How to choose the right wire cross-section. How can you find out the cable cross-section by the diameter of the core?
Hello. The topic of today's article is “ Cable cross-section by power". This information will be useful both at home and at work. We will talk about how to calculate the cable cross-section by power and make a choice using a convenient table.
Why is it even necessary? choose the correct cable section?
In simple terms, this is necessary for the normal operation of everything related to electric current. Be it a hair dryer, washing machine, motor or transformer. Today, innovations have not yet reached the wireless transmission of electricity (I think they will not reach it soon); therefore, the main means for transmitting and distributing electric current are cables and wires.
With a small cable cross-section and high power equipment, the cable can heat up, which leads to loss of its properties and destruction of the insulation. This is not good, so correct calculation is necessary.
So, selection of cable cross-section by power. For selection we will use a convenient table:
The table is simple, I don’t think it’s worth describing it.
Let's say we have a house, we are installing closed electrical wiring using a VVG cable. Take a sheet of paper and copy down the list of equipment used. Done? Fine.
How to find out power? You can find the power on the equipment itself; there is usually a tag where the main characteristics are written down:
Power is measured in Watts (W, W), or Kilowatts (kW, KW). Found it? We record the data, then add it up.
Let's say you get 20,000 W, that's 20 kW. The figure tells us how much energy all electrical receivers consume together. Now you need to think about how many devices you will use simultaneously over a long period of time? Let's say 80%. The simultaneity coefficient in this case is 0.8. Let's do calculation of cable cross-section by power:
We count: 20 x 0.8 = 16(kW)
To do selection of cable cross-section according to power, look at our tables:
The main and most common method of transmitting electricity to the consumer is an electrical wire and electrical cable. An electrical wire and electrical cable is an electrical product consisting of a metal conductor or several conductors. Each core is electrically insulated. All insulated conductors of a wire or electrical cable are placed in general insulation.
Currently, the industry produces a wide variety of electrical wires and electrical cables. Cables and wires are mainly copper and aluminum, i.e. the composition of the cable or wire cores is copper or aluminum.
Electrical cables and wires can be single-core or multi-core. The core of a cable or wire can be either single-wire (monolithic) or multi-wire. The cores are made mainly in round shape, however, often for electrical cables with a large cross-section, the shape of the stranded core can be made in the form of a triangle. Today we will tell you how to calculate the cross-section of a wire by diameter.
Marking of electrical cable (wire)
There is a standard range of wire and electrical cable cross-sections that are used. This is 1mm 2; 1.5mm 2; 2.5mm 2; 4mm 2; 6mm 2; 8mm 2; 10mm 2 etc. The type, cross-section and number of cores are indicated either on the tag that comes with the cable or wire, or on the product itself. For example, markings are often applied to the general insulation of cables and wires. Also, technical data of electrical conductors are indicated in the product passport.
Let's say there is a VVGng 3x2.5 cable available. This marking is deciphered quite simply: a copper cable with PVC insulation, in a PVC sheath, non-flammable, the number of cores is three, the cross-section of each core is 2.5 mm 2. If the letter “A” appears at the beginning of the marking, i.e. The cable type will be AVVG, which means that the cable has aluminum cores.
By marking the wire, you can also find out not only the type of wire itself, but also the number and cross-section of current-carrying wires. For example, PVS wire 3x1.5. The decoding is as follows: wire with PVC insulation and PVC sheath, connecting. The number of cores is also three, and the cross-section of each wire is 1.5 mm 2 .
Conductor cross-section
Each wire and cable core has its own cross-section. It can be either very small (1mm 2 or less) or very large (95mm 2 or more). The cross-section of the conductor affects the ability to withstand a certain amount of electric current for a long and short time. The larger the cross-section of the core, the greater the current it can withstand for an almost unlimited time.
An incorrectly selected cross-section during design may subsequently cause overheating of the conductor, damage (destruction) of its insulation during the process of high heating, which may result in a short circuit and, as a result, fire and fire.
Section mismatch
The cause of overheating of a cable or wire during operation may not always be an incorrect calculation of the cross-section. As often happens in practice, the reason is very simple. Not all manufacturers of cable and wire products are conscientious about the quality of their products. The fact is that very often the cross-section of manufactured cables and wires is actually underestimated, i.e. does not correspond to the declared value.
To avoid purchasing an electrical cable or wire with an undersized cross-section, you must first visually assess its actual cross-section. Almost any electrical specialist is able to “by eye” determine the cross-section of a conductor. But when this is not enough, a professional can independently calculate the cross-sectional area of the electrical conductor. The cross section is calculated using the usual mathematical formula:
S = π*D 2 /4– formula No. 1
S=π* R 2 – formula No. 2
where: π is a mathematical constant, which is always equal to approximately 3.14;
R – wire radius;
D – wire diameter.
The radius is equal to half the diameter:
R=D/2– formula No. 3
Calculation of the actual cross-section of the electrical conductor
Knowing the formula for calculating the cross-section of a conductor, you can calculate its actual value and find out how much the manufacturer’s declared cross-section value is underestimated or overestimated (which happens rarely).
