Wire cross section for home wiring: how to calculate correctly

How is the calculation of power consumption done

You can also calculate the approximate cross section of the cable yourself - it is not necessary to resort to the help of a qualified specialist. The data obtained as a result of the calculations can be used to purchase a wire, however, the electrical installation work itself should only be trusted by an experienced person.

The sequence of actions when calculating the section is as follows:

1. A detailed list of all electrical appliances in the room is compiled.
2. Passport data of the power consumption of all found devices are established, after which the continuity of operation of this or that equipment is determined.
3. Having identified the value of power consumption from devices that operate constantly, this value should be summed up, adding to it a coefficient equal to the value of periodically turning on electrical appliances (that is, if the device works only 30% of the time, then one third of its power should be added).
4. Next, we look for the obtained values ​​​​in a special table for calculating the wire section. For a greater guarantee, it is recommended to add 10-15% to the obtained value of power consumption.

To determine the necessary calculations for the selection of the cross section of electrical wiring cables according to their power within the network, it is important to use data on the amount of electrical energy consumed by devices and current devices. At this stage, it is necessary to take into account a very important point - the data of power-consuming devices do not give an exact, but an approximate, averaged value

Therefore, it is necessary to add about 5% of the parameters specified by the equipment manufacturer to this mark.

At this stage, it is necessary to take into account a very important point - the data of power-consuming devices do not give an exact, but an approximate, averaged value. Therefore, about 5% of the parameters specified by the equipment manufacturer must be added to this mark.

Most far from the most competent and qualified electricians are sure of one simple truth - in order to properly conduct electrical wires for lighting sources (for example, for lamps), it is necessary to take wires with a cross section of 0.5 mm², for chandeliers - 1, 5 mm², and for sockets - 2.5 mm².

Only incompetent electricians think about it and think so.But what if, for example, a microwave oven, a kettle, a refrigerator and lighting work in the same room at the same time, for which wires with different cross sections are needed? This can lead to a variety of situations: a short circuit, rapid damage to the wiring and insulating layer, as well as fire (this is a rare case, but still possible).

Exactly the same not the most pleasant situation can happen if a person connects a multicooker, a coffee maker and, say, a washing machine to the same outlet.

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Determine at what height the sockets and switches will be located, the easiest way is to measure the lines of sockets and switches from the ceiling, because the floors in apartments are most often crooked. For example, if the height is from floor to ceiling after renovation will be 250 cm, and you want to raise the sockets by 30 cm, measure 220 cm from the ceiling. If there are several sockets and switches in one group, draw a horizontal line along the level and put a mark every 7 cm (socket size 71 mm), the same applies to vertical groups.

For lovers of standards, to be "like everyone else" or "as they do" - remember they do not exist! There are requirements for kindergartens, kindergartens and schools where sockets and switches are installed at a height of at least 160 cm. Everything else, especially at home, you can do as you like. For example, some make sockets in window slopes or even in the floor.

Selection of the circuit breaker rating by current and load power

To select a suitable machine, it is convenient to calculate the current strength per kilowatt of load power and compile the appropriate table. Applying formula (2) and a power factor of 0.95 for a voltage of 220 V, we get:

1000 W / (220 V x 0.95) = 4.78 A

Considering that the voltage in our electrical networks often falls short of the prescribed 220 V, it is quite correct to take a value of 5 A per 1 kW of power. Then the table of the dependence of the current strength on the load will look like in table 1, as follows:

power, kWt	2	4	6	8	10	12	14	16
Current strength, A	10	20	30	40	50	60	70	80

This table gives an approximate estimate of the strength of the alternating current flowing through a single-phase electrical network when household appliances are turned on. It should be remembered that this refers to the peak power consumption, and not the average. This information can be found in the documentation supplied with the electrical product. In practice, it is more convenient to use the table of maximum loads, taking into account the fact that the machines are produced with a certain current rating (table 2):

Wiring diagram	Ratings of automatic machines for current
	10 A	16 A	20 A	25 A	32 A	40 A	50 A	63 A
Single phase, 220 V	2.2 kW	3.5 kW	4.4 kW	5.5 kW	7.0 kW	8.8 kW	11 kW	14 kW
Three-phase, 380 V	6.6 kW	10,6	13,2	16,5	21,0	26,4	33,1	41,6

For example, if you need to find out how many amperes an automatic machine is needed for a power of 15 kW at a three-phase current, then we look for the nearest larger value in the table - it is 16.5 kW, which corresponds to an automatic machine for 25 amperes.

