Calculation of the cross section of the wire in the apartment. Electric cable for input to the apartment: the section matters

The ability to choose the right cable cross section over time can be useful to each, and for this it is not necessary to be a qualified electrician. Incorrectly calculating the cable, you can expose myself and your property of serious risk - too thin wires will warmly warm up, which can lead to the appearance of fire.

What is the calculation of the cable cross section

Main distribution, carrying out this rigorous complicated procedure is necessary to ensure the safety of both the rest of the room and the people being in it. Today, humanity does not invented the more convenient method of distribution and delivery of electrical energy to the consumer, both on the wires. For people almost daily, the electrician services are needed - someone needs to connect the outlet, someone needs to install a lamp, etc. From this it turns out that even such a selection of the required section is associated with the operation, it would seem to be a minor procedure as the installation of a new lamp . What then to talk about connecting the electric stove or water heater?

Failure to comply with the rules can lead to a violation of the integrity of the wiring, which often becomes cause of short circuit or even electric shock.

If you make an error when choosing a cable cross section, and purchase a cable with a smaller conductor area, it will lead to a constant cable heating, which will cause the destruction of its insulation. Naturally, all this negatively affects the duration of the wiring operation - there are cases of cases when a month after successfully installation, the wiring has stopped working, and a specialist intervention was required.

It should be remembered that from a properly selected value of the cable cross section directly depends on the electron and fire safety in the building, and therefore the life of the tenants themselves.

Of course, each owner wants to save as much as possible, but you should not do this at the cost of your life, putting it at risk - because the fire may happen in a short circuit, which can completely destroy all the property.

To avoid this, before starting electrical work, you should choose the optimal section cable. For the selection it is necessary to take into account several factors:

• the total number of electrical devices located indoors;
• the total power of all devices and the load consumed. To the resulting value should be added "about the supply" 20-30%;
• then, by disadvantaged mathematical calculations, to translate the resulting value into the wire cross section, while taking into account the material of the conductor.

Attention! Due to lower electrical conductivity, wires with aluminum cores should be purchased with a large cross section, rather than copper.

What affects the heating of wires

If wiring is heated during the operation of household appliances, then all necessary measures should be immediately taken to eliminate this problem. There are many factors that affect heat heating, but the main one can attribute the following:

1. Insufficient cable cross section. I am expressed by an affordable language, you can say so - the thicker will be the cable of the core, the greater the current it can transmit, without basking. The magnitude of this value is indicated in the labeling of cable products. You can also measure the cross section yourself with the help of a caliper (it should be verified that the wire is not under voltage) or on the brand of the wire.
2. The material from which the wire is made. Copper cores better transmit tension to the consumer, and have less resistance, compared with aluminum. Naturally, they are heated less.
3. Type of housing. The cable may be single-core (lived consists of one thick rod) or stranded (lived consists of a large number of small wiring). Strategic cable more flexible, but significantly inferior to one-liner according to the permissible strength of the transmitted current.
4. Method of laying cable. Tightly laid wires, at the same time, in the pipe, warm more significantly, rather than open wiring.
5. Material and insulation quality. Inexpensive wires, as a rule, have low quality isolation, which adversely affects their resistance to high temperatures.

How the calculation of power consumed

Calculate the approximate cross section of the cable can be independently necessary to resort to the help of a qualified specialist. The data obtained as a result can be used to buy a wire, however, the electrical work themselves should be trusted only by an experienced person.

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

1. A detailed list of all placed electrical appliances is compiled.
2. The passport details of the power consumption of all the devices found, after which the continuity of the operation of this or that equipment is determined.
3. Having retentioning the value of power consumed from devices that work constantly, you should summarize this value by adding a coefficient to it, equal to the value periodically turning on the electrical appliances (that is, if the device works only 30% of the time, then you should add a third of its power).
4. Further, we are looking for the obtained values \u200b\u200bin a special table calculation of the cross section of the wire. For a greater guarantee, it is recommended to add 10-15% to the resulting power consumption.

