What cross-section, quality and type of grounding wire to choose for an apartment and a house. Ground wire Tips from an experienced electrician to connect the auxiliary ground wire

In this article we will deal with you, how to connect ground... This topic is quite extensive and has many nuances, and here it is not so easy to say - do it or connect it here. Therefore, so that you understand me, and it would be easier for me to explain to you, there will be both theory and practice.

Grounding in our modern life is an integral part. Of course, you can do without grounding, because how long we lived without it. But, with the advent of modern household appliances, grounding is simply a prerequisite for protecting a person from electric shock.

General concepts.

Earthing- deliberate electrical connection of any point in the network, electrical installation or equipment with a grounding device.

Grounding is for leakage currents arising on the body of electrical equipment during emergency operation of this equipment, and provision of conditions to immediate disconnection of voltage from the damaged section of the network by triggering protective and automatic shutdown devices.

For example: there was a breakdown of insulation between the phase and the body of the electrical equipment - a certain phase potential appeared on the body. If the equipment is grounded, then this voltage will flow through the protective ground, which has a low resistance, and even if the residual current device does not work, when a person touches the case, the current that remains on the case will not be dangerous to humans. If the equipment is not grounded, all current will flow through the person.

Grounding consists of earthing switch and grounding conductor connecting grounding device with earthed part.

Earthing switch is a metal rod, most often a steel, or other metal object in contact with the ground directly or through an intermediate conductive medium.

Grounding conductor Is a wire that connects the grounded part (equipment case) to the grounding conductor.

Grounding device Is a set of grounding conductors and grounding conductors.

A bit of theory.

You have all seen small brick structures in the courtyards, into which power cables enter and exit - this is transformer substations(electrical installations). Transformer substations are used to receive, convert and distribute electrical energy. Any substation has a power transformer for voltage conversion, switchgear and automatic control and protection devices.

One of three phases is used to power single-phase household equipment (TV, refrigerator, iron, computer, etc.) L1; L2; L3 and zero worker conductor " N».

This is a standard scheme for providing consumers with electrical energy, on the basis of which additional schemes have been developed that differ in the method of connecting protective grounding, connecting and protecting electrical equipment, as well as measures taken to protect people from electric shock.

The transformer substation has its own ground loop, to which all metal enclosures of the substation equipment are connected. The ground loop consists of metal rods driven into the ground, connected by a metal bus by welding. This bus is called ground bus.

The grounding bus is led into the substation building and is laid along the perimeter of the building. Bolts are welded to it, to which already after grounding conductors all substation equipment is connected.

According to the PUE (Electrical Installation Rules), the grounding conductor ( zero protective) on electrical diagrams has the letter designation " PE»And color coding with alternating transverse or longitudinal stripes of yellow and green.

Grounding systems.

Grounding systems differ in the way of grounding zero worker"N" conductor on the secondary winding of the power transformer and consumers of electrical energy (engine, TV, refrigerator, computer, etc.) powered by this transformer.

The free ends of the coils are connected to the wires of a three-phase network that goes to consumers of three-phase or single-phase electrical energy. This neutral connection is called deafly grounded and is used in grounding systems such as TN.

Here is neutral " N", Or else it is called working zero, performs two functions:

1. Together with one of the three phases, it forms a voltage of 220 volts.
2. Performs a protective function, as it has direct contact with the ground.

At the moment, there are 3 types of grounding systems:

1. TN- a system in which the neutral of the transformer is grounded and the exposed conductive parts are connected to the neutral;
2. TT- a system in which the neutral of the transformer is grounded and the exposed conductive parts are grounded by a grounded device electrically independent from the grounded neutral of the transformer;
3. IT- a system in which the neutral of the transformer is isolated from earth or earthed through high resistance devices and the exposed conductive parts are earthed.

All three grounding systems are designed to protect people and electrical equipment from electric shock. These grounding systems are considered equivalent for protecting people, but they are not equivalent in terms of the method of ensuring the reliability (reliability, maintainability) of power supply to consumers with electrical energy.

Grounding systems are designated by two letters.
The first letter defines the connection of the neutral of the transformer to earth:

T- neutral is grounded;
I- neutral isolated from earth.

The second letter defines the connection of the exposed conductive parts to the ground:

T- exposed conductive parts are directly grounded;
N- open conductive parts are connected to the solidly grounded neutral of the transformer.

Now let's look at all the systems in order.

1. TN earthing system.

System " TN"Is a system in which neutral transformer grounded, and the exposed conductive parts are connected to neutrals through zero protective conductors.

Open conductive part- a conductive part of the electrical installation accessible to touch (for example: the housing of household electrical appliances), which in normal operation of the electrical installation not energized, but maybe be energized in case of damage to the insulation.

As a rule, insulation damage can be caused by many factors: aging of equipment, mechanical damage, prolonged operation at maximum loads, dust accumulation between the equipment case and live parts, moisture formation on a dusty surface near live parts, climatic effects, factory marriage, etc.

So, in turn, the system TN is divided into three more subsystems:

1. TN-C- a system in which zero protective "PE" and zero working "N" conductors are combined in one conductor "PEN" throughout the entire system;
2. TN-S- a system in which zero protective "PE" and zero working "N" conductors are separated throughout the system;
3. TN-C-S- a system in which the functions of zero protective "PE" and zero working "N" conductors are combined in one conductor in some part of it, starting from the power transformer.

TN-C system.

System TN-C- This is one of the first grounding systems, which is still found in the old housing stock built before the mid-90s, but, despite this, it still exists and operates. This system is being laid four-wire cable, in which there are 3 phase wires and 1 null.

Here is a zero protective " PE"And zero worker" N»Conductors are combined in one conductor throughout the entire system. That is, one " PEN»Conductor, and this is by far the main disadvantage of the system TN-C.

At that time, there was practically no electrical equipment requiring a three-wire connection and therefore no special requirements were attached to protective grounding, and such a system was considered reliable. But with the advent of modern three-wire equipment in our everyday life, where a grounding conductor "PE" is provided, the TN-C system ceased to provide the required level of electrical safety.

Today, almost all modern equipment is powered through switching power supplies that do not have galvanic isolation with a 220 volt network.

This is due to the fact that switching power supplies have suppression filters, which are designed to suppress high-frequency noise from the 220 Volt supply network, and which are connected to the equipment case through decoupling capacitors.