Single-wire (monolithic core)
First, you need to remove the insulation layer from a wire core or an electrical cable core to expose the core itself. Then the diameter of the core is measured with a caliper. Because the vein is monolithic, then there will be only one measurement. After measuring the diameter of the core, you need to substitute the value of the diameter (radius) into one of the above formulas.
Example No. 1
Let’s say that a cable or wire has a declared core cross-section of 2.5 mm 2 . When measured, the core diameter turned out to be 1.7 mm. Substituting the value into formula No. 1, we get:
S = 3.14*1.7 2 /4 = 2.26865 ≈ 2.3mm 2
Calculation using formula No. 1 showed that the cross-section of the core is underestimated by 0.2 mm 2 from the standard value.
Now let’s calculate the actual value of the cross-section using formula No. 2, but first, let’s determine the radius using formula No. 3:
R = 1.7/2 = 0.85mm
We substitute the radius value into formula No. 2 and get:
S = 3.14*0.85 2 = 2.26865 ≈ 2.3mm
The calculation using the second formula turned out to be similar to the calculation using the first. Those. The cross-section of the cable core turned out to be underestimated by 0.2 mm 2.
Example No. 2
Let’s say the core diameter, when measured with a caliper, turns out to be 1.8 mm. Substituting this value into formula No. 1, we get:
S = 3.14*1.8 2 /4 = 2.5434 ≈ 2.5 mm 2
Those. the actual cross-section was 2.5 mm 2, which in principle corresponds to the standard value.
Stranded core
If you determine the cross-section of a stranded conductor, then you cannot measure the diameter using the monolithic conductor method, because the calculation will have a large error. To determine the cross-section of a stranded core, it is necessary to measure the diameter of each individual wire in the core.
If the total cross-section of the core is large enough, then measuring each wire is quite possible, because You can actually measure the diameter with a caliper. But if the stranded core has a small cross-section, then determining the diameter of each wire is very problematic due to the thinness of the conductor.
Most of the cost of materials when replacing electrical wiring comes from cable products. At the same time, there is a temptation to save on it. But unreasonably underestimating the cable cross-section leads to fatal results if they carry a load current that exceeds their carrying capacity. When an electric current passes, any conductor heats up. When a certain heating temperature is reached, the insulation melts, the phase and neutral conductors are connected to each other, a short circuit and a fire occurs.
To avoid these troubles, before starting installation work, the cable cross-section is calculated. It allows you to calculate the value that will be sufficient to ensure the safe operation of your electrical equipment.
Initial data for calculation
We will need to calculate the total electrical power of all electrical appliances in a house or apartment. Of course, chargers for mobile phones can be neglected. When calculating, the assumption is made that the entire load will be turned on simultaneously. Don't think that you can never turn on a microwave oven and a kettle together if they are powered by the same socket. The time will come - they will be turned on through a tee.
This also applies to lighting. There is no guarantee that you will always use only . Use an incandescent lamp of 60 - 75 W as the equivalent load for each lamp. By multiplying this power by the total number of lamps in the house, you will get the calculated value. For a country house, do not forget about outdoor lighting and the prospects for its development.
Be sure to include household appliances that you don’t have now but plan to purchase in the future, such as a dishwasher or another electric heater.
If your house has a 1.5 kW boiler, consider whether you would like to increase its power to 3 kW in the future.
You can find out the power of your electrical appliances from the operating instructions. If it is not there, read it on the plate located on the device body. For approximate calculations, a table of average statistical loads is used.
Such a table, compiled by you yourself for your home, will help in further calculations.
Input cable calculation
After calculating the total power of single-phase consumers, the corresponding current is calculated using the formula:
where P is the total power you calculated, W;
U – network voltage equal to 220 V;
cos (φ) – power factor, for household appliances is taken equal to unity;
Ki is the coefficient of load simultaneity, taking into account that your electrical appliances are unlikely to work at the same time. Its exact value is difficult to predict, so for calculations you can take Ki = 0.75.
For a three-phase load in a 380 V network, the current is calculated using the formula:
Now you can find out the cross-section of the input cable through which power will be supplied to the apartment or country house. To select it, you must use the table for calculating the cross-sections of cables with polyvinyl chloride and polymer insulation. Most products used for laying household electrical wiring have such insulation. For rubber insulation and cross-linked polyethylene, a different table is needed; it can be found in GOST 31996-2012.
| Cables with copper conductors | ||||
| Core cross-section, mm 2 | Permissible current loads | |||
| Single-core | Stranded | |||
| On air | In the ground | On air | In the ground | |
| 1,5 | 22 | 30 | 21 | 27 |
| 2,5 | 30 | 39 | 27 | 36 |
| 4 | 39 | 50 | 36 | 47 |
| 6 | 50 | 62 | 46 | 59 |
| 10 | 68 | 83 | 63 | 79 |
| 16 | 89 | 107 | 84 | 102 |
| 25 | 121 | 137 | 112 | 133 |
| 35 | 147 | 163 | 137 | 158 |
| 50 | 179 | 194 | 167 | 187 |
| 70 | 226 | 237 | 211 | 231 |
Cables with aluminum conductors |
||||
| Core cross-section, mm 2 | Permissible current loads | |||
| Single-core | Stranded | |||
| On air | In the ground | On air | In the ground | |
| 2,5 | 22 | 30 | 21 | 28 |
| 4 | 30 | 39 | 29 | 37 |
| 6 | 37 | 48 | 37 | 44 |
| 10 | 50 | 63 | 50 | 59 |
| 16 | 68 | 82 | 67 | 77 |
| 25 | 92 | 106 | 87 | 102 |
| 35 | 113 | 127 | 106 | 123 |
| 50 | 139 | 150 | 126 | 143 |
| 70 | 176 | 184 | 161 | 178 |
| 95 | 217 | 221 | 197 | 214 |
In order to determine the permissible load on four-core and five-core cables, the data from the table must be multiplied by a factor of 0.93.