To determine the desired calculations for the selection of electrical wiring cables according to their power, it is important to use data on the amount of electrical energy consumed by devices and current instruments.

At this stage it is necessary to take into account very important moment - The data of submissive devices are not accurate, but an approximate, averaged value. Therefore, it is necessary to add about 5% of the parameters specified by the manufacturer of the equipment to such a mark.

Most of the far from the most competent and qualified electricians are confident in one simple truth - in order to properly carry out 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 outlets - 2.5 mm².

This is thought and so consider only incompetent electricians. But what if, for example, in the same room, the microwave, kettle, refrigerator and lighting, for which wires with different cross-section are needed? This can lead to a variety of situations: short circuit, rapidly damping and insulating layer, as well as to ignition (this is a rare case, but still possible).

Exactly the same is not the most pleasant situation may occur if a person will connect a multicooker to the same rosette, a coffee maker and, for example, a washing machine.

Features of calculating power of hidden wiring

If the project documentation implies the use of hidden wiring, then it is necessary to purchase cable products "with a margin" - to the resulting cable cross section should be added about 20-30%. This is done to avoid the heating of the cable during operation. The fact is that in the conditions of the constrained space and the lack of air access, the heating of the cable occurs significantly more intense than when mounting open wiring. If there is not a single cable in the closed channels, but at once several, then the cross section of each wire should be increased by no less than 40%. It is also not recommended to stack various wires tightly - ideally, each cable must be a corrugation providing its additional protection.

Important! It is by the meaning of the power consumption, professional electricians are focused when a cable cross section is selected, and only such a method is correct.

How to calculate cable cross sections

With a sufficient value of the cable cross section, the electric current will pass to the consumer, without causing heating. Why is heating? We will try to explain the most accessible as possible. For example, the kettle is included in the outlet of the 2 kilowatta consumed, but the wire running to the rosette can pass the current for it only 1 kilowatt. Cable bandwidth is associated with conductor resistance - than it is more, the smaller the current can be transmitted over the wire. As a result of high resistance in the wiring and the cable is heated, gradually destructive isolation.

With the corresponding section, the electrical current comes to the consumer in full, and the heating of the wire does not occur. Therefore, designing wiring, you should consider the power consumption of each electrical instrument. This value can be found from the technical passport on the electrical appliance or from the label pasted on it. Summing up maximum values \u200b\u200band using a non-hard formula:

and we get the value of the total current.

PN means specified in the passport power of an electrical appliance, 220 - nominal voltage.

For a three-phase system (380 V), the formula looks like this:

I \u003d (p1 + p2 + .... + pn) / √3 / 380.

The resulting I value is measured in amperes, and on the basis of it and the corresponding cable cross section is selected.

It is known that the bandwidth of the copper cable is 10 A / mm, for aluminum cable, the bandwidth value is 8 A / mm.

For example, calculate the cable cross section for connecting washing machineThe power consumed of which is 2400 W.

I \u003d 2400 W / 220 V \u003d 10.91 A, rounding 11 A.

11 A + 5 A \u003d 16 A.

If we take into account that the apartments use three-core cables and look at the table, then to 16 and a close value of 19 A, therefore, a wire is required to install a washing machine, a cross section is not less than 2 mm².