High frequency disturbances in the mains supply through the decoupling capacitors, the protective earth conductor "PE", the three-pole plug and the socket, drain to earth. That is why there is a danger of phase voltage appearing on the equipment case in case of breakdown of insulation between the phase and the case or the disappearance of the working zero "N" when powering modern equipment using the TN-C grounding system that does not have a separate PE conductor.

For example: if your working zero "N" comes off or burns off between the floor and apartment boards, then there is a danger of phase voltage appearing on the housing of the household equipment that is currently operating. And if it is not grounded, then when you touch the metal unpainted case with your bare hand, a current will flow through you, and you will receive a charge.

Although, thanks to switching power supplies, modern technology has become smaller, cheaper and lighter, but, naturally, the requirements for the level of electrical safety have already become higher.

But, as they say, the rescue of drowning people is the work of the drowning people themselves, and therefore some craftsmen, in order to protect themselves, pull the grounding on their own. Some sit on central heating batteries, others are connected to the building of the floor board, put a jumper in the outlet, install an RCD, and some even make their own ground loop.

For example: you connected the third conductor to the building of the floor board and think that you are grounded. This is a big misconception. you did vanishing- and nothing more.

Protective grounding- this is a deliberate electrical connection of exposed conductive parts of an electrical installation (for example, the equipment case) with a dead-grounded neutral of a generator or a power transformer for electrical safety purposes.

Deaf earthed neutral- this is the neutral of the transformer connected directly to the grounding device.

So, vanishing on the building of the floor board is dangerous because in the event of a break in your working scratch"N" power supply of household appliances that are currently plugged into the socket will pass through the "PE" protective conductor.

And this is already wrong a power circuit for household appliances that will result in short circuit and breakdown of all equipment. The circuit breaker will work, but only from the short-circuit current, which will be created by your already burnt-out equipment. And if at this moment you take up an unpainted metal case, then in addition, for a moment, you will get a boost of vivacity.

Although in PUE No. 7, grounding is allowed and is considered an additional protection measure. But again the question arises: in what place to make zeroing... It is up to you to decide.

Another example.
You connected to central heating battery, trying in this way to deceive the meter or to ground. On your riser, the neighbor below is making repairs and replaced the old rusty pipes with plastic ones. As a result, you were cut off from your imaginary land. Now you and the neighbors from above will be in constant danger.

Or another example.
You have taken into account all the nuances and decided to ground yourself in a different way. They dug a hole in the basement of the house or near the house, drove in the pins, made it according to all the rules ground loop, and the grounding conductor "PE" was led to their apartment. Everything is done, and now you can sleep peacefully. But no.

Suddenly, your neighbor decided to play a trick on you out of harm or simply out of envy that you have grounding, but he does not. Take and cut off the grounding conductor. Or the person in charge of the house will see the wire that was not laid out in the project and remove it, but you live and do not know that you are left without grounding. In addition, the grounding must be periodically checked with special devices. Will you do this? Do you have such devices?

As a protection option, you installed in a two-wire line RCD... In principle, this is not such a bad option, but it also has its own nuances.

The RCD operates on leakage currents of 10 mA, 30 mA and 300 mA, but for this it needs protective conductor"PE", relative to which the RCD sees these currents. In system TN-C protective conductor "PE" No, but it is in the system TN-S, for which the RCD was developed. On a two-wire line, the RCD will also work, but through the leakage current that you create with my body.

Take, for example, the same breakdown of insulation on the case, and at the same time, the simultaneous touch of a bare central heating battery.

In system TN-S the leakage current generated on the case will immediately go through the protective conductor " PE”, And if its threshold exceeds the RCD setting, it will trip and cut off the power supply. And even when the threshold for the RCD is small and it does not work, you will not feel anything, or you will just be tingled a little.

In system TN-C another case. At simultaneous touching the body and a bare central heating battery current will flow through you to the battery. If there is an ordinary machine gun, then you, depending on current strength, and you will remain hanging between two fires, since passing through you current will not be short-circuit current... If it will stand RCD, then upon reaching the threshold of the setting, it will work and turn off the power.

And here comes the moment of truth: RCD, in the TN-C system, will not save you from electric shock... You will receive your energy boost. The only question is time under the influence of electric current.

In the PUE No. 7, regarding the installation of an RCD in the TN-C system, it says:

1.7.80. It is not allowed to use RCDs that react to a differential current in four-wire three-phase circuits (TN-C system). If it is necessary to use an RCD to protect individual electrical receivers powered by the TN-C system, the protective PE conductor of the electrical receiver must be connected to the PEN conductor of the circuit supplying the electrical receiver to the protective switching device.

Again the question arises: where to pull the protective conductor from. So, here again it is up to you to decide.

Therefore, if you live in old buildings and you have a two-wire network, then having secured your apartment with grounding, as it seems to you, the problem cannot be solved, but will only worsen for you or your neighbors. The problem of a two-wire network must be solved collectively - with the whole house:

1. Alteration or change of the power supply system of the house from a four-wire to a five-wire line.
2. Replacement of old floor boards with new ones designed for a five-wire line.

But do not think that everything is so scary. In this part of the article, I talked about the possible situations that may arise with us in case of incorrect connection and use of protective grounding. In the article, we will continue to deal with the remaining grounding systems.
Good luck!

The grounding mechanism is the ability to reduce or completely eliminate electric shock in the event of any malfunction in the electrical network. However, this condition is fulfilled only with a high-quality connection to the system of special grounding conductors.

In order to correctly and safely organize the wiring, you need to know how to determine, among others, the grounding wire, connect or choose a new one for replacement. For each item, see the details below.

What is grounding responsible for?

The word “grounding” in electrical engineering can be safely replaced by “safety” and “protection”, because this system implies connecting live devices to wires, which in turn are connected to an iron circuit submerged in the ground.

In the event of a current leak, due to a malfunction of equipment or damage to the insulating body, lethal volts will go into the bowels of the earth, and human health will be saved.

How to know the grounding

Among the many cores in the wire, it is important to correctly identify the grounding conductor, so that the error does not subsequently lead to sad consequences. There are several ways to determine the protective conductor:

By the order of the arrangement in the wire;
By the color of the insulating shell;
By letter marking;
According to the degree of stress.

Most often, grounding is included in the stranded wire along with the “zero” and phase conductors. It is possible to designate grounding in the order of location: grounding in a three-core wire will be the third, and among the five cores - the fifth.

