Functional grounding .. Zahisne grounding .. Dzherela overshoot at the grounding lines. insulated neutral.. Galvanic decoupling according to life .. Separate transformer .. Electromagnetic earthing system (EMS) .. Options for functional grounding .. Reconstruction of live facilities .. Design of new facilities .. Independent functional grounding .. Head busbar grounding .. GZSH) grounding (SHFZ) .. Zone of zero potential .. Protective bus PE .. Functional bus FE.

Functional (robot) grounding will prevent the normal functioning of the electrical installation and the installation, tobto. for their work in the normal mode, not with the help of electrical safety, therefore, the only grounding system is categorically blocked.

This type of grounding can be lifted from behind grounded grounds, or it can be upgraded to a new one, depending on the nature of the owner, the substitute, or regulatory documents.

Zahisne grounding in the most part - overvoltage and conductive surges in low-current systems of automatic keruvannya, vimiruvalny, informational, or even more sensitive to the injection effective ways protection of a similar possession in the form of various overvoltages and overvoltages.

Ways to protect the informational possession from the pereshkod

1. Merezha from insulated neutral. Radical solutions described more problems from jumper codes from power grounding є stoppage of galvanic decoupling (IT - wire) with separate grounded power and electrical parts of the system, which includes the interruption of streams from power ground.
The installation of galvanic decoupling can be connected to an additional decoupling (separate) transformer, or to an additional autonomous gerel living: galvanic batteries and accumulators.

The main idea of ​​galvanic decoupling I believe in the fact that the way is used in the electric lance, as it is possible to transfer a conductive switch. Shards in such a measure do not have a galvanic connection between the earth, phase and neutral, then there are no short circuits of the strum circuit from the earth and the interception of any of the power outputs of the branch transformer is safe. Strumi coil on the ground lay microamps, which means less equal strumiv safety and not become a threat to people.
A separate transformer, moreover, has a frontal protection against impulse, lightning surges, which ensures more reliable operation of the connected equipment.
Such a rank, high superiority, electrical safety and pereskodozahisnist merezh іz insulated neutral є їх non-transverse perevagoy.
Together with Tim, zastosuvannya rozdіlovyh transformerіv іz systems monitoring _izoljatsiї (SKI) vimagaє chimalih vitrat and vinikaє legally nurturance schodo dotsіlnostі such vitrates. Tsya topic is meritorious.

2. Electromagnetic summ_snіst statkuvannya (EMZ).

In most cases, failures and faults in robotic automation systems, counting and simulation techniques, it is possible to avoid a lot of electromagnetic interference and the rules of grounding such systems:

zastosuvannya obladnannya, scho vіdpovidaє vymogam vіdpovіdnyh standards for electromagnetism (EMS);
Zastosuvannya in the lansyugs of fiderіv zhivlennya I will add a zakhista in the form of overvoltage;
Delivery of metal sheaths of cables to the summed up system of potential enhancement;
Podіl power and signal cables and correctly wired them;
The installation of signal and information cables, which allow the virobnik to act as an electromagnetic continuum;
Power and signal cables are connected to the wires, but they are connected to the strumov_dvodіv systems of protection from the bliskavka. minimum wage otherwise, for help, screening is valid up to IEC 62305-3.
The power supply of low-voltage microprocessor attachments must vibrate in the presence of an uninterrupted power supply (UPS), which can operate the filters.
Exterior stretching lines of electrical supply must be laid with a cable with a sheath, which screen, which is connected to the wild circuit zahisnogo grounding.
Z'dnannya zemlyuvachіv functional and zakhisnoy grounding with the method of zvіvnyuvannya potencialіv between them can be connected at one point on the bus SUP or GZSH - a stream of turns on the PE conductor is not to be spent on the screen of the cables.

3. Correctly grounded. Tse one of the main ones available methods changing the impulse surge and overvoltage, which can lead to a failure in the operation of a low-current microprocessor control. Proper grounding ring out verse b about more part of the power supply is reduced overvoltage and overvoltage.

4. Building potential between grounding outbuildings other appointmentsє the main mental safety of electrical safety for the personnel. In appli- cations that are recognized as robotically sensitive to equipment changes, it is obligatory to stun the system of potential surveillance. On the inner perimeter, the roztashovuvatysya koltsevy z'ednuvalniy conductor, connected with the head bus, which is grounded, is to be blamed. Kіltsevі provіdniki zіvnyuvannya potencialіv povnіnі but roztashovanі also on the dermal version. The butt of the internal contour of the system for monitoring potentials along the perimeter of the building is shown in Rice. one.

