Re-grounding electrical installations

In electrical installations from a dead-earthed neutral up to 1 kV, if it is not possible to provide electrical safety only for the assistance of an automatic power supply, switch on the electrical installation of re-grounding.

Re-grounding- the price of the arrival in electrical installations up to 1 kV of a zero-voltage conductor (PE) of a lansyug to a grounding outbuilding, which may or may not be connected electrically from the grounding outbuilding of the living room.

PUE-7 p. 1.7.61

Re-earthing of electrical installations with a voltage of up to 1 kV, which maintain life along repeated lines, must be duly charged until 1.7.102-1.7.103. The term “Recommended” means that, as always, the main system of building potentials to such an adjoining structure, which is vicorated as a natural grounding device, then re-grounding is safe with natural grounding devices and electrical installation of piece grounding. Re-earthing should be grounded on redundant lines and wired in them, up to PUE-7 p. 1.7.102 and p. 1.7.103

PUE-7 p. 1.7.102

PUE-7 p. 1.7.103
1.7.103. Gale opіr roztіkannu zamlyuvachіv (among them natural) of all repeated grounding PEN-conductor skin BL at some point in time may not be more than 5, 10 and 20 ohm rated at a line voltage of 660, 380 and 220 V dzherela triphasic struma or 380, 220 and 127 dzherela single-phase strumu. When opіr roztіkannya dermal grounding from repeated grounding can be no more than 15, 30 and 60 ohm, it is suitable for the same voltage. With a pet earth support ρ > 100 Ohm⋅m, it is allowed to increase the designated norms by 0.01 ρ times, but not more than ten times.

Electrical installation of re-grounding is to be installed to reduce the voltage of the dot on critical conductive parts (metal cases of electrical equipment, etc.) afterward, reducing the damage electric jet in case of single-phase earth faults, on external conductors or third-party conductive parts.

Re-grounding is installed in order to prevent the entry into the electrical installation of the potential for building up potentials on the outer communications, which is included in the alarm to reduce the potential incurred on the grounding of the housing of the electrical receiver when shaving the zero working conductor.

If a re-grounding is installed, then when it flickers to the body of a nearby electrical receiver, the flickering stream does not pass only along the zero protection conductor, but often also on the ground through the supports of the grounding device and the re-grounding. After that, the voltage of the earth on the case of a low-voltage electrical receiver decreases, and the voltage of the neutral conductor rises. Spіvvіdnoshennia tsikh naprug proportional to spіvvіdshennya pods vіdpovіdnyh zemlyuvachіv.

At the rozpodіlnyh merezhakh mist, factories that industrial enterprises The scheme of distribution of electrical potentials is more complicated, so that in one transformer, often, live a few electrical installations, where natural grounding devices are used for re-grounding, it is practically impossible to use them. Therefore, up to PUE-7, clause 1.7.61, in the event of electrical testing of grounding equipment, re-grounding is not standardized.

PUE-7
1.7.61. When the TN system is blocked, it is recommended to re-ground the PE PEN-conductors at the introduced electrical installations, as well as in other accessible places. For re-grounding, we must first vicorate natural grounding devices. Opir grounding re-grounding is not standardized. The middle of the great and richly superficial buds have a similar function of raising the level of potential for the help of adding a zero protection conductor to the main bus, which is grounded.

Re-earthing of electrical installations with a voltage of up to 1 kV, which maintain life along repeated lines, must be duly charged until 1.7.102-1.7.103.

For standing electrical appliances of an outdoor installation, as well as for buddies or spores with a metal case near them, re-grounding the viconu is also the function of raising the potential between the accessible parts of these spores and the earth.

In the middle of the houses, the land is unavailable. The danger of damage by an electric strum in case of single-phase flickering in these minds is determined by the values ​​​​of the difference in potentials between the conductive parts that are simultaneously accessible to the dot, to reduce this, it is necessary to increase the potentials on the substations of PUE-7 p. 1.7.828 and 1.7.828.