In reality, there are restrictions on the allocated power. In particular, in modern urban apartment buildings with an electric stove, the allocated power is from 10 to 12 kilowatts, and a 50 A automatic machine is installed at the entrance. It is reasonable to divide this power into groups, taking into account the fact that the most energy-intensive appliances are concentrated in the kitchen and in the bathroom. Each group has its own automatic machine, which makes it possible to exclude a complete de-energization of the apartment in the event of an overload on one of the lines.

In particular, it is advisable to make a separate input under the electric stove (or hob) and install a 32 or 40 ampere machine (depending on the power of the stove and oven), as well as a power outlet with the appropriate rated current. Other consumers should not be connected to this group. Both the washing machine and the air conditioner should have a separate line - a 25 A automatic machine will be enough for them.

To the question of how many outlets can be connected to one machine, you can answer with one phrase: as many as you like. Sockets themselves do not consume electricity, that is, they do not create a load on the network. You just need to make sure that the total power of the electrical appliances turned on at the same time corresponds to the cross section of the wire and the power of the machine, which will be discussed below.

For a private house or cottage, the introductory machine is selected depending on the allocated power. Not all owners manage to get the desired number of kilowatts, especially in regions with limited power grids. But in any case, as for city apartments, the principle of dividing consumers into separate groups remains.

Introductory machine for a private house

Determining the power of consumers

Next, it is necessary to determine the total power of consumers; without this, a competent calculation of electrical wiring is not feasible.

We will try to list the main electrical appliances that consume electricity:

– water heater – 2 kW;

– electric iron – 2 kW;

– electric kettle – 2 kW;

- washing machine - 1 kW;

- refrigerator - 0.7 kW

- TV - 1 kW;

- microwave - 0.7 kW;

- light - 0.5 kW;

– other household electrical appliances.

The minimum electricity consumption, taking into account the use of this technique, is approximately 12 kW, an average of 15 kW is allocated to an apartment.

For convenience and safety, all electrical wiring must be divided into groups, each group will be connected to a separate circuit breaker on the electricity meter. First of all, this will protect the network from possible overloads and failures, if, for example, for some reason, the socket in the kitchen shorts out, then the appliances in the rooms will not be affected due to a power surge. It's also handy for repairs. By changing the switches in one room, you do not have to de-energize the entire apartment, the sockets remain connected to the network.

Grouping can be done as follows:

– sockets in the room;

- sockets in the kitchen;

– sockets in baths;

- sockets in the hallway;

- lighting.

To supply the kitchen with energy, it is necessary to take into account the fact that the largest consumers are located here - a refrigerator, a microwave oven, an oven, a kettle, etc.

Also, special attention will need to be paid to the machine for the kitchen.

In principle, there should not be sockets in the bathroom, due to the humid environment of the room. The water heater and washing machine are usually connected directly to the circuit breakers on the meter. The socket may be one for a razor, but it is mounted in a special way and connected to a separate transformer.

Types of wires

In the case of a brand of wire, the best solution would be the PVA or KG option. The first type stands for vinyl connecting wire. This product has conductors made of copper, each protected by insulation and all of which are in a white sheath.Such a power wire can withstand voltages up to 450 V, and the insulating material does not burn, which allows the wire in question to be heat-resistant.

It also features high strength and excellent bending resistance. Can be used even in unheated and damp buildings, where it will last 6-10 years, depending on operating conditions. Great for connecting electric stoves.