The use of aluminum wires for the installation of electrical wiring in buildings has been prohibited since 2001. But it is possible to supply power to the house with an aluminum cable if its cross-section is at least 16 mm 2.
There are also restrictions on the minimum cross-section of cable lines.
Calculation of load and cross-section of group network cables
For further calculations, it is necessary to plan the distribution network in the house. Typically, the input cable goes to the panel in which the input circuit breaker, electric meter and circuit breakers are installed, powering individual groups of electrical receivers. You need to divide all your sockets and lamps into these groups.
In this case, the washing machine, boiler and electric stove must be powered via a separate cable line and protected by a separate circuit breaker. To connect kitchen outlets, a personal line is usually allocated. The rest of the load can be divided arbitrarily. It is better to power lighting networks separately, based on the fact that usually their power supply does not require a cross-section of more than 1.5 mm 2. And it’s more convenient to change the socket when the lighting is on.
Now we select the cable cross-section individually for each line, calculating its total load current using already known formulas. Along the way, using this current, you can select the rated data of circuit breakers and RCDs to protect lines from short circuits and overloads.
Be sure to check whether you can lay the distribution network cables in such a way as to connect the electrical receivers of individual groups to them. This way you will plan the laying routes and the location of the junction boxes.
As you can see, the calculation of cable cross-sections is carried out comprehensively simultaneously with the design of all electrical wiring. Now all that remains is to calculate their total length, the number of sockets, switches and junction boxes, buy it all and begin installation.
Calculation of wire cross-section for a distribution panel
There remains one element of the electrical network that you need to assemble yourself. This is a distribution board. To connect the elements inside it, you will need wires.
Some conductors must have a certain color. Neutral working conductors (N) are painted blue, neutral protective conductors (PE) - yellow-green. The conductors for the corresponding purpose in the cables are painted in the same colors. Their use for other purposes is not permitted.
The use of aluminum conductors with a cross section below 16 mm 2 for assembling shields is prohibited.
To determine the rated current of conductors, you must use the same calculation formulas as for cables, and the cross-section of the wires can be selected from the table. The data in it is applicable to wires with polyvinyl chloride and rubber insulation, both single-core and multi-core.
Major home renovations necessarily include replacement of electrical wiring. There are two main reasons for this action.
The first is the age of this wiring itself. As a rule, major or any serious repairs are carried out 15-20 years after the apartment is handed over. During this time, even a properly made home electrical network ages and wears out. This means it potentially becomes a source of danger for the inhabitants of the home.
The second reason is the redevelopment and major renovation of individual premises with the addition of new electrical appliances. Tie-ins and other connections of new wiring with old are extremely undesirable. Due to a mismatch in the characteristics of the cable or materials in it.
So, the question of whether to change the electrical wiring is considered resolved; it remains to deal with its practical implementation. And you need to start with choosing a cable.
Cable for electrical wiring in an apartment - 300 brands and 5000 varieties
Which side should we start with? A person who is far from electrical installation will grab his head. And there is something to grab onto. Because there are not just a lot of cables and wires, they literally cannot be counted, like Don Pedro in Brazil. Even professional electricians sometimes get overwhelmed and confused by the abundance of manufacturers and products.
The choice of wire for electrical wiring in an apartment is not only a question of the cost of repairs. A much more important point is that the wiring must ensure the “delivery” of electricity to any corner of the apartment and be safe, that is, not “bite” with current. And also be fire resistant and reliable.
Attention! The key to reliable electrical wiring is finding the right electrician. A specially trained technician must do electrical work and select cables for wiring in an apartment! Who has access to electrical installation work and practical experience.
We will briefly talk about cables and wires, their cross-section, markings, materials and types. We will explain what is suitable for home wiring and what cannot be used. So that you are aware of what your electrician is doing and why.
Characteristics of wires and cables that you should pay attention to when choosing
Let us immediately clarify that we are talking about a household power cable or wire with a voltage of 220/380 V for transmitting electric current in a home network. We are not currently considering all other types such as heating, television, computer and others.
The general list of characteristics looks like this:
- core material;
- design;
- section;
- thickness of conductor insulation;
- shell thickness;
- marking;
- core color;
- package;
- certificate;
- product condition.
1. Material and design
According to the composition of the vein, cable products are divided into copper and aluminum. Copper products are more reliable, the resistance is lower, the current is higher, and the heating is less when compared with aluminum of the same cross-section. In addition, copper oxidizes less and is more ductile, which means the cable lasts longer without loss of properties and characteristics.
Attention! Wiring aluminum cables in an apartment is prohibited according to the requirements of the PUE (electrical installation rules).
