Technical characteristics can vary significantly depending on what type of wire it is, what marking it has, how many cores it contains, and other parameters. However, it is possible to identify a number of key characteristics that, to one degree or another, apply to each of the power cables of this type.
The VVG cable is manufactured according to OKP code 352100.
Description and technical documentation
The dimensions of the cable largely depend on the number and type of cores that it contains. The minimum diameter of the core gives 1.5 mm 2 in its cross-sectional area. The maximum cross-sectional area of the core is 240 mm 2 in a single-core cable, 95 mm 2 in a two- or four-core cable and up to 50 mm 2 in a five-core cable. The cross-sections of neutral conductors (in the case of a smaller cross-section than the main ones) and grounding conductors, depending on the cross-section of the main conductors up to 50 mm 2, are given below.
Larger options are much less common. The most common among VVG cables with conductors of unequal cross-sections are cables with three main and one neutral conductor (the so-called “three plus”).
The outer diameter of the electrical wire is directly proportional to the number of cores and the nominal cross-section. With an area of 1.5 mm2, the cable diameter starts from a size of 5 mm and can reach up to 53.5 mm in four-core versions. In the same way, the weight of one kilogram of cable increases, starting from 39 kg/km and reaching several tons, so the weight of the wire must be taken into account when designing its installation.
The nominal and minimum values of the radial insulation thickness for VVG cables with a cross-section of up to 50 mm 2 for an operating voltage of 0.66 kV and 1 kV are given in the table.
The thickness of the protective sheath of the VVG electrical wire depends on the twisting diameter of the insulated conductors under the sheath. The nominal and minimum values of the shell thickness are given in the table.
Continuous-permissible current VVG
The continuous-permissible current that a given cable supports varies depending on the number of cores, their cross-section, and also on where the electrical wire runs - in the ground or in the air. The minimum current is 19 A, in any case, it is better to check the specifications of the specific cable that you are purchasing. Permissible load currents for electrical wires with a cross-section of up to 50 mm 2 laid in air are indicated in the table.
| Nominal cross-section of cores, mm2 | Permissible load current, A | ||
| With two main cores | With three main cores | With four main cores | |
| 1,5 | 24 | 21 | 19 |
| 2,5 | 33 | 28 | 26 |
| 4 | 44 | 37 | 34 |
| 6 | 56 | 49 | 45 |
| 10 | 76 | 66 | 61 |
| 16 | 101 | 87 | 81 |
| 25 | 134 | 115 | 107 |
| 35 | 166 | 141 | 131 |
| 50 | 208 | 177 | 165 |
The rated current, in this case, can be 0.66 or 1 kilowatt, and its frequency is 50 hertz. The power with a minimum cross-sectional area of the cable reaches 3.5 kW. As for resistance, it varies depending on the cross-sectional area of the cores. When it is 1.5 mm2, the resistance is 12 MOhm/km, when it is less than 4 mm2 – 10 MOhm/km, when it is 5 mm2 – 9 MOhm/km, and from 10 to 240 mm2 this figure is 7 MOhm/km . It is customary to take into account the resistance at a temperature of +20 degrees Celsius.
Technical characteristics of VVG power cable
The electrical resistance of the current-carrying cable cores up to 50 mm 2 at direct current should be no more than that indicated in the table.
The electrical resistance of the insulation per 1 km of length at a temperature of 20 0 C is at least 7 - 12 MOhm, depending on the cross-section of the conductors.
Finished cables must withstand alternating voltage testing at a frequency of 50 Hz for 10 minutes. The voltage is applied between the cores and is 3 kV for cables with a rated voltage of 0.66 kV and 3.5 kV for cables with a rated voltage of 1 kV.
Power cable storage conditions
Wires are stored under canopies or in closed rooms. It is also permitted to store cables on drums in open areas in a sheathed form. At the same time, the shelf life changes: in closed premises the shelf life will be 10 years, under a canopy in the open air - 5 years, on drums in open areas - only 2 years.