If we talk about the wire type KG, then its name stands for flexible cable. Its shell is made of a special type of rubber. In addition, the same sheath protects tinned conductors made of copper. Between the wires there is a special film that performs a protective function. It should prevent strands from sticking together due to heat from use.

Usually the KG wire contains from 1 to 5 cores. As you can understand, the core section determines the power that the cable can withstand. This cable is operated in the temperature range from -40 to +50 degrees. The KG cable can withstand voltage up to 660 V. Usually this wire has the following designation: KG 3x5 + 1x4. This means that there are 3-phase conductors with a cross section of 5 square meters. mm, and one grounding conductor with a cross section of 4 sq. mm.

Regardless of which wire will be selected to connect the electric stove, it should be bought with a margin of length so that you can move the product. In addition, the wiring going inside the premises and at the entrance to the apartment must be of high quality, which should also be checked before starting the connection.

Diagram help!

It is best and most accurate to perform the calculation by first drawing up a wiring diagram in the house.

The following points should be indicated on the prepared project:

The exact number of sockets, switches and junction boxes, as well as the height of their mounting and the method of connecting to the network (through junction boxes in rooms or directly from the shield)

Read more about the location of sockets in the apartment in the article:
Installation locations for all lighting fixtures in the rooms: sconces, chandeliers and, most importantly, spotlights. By the way, before you calculate the length of the cable for electrical wiring, decide on the height of the ceiling

You must understand that the margin will be about 20 cm if the ceilings do not fall, and about 50 cm if the ceiling drops 30 cm.
The selected cable section for the socket group, the connection of powerful electrical appliances and the lighting line. For example, when designing lighting, wires with a cross section of 3 * 1.5 mm2 are usually used; sockets need a cable with more powerful cores - 3 * 2.5 mm2. As for powerful electrical appliances, even for connecting the hob, a cable with a cross section of 3 * 6 mm2 should be used (according to SP 256.1325800.2016, paragraph 10.2). As you understand, this is a very important point when calculating the length of the wiring, because. You will have to buy each type of wire separately in the right quantity. You can calculate the cable cross-section for power and current without any problems.

By the way, with the connection of household appliances, you also need to decide immediately. Most likely, each group of electrical appliances will have to run a separate wire from the shield, and not just bring a new line from the junction box in the room!

Having already prepared a visual wiring project, you can calculate how much cable is needed to power a house or apartment.Of course, it would be ideal to immediately mark the walls and ceiling for wiring, so that later you can simply measure all the drawn lines with a tape measure and calculate the total number of each type of wire for the network being designed, but, as practice shows, no one does this.

Additionally, you must make the following adjustments to the calculation, which you may not have known about:

• Multiply the total number of wires by a factor of 1.1-1.2. This is a reserve that will not allow a situation where a few meters are not enough to the sockets and you have to go to buy more material.
• On sockets and switches, leave a margin of at least 20 cm for connecting electrical wires.
• If you have not decided on the ceiling, it is better to calculate a margin of at least 50 cm of cable for connecting fixtures.
• To assemble the switchboard, the stock should be about 50 cm.

Here, according to this principle, you can independently calculate the amount of materials for the installation of electrical wiring in a house or apartment. We will discuss a simpler calculation technology below.

An example of calculating the cable cross-section using the example of BBGng 3 × 1.5 and ABBbShv 4 × 16

The three-core cable BBGng 3 × 1.5 is made of copper and is designed for the transmission and distribution of electricity in residential buildings or ordinary apartments. The current-carrying conductors in it are insulated with PVC (B), the sheath consists of it. Another BBGng 3×1.5 does not spread combustion ng(A), so it is completely safe to use.

Cable ABBbShv 4×16 four-core, includes aluminum conductors. Designed for laying in the ground. Protection with galvanized steel tapes provides the cable with a service life of up to 30 years. In the Bonkom company you can buy cable products wholesale and retail at an affordable price.A large warehouse always has all the products in stock, which allows you to complete orders of any assortment.

