What cable cross-section is needed to connect an apartment?

The cable with which a consumer object (house, apartment, workshop, store, etc.) is connected to a power source is called an input cable. Most often, the input cable is connected directly to the electrical energy meter. To protect the meter, a circuit breaker may be installed in front of it, but such a scheme must be agreed upon with the electricity supplier and reflected in the technical specifications. In this case, the circuit breaker is sealed to prevent energy from being drawn to the meter.

Section diameter is an indicator of cable power

Physical laws say that the maximum amount of current that this conductor can conduct through itself without heating depends on the cross-sectional diameter of the conductor. If you try to conduct a current more than the limit figure, this will lead to heating of the conductor, and the greater the current and the duration of the “session”, the higher the temperature.

For a residential subscriber, the above is interpreted as follows.

The diameter of the cable cross-section means the maximum permissible number of kilowatts (kW) that can be consumed in the apartment. That is, which and how many electrical appliances can operate simultaneously. The larger the diameter, the more devices can be used simultaneously without any fear for life and health. Theoretically, it is possible to “hang” more power on the cable than its diameter allows. But in this case, heating of the current-carrying conductor, damage to the insulation, followed by the effects of burnout, combustion... ignition, is inevitable.

Therefore, the choice of the cross-section of the input cable must be approached with all seriousness: after all, both the safety and ease of use of household electrical appliances depend on it.

conclusions

In order to find (or install) a wiring diagram in an apartment panel building, you need to know data about the house itself. The luckiest ones will be able to find documentation for this particular type of construction, but they will have to rely on the builders to comply with it unquestioningly. Do not forget that the channels intended for routing wires often had manufacturing defects - they were clogged with rubble or did not have sufficient depth at all.

It is also worth remembering the basic principles of cable management that were followed in all Soviet houses:

But one should not rule out the appearance of cables under the baseboards or floors - such passages were not uncommon in panel houses. Particular attention should be paid to the gaps between the slabs: the ban on placing wires in them was often ignored by electricians for lack of other options.

Of greatest interest to craftsmen are devices for finding hidden wiring. It is much better to choose portable metal detectors - they will help you find both de-energized conductors and live wires. Budget solutions include the domestic "Woodpecker" and the Chinese MS, and in the more expensive segment - Bosch. It is better not to use thermal imagers and improvised means (indicator screwdriver, receiver, etc.): the search depth is a couple of centimeters, and the accuracy leaves much to be desired.

Section calculation algorithm

There is a proven diagram for calculating the cross-section of the input cable, which is used in design. It is based on the postulate that the cross-sectional diameter of the input cable is selected depending on the expected power of all devices operating in the apartment.

Stage 1: Inventory

At the first stage, a list of electrical appliances that are present in the apartment is compiled. It is assumed what equipment will be purchased in the future and the list is expanded. Assumptions, of course, are best made with a reasonable margin for the long-term future. Each device is assigned an approximate power consumption.

You can use a table that roughly shows a list of typical household electrical appliances and their approximate power consumption.

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Stage 2: Simple Arithmetic

Next, the total cardinality of our list is calculated. The approximate power required for lighting is added, depending on the size of the apartment, the expected lighting intensity, and the expected type of lighting fixtures.

The resulting figure is an estimate of the power consumption in the apartment for the case if all devices are turned on at the same time. However, such a situation is very unlikely, and therefore in electrical engineering it is generally accepted that a maximum of 75% of the available equipment is turned on at the same time. And the resulting total power is multiplied by a factor of 0.75, and the resulting figure is taken as the basis for calculating the cross-section of the input cable.

Stage 3: Logic and Physics

Currently, electrical cable cores are made of copper and aluminum. There are formula relations that connect the maximum permissible current (and, accordingly, power) for a copper cable with the diameter of its cross-section. For standard copper cable sizes, there are calculated current and maximum power ratings for 220V and 380V AC. The following table provides these figures in a "usable" form.