PUE-7
1.7.82. The main system for monitoring potentials in electrical installations up to 1 kV is responsible for interconnecting such conductive parts (Fig. 1.7.7):

1. null zahisny PE-or PEN-conductor of the line of life in the TN system;
2. grounding conductor, connecting to the grounding extension of the electrical installation, in IT and TT systems;
3. grounding conductor, coming to the grounding device for re-grounding at the entrance to the working day (as a grounding conductor);
4. metal pipes of communications that come in before waking hours: hot and cold water supply, sewerage, scorching, gas supply is empty. If the gas pipeline pipeline may have an insulating insert at the entrance to the building, only that part of the pipeline, where there is an insulating insert on the side of the building, is connected to the main system;
5. metal parts of the frame budіvlі;
6. metal parts of centralized ventilation systems and air conditioning. For the presence of decentralized ventilation systems and air conditioning, metal air conditioners should be connected to the PE busbar of the fan and air conditioning shields;
7. grounding attachment of the system to the bliskvkozakhist of the 2nd and 3rd categories;
8. grounding conductor of functional (working) grounding, as well as the same daily interfacing at the entrance of the working grounding to the grounding outbuilding zahisnogo grounding;
9. metal sheathing of telecommunication cables

Conducting parts, which enter the booths of the call, must be brought closer to the point of their entry into the booths. For connection with the main system of potential monitoring, all parts of the fault are connected to the main grounding bus (div. 1.7.119-1.7.120) for an additional conductor of the potential monitoring system.

PUE-7 p. 1.7.83
1.7.83. System dodatkovogo zrіvnyannya potentsіalіv guilty z'єdnuvati mіzh him OAO All odnochasno dostupnі dotiku vіdkritі provіdnі Chastain statsіonarnogo elektroobladnannya that storonnі provіdnі Chastain, vklyuchayuchi dostupnі dotiku metalevі Chastain budіvelnih konstruktsіy budіvlі and takozh nulovі zahisnі provіdniki in sistemі TN that zahisnі provіdniki zazemlyuyuchі in IT i TT systems , including zahisnі conductors socket outlets. To increase the potential, there can be specially transferred conductors or other third-party conductor parts, so that the stench can lead to the help of 1.7.

PUE-7 p. 1.7.122
1.7.102. At the ends of the submarine, or both, the distance between them is over 200 m, and also at the introduction of the submarine to the electrical installations, in which case wicked sunset at indirect dotik stuck automatically turn on life is due to buti and re-grounding of the PEN-conductor. At the same time, in the first place, natural grounding, for example, underground parts of supports, as well as extensions, which are grounded, are recognized for lightning surges (div. ch. 2.4). The indications are repeated groundings, as a part of the grounding for the minds of the defender in the form of lightning surges is not needed. Repeated grounding of the PEN-conductor in the chains of the permanent struma is due to buti vykonanі for help piece earthing machines, yakі not guilty of the mother of metal construction with underground pipelines. Grounding conductors for repeated grounding of the PEN-conductor of the guilty mother of the earth are not less than those indicated in the table. 1.7.4.

The main task is to re-ground the zero-voltage conductor at a reduced voltage on the critical conductive parts and for a slightly shaved shave. The most unsafe thing is the loss of a zero conductor shaving with single-phase shorting to the body (ground) for a shaving. In this case, due to the time of repeated grounding, the voltage on the cases of all electrical receivers for shaving will be close to the phase pull of a three-hour hour, the shards of the same kind cannot be automatically turned on by the devices.

Dzherelami zhivlennya spozhivachіv є generators chi power transformers. chime in three-phase windings hunker down at the mirror. The hot point of the middle is called the neutral. It’s like it’s out of the middle, or through a small opir (struma transformer) it connects with the ground loop, without a middle, there’s an electric power supply, the whole is a dead-earthed neutral.

The operation of neutrals from grounding is just one of the possible modes of operation. Fallow in the minds of robots and fences in case of single-phase flickering to the ground, the necessary methods to protect people from damage by an electric streak, other modes of overvoltage in exchange for electricity:

• from ungrounded (isolated) neutral;
• from a compensated (resonantly grounded) neutral;
• from an effectively grounded neutral.

Qi modes are typical for electrical installations with a voltage of 6 kV and more. The system is protected from the insulated neutral and for voltages up to 1000 U, but from the flooring it is wide, as it is grounded. It will ensure high safety for the hour of operation of overflowing electrical installations, high-rise enterprises, deviating the ground loop for ensuring electrical safety, which is not necessary, but not effective.

Installation in a neutral conductor of compensating installations allows to change the strum of the earth fault of electrical installations higher than 1000 V. At the point of strumming on the ground, the strum for a new compensation becomes equal to zero. Dodatkovo effective spratsovuvannya zahistu vikoristovuetsya resistive earthing neutral. She's creating an active warehouse stream, to which relay reacts the middle, to live a poor line.

Efficiently earthed neutrals are fixed on power lines with a voltage of 110 kV and more.

Usі pobutovі, silskі, dachnі elektromerezhi live in the transformer substation from the dead-earthed neutral. Therefore, we can look at the features of this work and report.