Calculation of electrical wiring in the apartment

First of all, it must be remembered that the calculation of electrical wiring in an apartment begins with drawing up a wiring diagram

If you decide to do the wiring yourself, you need to pay special attention to such issues:

• determination of the cross section of wire cores;
• under what conditions will the wire be laid;
• how to connect the counter;
• grounding;
• total;
• power grid protection.

The average one-room apartment relies on a total power of 15 kW. It is more convenient to calculate the power consumption if you conditionally divide the wiring into several groups. For example, sockets for:

• bathroom;
• rooms;
• kitchens;
• corridor.

And please note separately. So it will be easier for you to calculate the maximum load of electrical appliances in your home. If in doubt, use a special calculator that you can find on the Internet in construction forums.

Without electricity, today, it is impossible to imagine any room. Often, in industrial, commercial and high-rise residential buildings, the laying of electrically conductive cables is carried out by a construction company. At the same time, experts carry out preliminary calculations of the current-carrying network. But, if you want to repair the wiring in the apartment with your own hands, lay a network of electrical wires in a private house or in the country, then you will have to carry out the calculations yourself.

Cable calculation by power and length

If the power line is long - several tens or even hundreds of meters - in addition to the load or current consumption, it is necessary to take into account the losses in the cable itself.Usually long distances of power lines when entering electricity from the pole into the house. Although all data must be specified in the project, you can play it safe and check. To do this, you need to know the allocated power to the house and the distance from the pole to the house. Further, according to the table, you can select the wire cross-section, taking into account the losses along the length.

Table for determining the cable cross-section by power and length

In general, when laying electrical wiring, it is always better to take some margin over the cross section of the wires. Firstly, with a larger cross section, the conductor will heat up less, and hence the insulation. Secondly, more and more devices powered by electricity appear in our lives. And no one can guarantee that in a few years you will not need to install a couple of new devices in addition to the old ones. If a stock exists, they can simply be turned on. If it is not there, you will have to be smart - either change the wiring (again) or make sure that powerful electrical appliances do not turn on at the same time.

How many outlets can be connected to one 2.5 wire?

The fact that electrical wiring for sockets in apartments or houses should be carried out with a VVGNG-LS cable with a core cross section of 2.5 mm.kv. is known to many, but in addition to this, other questions often arise, one of the most common ones asked to me is “How many sockets can I connect to one 2.5 wire?”.

You can hang almost as many electrical outlets on such a cable as you want, and this is not a joke.This is because the sockets themselves do not consume electricity and are, in fact, the same conductor as the electric cable, so they themselves do not have any significant impact on the network.

The choice of the number of sockets that you could connect with one cable with 2.5 mm2 conductors depends only on the power consumption of the devices that will be included in these sockets.

Any wire, depending on the material of manufacture, section, as well as some other characteristics, has its own limitations on the maximum transmitted current and power.

Therefore, if you turn on devices in several outlets connected to one cable, the total power consumption is higher than the threshold value for this cable, the conductor will begin to heat up and collapse.

Often this is the cause of a fire.

So, for example, a cable made in accordance with GOST, having an honest cross-section of copper conductors of 2.5 mm.kv, on average, can withstand a current of 25-27 Amperes for a long time, which, if considered roughly, equals a power of 5.5-5.9 kW.

These values ​​​​are taken for standard living conditions, they may vary depending on the length of the route and the method of laying, but usually, when designing the electrical wiring of an apartment or a small private house, you can rely on these indicators.

No matter how many sockets you install on one wire with a cross section of 2.5 mm2, they will only withstand electrical appliances with a total power of not more than 5500 W - 5900 W. If you need more power, I recommend dividing the sockets into two or more groups, each of which is connected by its own cable.

To protect the cable from destruction, when turning on too energy-intensive electrical appliances, it is customary to install an automatic switch (AB, automatic).For a cable with a cross section of 2.5 mm.kv.

, for a number of reasons, a circuit breaker with a nominal value of 16A is installed, which corresponds to approximately 3.5 kW of power.