The letter marking of the grounding wires also serves to quickly determine its purpose and eliminate confusion when connecting. International and Russian standards require a combination of letters “PE” to be applied to the protective line. If the wire is both grounding and zero, then the letter “N” is added to the indicated inscription.

The generally accepted colors of grounding wires in Russia and abroad are yellow and green, both individually and as part of horizontal, vertical and spiral patterns. It is important not to ignore this standard in order to facilitate installation, to protect your health and property.

However, color coding is not always respected by both manufacturers and installers, therefore it is recommended to apply all determination methods at once, and use the voltage test as a final one.

So, using a voltmeter, the indicators are measured on each core, where the highest value will belong to the phase, the lowest value to zero, and the intermediate value between them is protection.

How to choose a new wire

Replacing or setting up a new network - it doesn't matter, the main thing is to know what parameters a wire with a grounding function should meet. The main in the performance is the section. Competent selection of the diameter will exclude its heating over 400 ° C in the event of a short circuit.

What cross-section of the grounding wires is permissible is determined by a number of regulatory documents of the Russian and international level. So, the following numbers are called the maximum diameter:

For copper - 25 mm2;
For aluminum - 35 mm2;
For steel - 120 mm2.

However, in the installation of home wiring, it is better to be guided by the diameter of the supply conductor when choosing a cross-section.

Also, popular brands that differ from each other in the material of manufacture, type of core, rated voltage, withstand temperature and other parameters that are selected taking into account the existing wiring at home can also become a reference point.

“NYM” is a standard intermediate insulated copper wire capable of withstanding voltages up to 660 volts.
“VVG” is a multi-wire grade with reinforced insulation that does not spread combustion and is resistant to ultraviolet rays: polyvinyl chloride sheath, steel armor, fiberglass winding, bitumen mortar coating.
“PV-3” is an inexpensive single-core conductor with easily removable insulation.
"PV-6-3P" - for portable grounding, with a transparent protective shell and increased elasticity.
"ESUY" is a German product with increased short circuit protection due to resistance to high temperatures and chemicals.

How to connect

A well-chosen wire must be able to connect correctly, because by mixing up the clamps, it is easy to cause a short circuit and even a fire. At the same time, protection is present in almost all cords and devices connected to the network: household appliances, sockets, lighting fixtures.

To avoid mistakes, it is important to follow the instructions for connecting the wires:

Identify the ground wire in the shield.
Disconnect the power supply to the apartment or house.
Connect the wires: phase to phase, zero to zero.
Do not connect the neutral and ground wires together!
Lead the protective cable to the cover.
Check the operation of the network by switching on the current.

The photographs of the grounding wire show that outwardly it does not differ from other conductors, therefore it is important to be able to determine the purpose of the conductor if the manufacturers do not comply with the marking standards.

Once the grounding mechanism is properly configured, life will become calmer due to greater safety from nearby energized devices and devices.

Photo of ground wires

Grounding is the connection of non-current-carrying parts of electrical equipment to a grounding conductor. This ensures the presence of ground potential on the enclosures of electrical appliances. This is to prevent electric shock from touching housings and other structural parts of damaged equipment. The connection to the ground bus is made with a wire or cable. In this article, we will tell you what should be the grounding wire so that you can choose the right brand, section and other parameters.

Briefly about terms

To make the article understandable even for those who are far from electrical engineering, we have given an explanation of the terms that will be used in it.

An earthing switch is the basis of a grounding system. It is usually made of metal pins driven into the ground at an equal distance from each other, forming a shape like a triangle.

The grounding bus or is called a metal strip laid around the perimeter of the room or near the protected devices, which connects all grounding conductors of electrical appliances to the grounding conductor.

The grounding wire or core is the conductor that provides the connection of the ground electrode with the GZSH.

Metal bond is a concept that characterizes the contact between metal parts of electrical equipment cases, including the doors of electrical panels or cabinets with their cases.

Cross-section of the ground wire

To ensure reliable protection against electric shock and the operation of protective switching devices, the ground wire is selected depending on the phase section. This is necessary so that in the event of an accident it can withstand high currents and not burn out. If this happens, then the protection will not work, and the dangerous potential will be on the body of the electrical appliance.

The cross-section of the grounding wire must be:

If the phase is used with a cross section of up to 16 sq. mm - the grounding conductor must be of the same size.
If the cross-sectional area of the phase is from 16 to 35 sq. mm, then at the "ground" it should be 16 square meters. mm.
When the phase section is more than 35 sq. mm - the minimum cross-section of the grounding wire must be at least half of the phase cross-section.

Let's give two examples to answer the question of what cross-section should be at the grounding of the device:

You connect the electric stove with a cable with a cross section of 4 sq. mm. This means that the cross-section of the protective conductor must be the same.
An input cable with conductors of 50 square meters is connected to the electrical cabinet. mm. In this case, the grounding cross-section must be at least 25 sq. mm. More is possible.

Brand and requirements for conductors

The core of the grounding wire or cable can be both single-core and multi-core - it only depends on where it will be used. For example, to ground the door in the electrical panel, you need to ensure its mobility. A rigid vein will break from constant door openings and bending. Therefore, the conductor must have an appropriate flexibility class that does not interfere with opening, for example 3 or higher.

At the same time, to connect, for example, the electric motor housing of a pumping station to the GZSh, it is not necessary to provide mobility, since this type of electrical equipment belongs to permanently mounted. Therefore, rigid conductors can be used.

The grounding conductor can be:

isolated;
uninsulated;
is part of the cable;
be a separate solid wire;
aluminum;
copper.

Hence the question: so which wire to use to connect the ground?

The stores sell cable products with a different number of cores: 2, 3, 4, 5. This is necessary for assembling certain circuits for switching devices and connecting electrical equipment to networks with a different number of phases.

To connect grounding in sockets and other electrical equipment of a single-phase network, it is convenient to use three-core cables, for example, VVG 3x2.5. And for connecting three-phase equipment to the network and grounding, four-core cables are intended, for example, AVVG 4x32. In this case, in thick cables, the grounding conductor usually has a smaller cross-section than that of phase conductors. Here are some examples.

If you got a cable with a color marking that does not comply with GOST, you can mark the ground, phase and zero using electrical tape or heat shrink tubing. In addition to color coding, there is also an alphabetic or numeric one:

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

For connection in the distribution panel (and other places), ground and zero buses are often used. This is a rail with a set of holes and screw clamps where the wires are connected. To connect a ground wire with a stranded core, it is necessary to crimp it or crimp it with a pin tip of the type and the like. This rule also applies to connecting any flexible conductors to the terminals of machines and other screw connections.