The construction of the mesh from a dead-earthed neutral

Transformers and generators, which are used for these electrical installations, can have three phases of power output and one neutral (zero). The tension between the phase windings is called linear, and between the phasic and zero windings - the phase. Line voltage determines the nominal voltage of all electrical installations. It can accept standard values ​​of 220, 380 and 660 V. The line voltage in the butt lines is 380 V.

The voltage phase is less than the linear one by √3 times, which is 127, 220 and 380 V. With a linear 380 In the phase, it is 220 V.

In this rank, a 380 V wire from a grounded neutral is suitable for living triphasic sleepers on a voltage of 380 and single-phase on a voltage of 220 V. Single-phase voltages are connected between phase and zero conductors and are equally divided in phases.

The substation, where a power transformer is installed, has a grounding loop: steel and copper parts are sunk into the ground by a singing rank. Geometrically expand the grounding contour so that the stench effectively sprinkles the rosette on the ground single-phase flicker. The building of the grounding outbuilding to carry out the entire strum is assessed by a rosette support. Permissible value of the PUE regulation parameter. For transformer substations, the ground loop is not responsible for overshooting 4 ohms for a nominal voltage of 380 V.

Visnovki in the ground loop at the substation are connected to the zero busbar - the metal smug of the sub-building, to which the conductor is connected to the zero output of the transformer. Before the line, the bus is connected to the main cables that come in. Fazni lived connected to Visnovkiv switching devices: knife switches, automatic switches, contact maidans

Cable lines, which enter the substations, are wired with chotirigine cables. In electrical installations, prompted earlier, they are stunned three-core cables with an aluminum shell, as if victorious like a null conductor.

Electrical installations for the introduction of a voltage of life may be entered into a separate attachment (VRU). It's also revenge zero bus like a substation. Before her, zeros are connected, they lived quietly, who live and enter cable lines. ASU may have a re-grounding circuit, which is also connected to a zero bus.

Defender of people in the face of a strum attack at the fence with a dead-earthed neutral

Now let's move on to a non-intermediate explanation of the fact that it is now necessary to try to ground the neutral of the transformer as such.

Theoretically, for any point of electric power lines, the potential of a zero conductor would be equal to zero. The loop of re-grounding at the rescuer is to rob the equanimity even more, especially, as it is far from the life-giving substation.

Hitting people with an electric jet is possible at times:

1. Destruction of the insulation in the middle of the electrical control, if the body is under pressure;
2. Damaged insulation of wires and cables, if metal structures are exposed under tension, laying behind such stench;
3. Destruction of the insulation of the stream-conducting parts or breakdowns of the electrical power, if on the surface of the earth or sub-logs there are zones of potentials that are not safe for people to pass through (a crock of stress);
4. Pardons during repairs and operation, which lead to a bezperedny dotik to the nodes of the electric power, which are under the phase voltage.

To turn off the situations described in paragraphs 1 and 2, all cases of electrical appliances and metal structures are connected to the ground loop. At the enterprises for which, along the perimeter of the facility with electrical installations, steel smuga is laid, until all metal parts are added. So their potential is forcibly compared to the potential of the earth.

If the phase conductors are faulted on grounding in such a rank, the case should be wound with a spratsovuvannya protection, a strum of the flickering of the grounding conductors to the ground loop. Opіr schodo earth tela people, yak bumping into the emergency corps, richer, lower opіr between the earth and the corps. Therefore, through the body of a person, there is no strum, which transcends the unsafe meaning.

Another principle of zahistu is to shut down the emergency regime. Aje strum pide not just to the circuit, vn pide at the direct neutral of the transformer. Organize a short zamikannya, a strum of some kind great value. I successfully react to the new zahisna equipment: zapobіzhnik or automatic vimikach. The accident will be liquidated mayzha mittevo, it will be possible for the business to join.

Now let's move on to point 3 and zakhistu vіd naprugi croku. Up lying on the wet concrete pіdlozі a bare dart does not fit safely. The unsafe life has the potential to disperse in the form of a whistle, like a cola on the water. If the legs show up on the trails under the logs with different potentials, you can take a blow with an electrostrum.

Even though such a situation is possible in such a situation, a system of vibrating potentials is in the middle of the sublogs: a metal grid is bricked up. The grid in a few places is connected from the ground loop. In this order, the legs of the passerby are shunted with metal bars of the lattice, most of the struma of the lower one.

Classification of grounding systems for PUE

A higher grounding scheme is described for the designation TN-C. The conductor, who connects the dead-earthed neutral with the helpers, sounds confused, the shards serve to transfer the stream of gravity, so the connection between the housings of the electrical control and the ground loop. Wear a short-coded PEN.

