Grounding des. Grounding of diesel generators. Compensation of the capacitive current to earth is necessary at the values ​​of this current under normal conditions

Bought a 1 phase generator. The neutral is separated from the earth. The house has a 3-phase input. On the input panel in the house, zero and earth are on the same block, that is, they are connected.
I plan to connect the generator through a reversible 4-pole switch, i.e. phases and zero in the gap. What about generator grounding? Is it possible to throw houses on the ground?

It is not possible, but by default, the generator frame must be connected to the house charger with a power cable. In general, there are also worse, budget options allowed by the norms and common sense, and better options when the generator frame is not connected to the house's memory. In any case, the generator frame must be grounded.

In addition to the fact that in 1-phase generators there is no zero by default, any power output should be groundedit is forbidden!

GOST R 50783-95 said:

ELECTRIC UNITS AND MOBILE POWER PLANTS WITH INTERNAL COMBUSTION ENGINES
10 SAFETY REQUIREMENTS

10.3 Wiring diagram for mobile generating sets and AC power plants three-phase current must have an isolated neutral.It is not allowed to use any devices that create an electrical connection of phase and (or) zero wires or neutral with housing or neutral conductors or neutral with housing or earth directly or through an artificial zero point, except for devices for suppressing radio interference.

10.4 In mobile generating sets and power plants with a capacity of 1 kW and above with a rated voltage of 115 V and abovethere must be a device for permanent insulation monitoring, which allows you to measure (estimate) the insulation resistance relative to the body (ground) of the conductive parts of the electrical unit and power plant that are energized. For operation in conjunction with the local electrical network, mobile generating sets and power plants must have an automatic shutdown device. These devices should be monitored for proper operation.

It is not allowed to use permanent insulation monitoring devices operating on the principle of voltage asymmetry.

Unfortunately, only some manufacturers of autonomous power supply sources indicate this.

ENERGO generator instruction said:

This manual is valid for petrol generating sets of the company:
SAWAFUJI ELECTRIC COMPANY (Japan)

EA 6500 (SH 6500 EX)

HAZARD WARNINGS
Do not connect to the local power supply without a disconnector installed by a qualified electrician. …

BASIC ELECTRICAL SAFETY RULES
― to prevent the operation of the electric unit in case of a short circuit to the case ...

When operating the unit IT IS FORBIDDEN:
ground the neutral or connect it to the body;

Illiterate in electrical safety owners of autonomous power supply sources, who themselves do not comply with and advise others not to comply with these standards, argue their case by stating that portable and smoke-type generators and other autonomous sources of power supply of 220/380 volts when they are supplied with power at home, this does not apply, since they constantly standing in one place.

It’s necessary to think of such an assertion, like because the generator is called portable, then it is worn during operation or because the generator constantly stands in one place, the electricity generated by it becomes safe!

Also, sellers-installers who are illiterate in electrical safety, including some certified service centers connecting generators, or just hacks, tightly connect one of the generator outputs to the neutral wire of the mains, since without switching the neutral wire simpler circuit, installation, cheaper and easier to find components, as well as to fool the clumsy flame control circuit of some boilers, arguing that they say they are doing it right because they did it many times and how it works, which is comparable to an illiterate statement that it is enough to do wiring without VDT , grounding, since in millions of houses there is no VDT, 2 wires and millions have not been killed, so it is not necessary to install differential protection and use wiring with PE.

Even if an autonomous power source is foolishly connected to a power system with a TN grounding type, then it is impossible to somehow connect one of the power outputs of an autonomous power source to the neutral wire of the mains!

GOST R 50571-4-44-2011 (IEC 60364-4-44:2007) said:

SAFETY REQUIREMENTS. PROTECTION AGAINST VOLTAGE DEVIATIONS AND ELECTROMAGNETIC INTERFERENCE.

444.4.7 Switching power supplies
In TN systems, switching power from one source to another sourcemust be carried out using a switching device that simultaneously switches the line conductors and the neutral conductor, if present in the electrical installation (see figures 44. R9A, 44. R9B, 44. R9C).

Non-compliance with the above-mentioned electrical safety standards is every day an increasing danger for those who violate these standards, animals, as well as for installers repairing the supply network, since every day there are more autonomous power supply sources and their power for the population illiterate in electrical safety. !

This is not to mention that non-compliance with the above-mentioned standards increases the likelihood of a generator failure, up to the impossibility of repair, for example, due to a minor leak in the generator insulation, even if the generator is not working, since the machine does not protect against such a malfunction, but when such a dangerous connection will not work!