Thus, when creating safe electrical wiring, the number of sockets in each group is calculated according to this indicator - no more than 3.5 kW of simultaneous load on each socket group.

Let me give you a few examples to make it clearer:

An electric kitchen oven is most often supplied with a standard electrical plug that plugs into a 220V single-phase outlet. At the same time, often, the power of the oven is close to 3.5 kW. Accordingly, in an electrical line with a cable cross section of 2.5 mm2, to which the oven will be connected, you can safely install only one outlet.

At the same time, all sockets, for example, in the hall, bedroom and children's rooms, in an ordinary three-room apartment, of which there are a total of 15-20 pieces, can also be connected all with one cable. Since the power of all electrical appliances used in these rooms often does not exceed 3.5 kW.

It should be noted that the most energy-intensive electrical appliances are most often located in the kitchen and in the bathroom, these are basically any devices that heat something (electric kettle, oven, washing machine, hair dryer, etc.). Therefore, it is especially necessary to carefully calculate the number of sockets on one cable, in these rooms.

There are a number of methods for dividing sockets into groups, which take into account, in particular, the power of the connected equipment, and besides this, a number of other characteristics that make the operation of apartment sockets convenient and safe. I will talk about them next time.

CONCLUSION: The number of sockets that can be connected to one cable 2.5 mm2.depends mainly on the power consumption of the electrical equipment included in them, there are no other restrictions.

It is best to calculate the number of sockets in such a way that the power of electrical appliances connected to them at the same time does not exceed 3.5 kW. When designing electrical wiring, this can be calculated quite accurately, knowing where and what equipment will be located, in what mode it will work.

Calculation of electrical wiring: where to start

First, we measure everything and count. The resulting figures should be multiplied by 1.15 or 15%. This is the standard margin for technical calculations.

If you cannot measure everything and you need to know “at least approximately”, then you can use a simple approximation: the area of ​​\u200b\u200bthe premises (in square meters) is multiplied by 2! That is, for a standard two-room apartment with a total area of ​​​​50-53 m2, about 100 m of cable will be required. As scary as it sounds. And if a designer enters the battle, then get ready to multiply by 3, and sometimes by 5. Usually he will calculate everything himself and “please” you.

What if multiple wire types are used? There is, unfortunately, a risk here. Try to take from the calculation 1:2. One part per
, two parts for electricity supply. If you want to lay a separate cable to a washing machine, air conditioner or electric stove, then you will have to measure the lengths along a specific path.

You don’t need to take the car with automatic switches right away. These things are bought for specific tasks and their quantity, as a rule, is always known. Just buy a moderately roomy electrical panel to increase the range as needed. For example, I bought a regular
in one place, then, if desired, you can install a differential for 2 places or an RCD.

You can’t take everything into account and not foresee, but you can try.

Everything is top notch here.

1. Number of energy consumption points (sockets, switches and lamps):

In the kitchen - twin sockets in all four corners plus 2 pads for 4-5 outlets in the work area for stoves, juicers, combines, electric kettles, etc. In the bathroom - 2 sockets (or 1 paired) for a washing machine, hair dryer, electric shaver, etc. In the rooms - paired sockets in all four corners, 2-3 more sockets for fumigators, nightlights, recharging various gadgets. Switches are installed at the rate of 1 switch per room, but if you have an apartment on two levels, therefore, with stairs, or there are 2 doors in the room and you want to put a switch near each, then you will need special switches and additional wiring. The number of lights on the ceiling and on the walls depends on your imagination, but at least 1 per room (less does not make sense).

2. Length
:

Calculate the total length of the wires according to the plan and multiply the result by 1.2. 1.2 is a correction factor that takes into account the additional consumption of wire during electrical work and possible errors in the calculations. There is a simpler, but less accurate way: multiply the area of ​​\u200b\u200bthe apartment by 3. For example, for a standard 2-room apartment of 50 m 2, 150 meters of wires are needed.