Let us assume that the calculated power of all devices is 12 kW, and with a coefficient of 0.75 - 9 kW. It turns out that you need to choose a cable for which the maximum permissible power will be at least 9 kW. For a voltage of 220 V, a cross-section with a diameter of 6 mm is required - it is capable of passing a current of 46 A and a power of 10.1 kW. For the smaller cross-section from the table - 4 mm - the maximum permissible current is 38 A, and the power is 8.3 kW. This is less than necessary, so a cable of this cross-section will not work and you should stop at a 6-mm cross-section.

If you choose a cable with a larger cross-section than necessary, this will provide a good reserve for the future (for example, the emergence of new powerful household appliances) and a reserve for wear. However, you should also not exceed the rated power too much: this will affect the cost of the input cable, and the input cable may turn out to be more powerful than the internal electrical wiring, which is not reasonable and safe.

What else is needed

A machine must be installed on the input cable, which will be tasked with turning off the power supply if the current approaches the maximum permissible level. The rating of the machine is selected slightly less than the maximum permissible current through the input cable: in this way an additional degree of protection is provided. In this example, you should install a 40 A machine.

So, the parameters of the input cable require careful selection. Errors threaten, for example, a “bottleneck” situation - when all the home electrical wiring is powerful enough, but the input cable is not able to provide the required power. The cross-sectional diameter of the input cable is selected taking into account the total power of electrical appliances that will be used in the room. In order for all the nuances to be taken into account and the input cable to serve for many years without any emergencies, it is better to entrust the reconstruction of the electrical wiring to professional electricians.

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According to the finished plan

As mentioned above, it is most accurate to calculate the cable length using a ready-made wiring diagram.

A well-developed plan diagram should include the following data:

You also need to decide on the method of connecting powerful electrical appliances. It is best if separate lines are laid for them from the electrical panel.

Using a ready-made plan diagram, where all this data is indicated, you can quite easily and accurately calculate the length of cables required to supply power to an apartment or private house. Ideally, at the design stage, the walls are also marked, which allows you to then use a tape measure to obtain the exact lengths of all lines.

Additionally, the following points should be taken into account when calculating:

What should be the cross-section of wires in apartment wiring?

Recently, visitors to our site contacted us with a request to dwell in more detail on such an issue as the cross-section of wires in a city apartment. This is the reason for the appearance of this article, which, I hope, will be useful for those who are planning to make repairs or are simply concerned about the state of the electrical wiring in their home.

Even an uninitiated person understands that the size of the cross-section is determined by the total power of the devices connected to the intra-apartment electrical network. Its different sections are subject to different loads, according to which the thickness of the cable should be selected, which can be:

1. Introductory.
2. Powering an electric stove or hob.
3. Serving socket groups.
4. Powering lighting fixtures.

It is from the above division that I will proceed when talking about what cross-section a cable laid in a certain part of the apartment wiring should have.

If you are planning to install electrical wiring in your apartment with your own hands, be sure to read this article! It will help you avoid a large number of possible mistakes.

4.2.96

Doors from the switchgear must open towards other rooms or outwards and have self-locking locks that can be opened without a key from the switchgear side.

Doors between compartments of one switchgear or between adjacent rooms of two switchgears must have a device that locks the doors in the closed position and does not prevent the doors from opening in both directions.

Doors between rooms (compartments) of switchgears of different voltages must open towards the switchgear with the lowest voltage.

Locks in the doors of switchgear rooms of the same voltage must be opened with the same key; keys to the entrance doors of the switchgear and other premises should not fit the locks of the cells, as well as the locks of doors in the fences of electrical equipment.

The requirement to use self-locking locks does not apply to switchgear of urban and rural distribution electrical networks with a voltage of 10 kV and below.

Residential input cable cross-section

The power per input cable and, accordingly, the strength of the current carried by it is limited by the amount of allocated power, determined by Energosbyt and controlled by the input machine. Its response threshold is usually 25A. Most often, in apartment buildings, incoming automatic machines are installed in electrical panels outside apartments. The cable laid from the machine inside the living quarters is precisely the introductory one, which I will now talk about.

