in the shield, and all forks and sockets have "grounding" contacts - I envy you, and you are nothing worry.

Ground connection rules

What is the problem, why cannot be connected to ground wires on heating or water supply pipes?

Really, in urban conditions, wandering currents, etc., interfering factors are so great that the heating battery may be anything. However, the main problem is that the protection current of the protection automata is large enough. Accordingly, one of the options of a possible accident - a sample of the phase on the body with a leakage current is just somewhere on the border of the automaton's response, that is, at best, 16 amps. Total division 220V on 16a - we get 15 ohm. Total thirty meters of pipes, and get 15 ohms. And the flow of the current somewhere, in the direction of not sawing forest. But it is no longer important. It is important that in the next apartment (up to which 3 meters, and not 30, the tension on the tap is almost the same 220.), But on, say, the sewer pipe is a real zero, or so.

And now the question is - what will happen to the neighbor, if he, sitting in the bathroom (connecting with the sewer by opening the cork) touches the crane? Guess?

Prize - prison. According to the article on the violation of the rules of electrical safety by the victim.

It is not necessary to forget that it is impossible to imitate the grounding scheme, connecting the "zero working" and "zero protective" conductor in the Euroreset, as some "crafts" practiced. Such a replacement is extremely dangerous. Not rare cases of heating "working zero" in the shield. After that, on the housing of your refrigerator, computer, etc. 220V is very firmly located.

The consequences will be approximately the same as with a neighbor, with the difference that no responsibility to bear is in addition who made such a connection. And as practice shows, this makes the owners themselves, because They consider themselves sufficient specialists not to cause electricians.

"Grounding" and "Rangery"

One of the options for "grounding" is. But not as in the case described above. The fact is that on the camshaft housing, there are zero potential on your floor, and if more precisely, the zero wire passing through this whitel, simply has contact with the shield housing by means of a bolted connection. Zero conductors with apartments located on this floor, also join the housing of the shield. Let's consider this moment in more detail. What we see, each of these ends is headed for their bolt (in practice, the truth is often found on the pair connection of these ends). That's just there and you need to connect our newly minted conductor, which will later be called "grounding".

This situation also has its own nuances. What prevents "zero" to burn at the entrance to the house. Actually, nothing. It remains only to hope that houses in the city are less than apartments, and therefore the percentage of such a problem is significantly less. But this is again Russian "Avos", which does not solve the problem.

The only correct decision, in this situation. Take a metal corner of 40x40 or 50x50, a long meter 3, to score him to the ground so that it was not stuffed for him, namely, the hole on two bayonet shovels in the depth and most of the score of our corner, but from it PV-3 (flexible , stranded), cross section of at least 6 mm. sq. Before, your distribution shield.

Ideally should consist of 3 - 4-corners, which are welded with a metal strip of the same width. The distance between the corners should be 2 m.

Just do not drill holes in the ground with a meter brown and lower the pin there. It is not right. Yes, and the efficiency of such a ground is close to zero.

But, as in any way there has its own minuses. You, of course, lucky if you live in a private house, or at least on the first floor. And what about those who live the floor at 7-8? Stock up a 30-meter wire?

So how to find a way out of the situation? I am afraid that the answer to this question will not be given even the most experienced electrical installations.

What is required for wiring around the house

To wiring around the house you will need a copper ground wire corresponding to the length, and a cross section of at least 1.5 mm. sq. And, of course, a socket with a "grounding" contact. Block, plinth, bracket - aesthetics business. The perfect option is when you make repairs. In this case, I recommend choosing a cable with three cores in double isolation, better than the IWC. One end of the wire is started under the free bolt of the distribution shield tire connected to the housing of the shield, and the second is on the "ground" contact of the socket. If you have an Uzo shield, the grounding conductor should not have a contact with N conductor anywhere on the line (otherwise it will work the RCD).

It is not necessary to forget that the "earth" does not have the right to break through, through any switches.

Today, almost every country house is equipped with electrical devices. The safety of their operation is ensured by the connection of electrical equipment installed in the accommodation with a grounding device. Competently performed protective grounding will exclude the likelihood of lesion by electric shock and prevent the failure of household appliances and complex technical devices from the effects of overvoltages if they are protected by the UZIP. The selection of the connection scheme depends on various factors. In a private house, in contrast to the multi-unit, the ground can be made independently. To understand this connection will help this instruction.

The main elements of the circuit of connecting the country house and the rules for their implementation

The grounding circuit in a country house is as follows: Electric shield - electrical shield - Ground conductor - Ground contour - Earth.