To connect the wire to the grounding bus, it is necessary to use round terminals NKI, NVI or other types of cable lugs with ring-shaped terminals.

This may be required when laying grounding from the loop to the shield. They are usually of two types:

Crimp. In order to fix them on the cable, they are crimped with a special tool. You should not do this with pliers, because you will not achieve a reliable crimp. The best compression is provided by press jaws (also called crimper) with hexagonal (hex) clamps.
With shear screws - to tighten them, simply tighten the screw until its head breaks off.

That's all we wanted to tell you in this article. Now you know what cross section and grade the grounding wire should be. Finally, we recommend watching a useful video

The electricity supplied to our homes is an impressive force that can easily kill a person. Therefore, when installing electrical wiring, first of all, you need to take care of the safety of users.

In electrical engineering, the word "grounding" can rightfully be considered a synonym for the word "safety".

In this article we will talk about what a grounding wire is for and what requirements it must meet.

Under normal conditions, live parts of electrical equipment are separated from all others by insulation, so touching, for example, the body does not threaten the user.

But as a result of an accident, aging of the material or its damage by rodents, the insulation can be broken, as a result of which the body or other element is energized. As soon as you touch it, an electric shock immediately follows.

Ground wire

In order in such a situation to weaken or even completely prevent (when connected through an RCD) the effect of current on the user, all parts of the equipment that may be energized are connected with a separate wire to a ground loop immersed in the ground. Now, upon contact, the charge will pass through the user only partially, since some of it will go into the ground.

If the device is connected through an RCD (residual current device), then, as already mentioned, electrical injury can be avoided altogether: the device will fix the current leak in the circuit and immediately disconnect it.

The grounding system in a residential or industrial building must be present without fail - this is a requirement of the PUE and other regulatory documents. Moreover, a special act must be drawn up in this regard.

Marking

You need to know what color the ground wire is.

Typically, the ground wire is a separate strand that is part of the stranded wire that powers the appliance or outlet.

Thus, in a 1-phase network, it will be the 3rd residential, and in a 3-phase network, it will be the 5th.

In this case, a special marking is provided for the grounding conductor, which allows it to be distinguished from the phase or neutral conductor and thus prevents confusion when connecting:

Literal. PUE prescribe to apply the letters "PE" to the insulation of the grounding wire. The same designation is provided for by international standards. The specification of the cross-sectional area, grade and material is optional.
Color. Domestic and foreign standards for the grounding wire are assigned a combination of yellow and green colors. Some foreign manufacturers of cable products designate such a core only in yellow or only in green.

In addition to grounding conductors, combined conductors are used, which simultaneously perform the function of a zero working and zero protective. They are designated by the letters "PEN" and the combination of blue with yellow or green. One color of the ground wire is the main one, the second is applied in the form of stripes at the ends.

Installing the ground wire

Thus, it is quite simple to distinguish the ground wire from the zero wire, which is assigned the blue color and the letter "N", and from the phase wire (has brown, black or white insulation, indicated by the letter "L"). Color-coded not only made it easier to install electrical systems, but also to find and replace burnt, broken or overloaded wires.

Some manufacturers paint the phase conductor in other colors: gray, purple, red, turquoise, pink, orange.

Please note that the color coding does not indicate whether the network is 1-phase or 3-phase, or whether AC or DC is supplied to it. Thus, the conductors and buses of DC networks (used in construction, electric transport, substations, etc.) are also painted in red ("+"), blue ("-") and blue (zero bus) colors. In 3-phase networks, phases A, B and C are usually denoted in yellow, green and red, respectively.

The designation of veins in different colors is not used in all wires. So, in a 3-core PPV cable, which seems attractive due to its relatively low cost, you will not find yellow-green insulation, so it is very easy to confuse the cores when connecting.

Working ground

If the marking is not visible or absent, you can determine the grounding conductor in the wire connected to the network using a voltmeter: the voltage is measured between the phase conductor (it is determined by the phase indicator) and each of the two remaining ones. When the probe contacts "ground", the value on the instrument panel will be higher than when it contacts "zero".

You can also measure the voltage between the tested cores and any grounded device, for example, an electrical panel housing or a heating battery. If the core is zero, the device will show some small value; if by "ground" - the display will display zero.

The phase indicator, with the help of which the conductor connected to the phase is determined, is similar to a screwdriver, only the handle has a diode lamp and a special contact (usually in the form of a ring under the lamp). To determine the phase, you need to put your finger on this contact and at the same time the tip of a screwdriver - to the tested conductor. If it is energized, the light will come on.

It should be understood that connecting the consumer to the ground wire is not yet a sufficient safety condition. The wire itself on the other side must be connected to the ground loop.

It is enough for a resident of an apartment in a city high-rise building to find the appropriate contact in the switchboard, but the owner of a private house will have to create such a circuit himself.

Usually it consists of metal pins driven into the ground (in the form of an isosceles triangle), connected by reinforcement.

Cross-section of wire for grounding

This parameter is primarily determined by the power of the protected equipment. It is regulated by the following documents:

Chapter 1.7 of the PUE ("Grounding and protective measures").
Chapter 54 in part 5 of GOST R 50571.10-96 "Electrical installations of buildings" (repeats the international standard IEC 364-5-54-80).
Appendix RD 34.21.122-87 "Instructions for the arrangement of lightning protection of buildings and structures."

Yellow-green color at the grounding terminals

The main task in selecting the cross-section of the grounding wire is to exclude its heating when the maximum current flows (single-phase short circuit) above a temperature of 400 0 C. The maximum cross-section for a copper wire is 25 sq. mm, aluminum - 35 sq. mm, steel - 120 sq. mm. It makes no sense to use wires with a larger than indicated cross section.

When installing a household electrical network for grounding, it is enough to use a wire of the same cross-section as the cores of the supply wire.

Popular brands

A separate conductor for grounding contains wires of the following brands:

NYM

It is used to connect stationary installations and is designed for voltages up to 660 V. It can be used in explosive areas: class B1 b, B1 g, VPa - in power and lighting networks; class B1 a - only in lighting.

NYM cable

Characteristics of NYM grounding cable:

core material: copper;
core type: single-wire;
there is an intermediate shell;
the cores are color-coded as standard.

Cutting and assembly is very easy.