By design single-core (single-wire) and multi-core (multi-wire) cables and wires are produced. Single-core varieties are more rigid and inflexible, especially with a large conductor cross-section.
Answering the question “which wire to use for wiring under plaster,” we can say that theoretically a single-core single-wire copper cable is also suitable. Plaster will create additional protection for such a conductor. But in fact, no one lays a single-wire home electrical network.
Multi-wire single-core cable is softer and more flexible. It tolerates bends and turns well and is suitable for both open wiring and hidden wiring under plaster. It is the three-core single-wire that is now used for laying in apartments.
Attention! Do not confuse cables in which each core consists of one conductor with wires where the core is made of several conductors. Multi-wire cable products are prohibited for permanent installation in an apartment due to the high fire hazard. Read more about them in the block“which wires should not be used for electrical wiring in an apartment”
2. Cable cross-section for wiring in an apartment
It is measured in “squares”, that is, square millimeters and shows the throughput. For a copper cable, one “square” carries 8-10 Amperes of current, for an aluminum cable only 5 A. For safe operation, the conductor should be selected with a reserve of carrying capacity, which ensures heating of the wire within the permissible value, or, more simply, so that it does not “float” under the load. insulation. In addition, with hidden wiring, it must be taken into account that it is cooled less efficiently, which means that the cross-sectional reserve must compensate for this.
Attention! Do not confuse the cable cross-section with its diameter, these are two big differences! The diameter can be measured with a ruler, or better yet, with a caliper. And then substitute it into the formula and calculate the cross-sectional area.
Also remember that the choice of cable for wiring in an apartment is always rounded up. If the calculation results in 2.3 “squares”, a two and a half cable is selected, not two “squares”.
Ideally, the cross-section should match the marking on the cable tag, but in fact it often differs to a smaller extent. Small discrepancies are acceptable because the cable is certified by resistance, not by wire cross-section. If the discrepancies are significant, it is a marriage. An experienced electrician will see it visually, and you can measure the diameter of the core and calculate the cross-section for interest or to help a friend who independently decides to buy a cable for apartment wiring.
Some electricians advise using a cable with a rating higher than the calculated one. For example, 4 “squares”, instead of 2.5, to cover the “shortage” of the section, if there is one. But then you will have to calculate the wiring protection accordingly and install the correct machines and RCDs.
Advice! For electrical wiring in an apartment, we recommend a cross-section of copper wires from 1.5 to 2.5 square meters. mm. Allow two and a half “squares” for sockets and one and a half for lighting.
3. Wire insulation thickness
Each core in a multi-core or single-core cable has insulation made of PVC plastic of the usual type or with reduced flammability; polymers and cross-linked polyethylene are also used. The thickness of the insulation is regulated by GOST standards and it must be sufficient. For household cables (rated voltage up to 660V) with a cross section of 1.5 and 2.5 mm 2 the thickness of the insulating layer according to the standard is 0.6 mm. Deviations are allowed, but the insulation should not be thinner than 0.44 mm.
Simply put, there is a range of thicknesses where the insulation must “fit” so that the wiring serves reliably and there are no problems during installation. Whether the manufacturer violated the technology cannot be determined without a micrometer unless you tinker with the cables every day. Therefore, if there is no experienced electrician nearby, you should only buy cables from well-known brands in trusted stores.
4. Shell thickness
The sheath encloses the cable over the insulated cores, secures them and protects them. It is made, like the core insulation, from PVC plastic or polymer, but is thicker. For multi-core cables, the thickness is 1.8 mm, for single-core cables - 1.4 mm. Deviations in a smaller direction are also possible, but insignificant.
The insulating shell is a mandatory element. For any residential wiring cable, even with minimal power, double insulation is prescribed. That is, first on the core, and then on top of it. This ensures the safety of people and protects the conductor itself from damage.
5. Marking
This is the inscription on the cable sheath for installing electrical wiring in the apartment. It contains all the necessary information for selection. The inscription is printed or extruded during the manufacture of cable products. It should be clear, contrasting, and easily readable.
The labeling indicates:
- The brand of the product (cable or wire), which encodes the main properties and characteristics.
- Manufacturer's name.
- Year of issue.
- Number of cores
- Section.
- Voltage rating.
The inscription is applied along the entire length of the conductor at small intervals.
On the price tag and in catalogs of online stores, they usually do not indicate the year of manufacture and manufacturer and write the marking in the form VVGng(ozh)-0.66 kV 3x1.5 or VVG, VVGng cable 3x1.5.
It stands for three-core copper cable with a core cross-section of 1.5 “square” (3x1.5), single-wire core design (ozh). Insulation and sheath made of PVC compound (VV), flexible cable (G), non-flammable (ng). Rated voltage 660 Volts.
Remember! The letter designation of the cable brand begins with the core material; for aluminum the letter A is always used, for copper — the letter is not indicated, therefore all VVG brand cables of all modifications have a copper conductor.
6. Core colors
What you need to know about the color is that it is either a solid color or a stripe is applied to the sheath along the entire cable, approximately a millimeter wide. This is the standard. Everything else, in the form of smudges, spots, stripes across it, is from the evil one. And he says that strange people were making the cable in some basement.