It should also be borne in mind if a circuit is being made that during a power failure in the network, only part of the wiring at home is powered from an autonomous source of electricity 220/380 volts, and the rest of the wiring remains connected to the mains, which is better not to do, then the installation of lines in the shield and in the wiring powered by an independent source of electricity and connected to the mains, which are located together, must be designed for 660 volts! This also applies to lines located nearby, fed from different autonomous power supplies 220/380 volts!

What power to take the generator? How to install it? Where to connect it? What can be connected to an electric generator?... In this article, we have collected the 10 most popular questions and tried to answer them in a simple, understandable language. We hope that the answers to them will help you in choosing an electric generator. Here are 10 basic questions about the generator and the answers to them.

1. How powerful should I get a generator?

The expected power of the generator depends on the amount of electrical loads that you want to use at the same time. Power is measured in Watts (W). First, add up all the loads that you are going to use at the same time. Then, as a precautionary measure, find out which household electrical appliances in your home may have high inrush currents (refrigerators, air conditioners, pumps) Add it all to the total.

The fact is that some appliances, such as air conditioners, refrigerators, pumps, tend to use a lot of energy when starting (starting up) - usually 2-3 times more than they use during operation.

You need to make sure that your generator can handle relatively large appliances starting normally, make sure they don't overload the system when starting all the appliances at the same time.

The generator has two units that determine its power: nominal and maximum. The generators are provided with overload protection, which can work at the time of the simultaneous start of electrical appliances. Therefore, you should purchase a generator with some power reserve.

2. What loads should be powered by the generator?

Based on our own many years of experience installing and maintaining generators, we recommend that you provide the main consumers, which include:

1) Heating and all devices related to providing heat (boiler, pumps, etc.).

2) A couple of lighting circuits.

4) Refrigerator.

5) Microwave.

6) Garage doors.

7) Downhole pump.

8) Alarm.

If the power of the backup generator is sufficient, then secondary loads can also be connected: drainage pump, ventilation...

Equipment manufacturers indicate the power of the devices on the devices themselves or in the product passport. Also on many sites you can find an online calculator that will help you choose the power of the generator.

4. Do I need to hire an electrician to connect the generator to electrical network Houses?

Most safe way connecting the generator to the electrical network at home is to use additional device- AVR - automatic switching on of the reserve. The ATS is connected to the mains after the meter, and the generator is connected directly to the automation. When you start the generator, it disconnects the house from the city power grid and powers only those electrical appliances that you have allocated. Thus, the generator will not be overloaded.

If you are an amateur electrician, you have some knowledge of electricity but no experience in installing equipment of this type, it is best to contact a specialist to install the equipment. After all, the reliability of the entire power system of your home largely depends on how competently and efficiently the installation and commissioning of equipment is carried out.

5. Can't I just plug the generator into an outlet?

No and no again! We have already seen many times what this can lead to. This is very dangerous for a number of reasons. For example, if someone forgets to turn off the main circuit breaker, then the generator can send power supply to the external network with all the ensuing consequences, if at that time repair work is underway on the line ...

Key points to know for correct connection generators are discussed in this article:

6. What is the difference between standby generator and emergency generator?

The backup generator is installed permanently and is designed to supply most electrical appliances. The emergency generator is a small, portable unit that can be taken outside the premises and connected to the ATS. Or it can be connected to electrical loads via extension cords.

7. If it's raining or snowing outside, can I put the generator in the garage and run it there as long as the door is left open?

No. Never run a generator inside a home, inside a garage, under a shed, on a porch, inside a porch, or near an open window. Even with the garage open, carbon monoxide (CO) from generator exhaust can cause poisoning or, in the worst case, death.

8. What other safety tips should I keep in mind?

If the generator is installed permanently, use smoke detectors and carbon monoxide detectors, at least when using the generator. The generator should be located at least three meters from the house to minimize the risks of poisoning carbon monoxide(CO). Never fill the generator with fuel while it is hot.

9. Generators are loud enough. What can be done about it?

Unfortunately there aren't many options. Use generators inverter type, where the speed depends on the load. You can also purchase generators in a soundproof casing. In addition, you can purchase a special soundproof all-weather container in which the generator is placed.

Some craftsmen are experimenting with additional mufflers from motorcycles and ATVs. This can be done if you have the necessary skills. But be aware that in most cases this will void the generator warranty.

The easiest way to reduce noise from a mini power plant is to reduce the electrical load.

10. Do I need to ground the generator?

Follow the instructions in the user manual. If the manual requires the generator to be grounded, do so. The easiest way is to connect a 4-6 mm wire to the ground terminal on the generator. Connect the wire to a copper or iron 1.5 m rod that can be driven into the soil next to the generator.