Fuse, circuit breaker and RCD are the main components of electrical safety. - connection diagram and professional advice.

An example of calculating a power supply for an LED strip is given.

Why is the light blinking when the switch is off and how to fix it, read.

VVG

Common to cables of this brand is the following:

core material: copper;
core type: multi-wire (twisting class - I or II);
insulation and sheath material: PVC (color coded);
there are two steel belts that serve as armor;
outside the cable is wrapped in fiberglass and coated with a bitumen compound.

The outer cover of the VVG cable does not spread combustion and does not collapse under the influence of ultraviolet radiation. Versions with a number of cores from 1 to 5 are available.

If the wiring has already been routed with 2-wire or 4-wire cable, the ground wire can be routed separately.

The following brands of cables are suitable for this:

PV-3

Stranded single core copper cable. Insulation - single layer, PVC. During installation, it should be easily removable from the core. If the insulation stuck to the copper, it means that violations were made during production or storage.

PV-3 cable is produced with a cross-section from 0.5 to 240 sq. mm.

PV-6-ZP

This cable is used for portable grounding.

Like the previous one, it is a copper multi-wire single-core, but it also has some differences:

the class of the vein is higher (No. 6 versus No. 2, 3 and 4 at PV-3);
the insulation is made of a transparent variety of PVC, which allows you to visually monitor the condition of the core;
withstands temperatures from -40C to + 50C;

PV6-3P is not afraid of alternating bends (at an angle of up to 180 degrees and a bend radius of at least 50 mm).

ESUY

This cable is manufactured in Germany. Designed for use as a grounding conductor in short circuit protection systems. It is able to withstand high temperatures and has a particularly strong and chemically resistant shell.

Since the ESUY cable was originally intended for the organization of grounding, the nominal voltage for it is not standardized.

Video on the topic

Almost any manual for the operation of a modern household electrical appliance indicates the need for its grounding. How to ground it? Can I turn on without grounding? Will it work normally at the same time? Can. Will.
Most of our fellow citizens live in houses where there is no grounding. And everyone has modern household appliances. Accordingly, most of the equipment designed for grounding is quite successfully operated without it.

Grounding is used to protect a person from electric shock. During normal operation of an electrical appliance, its body is reliably isolated from live parts under voltage. In the event of a breakdown of the device, live parts under voltage may touch the case and then it will be energized. A person who touches such a device will be electrocuted.

The automatic switch in this case will not help, since the current flowing through the person will clearly not be enough for its operation. But this current is quite enough to deprive a person of health and even life.
To avoid such situations, the housings of all electrical devices that a person can touch must be grounded, that is, electrically connected to the ground through conductors. In this case, the current from the device case, and with it the dangerous voltage, will go into the ground without causing any harm to humans.
To provide such grounding, Europeans added a ground wire to the electrical wiring of residential premises. The electrical wiring turned out to be three-wire. Two wires, as in our wiring - phase and zero, are designed to power electrical appliances, and the third is protective ground.
The sockets of such a wiring must have three contacts - neutral, phase and ground. Appliances designed for such wiring have a three-core cord and a three-prong plug. Two cores of the cord are phase and zero, and the third is designed to connect the device case to the ground of the wiring. The receptacle grounding contact (metal strips top and bottom) connects to the protective earth of the electrical wiring. The grounding contact of the plug is connected to the body of the appliance.
By plugging the plug into the socket, we connect the metal body of the device to a protective earth. Now, even when a voltage appears on the body of the device, the entire charge will drain into the ground, and the faulty device will not be shocked.
Grounding of household appliances is possible only if the house has a ground loop. Unfortunately, it is not in the old houses. In those days, the wiring was carried out with a two-core wire, one of the cores was zero, and the other was phase. Sockets and plugs also had two contacts, zero and phase. Nobody thought about any grounding at that time. Indeed, at that time, people practically did not have household appliances and there were quite enough safety plugs for six amperes in their houses. That is, if the power of all electrical receivers included in the apartment reached one and a half kilowatts, the plugs burned out.
With the development of technology in people's homes, more and more electrical assistants have become. Somewhere from the mid-sixties, TVs, refrigerators, washing machines, and electric irons began to appear in homes. The nineties brought computers, automatic washing machines, dishwashers, air conditioners, etc. into our everyday life. Along with the increase in the number and power of electrical receivers, the number of cases of electric shock to people from faulty electrical appliances began to increase. This problem had to be somehow solved and since 1997 the builders were obliged to equip all buildings under construction with protective grounding.
In houses of modern construction, all electrical wiring is performed with three wires, and there are no problems with the operation of modern technology.

In old houses, with two-wire wiring, even absolutely serviceable equipment can be electrocuted. The fact is that household electrical appliances are equipped with a built-in surge protector that protects the electronic circuits of the device from sudden voltage surges. The design of the filter is such that it connects the neutral and phase wires to the device body through capacitors. If the body of the device is not grounded, then a voltage of 110 volts appears on it. That is, there is a voltage of 110 volts on the case of a washing machine, refrigerator, microwave oven, computer.
If you live in a house with old wiring without grounding and you have some knowledge of electrical engineering, try measuring the voltage across your computer, refrigerator, and washing machine. It is possible that there will be a voltage of 110 V. This statement sounds like nonsense. After all, manufacturers are well aware that the equipment they produce must be absolutely safe for a person and in no case harm his health. But the creators of imported equipment, far from Russian reality, do not imagine that somewhere it can work without grounding. This circumstance allows us to understand the logic of the manufacturer. The new technique relies on a small amount of current to drain from the capacitors to ground through the instrument case. 110V voltage appears on the case only if it is not connected to ground.
Despite its large magnitude, this voltage does not pose a serious danger. The small capacitance of the filter capacitors limits the amount of current so that it cannot seriously harm humans. You can only get an unpleasant electric shock from it if you simultaneously touch the energized case and any grounded object, such as a battery or a water tap. Although it is not worth doing this on purpose, no one can guarantee the successful outcome of such an experiment.
The situation is much worse when, due to a breakdown of the device, its case is connected to the supply wire. In this case, there will be 220 V on the device case and the current value will no longer be limited by the capacitors of the mains filter. Touching such a device can, in an unfavorable combination of circumstances, lead to death.
Despite the fact that faulty household appliances can be a source of serious danger, most of the population of our country lives in houses without grounding and is not even aware of the dangers that lie in wait for them. Almost all of us were electrocuted, but few have experienced serious electrical injuries. What explains this selectivity of the current? Why does he maim and kill some, and only slightly clicks on others?
The effect of the current on the human body is determined by its magnitude. A person is able to sense a current of one milliampere. A current of one to ten milliamperes causes pain in a person. A current above ten milliamperes causes a convulsive contraction of the muscles, as a result of which a person cannot independently unclench his hand in order to break contact with the energized current-carrying part. With a current over forty milliamperes, respiratory paralysis occurs, and heart failure. A current of one hundred milliamperes leads to cardiac arrest and death.
The magnitude of the current flowing through the human body depends on the magnitude of the voltage applied to it and on the resistance of the circuit through which the current flows. In order to understand why, at the same voltage, the current in one case can only cause unpleasant sensations in a person, without causing him any harm, and in the other to kill, it is necessary to understand what a current circuit is and how it is created.
The current path is the path of current flow and this path is always closed. The current comes to our house from the transformer substation through the phase wire, after which it returns to the same substation through the neutral wire. Moreover, how much current came from the substation to the house, the same amount should return from the house to the substation, no more and no less.
The current does not necessarily return to the substation only through the neutral wire. If the insulation is damaged, current may leak to earth. In this case, part of the current will return to the substation via the ground, and some via the neutral wire. But in this case, the total current returned to the substation will be equal to the current flowing from the substation to the consumer.
If for some reason the return of the current to the substation is impossible, for example, the neutral wire at the substation has burnt out, then there will be no current in the consumer's houses. There will be voltage in the sockets, both in phase and zero contacts of 220 volts, but the current will not go through the devices and they will not work.