In apartments, the cross-section of the input cable can be:

• in single-phase networks - copper cable 3 × 10 mm 2 (three-core - phase, ground and neutral; 10 mm 2 for each core) paired with a 50 A circuit breaker;
• in three-phase networks - copper cable 5 × 4 mm 2 (five-core - three phases, ground and zero; 2.5 mm 2 for each core) paired with a 25 A circuit breaker.

The power supplied may vary depending on the age of the building and whether it has gas or electric stoves. Indirect evidence of the real value of this parameter can be the nominal value of the machine at the entrance to the apartment. In any case, you will never regret if the wires indicated just above are used as the input cable.

How much does a turnkey electrician cost?

Cost of electrician service in a turnkey apartment

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Cable for apartment sockets

The optimal cross-section of wires serving apartment socket groups is 2.5 mm 2. This allows them to withstand currents of up to 27 A, which corresponds to a total power of approximately 6 kW. The use of conductors with a larger cross-section, for example, 4 mm 2, is impractical because:

1. Such cables simply cannot fit into the terminals of socket mechanisms.
2. Laying such cables is significantly more expensive and is not economically feasible.

And there is no practical need for thicker cables, because... It is rare to find household electrical appliances plugged into an outlet whose power exceeds 3.5 kW. Thus, by placing cables with a cross-section of 2.5 mm 2 in the wiring of the socket groups, you can sleep peacefully: they are able to withstand any electrical appliances, even if they operate for a long time.

4.2.91

The width of the service corridor for switchgear with withdrawable elements and package transformer substations should ensure ease of control, movement and reversal of equipment and its repair.

When installing switchgear and package transformer substations in separate rooms, the width of the service corridor should be determined based on the following requirements:

for single-row installation - the length of the largest of the switchgear trolleys (with all protruding parts) plus at least 0.6 m;

for a double-row installation - the length of the largest of the switchgear trolleys (with all protruding parts) plus at least 0.8 m.

If there is a corridor at the rear of the switchgear and package transformer substations for their inspection, its width must be at least 0.8 m; Individual local narrowings of no more than 0.2 m are allowed.

When installing switchgear and package transformer substations openly in production premises, the width of the free passage must be determined by the location of the production equipment, ensure the possibility of transporting the largest switchgear elements to the switchgear substations, and in any case it must be at least 1 m.

The height of the room must be no less than the height of the switchgear, package transformer substations, counting from busbar entries, jumpers or protruding parts of cabinets, plus 0.8 m to the ceiling or 0.3 m to the beams.

A lower room height is allowed if this ensures the convenience and safety of replacement, repair and adjustment of switchgear equipment, package transformer substations, busbar inputs and jumpers.

Lighting system wire cross-section

Surely, you yourself understand that lighting fixtures place the least amount of stress on apartment electrical wiring. Therefore, a wire cross-section of 1.5 mm 2 is quite sufficient for a standard apartment in an apartment building. However, when laying the wiring, you should be absolutely sure that the total load of each lighting group does not exceed 3.5 kW. Due to the traditionally low load, all apartment lighting, as a rule, is reduced to one group, served by a 1.5 mm 2 cable.

A wire cross-section of 1.5 mm2 is quite sufficient for wiring that supplies power to lighting fixtures

So, to summarize, I’ll just remind you of the bare numbers. Most often, the cross-section of wires in a city apartment is:

• input cable – 3×10 mm 2 (single-phase network), 5×2.5 mm 2 (three-phase network);
• electric stove (hob) – 3×6 mm 2 (single-phase network), 5×2.5 mm 2 (three-phase network);
• rosette groups – 3×2.5 mm 2;
• lighting devices – 3×1.5 mm 2.

However, I must emphasize the phrase “most often” that I used. If you initially plan to install very powerful devices in your apartment, then before laying the electrical wiring you should make the necessary calculations so as not to make a mistake in choosing cables of the required cross-section. The best option is to contact a professional electrician.

Required Tools

Stripper for removing insulation
To reliably make a connection in the panel, you need to purchase special tools in advance. They must be professional and have insulated handles. Required tools include:

• Hammer.
• Bulgarian.
• Screwdrivers, including an indicator screwdriver for checking the absence of voltage on the wires.
• Knife.
• Device for stripping insulation.
• Pliers.
• Wire cutters.
• Portable lamp.