As an alternative to the ground rod, you can connect the ground wire from the generator to inside the house at the main switchboard.

STEN company: installation of ground loops according to all the rules, full complex electrical measurements

Many people have heard about such a necessary measure of electrical safety as grounding, and in general they imagine that grounding is intentional. electrical connection any point of the network or electrical equipment with a grounding device. What is grounding in relation to diesel power plants?

With regard to electrical safety measures, widely used diesel generators and their associated equipment (control panel, load switching panel, ATS, switchgear, etc.), which are part of a diesel power plant, refer to electrical installations with voltage up to 1 kV, operating in networks with isolated and dead-earthed neutral. Accordingly, neutral diesel generator can be either isolated or connected to a grounding device. The first option is more common when using a diesel power plant as an autonomous power source, and the second - when reserving a centralized network with a solidly grounded neutral. In the second case, without fail, the neutral of the diesel generator must be deafly grounded, and the grounding system of the power plant must correspond to the grounding system of the existing electrical installation in this network. Let's list these systems.

IT is a system with an isolated power supply neutral and grounding of exposed conductive parts of electrical installations.

TT - system with solidly grounded neutral of the power source and grounding of electrical installations using an independent grounding device. For electrical installations in networks with a solidly grounded neutral, several TN grounding systems are used, in which exposed conductive parts are connected to a solidly grounded neutral of the power source with neutral protective conductors.

IN TN-C system in one neutral conductor, along its entire length, the protective and working neutral conductors are combined. In the TN-S system, the protective and working neutral conductors are separated along its entire length.

In the TN-C-S system, the zero protective and zero working conductors are first combined in one, and then divided into independent ones.

It is clear that in any case, when operating diesel power plants, a grounding device is indispensable.

The figure shows the application of the TN-S earthing system for a power plant used as a backup power source and operating in conjunction with a four-pole ATS.

We must not forget that the grounding of a diesel power plant is a measure used for the safety of people, and therefore, carried out in strict accordance with the current rules (PUE-7). It is carried out using a grounding device, consisting of grounding conductors and grounding conductors.

A grounding conductor is a conductor (electrode) or a set of conductors that have electrical contact with the ground, and a grounding conductor is a conductor for connecting a grounding point to a ground electrode.

The grounding conductor is connected to the grounding conductor by welding, and its connection to the power plant by bolting. As natural grounding can be applied reinforced concrete foundations buildings, metal pipelines, etc. However, by various reasons, in In this case, it is not always possible to achieve a sufficiently low resistance of the grounding device. In addition, the use of pipelines for explosive and combustible substances is unacceptable. If the diesel generator is located in a building with a ground loop, it is allowed to ground it through this loop. The best solution for a power plant is its own ground loop. According to PUE-7, in networks with a solidly grounded neutral with a linear voltage of 380V, the resistance of the grounding device should be no more than 4 ohms. The lower the resistance of the ground circuit, the better, since in this case the breakdown current to the ground and the speed of operation of the protection relay are greater. It depends mainly on the surface area of ​​the electrodes, the depth of their grounding, resistivity soil. Moreover, the latter is the main factor determining the grounding resistance. In turn, soil resistivity is determined by temperature, moisture content, electrolytes and electrically conductive minerals, and therefore varies depending on the place and season. The figure shows a standard ground loop arrangement, where 3,4,5 are options for vertical grounding conductors made of angle steel, pipe and round steel, respectively, 2 is a horizontal grounding conductor made of strip steel that connects all vertical earthing switches and to which a ground conductor 6 made of round steel is welded. To him with bolted connection 1, a grounding conductor made of copper wire 8 is connected, which is connected at the other end to the main grounding bus (GZSH) in the input switchgear (ASU).

For effective grounding of the power plant and ensuring the safety of personnel, it is necessary to fulfill all the requirements for the elements of the grounding device, exact calculation its maximum allowable resistance. Such a calculation is possible only after measuring the soil resistivity using the device directly at the work site and must take into account seasonal factors. The measured resistance of the correct grounding device should not exceed the calculated norm. Later, during operation, different time year, the necessary checks and measurements must be carried out to control the condition of the power plant's grounding.

It is obvious that these works must be carried out by qualified specialists with the help of an electrical laboratory.

Our company has extensive experience in the installation of ground loops for power plants. The work is carried out in full compliance with the PUE and PTEEP, with the issuance of a passport for the ground loop. The STEN electrical laboratory performs the whole range of necessary measurements and checks, such as: checking the condition of the elements of the grounding device; checking the presence of a circuit and measuring the contact resistance between the grounding conductor, grounding conductors and grounded elements; earth resistivity measurement; measurement of resistance of any grounding device; device check protective shutdown; measurement of the loop current "phase - zero", etc. All results are recorded in the protocol.