3. Wire type
:

It is better to use a copper two-wire wire with stranded twisted conductors. If you use a plastic corrugated sleeve when laying wires, then it is enough to buy wires with ordinary insulation. In all other cases, it is better to use double-insulated wires, or, scientifically speaking, electrical cables.However, if you have an aluminum two or three-wire wire with cast strands of Soviet production in your stash, you can use it, so long as the rats do not eat through the insulation and there is enough section for your needs.

4. Section:

It all depends on what your maximum load will be. In the standard version, the main consumers of energy are a washing machine (power up to 2.2 kilowatts, current up to 10 amperes) and an electric kettle (power up to 2.2 kilowatts, current up to 10 amperes), other standard electrical appliances (food processors, vacuum cleaners , computers, televisions, lighting) can add up to 3 kilowatts, but if you use probability theory, you get 1 kilowatt. In total - 5.4 kilowatts or 24 amperes. This means that a standard cable with a core section of 2.5 mm is suitable for your main wiring. For lighting (wires from the room junction box to the lamp, between the lamps and from the box to the switch), a cable with a cross section of 0.5 - 0.75 mm 2 is sufficient. Electric stoves with ovens consume up to 10 kilowatts. Air conditioners will add 0.1 kilowatts per m 2 . Warm floors - 0.2 kilowatts per m 2. So consider, and you can determine the section you need according to the table:

The length of the main power cable in a high-rise building how many meters is a 10-storey building

The calculation of the length and cross section of the main power cable in a multi-storey building may be needed when repairing electrical wiring. So, residents of old apartments often change the wiring in favor of a more powerful one. In this case, the voltage on the power cable increases. Because of this, the cable heats up and becomes unusable.A reasonable question arises about replacing the main power cable at the entrance with a cable with a large cross section. The main problems that residents may face are obtaining permission from the housing and communal services of the housing department or HOA, the queue for the execution of the application by the repair team and the cost of the cable itself.

Since the main cable runs only from the ASU to the last floor, it will not be difficult to calculate its length: it will be equal to the height of the house, taking into account the necessary technological gaps.

For a ten-story building, the cable length will be about 35 meters. But all these preliminary calculations can only be used to calculate the estimated cost of the cable. The exact length and section need to be obtained only from the employees of the relevant utility company to which your home belongs.

Cable length calculation

The length of the necessary cables must be measured with a tape measure from the places where the sockets and lamps of the apartment are located to the shield.

If you are wiring for a separate electrical outlet, this is easy to do. However, if you are wiring for an entire apartment with several groups, you must first draw a wiring diagram with the designation on the diagram of the wiring groups and the cable route.

To the resulting cable length, you need to add 10% -15% for a margin. For the correct choice of cable tracing, you need to remember the rules for installing electrical wiring.

For example, let's calculate the electrical wiring in an apartment for a new washing machine. For example, I chose the Bosch WAN20060OE washing machine. Its maximum power consumption is 2300 W (according to the description).

For a washing machine, you need to make a separate group with your own circuit breaker and RCD.A separate protection group means that the outlet of the washing machine must be powered by an electric cable coming from the apartment switchboard and protected by a separate circuit breaker and preferably a separate RCD.

Current calculation:

We divide 2300 W by 220 Volts and we get the current strength of the circuit equal to 10.45 Amps. Here we round down, since the voltage can be 220-230 V.

We get the current of this circuit 10 amperes. According to the table, we look at the cable section. It is equal to 2.5 mm 2 for copper. We do not take aluminum cable into consideration.

We select the circuit breaker with a margin of 16 amperes. We select the RCD for a working current of 10 or 16 Amperes. RCD Tripping Current 30 mA.

To improve the ergonomics of the shield, it is better to replace a pair of circuit breaker + RCD with a differential circuit breaker (difavtomat). It will perform both protection functions. The nominal value of the differential circuit breaker is 16 Amperes.

We measure the length of the required cable with a tape measure from the installation site of the outlet to the installation site of the circuit breaker. Add 10% to this length.

