Grounding the power plant or grounding. Which is better to choose? Operating modes of neutrals in electrical installations Grounding container-type generator sets

Generally speaking, it can be noted that the great and terrible power of electricity has long been described, calculated, and entered into thick tables. Normative base, defining the paths of sinusoidal electrical signals frequencies of 50 Hz can plunge any neophyte into horror with its volume. And, despite this, any regular on technical forums has long known - there is no more scandalous issue than grounding. The mass of conflicting opinions 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 to understand grounding technology you need to turn (to begin with) to Chapter 1.7, which is called “Grounding and protective measures for electrical safety”.

In clause 1.7.2. said:

Electrical installations with regard to electrical safety measures are divided into:

electrical installations above 1 kV in networks with efficient grounded neutral(with large ground fault currents), ;
electrical installations above 1 kV in networks with isolated neutral(with low ground fault currents);
electrical installations up to 1 kV with a solidly grounded neutral;
electrical installations up to 1 kV with insulated neutral.

The vast majority of residential and office buildings in Russia use a solidly grounded neutral. Clause 1.7.4. reads:

A solidly grounded neutral is the neutral of a transformer or generator, connected to a grounding device directly or through low resistance (for example, through current transformers).

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

When describing the remaining options for electrical installations, the easiest way is to proceed as in one of the versions of the instructions for a Rolls-Royce - “if the car breaks down, your driver will probably know what to do.” At least, schemes other than a solidly grounded neutral are found in the construction of home networks a little more often than Rolls-Royces on the streets.

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

1.7.6. Grounding of any part of an electrical installation or other installation is the intentional electrical connection of this part to a grounding device.
1.7.7. Protective grounding is the grounding of parts of an electrical installation to ensure electrical safety.
1.7.8. Working grounding is the grounding of any point of live parts of an electrical installation, which is necessary to ensure the operation of the electrical installation.
1.7.9. Grounding 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 solidly grounded neutral of a generator or transformer in three-phase current networks, with a solidly grounded source terminal single-phase current, with a solidly grounded midpoint of the source in networks direct current.
1.7.12. A grounding electrode is a conductor (electrode) or a set of metallic interconnected conductors (electrodes) that are in contact with the ground.
1.7.16. A grounding conductor is a conductor that connects the grounded parts to the ground electrode.
1.7.17. A protective conductor (PE) in electrical installations is a conductor used to protect people and animals from electric shock. In electrical installations up to 1 kV, the protective conductor connected to the solidly grounded neutral of the generator or transformer is called the neutral protective conductor.
1.7.18. The neutral working conductor (N) in electrical installations up to 1 kV is the conductor used to power electrical receivers, connected to a solidly grounded neutral of a generator or transformer in three-phase current networks, to a solidly grounded terminal of a single-phase current source, to a solidly grounded source point in three-wire DC networks. A combined neutral protective and neutral working conductor (PEN) in electrical installations up to 1 kV is a conductor that combines the functions of a neutral protective and neutral working conductor. In electrical installations up to 1 kV with a solidly grounded neutral, the neutral working conductor can serve as a neutral protective conductor.

Rice. 4.5. Difference protective grounding 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 in this place). At the very least, they must be combined (or even can be done “in one bottle”). The only question is where and how it is done.

In passing, we note paragraph 1.7.33.

Grounding or grounding of electrical installations should be performed:

at voltage 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 high-risk areas, especially hazardous and in outdoor installations.

In other words, it is not at all necessary to ground or neutralize a device connected to a voltage of 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, which is coming into its own in practice (or the new edition of the PUE, which is close to it) is better, more reliable, and safer. But according to the old PUE, people lived in our country for decades... And what is especially important, houses were built in entire cities.

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

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

This results in a normative paradox. One of the visible results at the everyday level was the acquisition washing machines"Vyatka-automatic" with a coil 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, grounding must be performed. The use of grounding of electrical receiver housings in such electrical installations without grounding them is not allowed.