To place an order for the performance of work, to find out their cost, you just need to contact the manager using the phone or e-mail.

Generally speaking, it can be noted that the great and terrible power of electricity has long been described, calculated, listed in thick tables. Normative base, which determines the path of sinusoidal electrical signals with a frequency of 50 Hz, can plunge any neophyte into horror with its volume. And despite this, any frequenter of technical forums has long known that there is no more scandalous issue than grounding. The mass of contradictory opinions in fact does little to establish the truth. Moreover, this issue is actually serious, and requires closer consideration.

Basic concepts

If we omit the introduction of the "electrician's bible" (PUE), then in order to understand the grounding technology, you need to refer (to begin with) to Chapter 1.7, which is called "Grounding and Electrical Safety Protective Measures".

In clause 1.7.2. says:

Electrical installations in relation to electrical safety measures are divided into:

electrical installations above 1 kV in networks with an effectively grounded neutral (with high earth fault currents), ;
electrical installations above 1 kV in networks with isolated neutral (with low earth fault currents);
electrical installations up to 1 kV with dead-earthed neutral;
electrical installations up to 1 kV with isolated neutral.

In the vast majority of residential and office buildings in Russia, a dead-earthed neutral is used. Clause 1.7.4. reads:

A dead-earthed neutral is a transformer or generator neutral connected to a grounding device directly or through low resistance (for example, through current transformers).

The term is not entirely clear at first glance - a neutral and a grounding device are not found at every step in the popular science press. Therefore, below all incomprehensible places will be gradually explained.

When describing other options for electrical installations, it is easiest to do as in one of the Rolls-Royce instructions - "if the car breaks down, your driver probably knows what to do." At the very least, schemes other than dead-earthed neutral are slightly more common in the construction of home networks than Rolls-Royces on the streets.

Let's introduce a few terms - so it will be possible to speak at least one language. Perhaps the points will seem "taken out of context". But PUE is not fiction, and such separate use should be quite justified - as the application of individual articles of the Criminal Code. However, the original PUE is quite available both in bookstores and online - you can always turn to the original source.

1.7.6. The grounding of any part of an electrical installation or other installation is the intentional electrical connection of this part with a grounding device.
1.7.7. Protective grounding is the grounding of parts of an electrical installation in order to ensure electrical safety.
1.7.8. Working grounding is the grounding of any point of the current-carrying parts of the electrical installation, which is necessary to ensure the operation of the electrical installation.
1.7.9. Zeroing in electrical installations with voltages up to 1 kV is the deliberate connection of parts of an electrical installation that are not normally energized with a dead-earthed neutral of a generator or transformer in three-phase current networks, with a dead-earthed source output single-phase current, with a dead-earthed midpoint of the source in networks direct current.
1.7.12. A grounding conductor is a conductor (electrode) or a set of metal-connected conductors (electrodes) that are in contact with the ground.
1.7.16. A grounding conductor is a conductor connecting the grounded parts to the ground electrode.
1.7.17. A protective conductor (PE) in electrical installations is a conductor used to protect against damage to people and animals. electric shock. In electrical installations up to 1 kV, a protective conductor connected to a dead-earthed neutral of a generator or transformer is called a neutral protective conductor.
1.7.18. Zero working conductor (N) in electrical installations up to 1 kV is a conductor used to power electrical receivers, connected to a solidly grounded neutral of a generator or transformer in three-phase current networks, with a solidly grounded output of a single-phase current source, with a solidly grounded source point in three-wire DC networks. A combined zero protective and zero working conductor (PEN) in electrical installations up to 1 kV is a conductor that combines the functions of a zero protective and zero working conductor. In electrical installations up to 1 kV with a solidly grounded neutral, the zero working conductor can perform the functions of a zero protective conductor.

Rice. 4.5. difference protective earth and protective "zero"

So, a simple conclusion follows directly from the terms of the PUE. The differences between "ground" and "zero" are very small... At first glance (how many copies are broken at this point). At the very least, they must be combined (or even can be performed "in one bottle"). The only question is where and how it was done.

In passing, we note paragraph 1.7.33.

Grounding or grounding of electrical installations should be carried out:

at a voltage of 380 V and above alternating current and 440 V and above direct current - in all electrical installations (see also 1.7.44 and 1.7.48);
at rated voltages above 42 V, but below 380 V AC and above 110 V, but below 440 V DC - only in rooms with increased danger, especially dangerous and in outdoor installations.