On this versatility, there is a head shortfall of such a system. When passing through a zero stream of gravity, the PEN-conductor's pull-through establishes a difference in potentials. It is especially indicated for asymmetric ambition phases. Subsumok: potential on the electrical installation housings can be adjusted to the earth potential.

In electrical installations, especially old ones, it is theoretically possible to shave the PEN-conductor. Whenever on the new earth, there may be potential phase voltage. Tsey regime becomes a threat to the lives of people.

Blame the technical folds and the grounded buildings butovy electric appliances, connected to TN-C system.

For usunennya tsikh nedolіkіv zastosovuetsya system TN-S. It has a function of protection and commutation of a working stream divided between two zero conductors. The working strum is to carry out the zero working conductor N, and the zero wire PE is used to connect the housings with the ground loop.

Podіl PEN to N and PE are connected without a middle at the substation, where the neutral is grounded. Ale, when modernizing and reconstructing electrical installations, you can separate outbuilding. For this reason, the whole circuit can be called TN-C-S. The municipality needs the presence of a re-grounding circuit.

Measures from the isolated neutral according to the PUE are designated IT. There are no conductors for communication with the ground loop of the substation. The guard has a ground loop.

Use a TT system, which also has a solidly grounded neutral. On the view of TN systems, there is no more than a zero working explorer. Zero zahisniy to spozhivacha nadhodit vіd vlasnogo grounding outbuilding.

Electrical installations can be deaf-earthed and insulated neutral.

Deep-earthed neutral name the neutral of the transformer or the generator, I’ll come to the grounding outbuilding without a middle or through a male opir (transformer strumu and іn), and isolated- neutral, which is not delivered to the grounding outbuilding, or it is delivered through the equipment, which compensates for the strum at the fence, and other equipment, which may be a great opir. The grounding of the neutral of the generator or the transformer is called working grounding on the vіdmіnu zakhisnogo grounding.

Opir grounding outbuilding, to which neutral generators or transformers are connected, may not be more than 4 ohms for electrical installations with a voltage of 380/220V.

In electrical installations from a dead-earthed neutral, when the phase is switched on, and the grounding conductors can be safe, and automatically turn on the poshkodzhennoy dilyanka. Therefore, in electrical installations with a voltage of up to 1000V, it is necessary to connect the enclosures to the electrical installation from the grounded neutral of the installation. If the insulation is damaged, so that the electric connection of one phase with the case with a dead-earthed neutral, there will be a short flicker and a broken log will be turned on by the maximum automatic machine or by a buzzer.

Deafly grounded neutrals wink at the chotiriprovidnyh nets of the snake struma. Zero sockets of power transformers at this point are tightly grounded, and all parts that are grounded are directly grounded from a grounded zero conductor. Conducting a wire, connecting from the grounded neutral of the transformer, name zero dart. In the lancius of zero, it is not the fault of the zapobіzhniks, but the roses of the outbuildings. On redundant lines with a voltage of up to 1 kV from a dead-earthed neutral, a metal connection to the neutral of the transformer is installed behind an additional zero wire, which is laid on the quiet supports of the line itself, which are phases; Hooks and pins of phase wires and reinforcement of concrete supports are grounded with a zero wire, on the redundant lines from an insulated neutral - grounded.

On the Kіntzi of the R) Lynіj (Abo Vіdgazhennya) according to Budіvli, and I am inputs at Budіvlі, Elektro Installations of P_DLAGYUNYUNY NUNGERNY, VICTING RECEIVE NUMBER NATIONAL DROUND, FOR CHOE WORKING NASAMPERED NATNOE NATIONALS), and Torzhіzobetonnі, Vikonani for lightning surges.

For re-grounding of the zero wire, choose the size of the grounding conductors from the steel on the first, from the middle - not less than 4 mm2 and aluminum not less than 10 mm2. Opir of the grounding attachment of the skin and repeated grounding can be no more than 30 ohms for the 380/220V redundant line, and the grounding of the grounding attachment in all of the repeated grounding of the zero grounding of the skin repeating line is not more than 10 ohms. With great earth supports (more than 104 ohms per cm), it is allowed to change the values ​​​​of the supports of grounding outbuildings, with which the ground support is not guilty of changing 50 ohms.

AT installations from insulated neutral or the neutral, grounded through the great opir, is installed on the zero windings of power transformers punches, which turns on the problem of damage by a strum, which is to blame for poor insulation between the windings and the lower voltage. For the visibility of the winding line, on the side of the lower voltage of the transformer, put a penetrating protector on the phase.