Rice. one

Functional grounding options

1. Reconstruction of working objects. In this case, behind the minds of a robotic informational possession, it is often necessary to have a low-resistance grounding device, which is more likely to be connected to the obvious grounding of the electrical installation.
Valid up to PUE 1.7.55 " We are to blame buti dorimani vimogi to the earthly ground". In other words - in the first place, you can protect the life and health of people. Obviously, the functional grounding bus (ShFZ) is due to buti connected from the back groundings to the main grounding bus (GZSH) of the main system for monitoring the potential of the electrical installation, as shown in Rice. 2.

The grounding diagram is given. allows you to secure electrical safety up to the maximum GOST R 50571-4-44-2011 (MEK 60364-4-44), as well as PUE goal. 1.7 for your mind, what is obviously not grounded at the top of the ground to PUE.
The results of reconstruction of working objects show that it is practical for all objects, which are especially used in operation for 10 and more years, there are those other shortcomings from grounding: corrosion of grounding outbuildings, impossibility of grounding to the support of the grounding device, lack of manpower due to electromagnetism.
To that before the installation of informational possession it is necessary to carry out the lining of the outbuildings of the earthing ground. Outfitting of grounding outbuildings, including: a good lookout, rozting (if necessary) of conductors that are located in the ground, as well as a complex of monitoring the parameters of grounding outbuildings.
For the results of vimiriv the responsibility of the vikonaniya vіdpovіdny obyazh robіt z vіdnovlennya parametrіv zakhisnoy grounding, which is additionally connected with the installation of functional grounding and the transition (for consumption) to the system of electricity supply TN-S or TN-C-S.

Low-resistance functional earthing device with whom it is necessary to follow the "promenade" grounding scheme, which will ensure a stable operation of the possession. At the borders of the minds, it is possible to use a collapsible, clay grounding machine.

Functional grounding may be possible to the support of grounding, which allows to support the entrepreneurship-preparation of the equipment according to the relevant standards. For example, for the purposes of computational technology and informatics, it is CH 512-78 opir grounding may be no more than 1 ohm, for highly sensitive medical equipment it is suitable up to Additional assistance from design to SNiP 2.08.02-89- Not more than 2 ohms, etc.

2. Designing new objects.

Rice. 3

When designing new objects, there is a possibility vikonati grounding attachment of repeated grounding at the entrance to the electrical installation necessary support for functional grounding , what can be beaten at once for all kinds of life.
Scheme of the grounding outbuilding repeated grounding on the necessary support of functional grounding is shown in Rice. 3.
At budіvlі the main grounding bus (GZSH) is installed, to which it is connected: the grounding conductor of the repeated grounding, PEN conductor, the conductor of the potential maintenance system, the PE bus of the live line in the TN system, the grounding attachment of the system of the bliskavkozakhistu 3-їa category 2-ї functional grounding (SHFZ).

Such a scheme in the rest of the hour, a wide width is built up when designing new objects and rebuilding high level electrical safety.

3. Nezalezhne richly functional grounding. Some grounding devices of functional grounding should be placed okremo, after the zone of inflow of natural and piece grounding devices of electrical installations.

Vikonannya functional grounding, not connected with the grounding attachment of the protective grounding, and the main system for monitoring the potential of the wake, it is necessary to look at a special vypadok ,in some way, but to live in a special place to protect people from an electric shock, which includes the possibility of a one-hour dot to the parts that are connected to the system of monitoring the potential of the electrical installation to be part of the possession, coming to an independent grounding extension.

Always have the opportunity to develop retail potential between separate grounding systems, as well as grounding systems are rebuying at the boundaries of the zone of non-zero potential. The unsafe difference of potentials can be blamed, for example, when short flicker on the body of the electrical control in the TN-S mesh (until the system is spratsovuvannya zakhistu), with spratsovuvannya bliskavkozakhistu (krokov napruga), with the influx of zvnіshnіh elektromagnіtnih irrigating and іn.
I'll take a look at the electrical safety variant of independent functional grounding і m, so that the equipment lives in a separate transformer or grounding devices are located on such a station, where there is a zone of zero potential between them. Vіdstan mіzh tsimi two zemlyuvachami is guilty buti ≥ 20 m.
More details about territorially close and independent grounding outbuildings div. at the statiThe scheme of independent functional grounding is shown on Rice. 4.

The need to build an independent functional grounding You can blame, for example, if the description of informational possession directly indicates the need for autonomous grounding (without the “functional land” the possession is not practicable). In this case, the cabinet has two grounding tires:
zahisna RE;
functional FE.
Function rail FE insulated from the shaffi case. Screens of signal (control) cables are attached to it. The FE bus is connected with a medium insulated cable (so that the contact metal structures budіvlі) with a web of not less than 1x25 mm2 from the grounding, remotely from the grounding of the zahisny (or be it any other) grounding to a distance of not less than 20 m. Respectfully, this FE tire is used by the manufacturer itself.

Yak illustration on the Rice. five a variant of an independent functional grounding was installed, not connected with a grounding outbuilding of a protective grounding.