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

Grounding parameters

The next aspect to consider is numeric parameters grounding. Since physically it is nothing more than a conductor (or many 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 terminals 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 natural grounding agents, as well as grounding conductors for repeated grounding of the neutral wire of overhead lines up to 1 kV with a number of outgoing lines of at least two. In this case, the resistance of the grounding conductor located in close proximity to 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, higher 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 body of an electrical installation. The lower the resistance, the smaller part of the potential may be “on the body” in the event of an accident. Therefore, the hazard for higher voltages must be reduced first.

Additionally, it should be taken into account that grounding also serves for normal operation fuses. To do this, it is necessary that the line, during a breakdown “to the body,” significantly changes 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 grounding resistance should be lower (otherwise, in the event of an accident, the fuses will not trip minor change total circuit resistance).

The next standardized parameter is the cross-section of the conductors.

1.7.76. Grounding and neutral protective conductors in electrical installations up to 1 kV must have dimensions no less than those given in table. 1.7.1 (see also 1.7.96 and 1.7.104).

It is not advisable to present the entire table; an excerpt will suffice:

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

Grounding in a residential building

In a normal “domestic” situation, power grid users (i.e. residents) deal only with the Group network (7.1.12 PUE. Group network - a network from switchboards and distribution points to lamps, plug sockets and other electrical receivers). Although in old buildings, where the panels are installed directly in the apartments, they have to deal with part of the Distribution Network (7.1.11 PUE. Distribution Network - the network from the VU, ASU, Main Switchboard to distribution points and panels). It is advisable 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 are laid from group, floor and apartment panels to lamps general lighting, plug sockets and stationary electrical receivers must be three-wire (phase - L, neutral working - N and neutral protective - PE conductors). Combining zero working and zero protective conductors of different group lines is not allowed. The neutral working and neutral protective conductors are not allowed to be connected on panels under a common contact terminal.

Those. from a floor, apartment or group panel you need to lay 3 (three) wires, one of which is a protective zero (not ground at all). Which, however, does not at all prevent it from being used for grounding a computer, cable shield, or the “tail” of lightning protection. It seems that everything is simple, and it is not entirely clear why to delve into such complexities.

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

It is difficult to assume that a careless electrician will confuse phase and zero in the panel. Although this constantly frightens users, it is impossible to make a mistake in any state (although there are unique cases). However, the “working zero” goes along numerous grooves, probably passing through several distribution boxes (usually small, round, mounted in the wall near the ceiling).

It’s much easier to confuse phase with zero there (I’ve done this myself more than once). As a result, 220 volts will appear on the body of the incorrectly “grounded” device. Or even simpler - a contact will burn out somewhere in the circuit - and almost the same 220 will pass to the housing through the load of the electrical consumer (if it is a 2-3 kW electric stove, then it will not seem too small).

For the human protection function, frankly speaking, this is a bad situation. But for connecting grounding, lightning protection type APC is not fatal, since a high-voltage isolation is installed there. However, it would definitely be wrong to recommend this method from a security point of view. Although it must be admitted that this norm is violated very often (and, as a rule, without any adverse consequences).

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

From the further text of the PUE it can be noted that towards zero protective conductor you need to connect literally everything that is in the house:

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

In general, it is easier to imagine this with the following illustration:

Rice. 4.6. Grounding diagram.

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

But the relationship between safety and cost is statistical, and no one has canceled the savings. Therefore, it is not worth blindly placing a copper strip of a decent cross-section around the perimeter of the apartment (instead of a baseboard), placing everything on it, right down to the metal legs of the chair. How you shouldn’t wear a fur coat in the summer and always wear a motorcycle helmet. This is already a question of adequacy.

Also in the area of ​​an unscientific approach is the independent digging of trenches under the protective contour (in a city house this will obviously bring nothing but problems). But for those who still want to experience all the delights of life - in the first chapter of the PUE there are standards for the manufacture of this fundamental structure (in the very literal sense of the word).

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

If the group network is made of three wires, you can use protective zero. In fact, that’s what it was invented for.
If the group network is made of two wires, it is advisable to install a protective neutral wire from the nearest shield. The cross-section of the wire must be larger than the phase one (more precisely, you can check in the PUE).

With a two-wire network, the device body cannot be grounded to the working zero. IN as a last resort, and being careful, you can ground the lightning protection terminals with high-voltage isolation in this way.