Penetrating zapobіzhnik is a porcelain cartridge with two middle plates, between which mica is laid with openings. One plate of the protector is attached to the zero winding of the transformer, otherwise - to the main earthing bus. In case of poor insulation between the windings of the higher and lower voltages of the transformer, there is a transition to the potential from the windings. higher voltage on the winding of the lower one, the voltage at the zero voltage of the transformer is over 500V.

Today's life of a person, її comfort and security for all the necessary, is inextricably linked with electricity. Zavdyaki youmu people can earn for the reason that they can pour into the forces of nature with the method of taking the maximum hardness for their life. Ale to impersonal pluses, like electricity can, there is one great minus - attach that possession, which saves and vibrates electricity, a threat to the life of a person, so as not to follow the rules of their victories.

Electrical installations and their classification for security

The main factors that add to the level of insecurity for the life of people in electrical installations, no matter what type, are:

• voltage;
• neutral earthing type;
• the size of the struma that flashes to the ground;
• isolation of parts, with which the strum collapses;
• opir of the human body;
• opir land (ґruntu) near the zone of diї electric stream.

Vykhodyachi z tsikh main dzherel, at dіyuchih "Rules for the power of electrical installations" (PUE) all installations are divided into chotiri categories.

Firstly, installations with a dead-earthed neutral of transformers are put together, which work with a voltage of 220 kV and more, that with an effectively grounded neutral - installations with a voltage of 110 to 220 kV. The neutral is effectively grounded by the circuit see different supports (active, non-linear and reactive), as well as non-grounded neutral.

Before another enter the installation, de victorious insulated neutral or resonant grounding behind auxiliary resistors in arc-extinguishing reactors, which can be used in lines, the voltage of which can be from 3 to 35 kV.

The third is to represent electrical installations that vicorist a line with a dead-earthed neutral and work with a voltage of 110 to 600 V. In these installations, the jet flickering to the ground may have large values.

Safe operation of electrical installations

It is impossible to turn off the factors that threaten the health and life of people, as they work at electrical installations, because the stench may be a natural fit. But it is not only possible, but necessary, to reduce them to a minimum and to work the robot in installations as safe as possible. For all the services and maintenance of electrical installations, they are regulated in a single collection of rules and regulations: "Rules for the Power of Electrical Installations" (PUE). One of the most important factors of PUE is the protection of grounding electrical installations. The most important thing will be looked at in this article of the report.

Zahisne grounding poklikane to ensure the safety of personnel, which works and maintains the installation of the building, as well as the supply of electricity, which vikoristovuyut її in butt fittings and outbuildings. What does it take to ensure grounding? Bezpeka people in case of a sudden stop with metal parts of electrical installations, which are not strumovable, but slumped under an elastic breakdown of the insulation of the conductors, which are under the strum.

What is grounded at electrical installations?

Vymogi those rules when vikoristanny zakhisnogo zvedeni in a single document that regulates and signifies the standardization of the entire process - GOST. Grounding, which ensures the safety of the personnel and the support of the staff, is strictly enforced until Wimogami PUE and according to GOST. Zahisne grounding of electrical installations metal parts electrical installations from the earth, and for the presence of її - from a conductor who replaces the earth. It is also important that those parts of the installations are grounded, so as not to cause any other protection.

In this way, metal cases of electrical units, devices, machines, lamps, sockets and vimics are grounded, as well as cable and wire armor.

Іsnuyuchi systems of grounding electrical installations

The systems of protective grounding of electrical installations are rated on the basis of such characteristics. There are three main systems developed by the International Electrotechnical Commission (IEC): TN, IT and TT. Let's take a look at their report.

TN system and її subsystems

Systems with a dead-earthed neutral, in some metal parts of the electrical installation, are connected to the neutral for additional zero conductors, which are grounded, to be connected to the TN group. Have their own line, this group may subgroups, which are formed in the way of vikoristanny of a zero worker and a foreign conductor. So, if there are conductors in one dart along all the other lines, the subsystem is designated TN-C. This is an old radian system. Yakshcho well zahisny that robitnik zero wire confusion only at the station of the lansyug, which starts from the dzherel zhivlennya (transformer substations), the same as the TN-C-S subsystem. Well, at a glance, if there is a zero working and zahisny wire of separation along the okremih drota on the entire length of the line, this subsystem is designated TN-S. Won vvazhaetsya kraschoyu for the complete safety of the electrical installation.

IT and TT systems

The system, which is grounded in neutral, or not vikonan through resonant grounding, is designated as IT. In such a system, the metal parts of the electrical installation are grounded by earth conductors, which are connected to the grounding outbuildings.