Rice. five

Grounding of design solutions

So that we don’t blame folding For the purposes of this project, we will need to respect it when we take out technical specifications for the project. If on the object, which is being designed, it is sensitive to the influx of the overflow of the land, then it is necessary to power it up from the deputy, or at the passport picker on the date of the obladnanny, de blame buti is bound by the need for an annex of an independent grounding and it is indicated that the necessary support is required. Passports (certificates) for the possession, which are zastosovuєtsya, are added to the project and є priming design decisions at all stages of the project.
Independently functional grounding is connected to the circuit Rice. 4.

As an independent functional grounding device, the equipment is not transferred, then in any way functionally grounding can be done in one of these schemes ( Rice. 2, 3) s urahuvannyam could up to the electromagnetic summіsnostі. The insulated functional grounding bus can be installed in a closed grounding box in any way, which includes a one-hour dot to the parts, which can be supported under the threat of potential differences in case of poor insulation.
Butt such a functional earthing box is shown in Rice. 6.

Please come in in electrical installations. Come on zahistu with indirect dotik

Vazhlivim sunset, scho zabezpechuє elektrobezpeku obslugovuyuchogo elektroustanovki staff Je zahisne of grounding the vanishing abo metalevih of not live (constructive) Chastain elektroustanovok that elektroobladnannya, SSMSC not normally perebuvayut pid naprugi, ale mozhut opinitisya pid naprugi schodo zemlі in avarіynih modes (in razі poshkodzhennya іzolyatsії).

Grounded nazivaetsya navmisne elektrichne za'dnannya be-like points of a line, electrical installations or possession of a grounding outbuilding.

Grounding is subdivided into:

1. robotic grounding;
2. well grounded.

PUE give the following main designations for how to ground:

Working grounding The grounding point is called either the point of the jet-conducting parts of the electrical installation, as it is used for the safety of the electrical installation (for the safety of the installation's work in normal and emergency modes).

Robotic grounding can be done without intermediary or through special devices (opir, surge arresters, reactors, etc.)

Zahisnim zanulennyam in electrical installations with a voltage of up to 1 kV, it is called a navmisne connection of critical conductive parts from a dead-earthed neutral of a generator or a transformer in meshes triphasic struma, with a deaf-earthed visnovka single-phase strumu, from the grounded point of the dzherel in the merezh fast strumu, which is dependent on the method of electrical safety

Zero zahisniy guide- zahisny conductor in electrical installations up to 1 kV, applications for the connection of critical conductive parts to the neutral of a dead-earthed dzherel zhivlennya.

Zero working (neutral) conductor (N)- a conductor in electrical installations up to 1 kV, intended for live electrical supplies and connections from the neutral of a solidly grounded generator or transformer in the gait of a three-phase stream, with a dead-earthed wire of a single-phase stream.

Grounding extension- supply of grounding conductors and grounding conductors.

Grounding conductor- Conductor, who connects the grounding point from the grounding point.

grounding machine - a conductive part, or a combination of interconnected conductive parts, which are in electrical contact with the earth without a middle, or through an intermediate conductive middle.

Voltage at the grounding device - voltage, which is caused when the struma flows out of the grounding device into the ground between the point of introduction of the struma into the grounding device and the zone of zero potential.

Opir of the grounding outbuilding - voltage increase on the grounding extension to the strum, which drains from the grounding device into the ground.

Grounding to serve for the conversion of the hum to the body of the hum to the ground with the method of reducing the voltage on the hull above the ground to a safe value.

Zahisne grounding

The main features of zahisnogo grounding:

1. the use of an unsafe electric jet at the razor to the body of other non-current-carrying metal parts of the electrical installation, which stumbled under the pressure.

Zahisne grounding stop at 3 x phase meshes up to 1 kV with an insulated neutral in the meshes above 1 kV with any neutral mode. p align="justify"> 4.7.

4.7. Principal schemes grounding (a) at the bar from the insulated neutral and (b) at the bar from the grounded neutral.
1 - buildings of zakhish possession;
2 - grounding device of the zahisnogo grounding;
3 - earthing device of the working neutral earthing device; R3 і Ro - supports of the work ground.

The principle of dії zahisnogo grounding of foundations on the lowered voltage between the body, which was stubbed under the voltage, that earth to a safe value.

Let's explain the price on the butt line up to 1 kV from the insulated neutral.

Since the body of the electric power is not grounded and leaning in contact with the phase, then the dot of such a body of a person is equal to the dot to the phase wire. In which direction the strum, which passes through the person, can be determined by the formula (2.5).

With a small support vzuttya, sublogs and insulation of wires to the earth strum can reach unsafe values.