Everything, the calculation of the electrical wiring in the apartment for the new washing machine has been completed.

In this article, I showed a general calculation of electrical wiring in an apartment on my own. Of course, the calculation of all electrical wiring is more complicated, but it will be based on these general principles.

How to calculate the parameters of the desired cable

If the power line is of impressive length (100 meters or more), then all calculations must be done taking into account the current losses that will occur directly on the cable. Without fail, this is done when designing the power supply of houses. All initial data are entered into the project in advance, for control and reinsurance they are rechecked using the power rate allocated to the entire house and the length from it to the pole.The following table helps to calculate the necessary parameters:

The choice of a suitable wire section when installing electrical wiring is best done with a margin. If it is, all new devices that have appeared in the apartment can be safely turned on without fear of overload.

If the section is not enough, then there are only two ways out: replacing the wiring or refusing to use powerful home appliances at the same time.

If you urgently need to extend the outlet, but the required wire is not nearby, you can use different cables by linking them parallel to each other. This method is not used constantly, but resorted to in moments of emergency, but if it is already used, and even more so to connect a powerful device, then you need to use wires of the same cross section

If this requirement cannot be met, then when calculating whether the wire will withstand, only the cable of a smaller cross section should be taken into account.

Making a calculation

Any household-level electrical wiring in an apartment or in a private house originates from the input cable, which bears the entire load from appliances and lighting. To select this cable, you need to calculate the section in accordance with all the equipment in the house, so first you have to make a complete list of them. This includes refrigerators, televisions, computers, microwaves, table lamps, climate control equipment - in general, everything that requires an outlet.

Each household appliance has its own power, and you need to find out the total power value, and then multiply this number by 0.75 (coefficient). Power can be viewed on the device itself (usually there is a sticker with the necessary technical information on the bottom or back of the case).The table below includes the most common household appliances and their power consumption:

Having found the desired value, it will not be difficult to select the cable cross-section. For this, there is another table that shows the dependences of the cable cross-section, power and voltage. It displays data for copper cables, since no one uses aluminum today.

By the way, why did they refuse to use aluminum cables and wires for electrical wiring, because similar systems worked before, and everything was fine? If you look at it, then aluminum, as a material, is great for making wires - it is lightweight, conducts current well, does not corrode, and is completely irreplaceable when installing power lines. However, there is one big “BUT”, which put an end to the use of aluminum wires - high electrical resistivity (2 times higher than that of copper). Simply put, to ensure the same conductivity, an aluminum conductor is needed many times more powerful, and therefore heavier, than when working with copper.

Another disadvantage is that as a result of oxidation upon contact with air, a characteristic film is formed on the surface of an aluminum product, which degrades its quality as a conductor. At the point of electrical contact with such an oxide, an increased contact resistance may result, the contact will heat up and further increase the electrical resistance, and as a result, the wiring will burn out.

But back to the calculation of the cross section of the wiring. When you figured out the input cable, you can proceed to the calculation of the cross-section of cables and wires for sockets and lighting fixtures. Based on the data in the table, it becomes clear that 0.5 mm² wires must be used for lighting, and 1.5 mm² for sockets.But often they install more powerful wires: for lighting at least 1.5 mm², and for sockets - from 2.5 mm², unless, of course, the power of the devices corresponds to the wire.

For example, as you can see in the table, if the mains voltage is 220 V, then a wire with a cross section of 2.5 mm² will withstand voltages up to 27 A or 5.9 kW. In such a situation, in order to protect consumers of electricity and wires, it is recommended to install a special machine with a maximum operating current of not more than 25 A.

In addition to calculating the load of the electrical wiring, it is also necessary to take into account the length of the power line for the end consumer. Again, we will use the table and determine the cross section for other types of load. In the process of designing and wiring, do not forget about the selectivity of the machines.

Wherever you do the calculation of the electrical wiring load - in a private house or apartment, remember that such work does not tolerate negligence, and mistakes can turn into big troubles. If you are not sure of your abilities, it is better to entrust this to professional electricians.