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

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

It’s not possible, but by default the generator frame must be connected to the power supply at home with a power cable. In general, there are worse, budget-friendly options allowed by standards and common sense, and better options when the generator frame is not connected to the home’s charger. 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 must be groundedit is forbidden!

GOST R 50783-95 said:

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

10.3 Scheme electrical connections mobile electrical units and three-phase alternating current power plants must have an insulated neutral.It is not allowed to use any devices that create an electrical connection between phase and (or) neutral wires or neutral with housing or neutral wires or neutral with housing or ground directly or through an artificial zero point, except for devices to suppress interference to radio reception.

10.4 In mobile electrical units and power plants with a capacity of 1 kW and above rated voltage from 115 V and abovethere must be a device for continuous monitoring of insulation, which allows you to measure (evaluate) the insulation resistance relative to the body (ground) of the live parts of the electrical unit and power plant that are energized. For operation in conjunction with the local electrical network, mobile electrical units and power plants must have an automatic shutdown device. Monitoring of the serviceability of these devices must be provided.

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

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

Generator instructions ENERGO said:

This manual is valid for petrol electric units 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
― do not allow the electric unit to operate if there is a short circuit to the housing...

When operating the unit PROHIBITED:
ground the neutral or connect it to the housing;

Owners of autonomous power supply sources, ignorant in electrical safety, who themselves do not comply with and advise others not to comply with these standards, argue that they are right by declaring that portable and smoke-type generators and other autonomous power supply sources of 220/380 volts when powering their home from them are not affected by this, since they constantly stand in one place.

You have to think of something like this, like because the generator is called portable, it is carried during operation, or because the generator constantly stands in one place, the electricity it generates becomes safe!

Sales and installers are also ignorant in electrical safety, including some certified service centers those who connect generators, or simply hacks, tightly connect one of the generator terminals to neutral wire supply network since without switching the neutral wire the circuit, installation is simpler, it is cheaper and easier to find components, and also to fool the clumsy flame control circuit of some boilers, arguing that they are doing it right because they have done it this way many times and it seems to work, which is comparable with an ignorant statement that it is enough to do the wiring without VDT, grounding since millions of houses do not have VDT, 2 wiring and millions did not kill, so there is no need to install differential protection and use wiring with PE.

Even if the autonomous power source is stupidly connected via a power supply system with the TN grounding type, then it is impossible to somehow connect one of the power terminals of the autonomous power source to the neutral wire of the supply network!

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

SAFETY REQUIREMENTS. PROTECTION AGAINST VOLTAGE SURGERY AND ELECTROMAGNETIC INTERFERENCE.

444.4.7 Switching power sources
In TN systems, switching power from one source to another sourcemust be performed using a switching device that simultaneously switches the linear conductors and the neutral conductor, if it is present in the electrical installation (see Figures 44. R9A, 44. R9B, 44. R9C).

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

This is not to say that failure to comply with the above-mentioned standards increases the likelihood of generator failure, even to the point of 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, and It is impossible to use a RCCB in such a dangerous connection!

You should also keep in mind, if you are making a circuit, that during a power outage, only part of the house wiring is powered from an autonomous power source of 220/380 volts, and the rest of the wiring remains connected to the power supply network, which is better not to do, then the installation of lines in the switchboard and in the wiring fed from an autonomous source of electricity and connected to the mains, which are located together, must be designed for 660 volts! This also applies to nearby lines powered by different autonomous power sources of 220/380 volts!

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

1. To what extent powerful generator should I purchase?

The estimated power of the generator depends on the amount of electrical loads you want to use simultaneously. 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 precaution, find out which household electrical appliances your home may have large inrush currents (refrigerators, air conditioners, pumps) Add all this to the total.

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

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

The generator has two units that determine its power: nominal and maximum. Generators are equipped with overload protection, which can be triggered when electrical appliances are started at the same time. Therefore, you should purchase a generator with some power reserve.

2. What loads must be powered by the generator?

Based on our own many years of experience in installing and servicing 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 oven.

6) Garage doors.

7) Borehole pump.

8) Alarm.