A system with a dead-earthed neutral, in a metal part of an electrically controlled earth with a variety of outbuildings, which is not normally connected to a neutral, is indicated by TT and is reserved exclusively for mobile applications. In other situations, such a system will require a

Grounding extensions

Zgіdno z PUE, for the protection of people in the presence of unsafe voltages, the grounding circuit is installed, the installation is installed with a path of the electric circuit of the parts of the installation, and the parts of the installation are connected from the jet-conducting materials and insulated from the jet-conducting parts from the grounding. We have our own ground, earthing worker, we prepare a metal conductor, which can have good electrical conductivity and great square zіtknennya іz ґrunt. All at once - grounding and droti, which electrically connect with parts of electrical installations and ground attachments.

In the fall, in view of the stream, which is victorious in electrical installations up to 1000, a grounding scheme is installed with a dead-earthed neutral or insulated ( change strum), deaf-earthed or isolated midpoint ( constant strum). The neutral of the dzherel zhivlennya (generator or transformer) is called dead-earthed, as it is connected without a middle from the grounding extension, and that neutral is insulated, as it cannot be connected with it, but it is connected through the extension with a great support.

See grounding outbuildings

Grounding devices are divided into two types: piece and natural. The first type of grounding structures transmitting various metal objects. They can be tufts, haircuts and trumpets, which can be at least two and a half meters of that dawn (digging) at the ground. Between themselves, the stinks are filled with smugs of steel, or with metal rods - wire rod - of great diameter (not less than 8-10 mm) by the method of zvaryuvannya. Grounding conductors can be both metal and copper busbars, and also copper wires, which are connected with parts of the electric field or zvaryuvannya or bolted grounds.

Another type of grounding structures is transmitted as a grounding structure bud, vykonanyh from metal and above ground from the ground. Usі zalizobetonnі konstruktsії due to the mother of metal barriers for the arrival of conductors, which are grounded. For this type of grounding conductors, they do not interfere with conductors in any way, but they stop at piece grounding conductors.

Another type of grounding outbuilding is grounding. This type of grounding is grounded near the ground insulated parts of electrical installations from a dead-earthed neutral through a null wire. Zanulennya zabezpechuє viniknennya short circuit in case of any flickering of the phase on the body of the add-on and allow more efficient use of the zahisnoy equipment, which is switched on.

Vimogi to grounding outbuildings

Usі pristroi, scho vikoristovuyutsya for grounding, according to the standards approved by the power, budіvelni norms and PUE. Їhnє zavdannya - to ensure the safety of people, the protection of electrical installations and the modes of their operation.

At the same time, it is not allowed to have a few parts of the electrical installation with grounding conductors - the skin part is to blame for only one grounding cable, which may have a diameter of the cut not less than that of the PUE. Grounding conductors, placed in the open air, are protected from the inflow of an aggressive medium by a path of black coloration.

The technical ground of the grounding extension and re-verification of the grounding is carried out by looking around with an invisible eye of the visible part of the extension, looking at the partial roztin of the soil and vimiryuvannyam parameters of the grounding extension. Visible parts of the building look back once skin six months.

Vymogi until the end of the day of zahisnykh and grounding conductors

All grounding conductors and grounding conductors are grounded using the grounding method. Cases of electrical installations, machines and devices, the main grounding contact on the grounding circuit and supports of high-voltage lines are connected behind an additional conductor, which is grounded, bolted to the fasteners. Grounding conductors are made from steel or copper tires, as well as from copper harnesses. Also, as a grounding conductor, a grounding cable can be twisted. For these purposes, it is stagnant like a rich one, so single-core coppers allow you to build a low-energy building.

Reconstruction of the support of grounding outbuildings

In order to reconsider the support of the loose grounding outbuilding, the rules and instructions should be carried out to repair the essential support. The task of such a vimir is to sway the support of the grounding system of the struma at the designated size, so that it can pass through it to the ground - the so-called rosette struma.

Vimiryuvannya carried out in accordance with the necessary safety standards: avoidance of single-phase flickering and vikoristannya zabіv zabіv sobistі zahistu, scho include dielectric mittens and boots, as well as insulating tool.

Obladnannya that zavob for vimiryuvannya grounding support

The main attachment, which vibrates the support of the strums, which are roztkayutsya, є vimiryuvach grounding ІС-10. Tsej prilad pratsyuє in five ranges of vimіryuvannya, which explains yogo wide zastosuvannya. The minimum range is 0.01 to 9.99 ohm, then the range is 0.1-99.9 ohm, 1-999 ohm, 0.01-9.99 kOhm. The maximum opir, which is determined by this accessory, is set to a range of 1 to 999 mOhm. In addition to an attachment for vicory, there are wine strums and potential electrodes.