Cable cross section table relative to strength

Cross section provocative Wearing veins (mm 2)		Current (a), for wires laid
	Open that		in one trumpet
		two one- Household	three single Household	four single Household	one two- core	one three- core
0,5	11	-	-	-	-	-
0,75	15	-	-	-	-	-
1	17	16	15	14	15	14
1,2	20	18	16	15	16	14,5
1,5	23	19	17	16	18	15
2	26	24	22	20	23	19
2,5	30	27	25	25	25	21
3	34	32	28	26	28	24
4	41	38	35	30	32	27
5	46	42	39	34	37	31
6	50	46	42	40	40	34
8	62	54	51	46	48	43
10	80	70	60	50	55	50
16	100	85	80	75	80	70
25	140	115	100	90	100	85
35	170	135	125	115	125	100
50	215	185	170	150	160	135
70	270	225	210	185	195	175
95	330	275	255	225	245	215
120	385	315	290	260	295	250
150	440	360	330	-	-	-
185	510	-	-	-	-	-
240	605	-	-	-	-	-
300	695	-	-	-	-	-
400	830	-	-	-	-	-

How to choose a segment of the conductor

There are several more criteria that the cross section of the wiring used should correspond to:

1. Length of cable. The larger the wire in length, the largest current losses in it. This happens again as a result of an increase in resistance increasing as the length of the conductor increases. This is especially felt when using aluminum wiring. When applied copper wires To organize wiring in the apartment, the length is usually not taken into account - the standard stock at 20-30% (with hidden wiring) with more than enough to compensate for possible increase in resistance associated with the length of the wire.
2. Type of wires used. In domestic power supply, 2 types of conductors are used - based on copper or aluminum. Copper wires high quality and have less resistance, but aluminum is cheaper. With full accordance with the standards, aluminum wiring copes with its tasks not worse than copper, so you need to carefully weighed your choice before buying a wire.
3. Configuration of electrical panel. If all the wires that feed consumers are connected to a single machine, it will be a weak place in the system. The strong load will lead to the heating of the terminal blocks, and non-compliance with the nominal permanent response. It is recommended to divide the wiring into several "rays" with the installation of a single machine.

In order to determine the exact data for selecting the section of electrical wiring cables, you need to consider any, even the most minor parameters, such as:

1. View and type of insulation of electrical wiring;
2. Length of sites;
3. Methods and laying options;
4. Features of the temperature regime;
5. Level and percentage of humidity;
6. The maximum possible overheating;
7. The difference in the capacity of all current receiver belonging to the same group. All these and many other indicators allow you to significantly increase efficiency and benefit from the use of energy in any scale. In addition, the correct calculations will help avoid overheating or fast abrasion of the insulating layer.

In order to properly determine the optimal cable section for any human household needs, it is necessary to use the standardized following rules in all common cases:

• for all sockets that will be mounted in the apartment, it is necessary to use wires with a corresponding cross section of 3.5 mm²;
• for all elements of point lighting, it is necessary to use electrical wiring cables with a cross section of 1.5 mm²;
• as for high-power devices, they should use cables with a cross section of 4-6 mm².

If in the process of installation or calculations there are some doubts, it is better not to act blindly. The ideal option will refer to the corresponding table of calculations and standards.

Cable Cable Single Table

Current section conducted (mm)	Copper veins of wires and cables
	Voltage 220 B.		Voltage 380 B.
	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
16	80	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	265	57,2	220	145,2
120	300	66	260	171,6

Aluminum cable cross section table

So, the known power of each electrical appliance in the house, a known number of lighting devices and lighting points make it possible to calculate the total power consuming. This is not an accurate amount, since most of the values \u200b\u200bfor the capacity of various devices are averaged. Therefore, this figure should immediately add 5% of its value.

Averaged power readings for used electrical appliances

Consumer	Power, W
Television	300
Printer	500
A computer	500
Hair dryer	1200
Iron	1700
Electric kettle	1200
Toaster	800
Heater	1500
Microwave	1400
Oven	2000
Refrigerator	600
Washer	2500
Electric stove	2000
Lighting	2000
Flowing water heater	5000
Boiler	1500
Drill	800
Perforator	1200
Welding machine	2300
Lawn mower	1500
Water pump	1000

And many believe that this is enough to select almost standard variants of the copper cable:

• section 0.5 mm2 for wires to illuminate point lamps;
• section 1.5 mm2 for lighting wires for chandeliers;
• the cross section is 2.5 mm2 for all sockets.