After preparing the tool, you can begin installation.

Wire cross-section for entry into the apartment

Hello, I would like to rehang the panel in an apartment (new building, complete renovation) and accordingly I need to lengthen the input a little. I'm thinking of replacing it completely. Thinking about the section. The input is limited by a circuit breaker in the floor switchboard at 63A. On the Internet, or rather on Mastercity, there are two links to PUE tables » > » > According to the first, I need a section of 16 squares, and according to the second, 10 is enough. The question arose, how much is needed?

Nowadays it is almost impossible to find a cable with a non-undersized cross-section, so it is advisable to choose 16 mm2, because according to table 19 GOST R 53769-2010 back-to-back 10 mm2 is 63 A

At the same time, formally 10 mm2 is just 63 A, so it is an acceptable option, however, keep in mind that the machine can pass 1.45 nominal for up to 1 hour, and for a cable over several minutes this is no longer a short-term excess of current and Overheating may occur and damage the insulation.

In short, 16 mm2 is better, but 10 mm2 is also acceptable.

Quite right - 16 squares.

Alexiy wrote: At the same time, formally 10 mm2 is just 63 A, so it is an acceptable option, however, keep in mind that the machine can pass 1.45 nominal values ​​​​up to 1 hour, and for a cable over several minutes - this is no longer short-term excess current and possible overheating, which will damage the insulation.

as an option, use a -FRLS cable; it has a permissible core temperature of 90C for several hours instead of 70 and allows emergency overloads. but at the price of 16mm2 it might be cheaper.

So as not to think about it in the future. AB 40A - 6mm2 AB 50A - 10mm2 AB 63A - 16mm2 AB 80A - 16mm2

correct me if I'm wrong av 10a - 1.5 mm2 av 16a - 2.5 mm2 av 25a - 4.0 mm2 av 32a - 6.0 mm2 av 40a - 6.0 mm2 (I doubt it) av 50a - 10.0 mm2 av 63a - 10.0 mm2 av 80a - 16.0 mm2

Ok, thanks everyone. In general, if the wire is from the market, then it’s definitely 16 squares.

And a related question, so as not to clutter up with topics, is it necessary to use corrugation when laying wires in a screed? After all, the medium is fireproof, cooling is better and the diameter is smaller. VVG cable, house - monolith.

StarWind wrote: Ok, thanks everyone. In general, if the wire is from the market, then it’s definitely 16 squares.

And a related question, so as not to clutter up with topics, is it necessary to use corrugation when laying wires in a screed? After all, the medium is fireproof, cooling is better and the diameter is smaller. VVG cable, house - monolith.

The corrugation will save you in case of emergency. if a crack forms in the screed, which will easily rupture the outer sheath of the cable.

user0552 wrote: correct me if I'm wrong av 10a - 1.5 mm2 av 16a - 2.5 mm2 av 25a - 4.0 mm2 av 32a - 6.0 mm2 av 40a - 6.0 mm2 (I doubt it) av 50a - 10.0 mm2 av 63a - 10.0 mm2 av 80a - 16.0 mm2

63 A - 16 mm kV 80 A - 25 mm kV Ampere must be capitalized - this is the person’s last name.

Alexiy wrote: Nowadays it is almost impossible to find a cable with a non-undersized cross-section

Well, why: when I bought a cable for myself - and this is about 100 m, I did not hesitate to take a caliper with me and before buying I measured the diameter of the cores

Alexiy wrote: Nowadays it is almost impossible to find a cable with a non-undersized cross-section.

If you need 4mm, take the one that says “6 mm”, if you need 1.5 mm, buy it, which is passed off as “2.5 mm”, and so on. But it's better to do this:

Magirus wrote: without hesitation, he took a caliper with him and measured the diameter of the cores before purchasing

Magirus wrote: I took a caliper with me and measured the diameter of the cores before purchasing

there is an error of 0.05, and this. 1.79mm is 2.5mm2, and 1.74 is 2.35mm2 (narrower), but in real life you can easily make a mistake by a factor of ten with such a rough instrument for these measurements, and this. 1.69 - 2.25mm2 I measured 5 or more options with a micrometer - the best that was 2.4, the worst - 2 with microns (!). At the stated 2.5mm. And 6ka pvs turned out to be generally less than 5 (something around 4.7-4.8, emnip).