Why is it impossible to perform grounding in houses?

By the way, this case clearly shows why it is impossible to perform grounding in houses, that is, to connect the device cases to the neutral wire, as would-be electricians sometimes do in houses where there is no grounding. Indeed, as long as everything is working normally, there is not much difference to the neutral or ground wire, the cases of the protected electrical devices are connected. But when the neutral wire burns out on it, and therefore on all devices connected to the neutral wire, a voltage of 220 V will appear. The same will happen if, when repairing the switchboard, the electrician confuses the neutral wire with the phase one. In this case, the instrument cases will be connected not to zero, but to the phase wire, and a voltage of 220 V will also be present on them.
So, the current circuit is the path of current from the substation to the consumer and back from the consumer to the substation. If in some place it is broken, there will be no current in the circuit. The birds sitting on the wires are not electrocuted just because there is no circuit for the current to pass. An electrician standing on a rubber mat does not shock, because the mat prevents the current from returning to the substation along the circuit: phase wire -> electrician -> earth -> substation. This is the reason why, at the same voltage, the current can only slightly pinch a person, and maybe even kill. It all depends on whether he has a reliable path to return to the transformer station or not. If there is, then the person who has fallen under stress will not seem a little.
On the Internet, a tragic incident is described that happened to a boy who wanted to do his homework in the evening garden. He took a plugged in desk lamp with an extension cord and began to carry it out of the house. The lamp was defective - the live phase wire was touching the lamp body. The boy held in his hands the live lamp body, but he was not shocked. The dry wood floor prevented the current from returning to the substation. As soon as the boy got off the porch and stepped on the ground, a closed current circuit was created: transformer substation -> phase wire -> table lamp -> man -> earth -> transformer substation again and the boy was electrocuted. There could be no tragedy. If the lamp, extension cord and wiring in the house were grounded, then the current from the lamp body would flow through the ground without harming the boy.
If it is not possible to install grounding in the house, then at least it should be remembered that the current should not be able to return to the substation through the ground. Only on a specially designed neutral wire. Never touch electrical appliances and grounded parts such as batteries, water pipes, etc. at the same time to prevent the current from passing through you into the ground and returning to the substation. If the floor in the room is damp, then it is advisable that you have shoes with waterproof soles, which will become a barrier between you and the conductive floor, in case you accidentally get under stress.

What is an RCD?

If you are not satisfied with such methods of ensuring electrical safety, and it is not possible to install grounding, then there is another powerful tool that can reliably protect you from the traumatic effects of electric current. This is a residual current device, better known under the abbreviation RCD. It compares the phase current to the zero current. If the current in the phase conductor is even slightly more than the current in, then there is a leak and part of the current returns to the substation through the ground. In this case, the RCD will instantly turn off the line and if the cause of the leak is a person who is under voltage, through whom the current flows into the ground, then nothing terrible will happen to him. The RCD will have time to turn off the current before it has time to harm a person. Although accidents involving electric current in the home are very rare, it is not worth saving on such devices. After all, a person's life is too precious to neglect such a danger.

Video: why do you need grounding and what is an RCD

General concepts.

Earthing- deliberate electrical connection of any point in the network, electrical installation or equipment with a grounding device.

Grounding consists of earthing switch and grounding conductor connecting grounding device with earthed part.

Earthing switch is a metal rod, most often a steel, or other metal object in contact with the ground directly or through an intermediate conductive medium.

Grounding conductor Is a wire that connects the grounded part (equipment case) to the grounding conductor.

Grounding device Is a set of grounding conductors and grounding conductors.

A bit of theory.

Taking high voltage mains 6 - 10 kV(kilovolt) the substation converts it and transfers it to the consumer - that is, to us. Acceptance and conversion of voltage is provided by a power transformer, from the output of which a three-phase alternating voltage goes to the consumer 0,4 kV or 400 Volts... One of three phases is used to power single-phase household equipment (TV, refrigerator, iron, computer, etc.) L1; L2; L3 and zero worker conductor " N».

Grounding systems.

Let's consider the example of a transformer substation.
The secondary winding of the substation power transformer has three coils connected " star", Where the beginnings of the coils are connected to a common point, called neutral « N", Which is directly connected to grounding device... The free ends of the coils are connected to the wires of a three-phase network that goes to consumers of three-phase or single-phase electrical energy. This neutral connection is called deafly grounded and is used in grounding systems such as TN.

Here is neutral " N", Or else it is called working zero, performs two functions:

1. Together with one of the three phases, it forms a voltage of 220 volts.
2. Performs as it has direct contact with the ground.

At the moment, there are 3 types of grounding systems:

Grounding systems are designated by two letters.
The first letter defines the connection of the neutral of the transformer to earth:

T- neutral is grounded;
I- neutral isolated from earth.