There is a table for the colors of the cores that any experienced electrician knows. It describes what shade the main conductors are denoted by - phase, neutral, grounding. This was done for convenience during installation, in order to see where to connect which conductor. Phase and working conductors may differ in color, but the “ground” is always “painted” yellow-green.
7. Packaging
Standard for all types is a coil or drum. The coils are sold to stores and wound onto drums for wholesalers, builders and other large buyers. In any case, a label with a description is attached to the cable.
The contents of the tag repeat the information on the inscription on the shell with some additions. It states:
- plant name or manufacturer's trademark
- product brand (designation)
- GOST or TU
- Date of issue
- number of segments with their length
- drum number
- conductor weight
- conformity mark
- OK mark.
If you come to buy a cable for wiring in an apartment in a whole bay of 100 m, you will receive a tag along with it. But if they cut off a piece for you, they won’t give you the label, you can just look at it.
8. Certificate
Needed to confirm that the cable is of high quality. Typically, products have 2 documents - a certificate of conformity, which is responsible for the suitability of the cable as an electrical installation material, and a fire safety certificate. You can ask the seller for them to review. The documents must be filled out indicating GOST standards for the cable and have a valid period, for example, until the end of the current year. As a rule, the documentation indicates specifications (technical conditions) in accordance with GOST and for cable products this is equivalent to compliance with GOST.
9. Condition
This is the appearance of the power wire. Pay attention to how the cable looks, because bruises, strong kinks, and compression hide an internal defect. The veins may be broken and even shorted to each other. It is clear that such material cannot be laid, therefore, do not be lazy to inspect the cable in the store, even before paying for your own purchase.
What cable is needed for wiring in an apartment?
We have already said that electrical wiring in an apartment “requires” 2 cable sections.
For sockets you need to take a cross section of 2.5 mm 2, because the switched load can reach 3-4 kilowatts. And a cable of two and a half “squares” is designed for a maximum power of up to 5.9 kilowatts and a current of up to 27 Amperes. This does not mean that you need to “load” the cable line to its limit. The choice always comes with a margin of one third of the planned load. Moreover, the cable lying under the plaster is cooled less efficiently and this is also taken into account when selecting.
For the lighting circuit, a cross section of 1.5 mm 2 is used. The load here is much less, but even if you decide to arrange illumination in the apartment, there will be plenty of current and power reserves.
Important information! Since modern electrical safety rules require grounding household electrical appliances and installing special sockets, a three-core cable is used for installation. In which there is a working phase conductor, a working zero and a protective zero.
Which cable does the online store website recommend for hidden wiring in a house or apartment?
Let us remind you that the marking contains the main characteristics of cable products. Letter designations indicate the materials of conductors, insulation, sheathing and flexibility, digital designations indicate the number of conductive conductors and their cross-section.
VVG cable
The most common domestic cable for electrical installation in an apartment. It has single-core copper conductors, insulation and a sheath made of PVC plastic, and is used in rooms with normal and high humidity. Designed for voltages up to 660 Volts. Refers to flexible, unarmored power cables. It can include from 1 to 5 cores, with a cross-section from one and a half to 240 “squares”. The conductor shape is round, flat or triangular.
VVG cables are available in several modifications:
- VVG - basic type with vinyl insulation and sheath;
- VVGng is a non-flammable power wire, the insulation of the cores is self-extinguishing, that is, combustion does not spread;
- VVGng-LS - also has self-extinguishing non-flammable core insulation (ng) and a low smoke emission sheath;
- VVGng FR-LS - in addition to non-flammability and low smoke emission, this type of cable received additional fire protection from mica tape.
All brands with the ng prefix can be mounted in bundles, that is, several cable lines can be laid in one corrugation, pipe or pit.
| For sockets | For switches |
| VVGng 3x2.5 | VVGng 3x1.5 |
| VVGng-LS 3x2.5 | VVGng-LS 3x1.5 |
Conventional VVG is cheaper, but is not suitable for bundle laying and the casing is less fire-resistant and smoke-resistant. And the VVGng FR-LS brand is professional and is used in conditions of increased fire hazard in enterprises and is much more expensive.
NYM cable
European standard copper cable developed in Germany. Produced in Russian factories and complies with EU standards and GOSTs. The design is similar to the VVGng cable, rated voltage 660 V. Single-wire multi-core NYM cable with a cross-section of 1.5-10 mm2 and multi-wire with a cross-section of 16 mm2 are available. The number of cores is 1-5, the insulation and sheath are made of PVC, non-flammability is provided by the rubber filler between the core insulation and the cable sheath.
Note! In stores you can find cheap cables marked NUM. This “typo” says that this is a copy with reduced characteristics. By purchasing it, you risk receiving low-quality products. We advise you to refrain from dubious savings on security.
VVGng and NYM cables have similar characteristics and advantages of use:
- High quality performance. The cores, insulation, and sheath comply with GOST and this makes the cable reliable.
- Convenient installation and easy cutting. The round cable is easy to install due to the absence of twists and is easier to seal when inserting.
- High fire resistance and safety. Compliance with standards ensures safe operation of the cable under load, and special insulation allows it to be laid in bundles, without the risk of fire from mutual heating.