In other words, it is not necessary to ground or neutralize a device connected to 220 volts AC. And there is nothing particularly surprising in this - there is really no third wire in ordinary Soviet sockets. We can say that the Eurostandard (or a new edition of the PUE close to it) that comes into practice in practice is better, more reliable, and safer. But according to the old PUE, we lived in our country for decades ... And what is especially important, houses were built by entire cities.

However, when it comes to grounding, it's not just about supply voltage. A good illustration of this is VSN 59-88 (Goskomarchitectura) "Electrical equipment of residential and public buildings. Design standards" Excerpt from chapter 15. Grounding (zeroing) and protective safety measures:

15.4. For grounding (zeroing) metal cases household air conditioners, stationary and portable class I household appliances (not having double or reinforced insulation), household electrical appliances with a power of over. 1.3 kW, cases of three-phase and single-phase electric stoves, digesters and other thermal equipment, as well as metal non-current-carrying parts technological equipment premises with wet processes, a separate conductor with a cross section equal to the phase should be used, laid from the shield or shield to which this electrical receiver is connected, and in the lines supplying medical equipment - from the ASU or main switchboard of the building. This conductor is connected to the neutral conductor of the mains. The use of a working neutral conductor for this purpose is prohibited.

This creates a normative paradox. One of the results visible at the household level was the acquisition of washing machines"Vyatka-automatic" skein of single-core aluminum wire with the requirement to perform grounding (by the hands of a certified specialist).

And one more interesting point: 1.7.39. In electrical installations up to 1 kV with a solidly grounded neutral or a solidly grounded output of a single-phase current source, as well as with a solidly grounded midpoint in three-wire DC networks, zeroing must be performed. The use in such electrical installations of grounding the housings of electrical receivers without their grounding is not allowed.

In practice, this means - if you want to "ground" - first "zanuli". By the way, this is directly related to the famous issue of "batteries" - which, for a completely incomprehensible reason, is mistakenly considered better than zeroing(grounding).

Grounding parameters

The next aspect to consider is numerical parameters grounding. Since physically it is nothing more than a conductor (or a set of conductors), its main characteristic will be resistance.

1.7.62. The resistance of the grounding device, to which the neutrals of generators or transformers or the outputs of a single-phase current source are connected, at any time of the year should be no more than 2, 4 and 8 ohms, respectively, at line voltages of 660, 380 and 220 V of a three-phase current source or 380, 220 and 127 In a single-phase current source. This resistance must be provided taking into account the use of natural grounding conductors, as well as grounding conductors for repeated grounding of the zero wire of overhead lines up to 1 kV with the number of outgoing lines of at least two. In this case, the resistance of the ground electrode located in the immediate vicinity of the neutral of the generator or transformer or the output of a single-phase current source should be no more than: 15, 30 and 60 Ohms, respectively, at line voltages of 660, 380 and 220 V of a three-phase current source or 380, 220 and 127 In a single-phase current source.

For lower voltage, more resistance is acceptable. This is quite understandable - the first purpose of grounding is to ensure human safety in the classic case of a "phase" hitting the electrical installation case. The lower the resistance, the smaller part of the potential may be "on the case" in the event of an accident. Therefore, the risk for higher voltages must be reduced first.

In addition, it must be taken into account that grounding also serves for the normal operation of the fuses. To do this, it is necessary that the line during the breakdown "to the body" significantly change its properties (primarily resistance), otherwise the operation will not occur. The greater the power of the electrical installation (and the consumed voltage), the lower its operating resistance, and, accordingly, the ground resistance should be lower (otherwise, in case of an accident, the fuses will not work due to a slight change in the total resistance of the circuit).

The next normalized parameter is the cross section of the conductors.

1.7.76. Grounding and zero protective conductors in electrical installations up to 1 kV must have dimensions not less than those given in Table. 1.7.1 (see also 1.7.96 and 1.7.104) .

It is not advisable to give the entire table, an excerpt is enough:

For bare copper, the minimum cross section is 4 square meters. mm, for aluminum - 6 sq. mm. For isolated, respectively, 1.5 square meters. mm and 2.5 sq. mm. If grounding conductors go in the same cable with power wiring, their cross section can be 1 sq. mm for copper, and 2.5 sq. mm for aluminium.