If the power of the backup generator is sufficient, then you can connect secondary loads: drainage pump, ventilation...

Equipment manufacturers indicate the power of 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 a professional 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 a reserve. The ATS is connected to the power grid 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. This way 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 energy system of your home largely depends on how competently and efficiently the installation and adjustment 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, the generator can send power supply to the external network with all the ensuing consequences if repair work is being carried out on the line at this time...

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

6. What is the difference between a backup generator and an emergency generator?

The standby generator is permanently installed and is designed to power most electrical appliances. An emergency generator is a small, portable unit that can be taken outside the premises and connected to an automatic transfer system. Or it can be connected to electrical loads through extension cords.

7. If it's raining or snowing outside, can you put a generator in the garage and run it there while the door remains open?

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

8. What other safety tips should I remember?

If the generator is permanently installed, 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 risk of poisoning carbon monoxide(SO). Never fill the generator with fuel until it has cooled down.

9. Generators are quite loud. What can you do 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 sound-insulated casing. In addition, you can purchase a special noise-insulating all-weather container in which the generator is placed.

Some mechanics are experimenting with additional mufflers from motorcycles and ATVs. This can be done if you have the necessary skills. But be aware: in most cases, this will void your generator's warranty.

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

10. Does the generator need to be grounded?

Follow the instructions in the instruction manual. If the manual requires you to ground the generator, 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, which can be driven into the soil next to the generator.

As an alternative to a ground rod, you can connect a ground wire from the generator to the main distribution panel inside the house.

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 plugged directly into the generator outlet. This scheme is very simple and does not need explanation. It does not require the creation of any additional circuits or connections to the network.

The generator is connected to a consumer network that is in no way connected to the centralized network (it may be absent altogether). In this case, the wires coming from the generator are permanently connected to the wiring of power consumers. This connection diagram for a gasoline generator (diesel generator) is called permanent. The main thing that should be taken 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 diagram for a 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 backup.

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

Connection diagram for a generator as a backup power source

Circuit with manual mode switching. When the voltage in the central network disappears, by turning the switch key or the switch handle, they break the network of consumers from the central network and connect it to the wires from the generator. The switch must ensure that it is impossible to simultaneously connect electrical consumers to the centralized power grid and the generator (there must be an intermediate neutral position).

Reversing switches or changeover switches are used as a manual switch. When choosing these devices, you should pay attention to their current ratings. They must correspond to the current consumption (not be lower). Their design and connection diagram may differ significantly, for example, below is a diagram for a three-pole switch (one pole is not used) OT40F3C (far from the cheapest option).

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

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

Circuit with automatic mode switching. Automatic circuit connecting 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 an ATS (automatic transfer transfer) unit, consisting of a whole set of devices - contactors, voltage control relays, circuit breakers, display elements.

A generator that turns on automatically must have an electric starter. To turn on backup source into operation, you need to turn off the centralized network, start and warm up the generator, connect the wiring from it to the consumer network. When central stress appears, it is done reverse work. All this is performed by the AVR unit.

Exist various systems automatic reserve entry, differing in their functionality. They work as follows, using the example of the ATS block from Champion for gasoline generator GG7000E. When the power supply from the central network is interrupted, the ATS unit startup program 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 electricity consumers.

When the power supply is restored from shared network, the system monitors the stability of the supplied electricity. If stability is detected within 10 seconds, the 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 procedure

Connection errors

Both are unacceptable. Plugging the generator wires into a consumer network socket, in case of heavy load, can cause destruction of the socket and electrical wiring with the 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.

Electric generator installation

The installation site of the gas generator or diesel generator must be dry and level. There should be no fire hazards nearby.

Not every the room is suitable for installation of an electric 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. This will ensure the supply of cold air and the removal of heated air. If the generator is placed, for example, in a basement or pantry, it will overheat, even with an open window. As a result, the electric generator will break down.

Noise protection

When installing a diesel generator or gasoline generator, you need to 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 regular rubber gasket.

The noise emanating from the surface of the generator is reduced using noise-proof enclosures. Factory-made casings work most effectively - special containers in which shock- and vibration-insulating materials are used and supply and exhaust ventilation, providing the temperature regime necessary for 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 due to the need to ensure effective ventilation.