It should be noted that the earthing scheme is to be grounded according to strict rules - good conductors of the attachment, in the first line, to the current and potential electrodes, then to the attachment and in the rest to the grounding.

Methods for rechecking grounding

The value of the support of the stream, which is being expanded, for various grounding outbuildings is not the same and lie in the face of impersonal factors, such as the type of electrical installation, the ground in the installation site of the installation, as well as the vikorist type of such an outbuilding.

There are two ways to overcome the technique, which is in the rules, which is good for ІС-10 when vimiryuvann them the grounding support. I’ll build it as an opir, the passport has more than 5 ohms, there is a three-wire circuit. If the value is less than the value - the victorious scheme is chosen.

The deep-earthed neutral is recognized for protection against people being attacked by an electric jet. Have a different vindication emergency situations vіdbuvaєtsya vіvіvnyuvannya potencialіv, dotik to the surface of the body of possession will be safe. Shards simultaneously increase the strength of the strum, swiftly spratsyu installations at the lancers' attachments to the shack.

Poster for electrical safety "Installations with a solidly grounded neutral"

For the correct implementation of such a mechanism in practice, it is necessary to know and establish the normative legislation in the electric safety system. Stinks at the "Rules for the Arrangement of Electrical Installations" (PUE, given the name "Rules"), as approved by the Ministry of Energy of Russia at the order of 08. 07. 2002. Ninі actual є soma version of this document.

Mechanism dії

According to the Rules of this term, it is necessary to name the electrical neutrals of the generator (transformer) with the grounding attachment. For example, a three-way line is laid from the dzherel of life to the living house. Neutral through the shafu introduction is rozpodіlyaєtsya on the shields. Grounding circuits are connected to it. In tsikh lancers, the installation of fusible zapobіzhnikіv, another outbuilding, building damage to the integrity of the lancers is unacceptable.

Working zero is the last conductor. Between them and the third wire, the voltage of the phase, which is victorious, is blamed right machines, micro-furnaces and other possessions.

An example of an emergency situation. Under the influx of vibrations in the middle of the equipment, the phase wire was fixed in the regular place, becoming a dot to the metal case. Vinikne short zamikannya, sharply increase the strength of the struma. Automatic Wimicach or the fuse insert will lose its function, life will be disabled.

Opir R0 will be a smaller, lower path for the passage of the strum through the body of a person, which violently torn to the phase dart, which includes the strum attack (smaller below). In this scheme of representations, the option of grounding the neutral of the generator.

Scheme of a dead-earthed neutral

In order for such a scheme to work quickly and effectively, it is necessary to reach the provisions of the rules of the Rules. Vidpovidno before them, it is the fault of studyuvatisya akіsna is protected by the merezha.

Vimogi PUE

Necessary information is available at the branch 1.7 of the Rules. It is appointed there electrical installations up to one thousand volts. Let’s take a closer look at the butt line with a voltage of 220 V.

Here vikoristovuetsya single-phase jerelo struma. The grounding worker will come to one of the electrical installations of his outbuilding for the assistance of a special conductor. In order to speed up the passage of the strum and reduce windage, choose a place near the generating power (transformer).

Obov'yazkovo treba vrakhovuvati taka obezhennya. As soon as the foundation is grounded, then to the metal reinforcement in the concrete base, the connection is made at least at two points.

A similar number of arrivals can be cast to metal frames, installed at the bottom of the earth. Just like that, the grounding system is practicable and efficient enough to do it right.

As a dzherelom of life, I will add transformers, roztashovani on different surfaces of budіvl, pіd'єdnannya to neutral vikonuєtsya for the help of a good conductor. Yoga is connected dodatkovo to the metal frame of life.

When rozrahunku elektrichnyh parametrіv obov'yazkovo vіdpovіdny opіr.

Grounding connection is allowed to the metal frame

In the first and other options, the lances include melting inserts and other elements that destroy the integrity of the building. Survive the additional entrances, which change the vipadkovym or navmisnym ushkodzhennyam іz zastosuvannyam mekhanіchnyh vplivіv.