At the level of household use of electricity, such a scheme looks quite acceptable. While the kitchen simultaneously did not even solve the refrigerator and an electric kettle, while you watched TV there. The same unpleasant surprise overtakes you when you include a coffee maker, washing machine and microwave into one outlet.

Thermal calculation using correction coefficients

For multiple lines in the same cable channel, the maximum current values \u200b\u200bshould be multiplied by the corresponding coefficient:

• 0.68 - For the number of conductors from 2 to 5 pcs.
• 0.63 - For conductors from 7 to 9 pcs.
• 0.6 - For conductors from 10 to 12 pcs.

The coefficient refers to the wires (cores), and not to the number of lines passing. When calculating the number of laid cores, the zero working wire or ground wire is not taken into account. According to Pue and GOST 16442-80, they do not affect the heating of the wires when normal currents passing.

Summarizing the above, it turns out that for the correct and accurate selection of the cross section of the wires you need to know:

1. The sum of all maximum powers of electrical appliances.
2. Network characteristics: Number of phases and voltage.
3. Cable material characteristics.
4. Tabs and coefficients.

At the same time, the power is not the main indicator for a separate cable line or the entire internal power supply system. When selecting the section, it is necessary to calculate the maximum current current, and after checking it with the nominal current of the home network.

Below I will give a table of cross section of wires, but I recommend to gain patience by reading this small theoretical part to the end.

This will allow you to be more conscious in the selection of wires for installing wiring, in addition, you can make yourself calculation of the cross section of the wire, moreover, even "in the mind."

The passage of current on the conductor is always accompanied by heat release (according to heating), which is directly proportional to the power dissipated on the electrical wiring site. Its value is determined by the formula p \u003d i 2 * R, where:

• I is the value of the flowing current,
• R - wire resistance.

Excessive heating can lead to insulation disorders, as a result, a short circuit and (or) fire.

The current flowing through the conductor is depending on the load power (P) determined by the formula

I \u003d p / u

(U is a voltage that for household electrical network It is 220V).

The resistance of the wire R depends on its length, material and sections. For wiring in the apartment, cottage or garage, you can neglected the length, but the material and section when the wires are selected for the wiring must be considered.

Calculation of the cross section of the wire

The cross section of the wire s is determined by its diameter D as follows (hereinafter, I will simplify the formula as much as possible):
S \u003d π * d 2/4\u003d3.14*d 2/4\u003d0.8*d 2.

This may be useful to you if you already have a wire, and without labeling, which indicates immediately a section, for example, 2x1.5, adhesion 1.5 - section in mm 2, and 2 - the amount of live.

The greater the cross section, the greater the current load withstands the wire. With the same copper and aluminum wire sections - copper can withstand a larger current, in addition, they are less brittle, they are worse, therefore most preferred.

Obviously, with a hidden gasket, as well as wires laid in the corrugated box, the electrical box due to poor heat exchange will be heightened, it means that they should be selected with a certain reserve, so it has time to consider such a value as the current density (we denote it iρ).

It is characterized by the value of the current in the amps flowing through the unit of the cross section of the conductor, which we will take 1mm 2. Since this value is relative, then with its use it is convenient to calculate the cross section according to the following formulas:

1. d \u003d √ 1.27 * i / iρ \u003d 1.1 * √i / iρ - We obtain the value of the diameter of the wire,
2. S \u003d 0.8 * D 2 - previously obtained formula for calculating the section,

We substitute the first formula into the second, somewhat we can, we get a very simple ratio:

S \u003d I / Iρ

It remains to determine the value of current density iρ), since the operating current I) is determined by the load capacity, I led the formula above.

The permissible value of the current density is determined by the set of factors, the consideration of which I will omit and give the final results, and with the reserve:

Example of calculation:

We have: the total load power in the line is 2.2 kW, the wiring is open, the wire is copper. To calculate, we use the following units: current - amp, power - watt (1kW \u003d 1000W), voltage - volts.