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

The noise coming from exhaust gases, reduced with the help of mufflers. But manufacturers prohibit the installation of additional mufflers, and any changes to the design will void the warranty on the electric generator. Installing a muffler may result in reduced power and difficulty starting. In addition, this is not the most effective method of combating noise, because sounds arise not only from engine operation, but also from vibration. Therefore, it would be wiser to pay more attention to the place where the electric generator is installed. It is recommended to upholster the walls in a room or casing with a special soundproofing material- in one or two layers, depending on how noisy the generator is.

Grounding

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

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

Exhaust gas removal

The problem is that extending the exhaust pipe, like an additional muffler, creates additional resistance to the exhaust gases escaping. This significantly affects engine power, durability and fuel consumption. Resistance to the release of exhaust gases from the cylinder causes incomplete combustion of fuel, an increase in the operating temperature of the exhaust gases and the formation of soot. Typically, gas generator manufacturers prohibit lengthening the exhaust pipe and installing an additional muffler. To minimize exhaust outlet resistance, 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 reasonable limits) 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 bends should be as smooth as possible.

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

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

The exhaust discharge system must be equipped with a condensate sump with a condensate drainage device, located in the lowest part of the pipe indoors. Or the corrugated stainless steel hose must have a bend below the level of the generator exhaust pipe to prevent street condensation from getting inside the electric generator.

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

The hole in the wall through which the pipe passes to the street must be insulated from high temperature pipes and to absorb vibration.

Failure to properly remove exhaust gases can cause death. Here are some examples:

“In a private residential building, 14-year-old girls were found dead from carbon monoxide poisoning. The cause of death was a portable diesel generator. One of the girls, in the absence of her parents, invited two friends and, since the power supply was turned off in the house, she turned on the diesel generator herself. As a result of violation of operating procedures, three children suffocated from carbon monoxide."

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

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

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Most people know that grounding is required when installing any electrical appliance, including a generator, to ensure safety. However, few people understand what it is and how exactly the grounding system ensures safety.

So, why is grounding needed and what will happen if it is not there?

To answer these questions, you first need to remember from school course physics, what is electricity- movement of charged particles in a conductive substance (conductor). The human body is also a conductor of current.

Why is current dangerous? Everyone has heard the expression: “electric shock.” This blow lies in its danger to a person, from unpleasant sensations to death. To receive an electric shock, it is not enough to simply touch a live wire or part of a device - there must be an electrical circuit.

In practice, such a chain always exists, since we constantly stand on the ground or floor, hold on to or touch objects. When contacting a wet surface, the potential difference increases and an electric shock can be fatal.

In order to protect yourself from electric shock, you need grounding. Grounding is a special connection of the electrical network or electrical appliances with a grounding mechanism at a certain point. The essence of grounding is that all metal parts of the equipment are connected to a wire that goes into the ground. It is through this wire that the electric current goes into the soil, and not through a person, thereby ensuring the safety of the latter.

Before starting up and operating the electric generator, it must also be connected to a grounding circuit made in accordance with the requirements of the Electrical Installation Regulations.

• Grounding electrode (ground electrode). Copper-coated steel rods, which are buried in the ground according to a certain pattern, are best suited for this. Please note that in this case, underground water or gas pipelines cannot be used.
• Ground clamp. It is located near the main circuit breaker of the power plant.
• Grounding copper wire the corresponding section. It connects the electrode to the clamp. It is important to remember that the place where the grounding electrode and wire are connected must be protected from accidental damage and must be accessible for inspection. In this place, according to the requirements, a sign must be placed that states that the grounding system is located here.
• Grounding conductor. It connects all metal parts of the installation that are not live to the ground clamp.

In order to effectively carry out all procedures for grounding a power plant and ensure safety, it is necessary to strictly follow all PUE requirements(electrical installation rules) and accurately calculate the maximum allowable resistance. This calculation is only possible by measuring resistivity soil special device at the work site. Moreover, it is necessary to take into account seasonal factors.

Undoubtedly, the installation of a grounding device should be carried out only by qualified personnel using special tools.