Other exchanges, assigned to the Rules:

1. What is next for the PEN tire (global null conductors, working and zahisniy) cost a strum transformer, then the conductor of the grounding conductor is fixed directly behind the cis addition, to neutral.
2. Electric opir I will add grounding in single-phase mesh 220V is limited to a maximum value of 4 ohms (clause 1.7.104 of the Rules). Vignatkom є especially the power of the earth, create a high opir (pet value, over 100 ohms per 1 m.).
3. Yakshcho є repeat lines power lines, then double grounding devices are installed on the entrance and end parts. Tse allow control system practice effectively. But such a rule should be stopped only once, if there is no need in the installation of a larger number of outbuildings, the buildings should be put on the overhead voltage in the measure when the sparks strike.
4. Sob not to have mercy, it is required to vikoristovuvat standards how to minimally admissible sizes that materials of conductors, which are used for grounding systems (repeated type), laying near the ground. So, for example, if a small piece of black steel is stagnant, the thickness of the wall is to become 4 mm or larger. The roof area of ​​the transverse section for grounding conductors, which is connected to the head busbar, is regulated (clause 1.7.117 of the Rules):
   

• 75 mm 2
• 16 mm2 - aluminium;
• 10 mm2 - copper.

1. The automatic machine, which is installed for the protection of the TN circuit, is guilty of mother swidcode for a short circuit of at least 0.4 seconds at a voltage of 220 V.

Yakshcho vivchiti іnshі see the line, you can z'yasuvati, scho rated voltage, permits the electrical grounding support is to blame but below. Such a help is reasonable, even a head one is a good security equal. With less support in case of an accident on a grounded case, a relatively small potential is established, the system will perform its function effectively.

Similar mirkuvannya can vikoristovuvat and schodo work zahisnih outbuildings. As if the guilt of the discharge, then the measure of the guilty will be made up of the original change. When the pressure is increased, the pressure is reduced and the low working electric opir help to ground suvorishe. Nadmirne opir tsgogo lantsyug zdatne to reduce the amplitude of kolivanie in merezhі, the automatic machines cannot manage to finish the shvidko, but zovsim not to turn on the livelihood.

Automatically select from the improved parameters in the measure

Now varto go to the 220 V by-button line and point 7.1.36. Rules. It was indicated to the new one that it was necessary to lay a line from the overhead shields to the outbuildings of the trio with wires (one phase, zero robot and shut it down). Remaining - ce i є dead-earthed neutral. Tim once in a while to conduct an experiment and look at the water sockets in the apartment, then a lot of people remember there the presence of such a contact.

On the right, in the fact that the old standards, for which a lot of votchisnyanyh budіvel, razrakhovanі on visibly small strain. Ninі stink significantly matured. Equipped with air conditioners three-room apartment may be on the verge of vikoristannya in peak demand up to 6-7 kW. Close to 3 kW saves the oven, 1.5-2 kW - cooking panel.

For an effective zakhist for such minds, grounding is necessary. New yakіsnih booths it is mounted as standard. In old apartments, respected masters are installing yoga for the hour of vikonanny capital repairs. With the specified parameters of the conduction, the standards of the Rules for conductors made from various metals (clause 7.1.45) shall be established.

Pluses and minuses of schemes

It is important to understand the description of the circuit diagram so that it is possible to understand how it will function effectively when the nominal voltage is equal between the phase and neutral. Z її dopomogoyu bezpechuє shvidka spratsyuvannya typical outbuildings zahistu vіd revantazhen. With a short faucet, the electromagnet coliation is reduced, which can become the cause of additional accidents and ruins.

Otherwise, come in to zahistu

In order to protect the damage with a strum, zastosovuyut no less grounded neutral. Parts of possession, conductors are covered with additional balls of insulation. Special shells do not allow dotik directly to them. Vicorist low voltage, not zdatni zapodiyati shkodi. Industrial installations are fenced with special bar'er, placed behind a zone of free access for third-party systems.

We will use vicorist to develop a wide range of complex methods, you can look at them on the butt of a prying machine:

• the body and metal frame are connected to the third wire, connected through the socket to the grounded neutral.
• insulated with a farbi ball the surface does not conduct struma.
• On the little one below you can see that she herself pralna machine not equipped with a special rank. At the cord of life there is a conductor, which, when turned on to the outlet, connects with the ground line. Have a different vindication short hum spratsyuyut zahisnі outbuildings and turn on the voltage supply.

Proper connection to the laundry machine

• in order to change the damage caused by electricity, handles are made of plastic, the upper parts of the structure, on which bare metal elements can be seen.

Video about grounding systems

This video has a description of the grounding systems installed by the Rules for the construction of electrical installations.

As soon as the rule of dorimuvatisya is created, then a system has been created to zahistu bude vikonuvat its functions effectively and finish it quickly.