S \u003d I / Iρ \u003d (2200/220) / 10 \u003d 1mm 2

If you hold the appropriate calculations for the entire row of wire sections, you can get the appropriate table.

Table cross sections of wires

Immediately warn you, the data from different sources may differ. This difference is determined by the amount of power in power. When calculating, I took this stock at the maximum, having remembered that it was better to buy more powerful, respectively, more expensive wires than then redo the burnt wiring.

I bring to your attention the table promised at the beginning of the article:

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The materials presented on the site are informational and cannot be used as guidance and regulatory documents.

When laying wiring you need to know, the cable with the cores of which section you will need to lay. The selection of the cable cross section can be made either by power consumed, or by current consumed. Also consider the length of the cable and the laying method.

Select the cable cross section

You can choose the wire section in the power of the devices that will be connected. These devices are called the load and the method may still be called "on load". The essence of it does not change.

We collect data

To begin with, we find in passport data of household appliances consumed power, write it down on the leaflet. If it is so easier, you can look at the nameplates - metal plates or stickers fixed on the body of equipment and equipment. There are basic information and, most often, power is present. Identifying it easier by units of measurement. If the product is manufactured in Russia, Belarus, Ukraine is usually worth the designation of W or kW, on the equipment from Europe, Asia or America, it is usually an English designation of watts - W, and the power consumption (it is necessary) is denoted by the reduction of "TOT" or TOT MAX.

If this source is not available (the information was lost, for example, or you only plan to acquire equipment, but have not yet been determined with the model), you can take the average data. For convenience, they are reduced to the table.

Find the technique that you plan to put, write out the power. It is sometimes given with a big scatter, so it is sometimes difficult to understand what figure to take. In this case, it is better to take a maximum. As a result, during the calculations, you will have a slightly overestimated power of the equipment and the larger cable will be required. But to calculate the cable cross section is good. Only cables are burning with a smaller cross section than necessary. The tracks with a large cross section work for a long time, as they warm less.

The essence of the method

To choose a cross-section of the load on the load, fold the power of the instruments that will be connected to this conductor. It is important that all the capacities are expressed in the same measurement units - or in watts (W), or in kilowatts (kW). If there are different meanings, bring them to a single result. For translation, kilowatta is multiplied by 1000, and watts are obtained. For example, 1,5 kW will be transferred to Watta. It will be 1.5 kW * 1000 \u003d 1500 W.

If necessary, you can reverse conversion - watts translate to kilowatts. For this, the figure in watts is divided by 1000, we get kW. For example, 500 W / 1000 \u003d 0.5 kW.

Cable cross section, mm2	Conductor diameter, mm	Copper wire			Aluminum wire
		Talk, A.	power, kWt		Talk, A.	power, kWt
			220 B.	380 B.		220 B.	380 B.
0.5 mm2	0.80 mm	6 A.	1,3 kW	2,3 kW
0.75 mm2.	0.98 mm	10 A.	2.2 kW	3.8 kW
1.0 mm2	1,13 mm	14 A.	3.1 kW	5.3 kW
1.5 mm2	1.38 mm	15 A.	3.3 kW	5.7 kW	10 A.	2.2 kW	3.8 kW
2.0 mm2	1.60 mm	19 A.	4.2 kW	7.2 kW	14 A.	3.1 kW	5.3 kW
2.5 mm2	1.78 mm	21 A.	4.6 kW	8.0 kW	16 A.	3.5 kW	6.1 kW
4.0 mm2	2.26 mm	27 A.	5.9 kW	10.3 kW	21 A.	4.6 kW	8.0 kW
6.0 mm2	2.76 mm	34 A.	7.5 kW	12.9 kW	26 A.	5.7 kW	9.9 kW
10.0 mm2.	3.57 mm	50 A.	11.0 kW	19.0 kW	38 A.	8.4 kW	14.4 kW
16.0 mm2.	4.51 mm	80 A.	17,6 kW	30.4 kW	55 A.	12.1 kW	20.9 kW
25.0 mm2	5.64 mm	100 A.	22.0 kW	38.0 kW	65 A.	14.3 kW	24.7 kW