The connection begins with execution at the railway section of the grounding device in accordance with the rules defined in chapter 1.7 Pue 7th edition. The earthing is a metal structure having a large contact area with Earth. Designed to equalize the difference in potentials and reduce the potential of grounded equipment, in the event of a closure on the body or the appearance of excess voltage in the power grid. The design and depth of its installation is determined based on the resistance of the soil on the site (for example, dry sand or wet black soil).

From the grounding device performed on the site (ground), we deposit the grounding conductor, which connect to the main grounding bus using a bolted connection, clamping or welding. We select the conductor with a cross section of at least 6 mm2 for copper and 50 mm2 for steel, and it must comply with the requirements for the protective conductors specified in Table 54.2 GOST R 50571.5.54-2013, and for the TT system to have a cross section of at least 25 mm2 for copper. If the conductor is bare and laid in the ground, then its cross section must comply with the 54.1 GOST R GOST R 50571.5.54-2013 given in Table 54.1.

In the switchboard, the grounding conductor through the ground bus is connected to protective conductor laid to outlets having a grounding contact and other electrical receivers in the house. As a result, each electrical appliance is connected to the grounding system.

Dependence of the grounding circuit on the grounding circuit

If the power line column serves a re-ground, then the grounding circuit in the country house is performed using TN-C-S or TT systems. When the status of networks does not cause concerns, it should be used as a grounding device at home and connect the house in accordance with the grounding system TN-C-S. If the air line is old, or the quality of repeated grounding is doubtted, it is better to choose a system TT system and equip an individual grounding device at the railway site.

For a grounding device, first of all, natural earthing should be used - third-party conductive parts that are direct contact with the soil (water pipes, well pipes, metal and reinforced concrete structures of the country house, etc.). (see p.1.7.54, 1.7.109 Pue 7th publication).

In the absence of those, we carry out an artificial grounding device using vertical or horizontal electrodes that are swap in the ground. The selection of the entrance configuration is mainly from the required resistance and features of the local area.

The most effective in use, if on your area of \u200b\u200bthe soil is represented by a loamlock, peat, saturated with sand, waterfront clay. The standard rod length ranges from 1.5 to 3 m. Choosing the length of the vertical electrodes, we proceed from the water saturation of the accommodating rocks on the site. Outflowed soil vertical earthingers are combined with a horizontal electrode, for example, a strip, and to minimize shielding are located at a distance, a commensurate length of the pins themselves.

Dependence of the connection scheme from the type of grounding system

Grounding of residential fund objects are performed according to the following systems: TN (TN-C, TN-S, TN-C-S) or TT subsystems. The first letter in the title denotes the earthing of the power supply, the second is grounded by the open parts of electrical equipment.

Subsequent letters after N indicate the alignment in one conductor or the separation of the functions of zero working and zero protective conductors. S - zero working (N) and zero protective (re) conductors are separated. C - the functions of zero protective and zero working conductors are combined in one conductor (REN conductor).

Electrical safety is fully ensured when a decrease in the resistance of the earthing does not entail an increase in the circuit current indicators to the ground. Consider how the grounding scheme depends on the electrical network system performed on the object.

Grounding system TN-S

Figure 1. TN-S system

On objects equipped with a TN-S system, zero working and protective conductors are separated along the entire length, and in the case of a phase insulation breakdown, the emergency current is assigned to a protective re-conductor. Uzo devices and diffanttomates that respond to the appearance of current leakage through a protective zero, turn off the network with a load.

The advantage of the grounding subsystem TN-S is the reliable protection of electrical equipment and person from damage to emergency current when using power grids. Due to which this system refers to the most modern and safe.

To complete the grounding on the TN-S system, a gasket is required from the transformer substation of a separate grounding wire to its structure, which will lead to a significant increase in the cost of the project. For this reason, to ground the private sector objects, the TN-S ground subsystem is practically not used.

Grounding system TN-C. Need to transition to TN-C-S

Figure 2. TN-S system

Grounding on the TN-C system is most common for old buildings of the residential foundation. The advantage is economical and easy to perform. A significant disadvantage is the absence of a separate conductor of re, which eliminates the presence of a country house in the rosette houses and the possibility of equalizing the potentials in the bathroom.

Country buildings are supplied by air lines. Two conductor are suitable for the structure: phase L and combined Pen. You can connect ground, only if there is a three-in-room wiring in a private house, which requires the reworking of the TN-C system on TN-CS, by separating the zero working and zero protective conductor in the electrical shield (see section 1.7.132 Pue 7th edition) .