Tsypra, approximately, from memory, was a long time ago.

I wonder if you measured the PVC correctly?

lightning wrote: If you need 4mm, take the one that says “6 mm”, if you need 1.5 mm, buy it, which is passed off as “2.5 mm” and so on.

Most manufacturers cruelly cut the multi-core, taking advantage of the difficulty of measuring resistance and cross-section. For example, I buy PVA 2.5 and get the real 1.35. I checked one core with a micrometer and multiplied. Monofilament is not cut so cruelly.

I wrote about monocore

helios1969 wrote: there is an error of 0.05, and this. 1.79mm is 2.5mm2, and 1.74 is 2.35mm2 (narrower), but in real life you can easily make a mistake by a factor of ten with such a rough instrument for these measurements, and this. 1.69 - 2.25mm2 I measured 5 or more options with a micrometer - the best that was 2.4, the worst - 2 with microns (!). At the stated 2.5mm. And 6ka pvs turned out to be generally less than 5 (something around 4.7-4.8, emnip).

Tsypra, approximately, from memory, was a long time ago.

Well, as if I didn’t think about the error of measurements with a caliper. You're right. But I have a bar with a pitch of 0.02 mm

Well, at least the blatant bullshit is already “cut off.”

Yes, there are still many factors to take into account: we bought a VVG-NG 2 x 2.5 cable from us in Kyiv - “Odessa cable” - it looks good, it bends with effort. And then I bought more from Leroy Merlin - it’s like Dneprpetrovsk does, but in appearance - the outer shell is visually thinner and the veins bend like tin (roughly how it feels). Either some kind of alloy, or, I also read, annealed copper or vice versa. But I’m not sure - someone who knows can correct me

Curious: why after the introductory 32A is there 40A (at the surge arrester)? Or: only for the refrigerator there is an AB 16A + RCD. Hmm, it’s probably like in a decent canteen, if for some reason the RCD goes off, the food won’t go rotten? Or on the gate AB 16A + RCD (probably a 5 kilowatt motor), the same thing - roller shutters? And the garage has no RCD. In fact, the loads, at least the ones indicated, are small. Why so many lines and RCDs is unclear. Or, apparently you like 4-pole AVs, but for some reason there are 3 at the input? I'm not saying there's anything wrong. Just commenting. And another question:

MIK wrote: The meaning of 1P+N machines has been described on the site more than once.

If possible, a link where this is described: I have never seen such a description. Curious to see what people think about this. But your explanation is wrong. The sum of AB currents after the RCD should not exceed In RCD. And further:

Metall wrote: Quote Message from SKL View message In front of each 25A RCD there should be an equal current circuit breaker, or better yet with a lower rating is not correct..

In this case, SKL is right. Perhaps Mr. Metall misunderstood what SKL wrote. Usually it sounds like this: “the rated current of the RCD should be chosen equal to, or one step higher than the rated current of the circuit breaker protecting this RCD.”

Electrolamp wrote: Ampere must be capitalized - this is the person’s last name

More precisely, apparently, like this: in the rules of the Russian language, abbreviations of basic units, if it is someone’s last name, are written with a capital letter, and subordinate units with a small letter, For example: ampere - A, kiloampere - kA, volt - V, kilovolt - kV etc. In any case, that’s what I was taught about 50 years ago. Now it may be different.

General requirements

These requirements relate to the placement of wiring elements: meters, distribution boxes, sockets, switches and the placement of electrical wires.