To find the desired cable cross section in the corresponding column - 220 V or 380 V - we find a digit that is equal to or slightly more than the previously calculated power. The column is chosen based on how many phases on your network. Single-phase - 220 V, three-phase 380 V.

In the found line, we look at the first column. This will be the desired cable cross-section for this load (the power consumption of the instruments). Cable with veins of such a section and will need to look.

A little bit about the copper wire or aluminum. In most cases, when, use cables with copper cores. Such cables are more expensive aluminum, but they are more flexible, have a smaller cross section, work easier with them. But, copper cables with a large cross section, no more flexible than aluminum. And at large loads - at entering the house, in an apartment with a large planned power (from 10 kW and more) it is more expedient to use a cable with aluminum conductors - you can save a little.

How to calculate the current cable cross section

You can choose a cable cross section. In this case, we carry out the same work - we collect data on the plug-in load, but we are looking for the maximum current consumed in the characteristics. Having collected all the values, summarize them. Then we use the same table. Only we are looking for the nearest greater value in the column signed by the "current". In the same line, we look at the cross section of the wire.

For example, it is necessary with peak current consumption of 16 A. We will lay the copper cable, because we look in the appropriate column - the third left. Since there is no value exactly 16 A, we look at the line 19 A is the closest more. Suitable section 2.0 mm 2. This will be the minimum cable cross section for this case.

When connecting powerful household electrical appliances from pulling a separate power supply line. In this case, the selection of the cable cross section is somewhat easier - only one power value or current is required.

You cannot pay attention to a slightly smaller value. In this case, at maximum load, the conductor will warmly warm, which can lead to what isolation melts. What could be next? Can work if it is installed. This is the most favorable option. May fail appliances Or start a fire. Therefore, the selection of the cable cross section always makes the greater value. In this case, it will be possible to install the equipment even slightly more in power or consumed current without rewriting.

Calculation of power cable and length

If the power line is long - several dozen or even hundreds of meters - in addition to the load or current consumed, it is necessary to take into account the losses in the cable itself. Usually long distances of power lines at. Although all the data must be listed in the project, you can be reinsured and check. To do this, you need to know the dedicated power to the house and the distance from the post to the house. Next, on the table, you can choose a cross-section of the wire, taking into account losses on the length.

In general, when laying wiring, it is better to always take some margin on the cross section of the wires. First, with a larger cross section, the conductor will be warm, which means insulation. Secondly, more and more devices operating from electricity appear in our life. And no one can give guarantees that in a few years you do not need to put a couple of new devices in addition to the old. If the stock exists, they can simply turn on. If it is not, you will have to wise - or change wiring (again) or ensure that there are no powerful electrical appliances simultaneously.

Open and closed wire laying

How we all know, when passing current on the conductor, it heats up. The larger the current, the more heat allocated. But, when passing the same current, according to conductors, with a different section, the amount of heat released changes: the smaller the cross section, the more heat releases.

In this regard, with the opening of the conductors open, its cross section may be less - it cools faster, as the heat is transmitted. At the same time, the conductor cools faster, the insulation will not deteriorate. With a closed laying, the situation is worse - warm is slower thanks. Therefore, for a closed laying - in, pipes, in the wall - recommend taking a larger cable.

The selection of the cable cross section, taking into account the type of its gasket, can also be carried out using a table. The principle was described earlier, nothing changes. Just takes into account another factor.