Weight and dimensions: main parameters
Approximate external dimensions and weights of individual cables with a cross-section of up to 50 mm 2 for packaging and transportation purposes are given in the table below. Depending on the manufacturer, the indicated figures may vary with a 10% deviation.
| Cable cross-section | External size value for packaging and transportation purposes, mm | Weight value for packaging and transportation purposes, kg/km |
|---|---|---|
| Flat cables | (a x b) | |
| 2x1.5 | 5 x 7.5 | 70 |
| 2x2.5 | 5.5 x 8 | 90 |
| 2x4 | 6 x 9.5 | 140 |
| 2x6 | 7 x 10.5 | 180 |
| 3x1.5 | 5 x 9.5 | 95 |
| 3x2.5 | 5.5 x 11 | 135 |
| 3x4 | 6 x 13 | 200 |
| Stranded cables | Diameter | |
| 3x1.5 | 8 | 90 |
| 3x2.5 | 9,5 | 135 |
| 3x4 | 11 | 200 |
| 3x6 | 12 | 260 |
| 3x10 | 14,5 | 410 |
| 3x16 | 17 | 590 |
| 3x25 | 20,5 | 810 |
| 3x35 | 23 | 1300 |
| 3x50 | 27 | 1700 |
| 3x4+1x2.5 | 12 | 230 |
| 3x6+1x4 | 14 | 310 |
| 3x10+1x6 | 16 | 480 |
| 3x16+1x10 | 19 | 650 |
| 4x1.5 | 8,5 | 110 |
| 4x2.5 | 10 | 170 |
| 4x4 | 12 | 240 |
| 4x6 | 13 | 320 |
| 4x10 | 16 | 510 |
| 4x16 | 19 | 750 |
| 4x25 | 23 | 1150 |
| 4x35 | 26 | 1550 |
| 4x50 | 31 | 2200 |
| 5x1.5 | 9,5 | 135 |
| 5x2.5 | 11 | 205 |
| 5x4 | 13 | 300 |
| 5x6 | 14 | 405 |
| 5x10 | 17,5 | 630 |
| 5x16 | 21 | 950 |
| 5x25 | 26 | 1450 |
| 5x35 | 29 | 1900 |
| 5x50 | 35 | 2700 |
Temperature and operating conditions
Particular attention should be paid to the temperature conditions for which these cables are adapted. The temperature at which the electrical cable is laid should not be lower than -15 C. Operation is allowed in wider temperature ranges, which start at -50 C and reach +50 C. However, if unusual situations arise, the temperature can rise to + 70 C without any problems, and in an emergency the cable can withstand short-term heating up to +80 C. Humidity should not exceed 98%. The minimum bending radius is at least 7.5 times the cable diameter. Service life - 30 years.
Determining what size wire you need is only half the battle. We still need to find the required cross section. The fact is that some manufacturers, in order to increase profits, produce cables with wires of a much smaller cross-section than stated in the accompanying documents. For example, the declared cores are 4 mm 2, but in reality - 3.6 mm 2 or even less. This is a decent difference. If it is not noticed in time, the wiring may heat up and this, in turn, can lead to a fire. Therefore, we will further talk about how to find out the cross-section of a wire by diameter, because the diameter can always be measured. Next, based on the measurement results, we will find out the actual parameters of the core.
When purchasing an electrical cable or wire, to check the cross-section of the core, you need to measure its diameter. There are several ways to do this. You can use measuring instruments such as calipers or micrometers. They measure the size of the exposed part of the conductor. The device is simply attached to the core, clamped between the jaws, and the result is displayed on the scale.
How to measure the diameter of the core - take a caliper or micrometer
For private use, the measurements are quite accurate, with a small error. Especially if the devices are electronic.
For the second method, you only need a ruler and some kind of even rod. But in this case, you still have to do calculations, albeit very simple ones. More on this method later.
Ruler+rod
If there are no measuring instruments on the farm, you can get by with a regular ruler and any rod of the same diameter. This method has a high error, but if you try it will be quite accurate.
Take a piece of wire about 10-20 cm long and remove the insulation. We wind the bare copper or aluminum wire onto a rod of the same diameter (any screwdriver, pencil, pen, etc. will do). We lay the coils carefully, close to one another. The number of turns is 5-10-15. We count the number of full turns, take a ruler and measure the distance that the wound wire occupies on the rod. Then divide this distance by the number of turns. The result is the diameter of the conductor.
As you can see, there is an error here. Firstly, you can lay the wire loosely. Secondly, it is not enough to take accurate measurements. But if you do everything carefully, the discrepancies with the actual sizes will not be so large.
How to measure the diameter of stranded wire
If you need to find out the diameter of a stranded wire, measurements are carried out with one of the wires that make it up. The process is the same: remove the insulation, remove the braiding (if any), fluff the wires, highlighting one, take measurements in any way (micrometer or wound around a rod).
Multiply the found size by the number of wires in one conductor (spread and count). That's all, you have found the diameter of the stranded conductor. It remains to find out how to find out the cross-section of a wire by diameter, because when planning wiring, it is the cross-sectional area of the wires that is used.