Branching boxes, switches and sockets, electric meters are placed in places accessible for their maintenance (all current-carrying parts are covered). It is advisable to place switches in each room on one side of the door. Placement height – 1.5 meters from the level of the finished floor (floor covering)

Please note: when opening the door to the room, the switch must remain within reach. Sockets are mounted at a height of 0.5 - 0.8 m from the finished floor level. Their locations are determined by the planned arrangement of electrical equipment. There are also requirements for the number of sockets in an apartment: according to fire safety rules, they are installed at least one per six square meters

In the kitchen, regardless of its size, at least three of them must be installed. It is prohibited to install sockets in wet rooms - toilets and bathrooms. But there is one caveat here: to connect hair dryers and electric shavers, it is allowed to install sockets in bathrooms that are powered by double-insulated isolation transformers. It is not allowed to install sockets closer than half a meter from grounded radiators, gas stoves, steel pipelines and other metal devices. It is advisable to install sockets on the interior partition at one point on each side of the partition. In this case, they are connected in parallel through a through hole in the wall. All branches and connections of electrical wires in the apartment are made only in branch and junction boxes.

To avoid problems with damage to the electrical wiring during future repairs, wires should be laid only horizontally and vertically. Moreover, it is necessary to store the network laying plan. There are generally accepted standards for the placement of wires:

• horizontal sections are placed at a distance of 50 - 100 mm from beams and cornices and 150 mm from the ceiling and plinth (in the latter case, a distance of 200 mm is allowed);
• vertically located sections of the electrical network must be separated from the corners of the room and door and window openings by at least 100 mm. In this case, contact of the wire with the metal structures of the building (if any) is not allowed;
• if heating or hot water pipes are located near the wiring, it must be protected with asbestos gaskets. Another acceptable option is to use a wire with a thermal protective coating;
• if the wire is placed parallel to a gas pipe (or a pipeline with any other flammable substance), the distance between them must be at least 0.4 meters;
• It is prohibited to lay electrical wires in bundles in the apartment. It is also unacceptable to place them with a gap of less than 3 mm.

Diagram of correct electrical wiring in the house

The cores of the grounding and grounding wires are connected to each other by welding. Electrical devices to be protected are connected to the protective conductors using bolted connections.

To zero stationary electric stoves, a separate conductor is laid from the apartment meter. Its cross-section must be equal to the cross-section of the phase wire. This conductor is connected in front of the electric meter to the protective conductor of the power supply network. Grounding and neutral conductors should not have switches or fuses. This rule must be observed, otherwise, at the moment the protection is triggered, all household appliances will be exposed to the dangerous potential of the network.

All of the above requirements relate to the field of electrical safety.

Input cable to the apartment cross-section according to the standards

The cable with which a consumer object (house, apartment, workshop, store, etc.) is connected to a power source is called an input cable. Most often, the input cable is connected directly to the electrical energy meter. To protect the meter, a circuit breaker may be installed in front of it, but such a scheme must be agreed upon with the electricity supplier and reflected in the technical specifications. In this case, the circuit breaker is sealed to prevent energy from being drawn to the meter.

Selection of RCDs and automatic devices

The circuit breaker provides short-circuit protection, but it is not capable of detecting leakage current that may flow into the electrical equipment frame when the insulation coating is broken or through the human body. For these purposes, a residual current device (RCD) or differential circuit breaker is connected to the panel.

These devices are switching devices that constantly monitor the differential current of the electrical wiring, and if it deviates from the permissible value, a shutdown is performed. The principle of operation is clearly illustrated in the picture.

How does an RCD work?

The main purpose of these devices is to provide adequate protection in the event that a person becomes energized and to prevent fire that may be caused by a leak.

Main characteristics of the devices:

• rated current parameters (they must correspond to the circuit breaker or a higher value is allowed);
• operating voltage (220V or 380V, respectively, for single-phase and three-phase devices);
• The permissible leakage current parameter for household devices is considered safe 30mA.

In our circuit, it is necessary to install a 16A RCD with a permissible leakage current of 30mA (elements C – F). These differential protection devices do not need to be installed for hallway and kitchen lighting.

RCD for 16A

Input cable into the house - types of connection and choice of brand

The power supply to the house is connected from the power line, the connection is made on the nearest pole (support). In some cases, when power line supports are remote from the site (for example, they are located across the road from the connected house), it may be necessary to install an additional support.

The input cable can be laid in two ways:

by air, from the power line support to the input distribution device;

underground in a prepared trench.