Connecting grounding on the TN-C-S system

For the grounding subsystem, TN-C-S is characterized by a union of zero working and zero protective conductors on a plot from power lines before entering the building. The grounding on this system is sufficiently simple in technical execution, due to which it is recommended for widespread use. The ability to use the need for continuous modernization, to avoid the purple of the conductor PEN, as a result of which the electrical appliances may be under dangerous potential.

Consider a circuit of connecting the ground in a country house through the TN-C-S system on the example of transition to it from the TN-C system.

Figure 3. Scheme of the main distribution board

As already noted, to obtain three-core wiring, it is necessary to produce the correct separation of the PEN conductor in the distribution panel of the house. We start with the fact that in the electrical stopper set the bus with a strong metal connection with it, and connect the combined PEN conductor to this power line to this tire. Pen bus connect with a jumper with the next installed tire re. Now the PEN bus acts as a tire of the zero working conductor N.

Figure 4. Earth connection diagram (transition from TN-C on TN-C-S)

Figure 5. TN-C-S Ground Connection Scheme

After performing the specified connections, connect the distribution panel with the earthing: from the grounding device we will start the bus REP. Thus, as a result of simple modernization, we equipped the house three separate wires (phase, zero protective and zero working).

The rules of the electrical installation devices are required to perform re-ground for re-and Ren-conductors at the insertion in electrical installations, using, first of all, natural earthing agents, the resistance of which at a voltage of 380/220 B should be no more than 30 ohms (see paragraph 1.7 .103 Pue 7th publication).

Connecting grounding on TT system

Figure 6. TT system

Another schema variant is to connect the grounding of a country house through a TT system with a deaf-free neutral of the current source. Open conductive elements of electrical equipment of such a system are connected to a grounding device that does not have electrical communications with a neutral earthing power source.

In this case, the following condition must be observed: the value of the value of the validity of the operation of the protection device (IA) and the total resistance of the grounding conductor and the earthing (RA) should not exceed 50 V (see p.1.7.59 Pue). RA IA ≤ 50 V.

To comply with this condition, "instructions on the device for protective grounding and equalizing the potentials in electrical installations" and 1.03-08 recommends performing a grounding device with a resistance of 30 ohms. This system is fairly in demand today and is applied to private, mainly mobile buildings, if it is impossible to ensure a sufficient level of electrical safety with the TN system.

Grounding on the TT system does not require separation of the combined PEN conductor. Each of the individual wires suitable to the house connect to the bus isolated from the electrical panel. And the Pen itself is a conductor, in which case, we consider zero wires (zero).

Figure 7. Connection diagram for TT system

Figure 8. Scheme of the grounding and Uzo on the TT system

As follows from the scheme, the TN-S system and TT are very similar to each other. The difference is in the complete absence of an electrical connection between the grounding device and the PEN conductor, which, in the case of the regeneration of the latter from the power supply, guarantees the absence of excess voltage on the electrical instrument housing. This is the obvious advantage of the TT system, providing a higher level of security and reliability in operation. The disadvantage of its use can be called only high cost, because to protect users with an indirect touch, the installation of additional devices of protective power off (Uzo and voltage relay) is required, which, in turn, requires the passage of approbation and the certification of the Specialist of the Energy Pressor.

Conclusion

The grounding scheme in general is a compound of its elements: electrical equipment, an introductory-camshaft, grounding conductor re, earthing.

To install a grounding device in a country house, it is necessary to deal with the features of its connection, depending on the following factors:

• method of power supply of an electrical network (air lines or cable from the transformer substation)
• the type of soil at the railway area where the ground contour is performed.
• the presence of a system of lightning protection, additional power sources or specific equipment.

After connecting the grounding yourself, you must be guided by the provisions of section 1.7 of the rules of the electrical installation device. If it is impossible to use natural earthingers, we carry out a grounding device using artificial earthing. The grounding of a private house can be performed on two systems: TN-C-S or TT. The most widely used the upgraded TN-C - TN-C-S system was obtained, due to the simplicity of its technical performance. To ensure the electrical safety of the country house through the TN-C-S system, the PEN is required to separate the conductor to zero working and zero protective conductors.

By completing the grounding contour, it is necessary to check the quality of its installation, and perform measurements of resistance for compliance with PUE standards using special devices, which may require the involvement of specialists.

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