How to calculate using the formula
Since the cross-section of the wire is a circle, we will use the formula for the area of a circle (in the photo). As you can see, you can calculate the wire cross-section using the measured diameter or calculate the radius (divide the diameter by 2). For clarity, let's give an example. Let the measured wire size be 3.8 mm. We substitute this figure into the formula and get: 3.14 / 4 * 3.8 2 = 11.3354 mm 2. You can round the result - it will be 11.3 mm 2. Impressive cable.
The second part of the formula uses the radius. This is half the diameter. That is, to find the radius, divide the diameter by 2, we get 3.8 / 2 = 1.9 mm 2. Next, we substitute it into the formula and get: 3.14 * 1.9 2 = 11.3354 mm 2.
The numbers match, as they should. So, with a wire diameter of 3.8 mm, its cross-sectional area is 11.34 mm 2. You know how to find out the cross-section of a wire using the formula. But it is not always possible to do calculations. In this case, tables can help.
Determination of wire cross-section by diameter using tables
For cable and wire products there is a certain set of cross-sections that are specified in the standards. Knowing what cross-section you need, use the table to find the diameter of the conductor. Next, you just need to find products with the required parameters.
| Conductor cross-section | Diameter |
|---|---|
| 0.5 mm2 | 0.8 mm |
| 0.75 mm2 | 0.98 mm |
| 1.0 mm2 | 1.13 mm |
| 1.5 mm2 | 1.38 mm |
| 2.0 mm2 | 1.6 mm |
| 2.5 mm2 | 1.78 mm |
| 4.0 mm2 | 2.26 mm |
| 6.0 mm2 | 2.76 mm |
| 10.0 mm 2 | 3.57 mm |
Now a little about how to work with this table. You go for products with certain parameters. For example, you know that you need a cable with a core cross-section of 4 mm 2. Having found the corresponding value in the table, we look for the required parameters in the cable products. In this case, you will need to find wires with a diameter of 2.26 mm. If we find similar parameters in a store or market, that’s already good. It happens that the parameters indicated on the tag are too high, i.e. the actual cross-section of the conductors is smaller.
There are two ways to find what you need. The first is to look for products that meet the stated parameters. Perhaps, after spending some time, you will be able to find it. But it will take a lot of time to search. There are too few responsible producers. By the way, there is a sign by which you can navigate. This is the price. She is significantly above average. This is because more copper or aluminum is wasted. If you use this feature, it will take less time.
The second option is to look at products with a declared high denomination. In our case, we reason like this: we need a 4-square wire. The next one is 6 mm 2. It is very likely that the parameters of this cable in real life will be close to the required 4 squares. Perhaps the cross-section of the conductors will be larger, but this is good - the wiring will definitely not heat up. The disadvantage of this option is that you will spend more money, since such cables cost more.
In general, you know not only how to find out the wire cross-section by diameter, but also how to choose the right one. Even if the stated characteristics do not coincide with the real ones.
In theory and practice, the choice of transverse area current wire cross-section(thickness) is given special attention. In this article, analyzing reference data, we will get acquainted with the concept of “sectional area”.
Calculation of wire cross-section.
In science, the concept of “thickness” of a wire is not used. The terminology used in literature sources is diameter and cross-sectional area. Applicable to practice, the thickness of the wire is characterized by cross-sectional area.
Quite easy to calculate in practice wire cross section. The cross-sectional area is calculated using the formula, having first measured its diameter (can be measured using a caliper):
S = π (D/2)2 ,
- S - wire cross-sectional area, mm
- D is the diameter of the conductive core of the wire. You can measure it using a caliper.
A more convenient form of the wire cross-sectional area formula:
S=0.8D.
A small correction - it is a rounded factor. Exact calculation formula:
In electrical wiring and electrical installations, copper wire is used in 90% of cases. Copper wire has a number of advantages compared to aluminum wire. It is more convenient to install, with the same current strength, has a smaller thickness, and is more durable. But the larger the diameter ( cross-sectional area), the higher the price of copper wire. Therefore, despite all the advantages, if the current exceeds 50 Amperes, aluminum wire is most often used. In a specific case, a wire with an aluminum core of 10 mm or more is used.
Measured in square millimeters wire cross-sectional area. Most often in practice (in household electrics), the following cross-sectional areas are found: 0.75; 1.5; 2.5; 4 mm.
There is another system for measuring cross-sectional area (wire thickness) - the AWG system, which is used mainly in the USA. Below is section table wires according to the AWG system, as well as conversion from AWG to mm.