Air input

. Over-the-air power supply can be carried out by cable or self-supporting insulated wire (SIP).

Most types of installation cables (VVG, AVVG, etc.) are not intended for air suspension without the use of additional support. Such a support can be a stretched steel cable or wire. In the first case, the wiring is called cable, in the second - string. The ends of the cable or string are attached to the overhead line support on one side and to the building structures at the entrance to the house on the other. The cable being laid is rigidly attached to a supporting steel cable or wire.

Bare, uninsulated wires of overhead power distribution lines are gradually being replaced by self-supporting insulated wires (SIP). Power lines with insulated wires (VLI) are more reliable. The use of SIP eliminates the most common types of damage to overhead lines with bare conductors - overlapping of wires and their shorting by foreign objects. SIP is the most preferred option for an over-the-air input wire, which can be used when connecting to both an overhead line (line with a bare wire) and a VLI (line with an insulated wire).

The aerial connection of the input cable to power lines up to 1000 volts is carried out using SIP - 2 or SIP - 4 wires. The neutral and phase conductors of these wires are insulated. The zero conductor of SIP-2 is equipped with a steel supporting core, on which the wire is suspended. SIP-4 does not have a core; when it is suspended, the load is carried by the current-carrying conductors themselves.

Underground input

. For laying in a trench, a cable is selected that can withstand the weight of the soil and the shear force that occurs during its settlement. Therefore, the most suitable for this purpose are the VBBbShv cable with copper conductors or the AVBbShv aluminum input cable. The core insulation of these types of cables is made of PVC plastic. On top of the insulated cores there is a layer of PVC or unvulcanized rubber filling and an inner polyvinyl chloride sheath. This is followed by armor made of galvanized steel tape and an external pressed-out protective hose. VBBShV and AVBBShV conductors can be made single-wire or multi-wire, and the cross-section of the conductor can be in the shape of a circle or a sector.

Features of air and underground input. The advantages and disadvantages of installing the input cable over the air and underground are reflected in the table:

over-the-air input cable

over-the-air input cable

Video description

This video shows how to lay the lead-in wire in a trench:
It is necessary to lay the cable through the wall in a metal pipe at a slight angle (protection from water). For a 15 kW power network with this type of connection, it is recommended to use copper VBBShb with a cross-section of 10 mm². It is necessary to avoid crossing the electrical network with water supply lines and gas pipes under the house.

The recess must be placed parallel to the foundation at a distance of 60 cm, and in places where cars pass, the wire must be at a depth of 1.25 m and protected by a pipe. The advantage of this type of connection is the high protection of the cable from external mechanical damage and wear from weather conditions.

The disadvantage of such a connection is that it is labor-intensive and expensive, as well as the inability to quickly replace damaged areas.

Wire that is laid through the wall Source i.ytimg.com

Input cable to the apartment

General-purpose installation cables, such as VVG, are used as the input cable into the apartment. For systems with a working and protective neutral wire, the number of cable cores must be at least three.

The apartment input cable connects the floor panel and the apartment panel. In old-type houses, there may be no internal panel, and distribution within the apartment is carried out through connection boxes. When carrying out renovations in an old apartment, it is advisable to provide for the installation of an interior panel.

Important to know: Cable entry into the apartment is carried out using a two-wire or three-wire circuit. Input into apartments of modern houses is carried out using the TN–S or TN–C–S system using three wires:

L - phase conductor;

N - working neutral conductor;

PE - protective neutral wire.

In old houses, a TN-C grounding system is implemented, in which the working and protective neutral wires are combined, that is, power is supplied through two wires - L and PEN.

Checking the correct connection of conductors in junction boxes

After completing the installation work, the machines in the panel are turned on. If the fuse trips, check that the cables are connected correctly. Otherwise, the maximum load is connected to the line for 2-3 hours. The test allows you to determine poor-quality connections; when operating the test equipment, an increase in the temperature of the joints or the appearance of the smell of overheated wiring is not allowed. After completing the test, interrupt the current supply to the room, check the integrity of the insulation and close the boxes with standard lids.