Grounding in a residential building

In a normal "household" situation, power grid users (i.e. residents) deal only with the Group network (7.1.12 PUE. Group network - a network from shields and distribution points to lamps, socket outlets and other electrical receivers). Although in old houses where shields are installed directly in apartments, they have to deal with part of the Distribution Network (7.1.11 PUE. Distribution Network - a network from VU, ASU, Main Switchboard to distribution points and shields). It is desirable to understand this well, because often "zero" and "ground" differ only in the place of connection with the main communications.

From this, the first grounding rule is formulated in the PUE:

7.1.36. In all buildings, group network lines laid from group, floor and apartment shields to general lighting fixtures, socket outlets and stationary electrical receivers must be three-wire (phase - L, zero working - N and zero protective - PE conductors). It is not allowed to combine zero working and zero protective conductors of various group lines. Zero working and zero protective conductors are not allowed to be connected on shields under a common terminal.

Those. 3 (three) wires must be laid from the floor, apartment or group shield, one of which is a protective zero (not earth at all). Which, however, does not prevent at all from using it for grounding a computer, a cable screen, or a "tail" of lightning protection. Everything seems to be simple, and it is not entirely clear why go into such complexity.

You can look at your home outlet ... And with a probability of about 80% you will not see a third contact there. What is the difference between zero working and zero protective conductors? In the shield, they are connected on the same bus (albeit not at one point). What will happen if we use a working zero as a protective one in this situation?

It is difficult to assume that a negligent electrician will confuse the phase and zero in the shield. Although this constantly scares users, it is impossible to make a mistake in any state (although there are unique cases). However, the "working zero" goes through numerous strobes, probably passes through several junction boxes (usually small, round, mounted in the wall near the ceiling).

It is already much easier to confuse the phase with zero there (I did it myself more than once). And as a result, 220 volts will appear on the case of an incorrectly "grounded" device. Or even simpler - a contact will burn out somewhere in the circuit - and almost the same 220 will pass to the case through the load of the electrical consumer (if this is an electric stove for 2-3 kW, then it will not seem enough).

For the function of protecting a person, frankly, this is an unsuitable situation. But for grounding connection, lightning protection of the APC type is not fatal, since a high-voltage decoupling is installed there. However, it would be unequivocally wrong to recommend such a method from a security point of view. Although it must be admitted that this rule is violated very often (and usually without any adverse consequences).

It should be noted that the lightning protection capabilities of the working and protective zero approximately equal. The resistance (up to the connecting bus) differs slightly, and this is perhaps the main factor affecting the flow of atmospheric pickups.

From the further text of the PUE, it can be seen that to zero protective conductor you need to attach literally everything that is in the house:

7.1.68. In all rooms, it is necessary to connect open conductive parts of general lighting fixtures and stationary electrical receivers ( electric stoves, boilers, domestic air conditioners, electric towels, etc.) to the neutral protective conductor.

In general, it is easier to represent the following illustration:

Rice. 4.6. Grounding scheme.

The picture is quite unusual (for everyday perception). Literally everything that is in the house must be grounded on a special bus. Therefore, the question may arise - after all, they lived without it for decades, and everyone is alive and well (and thank God)? Why change everything so seriously? The answer is simple - there are more consumers of electricity, and they are more and more powerful. Accordingly, the risk of injury increases.

But the dependence of safety and cost is a statistical value, and no one has canceled the savings. Therefore, it is not worth blindly laying a copper strip of a decent section around the perimeter of the apartment (instead of a plinth), leading everything to it, up to the metal legs of the chair, is not worth it. How not to walk in a fur coat in the summer, and constantly wear a motorcycle helmet. This is a question of adequacy.

Also, independent digging of trenches under a protective contour should be attributed to the area of ​​\u200b\u200ba non-scientific approach (in a city house, apart from problems, this will certainly bring nothing). And for those who still want to experience all the delights of life - in the first chapter of the EMP there are standards for the manufacture of this fundamental structure (in the truest sense of the word).

Summarizing the above, we can draw the following practical conclusions:

If the Group network is made with three wires, you can use protective zero. It is, in fact, designed for that.
If the group network is made with two wires, it is advisable to have a protective neutral wire from the nearest shield. The cross section of the wire must be more than the phase one (more precisely, you can consult the PUE).

With a two-wire network, it is impossible to ground the device case to a working zero. IN last resort, and being careful, you can ground the conclusions of the lightning protection with high-voltage decoupling in this way.

This could end the presentation if the network was located within the same building (or rather, one room with a single bus). In reality, home networks have large air spans (and, what is most unpleasant, they are made at a decent height). Therefore, it is necessary to separately and in detail consider the issue of lightning protection.

When connecting an electric generator, you have to deal with three networks: a common centralized network, a network of energy consumers and wiring from the generator. Their connection and interaction determines the specific connection scheme. There are three ways to power devices that consume energy from an electric generator.