It is recommended to read the article about choosing the wire cross-section for direct current. The article provides theoretical data and discussions about voltage drop and wire resistance for different cross-sections. Theoretical data will indicate which current cross-section of the wire is most optimal for different permissible voltage drops. Also, using a real example of an object, the article on the voltage drop on long three-phase cable lines provides formulas, as well as recommendations on how to reduce losses. Wire losses are directly proportional to the current and the length of the wire. And they are inversely proportional to resistance.
There are three main principles when choosing the wire cross-section.
1. For the passage of electric current, the cross-sectional area of the wire (wire thickness) must be sufficient. The concept sufficiently means that when the maximum possible, in this case, electric current passes, the heating of the wire will be acceptable (no more than 600C).
2. Sufficient cross-section of the wire so that the voltage drop does not exceed the permissible value. This mainly applies to long cable lines (tens, hundreds of meters) and large currents.
3. The cross-section of the wire, as well as its protective insulation, must ensure mechanical strength and reliability.
To power, for example, a chandelier, they mainly use light bulbs with a total power consumption of 100 W (current slightly more than 0.5 A).
When choosing the thickness of the wire, you need to focus on the maximum operating temperature. If the temperature is exceeded, the wire and the insulation on it will melt and, accordingly, this will lead to the destruction of the wire itself. The maximum operating current for a wire with a certain cross-section is limited only by its maximum operating temperature. And the time that the wire can work in such conditions.
The following is a table of wire cross-sections, with the help of which, depending on the current strength, you can select the cross-sectional area of the copper wires. The initial data is the cross-sectional area of the conductor.
Maximum current for different thicknesses of copper wires. Table 1.
|
Conductor cross-section, mm 2 |
Current, A, for wires laid |
||
|
open |
in one pipe |
||
|
one two core |
one three core |
||
The ratings of wires that are used in electrical engineering are highlighted. “Single two-wire” is a wire that has two wires. One is Phase, the other is Zero - this is considered to be single-phase power supply to the load. “One three-wire” - used for three-phase power supply to the load.
The table helps to determine at what currents, as well as under what conditions it is operated. wire of this section.
For example, if the socket says “Max 16A”, then a wire with a cross-section of 1.5 mm can be laid to one socket. It is necessary to protect the outlet with a switch for a current of no more than 16A, preferably even 13A, or 10 A. This topic is covered in the article “About replacing and choosing a circuit breaker.”
From the table data it can be seen that a single-core wire means that no more wires pass nearby (at a distance of less than 5 wire diameters). When two wires are next to each other, as a rule, in one common insulation, the wire is two-core. There is a more severe thermal regime here, so the maximum current is lower. The more collected in a wire or bundle of wires, the less the maximum current should be for each conductor separately, due to the possibility of overheating.
However, this table is not entirely convenient from a practical point of view. Often the initial parameter is the power of the electricity consumer, and not the electric current. Therefore, you need to choose a wire.
We determine the current, having the power value. To do this, divide the power P (W) by the voltage (V) - we get the current (A):
I=P/U.
To determine power, having a current indicator, it is necessary to multiply the current (A) by voltage (V):
P=IU
These formulas are used in cases of active load (consumers in residential premises, light bulbs, irons). For reactive loads, a coefficient of 0.7 to 0.9 is mainly used (for the operation of powerful transformers, electric motors, usually in industry).
The following table suggests the initial parameters - current consumption and power, and the determined values - wire cross-section and tripping current of the protective circuit breaker.
Based on power consumption and current - choice wire cross-sectional area and circuit breaker.
Knowing the power and current, in the table below you can select wire cross section.
Table 2.
|
Max. power, |
Max. load current, |
Section |
Machine current, |
Critical cases in the table are highlighted in red; in these cases, it is better to play it safe without saving on the wire, choosing a thicker wire than indicated in the table. On the contrary, the current of the machine is less.
From the table you can easily select current wire cross-section, or wire cross-section by power. Select a circuit breaker for the given load.
In this table, all data is given for the following case.
- Single phase, voltage 220 V
- Ambient temperature +300С
- Laying in the air or in a box (located in a closed space)
- Three-core wire, in general insulation (wire)
- The most common TN-S system is used with a separate ground wire
- In very rare cases the consumer reaches maximum power. In such cases, the maximum current can operate for a long time without negative consequences.
Recommended choose a larger section(next in a series), in cases where the ambient temperature is 200C higher, or there are several wires in the harness. This is especially important in cases where the operating current value is close to the maximum.
In doubtful and controversial points, such as:
high starting currents; possible future increase in load; fire hazardous premises; large temperature changes (for example, the wire is in the sun), it is necessary to increase the thickness of the wires. Or, for reliable information, refer to formulas and reference books. But basically, tabular reference data is applicable for practice.