- Self-extinguishing and low smoke. The shell material is self-extinguishing and slows down combustion. It also provides low smoke without dangerous halogens. If the protection works slowly, the damage from the fire will be minimal.
- Wide range of options in brands at a price to suit any budget.
Which wire is not suitable for wiring in an apartment?
And one more important point. We understand that for most people, “wire” and “cable” are synonymous. In fact, these are different types of cable products. The main difference is that the cable always has a very strong two-layer insulation, with the first layer on top of the conductive cores and the second covering the entire bundle. Even if the cable has one core, the insulation is always double. The wire is a weaker structure with light insulation.
Note! Wiring your apartment with wire, even stranded or stranded, is a very bad idea.
The main problem with wires is their poor resistance to prolonged heating under constant load and their high flammability. Therefore, they do not comply with the requirements of the PUE for wiring in residential premises.
PVS wire
| PVS |
This is a copper connection wire with vinyl insulation and sheath. Used to connect household electrical appliances to the home network and to make extension cords. The number of conductors is 2-6, the core design is multi-wire, cross-section 0.75-10 mm2. Designed for a voltage rating of 380 V.
Attention! There is no need to take PVS wire for wiring on the advice of friends or to save money.
- Firstly, PVA have a multi-wire core structure. This means that all ends for connection must be tinned and soldered. This takes a lot of time and requires high-quality processing of the cores and extensive experience of the electrician.
- Secondly, the multi-wire construction of the core is a factor of increased fire hazard. Such a wire heats up more, which means the insulation wears out faster, which is dangerous and can result in a short circuit.
- Thirdly, the PVS wire cannot be laid in a bundle, like a cable. Only with the distance between the threads. That is, ditch the walls for each line separately.
So, the savings are very dubious and symbolic. The low price of the wire will be “eaten up” by the high cost of installation. And the quality of the wiring leaves much to be desired.
ShVVP and PVVP wire
| ShVVP, PVVP |
Installation cords or cables with single and multi-wire copper conductors. Used to connect electrical equipment and household appliances. They have a short service life; the stranded type requires processing of the ends and soldering during installation. They are not suitable for fixed wiring due to the lack of non-flammable insulation and poor characteristics.
Wire PUNP
Attention! PUNP has been banned for use for wiring since 2007 due to its unreliability.
Although there are “craftsmen” both among clients and among would-be electricians who use it. Motivating this by the fact that “all old apartments have this one.”
But “citizens” forget that since the times of the USSR, the equipment of household electrical equipment has changed greatly and its power has increased. That’s why PUNP was banned - it is low-power, has poor insulation and does not support modern loads.
The online store site offers only high-quality cables for electrical wiring in an apartment or house. Full list of brands and types in the section:
Come in and choose your cable!
And also ask any questions. Funny and naive first of all! They are the most correct! Because it’s better to make electricians laugh than firefighters, wouldn’t you agree?
We always answer questions and talk about all the intricacies of installation. We quickly select a complete set for installing apartment wiring from cables to sockets and switches. We take into account your wishes and budget.
Call and ask! Phones
The table shows power, current and cross sections of cables and wires, For calculations and selection of cables and wires, cable materials and electrical equipment.
The calculation used data from the PUE tables and active power formulas for single-phase and three-phase symmetrical loads.
Below are tables for cables and wires with copper and aluminum wire cores.
| Copper conductors of wires and cables | ||||
| Voltage, 220 V | Voltage, 380 V | current, A | power, kWt | current, A | power, kWt |
| 1,5 | 19 | 4,1 | 16 | 10,5 |
| 2,5 | 27 | 5,9 | 25 | 16,5 |
| 4 | 38 | 8,3 | 30 | 19,8 |
| 6 | 46 | 10,1 | 40 | 26,4 |
| 10 | 70 | 15,4 | 50 | 33,0 |
| 16 | 85 | 18,7 | 75 | 49,5 |
| 25 | 115 | 25,3 | 90 | 59,4 |
| 35 | 135 | 29,7 | 115 | 75,9 |
| 50 | 175 | 38,5 | 145 | 95,7 |
| 70 | 215 | 47,3 | 180 | 118,8 |
| 95 | 260 | 57,2 | 220 | 145,2 |
| 120 | 300 | 66,0 | 260 | 171,6 |
| Cross-section of current-carrying conductor, mm 2 | Aluminum conductors of wires and cables | |||
| Voltage, 220 V | Voltage, 380 V | current, A | power, kWt | current, A | power, kWt |
| 2,5 | 20 | 4,4 | 19 | 12,5 |
| 4 | 28 | 6,1 | 23 | 15,1 |
| 6 | 36 | 7,9 | 30 | 19,8 |
| 10 | 50 | 11,0 | 39 | 25,7 |
| 16 | 60 | 13,2 | 55 | 36,3 |
| 25 | 85 | 18,7 | 70 | 46,2 |
| 35 | 100 | 22,0 | 85 | 56,1 |
| 50 | 135 | 29,7 | 110 | 72,6 |
| 70 | 165 | 36,3 | 140 | 92,4 |
| 95 | 200 | 44,0 | 170 | 112,2 |
| 120 | 230 | 50,6 | 200 | 132,0 |
Example of cable cross-section calculation
Task: to power the heating element with a power of W=4.75 kW with copper wire in the cable channel.