Energy consumers are connected directly to the generator socket. This circuit is very simple and needs no explanation. It does not require the creation of any additional circuits and network connections.

The generator is connected to a consumer network that is not connected in any way with a centralized network (it may not exist at all). In this case, the wires coming from the generator are permanently connected to the wiring of energy consumers. This connection scheme of the gas generator (diesel generator) is called constant. The main thing to take care of in this case is that the cross sections of the wiring wires correspond to the rated current of the generator.

The generator, through manual or automatic switching devices, is connected into a single circuit with a centralized network and consumer wiring. This connection scheme of the gas generator allows, in the event of a power failure in the centralized network, to easily and quickly power all consumers from the generator. It's called a backup.

Unlike the first method, which does not require any preparation (the plug of the powered tool or device is connected directly, or through an extension cord, to the socket located on the generator control panel), the last two methods require competent preparatory work. The third (reserve) connection scheme is the most complex and in demand.

Generator connection diagram as a backup power source

Scheme with manual mode switching. In the event of a power failure in the central network, by turning the key of the switch or the handle of the knife switch, they break the consumer network with the central network and connect it to the wires from the generator. The switch must guarantee the impossibility of simultaneous connection of electrical consumers to the centralized power grid and the generator (there must be an intermediate neutral position).

Reversing switches or toggle switches are used as a manual switch. When choosing these devices, you should pay attention to their rated currents. They must correspond to the consumed current (not be lower). Their design and connection diagram can differ significantly, for example, the diagram below shows a three-pole switch (one pole is not used) OT40F3С (far from the cheapest option).

In addition to the manual switch, you can put an indicator, the function of which is to indicate the presence or absence of voltage in the central network. It turns on between the phase and zero of the central network. These can be special modular 220V indicators, or cheaper (20 times) 220V LEDs in a closed case and with wires already soldered.

The weak point of these indicators is that they are connected before the fuses.

Scheme with automatic mode switching. Automatic scheme connection of an electric generator allows, in the event of a power failure in the central network, to turn on the generator automatically without human intervention. This work is performed by the AVR (automatic transfer switch), consisting of a whole set of devices - contactors, voltage control relays, circuit breakers, indication elements.

The generator, which is switched on automatically, must have an electric starter. To turn on backup source to work, you must disable centralized network, start and warm up the generator, connect the wiring from it to the consumer network. When a central tension appears, reverse work. All this is performed by the AVR block.

Exist various systems automatic input of a reserve, differing in their functionality. They work as follows, using the example of the Champion ATS block for gasoline generator GG7000E. When the power supply from the central network is interrupted, the program for starting the ATS unit is launched. First, energy consumers are disconnected from the centralized network. After 2-3 seconds, the generator engine starts and its operation is checked. During normal operation of the unit, after 12 seconds. after starting the engine (warming up), the generator is connected to consumers of electricity.

When power is restored from common network, the system monitors the stability of the supplied electricity. If stability is detected for 10 seconds, ATS automatically switches consumers to power from the public network. The generator runs without load for another 5 seconds, then the ATS system stops it.

Load switching order

Connection errors

Both of these are unacceptable. Plugging the generator wires into a consumer network socket, in case of a heavy load, can cause destruction of the socket and electrical wiring with a risk of fire, since the size of the socket contacts and the cross section of its wires are not designed for high currents flowing in the generator network. And if you do not turn off the centralized network (for example, forgetting), then when voltage appears in it, the generator will fail.

Installation of an electric generator

The installation site of the gas generator or diesel generator must be dry and level. There must be no flammable objects nearby.

Not every the room is suitable to install a power generator. There are certain ventilation requirements. So, in a closed room, it is necessary to organize supply and exhaust ventilation using a duct system or built-in fans. Thus, the supply of cold air and the removal of heated air will be ensured. If the generator is placed, for example, in a basement or pantry, it will overheat, even if there is an open window. As a result, the generator will break down.

Noise protection

When installing a diesel generator or gas generator, make sure that the base on which the unit is installed is not rigidly connected to the building. It is advisable to install the generator on shock absorbers, the simplest of which can be a conventional rubber gasket.

The noise coming from the surface of the generator is reduced by means of noise protection covers. Factory-made casings work most efficiently - special containers in which sound and vibration insulating materials are used and supply and exhaust ventilation, providing the temperature regime necessary for the normal operation of the generator.

You can make a container yourself, but this is not as simple as it might seem at first glance. Mainly because of the need to ensure effective ventilation.