You can also find out the thickness of the wire using an empirical (experienced) rule:
The rule for choosing the cross-sectional area of the wire for the maximum current.
The right one cross-sectional area for copper wire, based on the maximum current, can be selected using the rule:
The required wire cross-sectional area is equal to the maximum current divided by 10.
Calculations according to this rule do not have a margin, so the result must be rounded up to the nearest standard size. For example, you need wire cross section mm, and the current is 32 Amperes. It is necessary to take the nearest one, of course, in the larger direction - 4 mm. It can be seen that this rule fits well into the tabular data.
It should be noted that this rule works well for currents up to 40 Amperes. If the currents are greater (outside the living room, such currents are at the input) - you need to choose a wire with an even larger margin, and divide it not by 10, but by 8 (up to 80 A).
The same rule applies to finding the maximum current through a copper wire, if its area is known:
The maximum current is equal to the cross-sectional area, multiplied by 10.
About the aluminum wire.
Unlike copper, aluminum conducts electric current less well. For aluminum ( wire of the same section, as copper), at currents up to 32 A, the maximum current will be less than for copper by 20%. At currents up to 80 A, aluminum transmits current worse by 30%.
Rule of thumb for aluminum:
The maximum current of an aluminum wire is cross-sectional area, multiply by 6.
Having the knowledge gained in this article, you can choose a wire based on the ratios “price/thickness”, “thickness/operating temperature”, as well as “thickness/maximum current and power”.
The main points about the cross-sectional area of the wires are covered, but if something is not clear, or you have something to add, write and ask in the comments. Subscribe to the SamElectric blog to receive new articles.
The Germans approach the maximum current depending on the cross-sectional area of the wire somewhat differently. A recommendation for choosing an automatic (protective) switch is located in the right column.
Table of the dependence of the electric current of the circuit breaker (fuse) on the cross-section. Table 3.
This table is taken from “strategic” industrial equipment, which may therefore give the impression that the Germans are playing it safe.
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.
Cable power table required to correctly calculate the cable cross-section, if the power of the equipment is large and the cable cross-section is small, then it will heat up, which will lead to the destruction of the insulation and loss of its properties.
To calculate the conductor resistance, you can use the conductor resistance calculator.
For the transmission and distribution of electric current, the main means are cables; they ensure the normal operation of everything related to electric current, and how good this work will be depends on the right choice cable cross-section by power. A convenient table will help you make the necessary selection:
|
Current cross-section |
||||
|
Voltage 220V |
Voltage 380V |
|||
|
Current. A |
Power. kW |
Current. A |
Power, kWt |
|
|
Section Toko- |
Aluminum conductors wires and cables |
|||
|
Voltage 220V |
Voltage 380V |
|||
|
Current. A |
Power. kW |
Current. A |
Power, kWt |
|
But in order to use the table, you need to calculate the total power consumption of devices and equipment that are used in a house, apartment or other place where the cable will be laid.
Example of power calculation.
Let's say you are installing closed electrical wiring in a house using an explosive cable. You need to write down a list of equipment used on a piece of paper.
But how now find out power? You can find it on the equipment itself, where there is usually a label with the main characteristics recorded.
Power is measured in Watts (W, W) or Kilowatts (kW, KW). Now you need to write down the data and then add it up.
The resulting number is, for example, 20,000 W, which would be 20 kW. This figure shows how much energy all electrical receivers together consume. Next, you should consider how many devices will be used simultaneously over a long period of time. Let’s say it turns out to be 80%, in which case the simultaneity coefficient will be equal to 0.8. We calculate the cable cross-section based on power:
20 x 0.8 = 16 (kW)
To select a cross-section, you will need a cable power table:
|
Current cross-section |
Copper conductors of wires and cables |
|||
|
Voltage 220V |
Voltage 380V |
|||
|
Current. A |
Power. kW |
Current. A |
Power, kWt |
|
|
10 |
15.4 |
|||
If the three-phase circuit is 380 Volts, then the table will look like this:
|
Current cross-section |
Copper conductors of wires and cables |
|||
|
Voltage 220V |
Voltage 380V |
|||
|
Current. A |
Power. kW |
Current. A |
Power, kWt |
|
|
16.5 |
||||
|
10 |
15.4 |
|||
These calculations are not particularly difficult, but it is recommended to choose a wire or cable with the largest cross-section of conductors, because it may be that it will be necessary to connect some other device.
Additional cable power table.