The second letter defines the connection of the exposed conductive parts to the ground:

T- exposed conductive parts are directly grounded;
N- open conductive parts are connected to the solidly grounded neutral of the transformer.

Now let's look at all the systems in order.

1. TN earthing system.

System " TN"Is a system in which neutral transformer grounded, and the exposed conductive parts are connected to neutrals through zero protective conductors.

So, in turn, the system TN is divided into three more subsystems:

TN-C system.

Today, almost all modern equipment is powered through switching power supplies that do not have galvanic isolation with a 220 volt network. This is due to the fact that switching power supplies have suppression filters, which are designed to suppress high-frequency noise from the 220 Volt supply network, and which are connected to the equipment case through decoupling capacitors.

In other words, conductor wires from the house and from the roof lead to one circuit, buried in the ground. A frame of 3 electrodes is enough. This is the name for type 1 conductors in contact with an ionic conductor.

The electrodes for the ground loop must be "bare", that is, without anti-corrosion dielectrics. They are limited to varnish in welding places.

It is necessary to take into account the gradual thinning of steel under the influence of corrosion. Therefore, the electrodes are taken with a cross-sectional margin. There are minimum requirements. So, the width of the galvanized rod should be 6 millimeters or more. The minimum for ferrous metal rods is a centimeter.

The electrodes in the ground loop are connected with a steel tape. This is called thrips. It is welded to the electrodes. Can be done DIY grounding... It is important to take the contour one meter away from the walls and 5 meters away from the walking paths and the porch of the house.

Accordingly, it is convenient to lead the conductors to the rear walls of the building and the roof slopes. However, there are houses with several entrances. It is important to remove the contour 5 meters from each.

In private houses, it is convenient to make a natural grounding system. It consists in using the elements already available in the structure to conduct current. For example, reinforcement can carry stress along the foundation. In general, you can save on the purchase of wire and maintain the natural look of the building. The wire, by the way, is called an artificial ground electrode.

In an apartment building, the grounding system is connected to the shields. They must be included in the circuit of the system. The connection with him takes place through ground bus... There are many conductors connected to it. The bus allows you to equalize the potential of the network.

The element is made of iron. In fact, copper and aluminum will do better, but are expensive and there is a risk of metal cutting out for delivery to collection points. You can even make a tire out of gold, which is also illogical in the presence of a cheap and uninteresting collectors of iron alloys.

The ground wire, even in an apartment, even in a house, must be included in the main wiring to coincide in cross section with the phase conductor in the wiring around the house. This is the standard. Accordingly, the wiring is done with three wires.

One "vein" in it is zero, the second is a phase, and the third is grounding. Socket with it is supplied with contacts. They are brought up to the body. Its inclusion automatically "starts" not only the running of the current, but also the work of the earthing switch.

The deterioration of the insulation does not only lead to short circuits. The circuit breakers react to them. Most often, small currents "drain" from the system. They are configured with an RCD. The abbreviation stands for Residual Current Device. However, both devices direct the surplus current to the ground wire, which leads the voltage to the ground.

In addition to stationary grounding, there is a portable one. It is used, as a rule, at enterprises during disconnection from the current of network sections near electrical installations. There is a risk of erroneous voltage supply or induced currents. The latter is understood as a kind of throwing of electrons from an adjacent line, which remains conducting.

Portable grounding- this is a conductor carried with you, preferably made of copper. Her resistance is minimal. The wire is connected to a live line. It is previously de-energized. The other end of the portable conductor is connected to grounding conductors. We are talking about natural or artificial outlets of the electron flow.

Which tool will come in handy

For artificial earthing, steel rods, corners and pipes are taken. The latter can be either circular or rectangular. Concrete is also fine. It has a conductive type. The use of concrete is beneficial in terms of the material's resistance to corrosion.

The electrodes are driven into the ground with a sledgehammer. With factory sets, they work with bumpers. Brass threaded couplings are used to connect the pins. The connection of the conductive wire to the electrode goes through the clamp. Take steel.

A special paste helps to reduce the resistance at the joints. You can find it in electrical stores. The structure is welded, of course, with a welding machine or in the old fashioned way with a soldering iron. A stepladder also comes in handy during installation.

Do not forget about the steel, copper sleeve, if we make grounding in an apartment building. In general, the exact set of inventory depends on the type of building, its number of storeys, and the power of the network.

It's no secret that a huge number of houses in our country have the old TN-C grounding system. This is when two-wire electrical wires are divorced in apartments. One wire is the "L" phase, and the second wire is the "PEN" conductor (combined zero working and zero protective conductors).

Today, gradually, but very slowly, there is a modernization of the power supply of apartment buildings, i.e. transfer to a more modern and safe grounding system TN-C-S. If this has already happened in your house, then this is just happiness for you)))

But the repair of the old electrical wiring in the apartments falls on the shoulders of the owners themselves. Here, many people are reasoning sensibly and, during a major overhaul, they change all the electrical wiring. If your house has a new TN-S grounding system or an already modernized TN-C-S, then you simply have to connect all the sockets with a three-core cable, i.e. N and PE conductors must be separate conductors.

If your home still has the old TN-C grounding system, then also use three-core cables when replacing electrical wiring. Look ahead to the future. What if, in the near future, electricians will come to your house and modernize the power supply of the whole house. In this situation, you will only need to connect the neutral protective conductors to the grounding bus of the floor board. If you don't take care of the future, save a little money and lay two-core cables, then in order to transfer your apartment to a safe grounding system, you will need to do a major overhaul again with the replacement of all cables.

So, now I am gradually moving on to the most important point of the article itself.

Your house is with the old TN-C grounding system and you laid three-core cables everywhere during the replacement of electrical wiring. That's the right decision . Where to connect the two cores - this is "phase" and "zero" is clear. In such a situation, people often have another question: where do you need to connect the third yellow-green cores of cables, which are designed to perform the functions of zero protective conductors? In such a house, there is still no separate main protective conductor.

Very often I hear the following answers to the question of where to connect the ground wires if the house has an old TN-C grounding system:

Grounding conductors must be connected to risers and radiators for heating and water supply, as they are grounded.

Personally, I think all these answers are incorrect, erroneous and dangerous for the very same apartment owners. Below I will try to explain my point of view. In the comments, you can express your opinion on this matter.

Let's first consider the situation in a house with a new TN-S grounding system. Below is an elementary diagram of the switchboard. The apartment panel in the house with the modernized TN-C-S grounding system will have a similar scheme.