Container for gasoline generator. Air is forced through the lower air duct closer to the engine.

Noise coming from exhaust gases, reduce with silencers. But manufacturers are prohibited from installing additional mufflers, and making any changes to the design will void the warranty. Installing a silencer can result in reduced power and difficult starting. Moreover, it is not the most effective method noise control, because sounds arise not only from the operation of the engine, but also from vibration. Therefore, it would be wiser to pay more attention to the place where the generator is installed. In a room or casing, walls are recommended to be upholstered with a special soundproof material- in one or two layers, depending on how noisy the generator is.

grounding

• metal rod with a diameter of at least 15 mm, a length of at least 1.5 m;
• a metal pipe with a diameter of at least 50 mm, a length of at least 1.5 m;
• a sheet of galvanized iron with a size of at least 500x1000 mm.

Any grounding conductor must be immersed in the ground to constantly wet soil layers. Grounding conductors must be equipped with clamps or other devices that ensure a reliable contact connection of the ground wire with the grounding conductor. The opposite end of the wire is connected to the generator ground terminal.

Exhaust gas outlet

The problem is that the extension of the exhaust pipe, as well as the additional muffler, creates additional resistance to the exit of the exhaust gases. This significantly affects engine power, durability and fuel consumption. The resistance to the release of exhaust gases from the cylinder causes incomplete combustion of the fuel, an increase in the operating temperature of the exhaust gases, and the formation of soot. Typically, manufacturers of gas generators prohibit extending the exhaust pipe and installing an additional muffler. To minimize the resistance to the exhaust outlet, the following principles should be followed:

• The inner diameter of the pipe must be larger than the diameter of the generator exhaust pipe. The more (within reason) the better. And the longer the pipe, the larger the diameter should be.
• The length of the work should be as short as possible.
• Must be least amount bends.
• The curves should be as smooth as possible.

Parts of the exhaust system must not be located near wood or other combustible materials. To reduce the room temperature, it is necessary to use non-flammable thermal insulation materials. Layer insulating material, wrapped around the piping, can significantly reduce heat radiation into the room from the exhaust system. Thermal insulation The exhaust pipe is especially important when the generator is running in a wooden container.

Corrugated stainless steel hose installed between the generator exhaust pipe and the rest of the pipeline reduces the transmission of vibration from the engine to the pipeline and the building, compensates for the forces resulting from thermal expansion. The design of the flexible section must allow displacement of either end in any direction without damage. The piping must not rest on the exhaust pipe of the generator.

The exhaust system must be equipped with a condensate trap with a condensate drain, located in the lowest part of the pipe inside the room. Or a corrugated stainless steel hose should have a bend below the level of the generator exhaust pipe, in order to prevent street condensate from entering the generator.

The outlet must be under a canopy to prevent atmospheric precipitation from entering the system. It is also recommended to provide for restrictions on children's access to the outer pipe, as the temperature and composition of the exhaust gases may pose a threat to their health.

In the hole in the wall through which the pipe passes to the street, insulation must be provided from high temperature pipes and to absorb vibration.

Neglect in the removal of exhaust gases can cause death. Here are some examples:

“In a private residential building, dead girls of 14 years of age were found poisoned by carbon monoxide. The cause of death was a portable diesel generator. One of the girls, in the absence of her parents, invited two girlfriends and, since the power supply was turned off in the house, turned on the diesel generator on her own. As a result of a violation of the operating technique, three children suffocated from carbon monoxide.

“A family that died in the village of Yuzhnaya Koryaki suffocated due to a working diesel generator, the exhaust gases of which got into the house. Long-term power outages forced the family to use an alternative source of electricity. As already reported, after the cyclone, part of the Yelizovsky district remained without electricity for about a day and people fled from the cold whoever can. And only today the whole family, consisting of two sons, one of whom was a minor, mother, father and their close relative, were found without signs of life by neighbors.

"According to preliminary data, on the evening of February 12, the men decided to take a steam bath in wood-burning bath. Her 65-year-old Kurchatovian arranged in the basement of his garage. The bathhouse was lit by a gasoline generator. Steam room lovers started the generator and began to put firewood into the firebox. The door was closed and the exhaust gases from the gasoline generator quickly filled closed room garage. 50-year-old Kurchatov became ill. He fell in the waiting room - suffocated with carbon monoxide. The owner of the garage, feeling the lack of oxygen, rushed to the garage door to open it. But he didn't manage to do it. Having lost consciousness, the man fell on the threshold and also suffocated. The next day, relatives of the Kurchatovites, worried about their long absence, opened the garage and, finding two corpses there, called the police.

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