As well as a grounding body, then a strum, to pass through a person R pro= R n = 0, can be attributed to the offensive virase:

(4.1)

Tse viraz is taken away by the approaching path:

from the grounded body (Fig. 4.8) the jet flows into the ground through the grounding device ( I) i through people ( I h). Zagalny strum signified by viraz:

de:
R zag - scorching opir parallel to the Rі R h:

4.8. Before reading about the principle of dielectric grounding at the fence from an insulated neutral.

3 schemes in fig. 4.8

I h × R h \u003d I s R s \u003d I zag × R zag., strum stars through the body of a person will be:

vikonavshi the simplest transformations are taken away viraz (4.1).

With a small R split from R hі R tsey viraz asks:

(4.2)

de:
R- support grounding to the body, Ohm

At R= 4 ohm, R h\u003d 1000 Ohm, R\u003d 4500 Ohm, strum through the body of a person will be:

Such a strum is safe for people.

The tension of the dotik in this vipadka will also be insignificant:

U pr=I h × R h = 0.00058×1000=0.58

Chim less R- more often than not, the protection of the authorities of the zahisnogo grounding is more beautiful.

The process of exploitation of the electric power is due to the need for alternative grounding outbuildings. Zalezhno vіd prichennya mozhe vykoristovuvatisya zahisne that roboché grounding. The first one needs to ensure the safety of personnel working on electrical installations, while the other one needs to know about the normal operation of the attachments in the emergency and emergency modes. Offended grounded people are divided among themselves and cannot be vikoristan in common. In order to better understand the recognition of that principle of diy, it is necessary to take a closer look at the skin of them.

What is called zahisnym grounding

Attachment of the zahisnogo grounding is connected with the path of the navmis electric grid from the ground metal parts, until which not given electric strum and yakі can opine uneasily under the strain.

The main function of the protective grounding is the protection of people against the impact of a strum at various grounds with metal non-current-carrying parts, which are supported by stress from various causes, mainly through poor insulation.

Zahisne grounding is not a stray with a worker and repeated grounding, zero zahisnym guide. Yogo diya in the first line is straightened to a decrease to a safe value of the voltage to the crock and dot, which settle down when zamikanny on the body. It does not reach the lower potential of the grounded possession for the change in the support of the annex, which is grounded. At once, the potential of the foundation is vibrated, where the person and the grounded possession are found.

Zahisne grounding vikoristovuєtsya in the following areas:

• voltage up to 1 kV s.
• In single-phase double-wire lines snake struma, insulated from the ground, with voltage up to 1 kV.
• In double-wire nets of a fast struma, in some of them the middle point of the windings is isolated struma.
• In the chains of a variable and permanent strum, there are some modes of windings for a strum at a voltage of over 1 kV.

Bezposredniy zіtknennya from the earth or її equivalent zdіysnyuєtsya for additional grounding. The stench is divided into two main types:

1. Piece grounding machines. Zastosovyvatsya less with the method of grounding. The stench is prepared from the rіznih steel structures and not guilty to farb. For protection against corrosion, it is possible to use galvanized coating, increase the number of grounding devices, special electric protection. In some cases, as a grounding device, electrically conductive concrete can be broken.
2. Natural grounding. With the help of this method, electrically conductive parts of the network of communications are victorious in wake-up calls and disputes, which are transferred from the dot to the ground. Grounding of electrical installations is recommended natural grounding. Slid vikoristovuvaty pipe water supply and systems of scorching, construction and sporuds from metal and concrete, lath, lead sheathing of cables thinly. It is not possible to bend the pipelines, which are used to supply fuel, gas, or sumish.

What is called robotic grounding

Working groundings are respected for navmisne z'ednannya from the earth singing points, which are in electric lancers. Nasampered, tse neutral points of the generator and transformer windings. How to stop the guards, and to create a special installation as penetrating guards, dischargers, resistors, too.

The main indications of a working grounding are the elimination of faults and malfunctions, the system support in case of an emergency situation. Under the influence of yoga, there is a decrease electrical voltage in details, that part of the mechanism, which without interruption is interrupted under tension. Come in to live to eliminate the localization of electrical failures, their introduction and prevention of a distant extension.

Vіdpovіdno to the rules of safety engineering, zaboronyаєєє poddnuvati zahisne that roboche grounding. Tse zv'azano z tim scho different streams pereshkod, for example, atmospheric electrical discharges can overlap the streams that flow in single-wire lances. Tse mozhe cause damage to zvnіshnіh zv'yazkіv pristroїv i navit poshkodzhennya equipment. In addition, similar cases can generate ineffective voltage protection. In times emergency situations won't work like a worker or not functional in the fire.

Opir working grounding can be three times more than 4 ohms. Such an exchange is connected with the magnitude of the voltage, which is to blame for the nature of the earth on zero dart, in the process of passing the struma, the earth flickering through the robotic grounding is especially important when the transformer winding is flickering high voltage to the low voltage winding.