Current calculation: I = W/U. We know the voltage: 220 volts. According to the formula, the flowing current I = 4750/220 = 21.6 amperes.
We focus on copper wire, so we take the value of the diameter of the copper core from the table. In the 220V - copper conductors column we find a current value exceeding 21.6 amperes, this is a line with a value of 27 amperes. From the same line we take the cross-section of the conductive core equal to 2.5 squares.
Calculation of the required cable cross-section based on the type of cable or wire
| № | Number of veins section mm. Cables (wires) | Outer diameter mm. | Pipe diameter mm. | Acceptable long current (A) for wires and cables when laying: | Permissible continuous current for rectangular copper bars sections (A) PUE |
|||||||||||
| VVG | VVGng | KVVG | KVVGE | NYM | PV1 | PV3 | PVC (HDPE) | Met.tr. Du | in the air | in the ground | Section, tires mm | Number of buses per phase | ||||
| 1 | 1x0.75 | 2,7 | 16 | 20 | 15 | 15 | 1 | 2 | 3 | |||||||
| 2 | 1x1 | 2,8 | 16 | 20 | 17 | 17 | 15x3 | 210 | ||||||||
| 3 | 1x1.5 | 5,4 | 5,4 | 3 | 3,2 | 16 | 20 | 23 | 33 | 20x3 | 275 | |||||
| 4 | 1x2.5 | 5,4 | 5,7 | 3,5 | 3,6 | 16 | 20 | 30 | 44 | 25x3 | 340 | |||||
| 5 | 1x4 | 6 | 6 | 4 | 4 | 16 | 20 | 41 | 55 | 30x4 | 475 | |||||
| 6 | 1x6 | 6,5 | 6,5 | 5 | 5,5 | 16 | 20 | 50 | 70 | 40x4 | 625 | |||||
| 7 | 1x10 | 7,8 | 7,8 | 5,5 | 6,2 | 20 | 20 | 80 | 105 | 40x5 | 700 | |||||
| 8 | 1x16 | 9,9 | 9,9 | 7 | 8,2 | 20 | 20 | 100 | 135 | 50x5 | 860 | |||||
| 9 | 1x25 | 11,5 | 11,5 | 9 | 10,5 | 32 | 32 | 140 | 175 | 50x6 | 955 | |||||
| 10 | 1x35 | 12,6 | 12,6 | 10 | 11 | 32 | 32 | 170 | 210 | 60x6 | 1125 | 1740 | 2240 | |||
| 11 | 1x50 | 14,4 | 14,4 | 12,5 | 13,2 | 32 | 32 | 215 | 265 | 80x6 | 1480 | 2110 | 2720 | |||
| 12 | 1x70 | 16,4 | 16,4 | 14 | 14,8 | 40 | 40 | 270 | 320 | 100x6 | 1810 | 2470 | 3170 | |||
| 13 | 1x95 | 18,8 | 18,7 | 16 | 17 | 40 | 40 | 325 | 385 | 60x8 | 1320 | 2160 | 2790 | |||
| 14 | 1x120 | 20,4 | 20,4 | 50 | 50 | 385 | 445 | 80x8 | 1690 | 2620 | 3370 | |||||
| 15 | 1x150 | 21,1 | 21,1 | 50 | 50 | 440 | 505 | 100x8 | 2080 | 3060 | 3930 | |||||
| 16 | 1x185 | 24,7 | 24,7 | 50 | 50 | 510 | 570 | 120x8 | 2400 | 3400 | 4340 | |||||
| 17 | 1x240 | 27,4 | 27,4 | 63 | 65 | 605 | 60x10 | 1475 | 2560 | 3300 | ||||||
| 18 | 3x1.5 | 9,6 | 9,2 | 9 | 20 | 20 | 19 | 27 | 80x10 | 1900 | 3100 | 3990 | ||||
| 19 | 3x2.5 | 10,5 | 10,2 | 10,2 | 20 | 20 | 25 | 38 | 100x10 | 2310 | 3610 | 4650 | ||||
| 20 | 3x4 | 11,2 | 11,2 | 11,9 | 25 | 25 | 35 | 49 | 120x10 | 2650 | 4100 | 5200 | ||||
| 21 | 3x6 | 11,8 | 11,8 | 13 | 25 | 25 | 42 | 60 | rectangular copper bars (A) Schneider Electric IP30 |
|||||||
| 22 | 3x10 | 14,6 | 14,6 | 25 | 25 | 55 | 90 | |||||||||
| 23 | 3x16 | 16,5 | 16,5 | 32 | 32 | 75 | 115 | |||||||||
| 24 | 3x25 | 20,5 | 20,5 | 32 | 32 | 95 | 150 | |||||||||
| 25 | 3x35 | 22,4 | 22,4 | 40 | 40 | 120 | 180 | Section, tires mm | Number of buses per phase | |||||||