Now let's imagine an emergency situation where a hazardous voltage is applied to the grounding pin of an outlet. This can happen due to the failure of the outlet itself, due to breakdown of household appliances, etc. I depicted this situation in the diagram below for the third outlet. Let's assume that the phase "L" has got to the contact of the socket "PE". Believe me, this happens quite often. Since we have all grounding contacts connected to the building's ground loop and the ground potential is considered to be zero, this "emergency" current will run along the path of least resistance.

Namely, its path will be as follows: the grounding contact of the outlet - the zero protective conductor in the apartment - the grounding bus of the apartment shield - the zero protective conductor from the apartment to the floor shield - the grounding bus of the floor shield - the main zero protective conductor - the grounding circuit of the building.

Thus, it turns out that the potential dangerous to humans will "run" along the path of least resistance and go into the ground. If this outlet is protected by an RCD or a difavtomat, then these protective devices will immediately work and de-energize the faulty line. So the person will be protected.

Below in the diagram, I showed the path of the current movement with arrows.

Now, a similar elementary diagram of a switchboard for a house with the old TN-C grounding system is presented below. Here two wires "L" and "PEN" come into the shield, and a new three-core electrical wiring goes to the sockets. This diagram shows the most common situation. This is when all zero protective conductors are connected to the contacts of the sockets on one side and connected to a common ground bus on the other side, but the ground bus itself is not connected to the building of the floor board.

Let's now imagine a similar emergency here and see what happens. In the third socket, phase "L" has hit the grounding pin of the socket. Where will she run next?

The answer here is logical - it will not run anywhere, but simply the dangerous potential will first fall on the common ground bus and then spread from it to all grounding contacts of all remaining sockets, and through them to the metal cases of electrical appliances (refrigerator, washing machine, microwave, etc.) etc.). In this grounding system, there is no connection between the PE bus and the ground loop and there is no point with zero potential to which the current would tend. The conclusion from this can be made such that in this situation a person can get an electric shock and household appliances can fail.

Now let's analyze all the answers that I have already listed above for the question where do you need to connect the ground wires if the house has an old TN-C grounding system?

All grounding conductors must be brought into the home panel, connected in it to a common grounding bus and then this grounding bus itself must be connected to the housing of the floor panel.

My answer: This cannot be done, since the floor shield may not be grounded and the dangerous potential may appear on its body and on the metal cases of your household appliances. This will pose a great danger to you and to other residents of the house.

All grounding conductors must be brought into the home panel, connected there to the common grounding bus, and this grounding bus itself must not be connected to the housing of the floor panel.

My answer: You can't do that. I have already considered this situation above in the described emergency for a house with a TN-C grounding system.

All grounding conductors must be brought into the home panel, connected in it to the common grounding bus and then connected with a jumper to the zero bus, i.e. make the transition from TN-C to TN-C-S in the apartment panel.

My answer: You can't do that. The essence of the transition to the TN-C-S grounding system is to re-ground the PEN conductor at the point of its separation so that the dangerous potential goes into the ground. This cannot be done in the dashboard. If, with this connection of the conductors, an emergency occurs and the phase falls on the grounding contact of the outlet, then a short circuit will simply turn out. The PE conductor is connected with a jumper to the N conductor, and therefore it turns out that the "phase" immediately falls to "zero". And we know that a short circuit occurs with sparks and burnout of contacts. A "bang" can happen at your outlet or home appliances, which can be very dangerous.

All grounding contacts in the sockets themselves must be connected with jumpers to the contacts of zero working conductors.

My answer: You can't do that either. This situation is similar to the situation from answer # 3.

Grounding conductors must be connected to risers and radiators as they are grounded.

My answer: You can't do that. The grounding of the heating and water supply pipes may be interrupted. For example, someone on the floor below, during a renovation, cut out old metal pipes and installed new polypropylene pipes. The connection of the metal pipes of the upper floors with the "ground" will be broken. In such a situation, if a dangerous potential gets to the grounding contact of the outlet, then the risers and pipes of heating and water supply will be energized. This is very dangerous for you and for other residents of the house.

Now I turn with my answer to the question of where to connect the ground wires if the house has an old TN-C grounding system.

Personally, I believe that neutral protective conductors must be connected as follows:

In the apartment panel, you need to install a common grounding bus and connect to it all the third yellow-green cable cores coming from the sockets.
During repairs, lay a separate wire, for example, PUGV, to organize the grounding of the PE bus of the apartment panel from the PE bus of the floor panel, or use a three-core lead-in cable for this purpose. In a home shield, the neutral protective conductor can be connected to the ground bus. Do not connect it in the floor panel, but simply twist it carefully and hide it from unauthorized persons.
In the sockets themselves, do not connect the zero protective conductors to the grounding contacts of the sockets. They just need to be carefully twisted and hidden deep into the socket.

Someone will say that it is better to connect zero protective conductors in the outlets themselves, and not connect them only to the PE bus in the apartment panel. Also, later, when transferring a house to the TN-C-S grounding system, it will be easier to just put them on the PE bus and not open all the sockets, of which there may be several dozen.

I answer why it is not worth doing this. As a rule, one outlet group (line) can include several outlets. If zero protective conductors are connected in them and their common PE conductor is not connected in the shield, then the following situation will result. All yellow-green cores of one socket group are always combined into one line (core) on the way to the panel, for example, in a junction box. Only one cable from several outlets comes to the shield. Therefore, all receptacles in the same receptacle group will have a good connection between the grounding pins. If the "phase" in one of these sockets hits its grounding contact, then this "phase" will also fall on the grounding contacts of the remaining sockets. So there will be a dangerous situation in multiple outlets.

So, if you connect the grounding wires according to the proposed scheme, then a dangerous situation will be excluded with the phase hitting the grounding contacts of all sockets and on the metal cases of household appliances. Here, the phase that has fallen on the grounding contact of the outlet will not go anywhere further and the emergency situation will be only at one point, and not in the entire apartment.

Below is the correct connection diagram for grounding wires in a house with an old TN-C grounding system. Red crosses mean that a zero protective conductor comes here, but is not connected.

I hope my reasoning and arguments on this issue are clear to you. If you have a different opinion and think that I am wrong and wrong, then be sure to write it down in the comments. Finding the correct and safe solution in connecting ground wires in houses with a TN-C grounding system will be very useful to you and myself. Thanks!

Let's smile:

High voltage is dangerous for your health, and low voltage is pleasant or beneficial)))