| 26 | 4x1 | 8 | 9,5 | 16 | 20 | 14 | 14 | 1 | 2 | 3 | ||||||
| 27 | 4x1.5 | 9,8 | 9,8 | 9,2 | 10,1 | 20 | 20 | 19 | 27 | 50x5 | 650 | 1150 | ||||
| 28 | 4x2.5 | 11,5 | 11,5 | 11,1 | 11,1 | 20 | 20 | 25 | 38 | 63x5 | 750 | 1350 | 1750 | |||
| 29 | 4x50 | 30 | 31,3 | 63 | 65 | 145 | 225 | 80x5 | 1000 | 1650 | 2150 | |||||
| 30 | 4x70 | 31,6 | 36,4 | 80 | 80 | 180 | 275 | 100x5 | 1200 | 1900 | 2550 | |||||
| 31 | 4x95 | 35,2 | 41,5 | 80 | 80 | 220 | 330 | 125x5 | 1350 | 2150 | 3200 | |||||
| 32 | 4x120 | 38,8 | 45,6 | 100 | 100 | 260 | 385 | Permissible continuous current for rectangular copper bars (A) Schneider Electric IP31 |
||||||||
| 33 | 4x150 | 42,2 | 51,1 | 100 | 100 | 305 | 435 | |||||||||
| 34 | 4x185 | 46,4 | 54,7 | 100 | 100 | 350 | 500 | |||||||||
| 35 | 5x1 | 9,5 | 10,3 | 16 | 20 | 14 | 14 | |||||||||
| 36 | 5x1.5 | 10 | 10 | 10 | 10,9 | 10,3 | 20 | 20 | 19 | 27 | Section, tires mm | Number of buses per phase | ||||
| 37 | 5x2.5 | 11 | 11 | 11,1 | 11,5 | 12 | 20 | 20 | 25 | 38 | 1 | 2 | 3 | |||
| 38 | 5x4 | 12,8 | 12,8 | 14,9 | 25 | 25 | 35 | 49 | 50x5 | 600 | 1000 | |||||
| 39 | 5x6 | 14,2 | 14,2 | 16,3 | 32 | 32 | 42 | 60 | 63x5 | 700 | 1150 | 1600 | ||||
| 40 | 5x10 | 17,5 | 17,5 | 19,6 | 40 | 40 | 55 | 90 | 80x5 | 900 | 1450 | 1900 | ||||
| 41 | 5x16 | 22 | 22 | 24,4 | 50 | 50 | 75 | 115 | 100x5 | 1050 | 1600 | 2200 | ||||
| 42 | 5x25 | 26,8 | 26,8 | 29,4 | 63 | 65 | 95 | 150 | 125x5 | 1200 | 1950 | 2800 | ||||
| 43 | 5x35 | 28,5 | 29,8 | 63 | 65 | 120 | 180 | |||||||||
| 44 | 5x50 | 32,6 | 35 | 80 | 80 | 145 | 225 | |||||||||
| 45 | 5x95 | 42,8 | 100 | 100 | 220 | 330 | ||||||||||
| 46 | 5x120 | 47,7 | 100 | 100 | 260 | 385 | ||||||||||
| 47 | 5x150 | 55,8 | 100 | 100 | 305 | 435 | ||||||||||
| 48 | 5x185 | 61,9 | 100 | 100 | 350 | 500 | ||||||||||
| 49 | 7x1 | 10 | 11 | 16 | 20 | 14 | 14 | |||||||||
| 50 | 7x1.5 | 11,3 | 11,8 | 20 | 20 | 19 | 27 | |||||||||
| 51 | 7x2.5 | 11,9 | 12,4 | 20 | 20 | 25 | 38 | |||||||||
| 52 | 10x1 | 12,9 | 13,6 | 25 | 25 | 14 | 14 | |||||||||
| 53 | 10x1.5 | 14,1 | 14,5 | 32 | 32 | 19 | 27 | |||||||||
| 54 | 10x2.5 | 15,6 | 17,1 | 32 | 32 | 25 | 38 | |||||||||
| 55 | 14x1 | 14,1 | 14,6 | 32 | 32 | 14 | 14 | |||||||||
| 56 | 14x1.5 | 15,2 | 15,7 | 32 | 32 | 19 | 27 | |||||||||
| 57 | 14x2.5 | 16,9 | 18,7 | 40 | 40 | 25 | 38 | |||||||||
| 58 | 19x1 | 15,2 | 16,9 | 40 | 40 | 14 | 14 | |||||||||
| 59 | 19x1.5 | 16,9 | 18,5 | 40 | 40 | 19 | 27 | |||||||||
| 60 | 19x2.5 | 19,2 | 20,5 | 50 | 50 | 25 | 38 | |||||||||
| 61 | 27x1 | 18 | 19,9 | 50 | 50 | 14 | 14 | |||||||||
| 62 | 27x1.5 | 19,3 | 21,5 | 50 | 50 | 19 | 27 | |||||||||
| 63 | 27x2.5 | 21,7 | 24,3 | 50 | 50 | 25 | 38 | |||||||||
| 64 | 37x1 | 19,7 | 21,9 | 50 | 50 | 14 | 14 | |||||||||
| 65 | 37x1.5 | 21,5 | 24,1 | 50 | 50 | 19 | 27 | |||||||||
| 66 | 37x2.5 | 24,7 | 28,5 | 63 | 65 | 25 | 38 | |||||||||