And finally, several practical Soviets. Going to the market behind the cable, take a caliper with you. Too often, the declared cross section does not coincide with reality. The difference can be in 30-40%, and this is a lot. What threatens it? By burning wiring with all the ensuing consequences. Therefore, it is better to check if this cable is really the required core section (diameters and corresponding cable cross sections in the table above). A Read more about the definition of section cable for its diameter can be read here.

This article will be described how to carry out the calculation of the cross section of the power consumption on their own. It is necessary to know this not only with in the house, but also when carrying out works in cars, for example. If the wire section is insufficient, it will begin to heat up very strongly, which will lead to a significant loss of security. Given all the recommendations that will be outlined below, you can independently calculate the parameters of the wires for the installation of power supply in the house. But if not confident in your abilities, better contact the specialists in this area. Moreover, it should be noted that the calculation of the cross section of the power consumption (12V and 220V) is made similarly.

Calculation of the wiring length

For any type of electronic system, the most important condition for stable and trouble-free operation is the competent calculation of the sections of all current and power wires. First of all, you should calculate the maximum length of all wiring. There are several ways to do this:

1. Measurement of the distance from shields to sockets, switches according to the installation scheme. Moreover, it can be done by a ruler on a predetermined electrical wiring plan - sufficiently obtained lengths of the length are multiplied by scale.
2. And the second, more accurate way is to arm a ruler and walk through all rooms, after measuring. Moreover, it should be borne in mind that the wires must somehow connect, therefore, the stock must always be present - at least one or two centimeters from each edge of the wiring.

Now you can proceed to the next step.

Calculation of the load on wiring

To calculate the total load, you need to fold all the minimum power of consumers throughout the house. Suppose you carry out the calculation for the kitchen, there are lamps, microwave, electric kettle and stove installed dishwasher etc. All power must be summarized (see on the rear caps consumed power, but you have to calculate yourself on this parameter even the current). After multiplied by the correction factor of 0.75. It is also called the simultaneity coefficient. The essence of it is clear from the very name. This figure, which will result in computing, will be needed in the future to calculate the parameters of the wires. Note that the entire power supply system must be safe, reliable and durable. These are the basic requirements that need to be taken into account when the cross section of the wire for power consumed is 12V and 220V.

Current consumption of electrical installations

Now about how to calculate the current consumption of an electrical instrument. You can do it in the mind, but you can also on the calculator. See the instructions for the device as the value of power consumed. Of course, there is an alternating current with a voltage of 220 volts in the household power grid. Therefore, using a simple formula (power consumption to divide the supply voltage), you can calculate the current. For example, the electric kettle has a power of 1000 W. So, if divided 1000 to 220, we obtain a value of approximately 4.55 amps. It is performed very simply by power consumed. How to implement this, told in the article. In the kettle mode, the kettle consumes 4.55 amp from the network (it is necessary to install a larger circuit breaker for protection). But pay attention to the fact that it is not always exact value. For example, if an engine has an engine in an electrical appraction, it is possible to increase by about 25% of the resulting value - the motor consumption current in the start mode is much more than when working at idle.

But you can use the Code of Rules and Standards. There is such a document as the rules of the electrical installation device, it is he who regulates all the standards for the installation of wiring not only in private possessions, but also at factories, factories, etc. According to these rules, the electrical wiring standard is the ability to withstand the load of 25 amps for a long time. Therefore, all electrical wiring should be performed in apartments only with the use of copper wire, it is no less than 5 square meters. mm. Each living should have a cross section over 2.5 square meters. mm. The conductor diameter must be 1.8 mm.

So that all the wiring worked as safe as possible, an automatic switch is installed on entering. He will lock the apartment from short circuits. Also recently, most residential holders are installed in the installation of protective shutdown devices, which instantly act on the resistance change in the chain. In other words, if you accidentally touch the voltage, they will instantly make it possible and you will not get a blow. It is necessary to count on the current, and it is necessary to choose with a margin so that there is always an electrical appliance in the house. Competent calculation of the cross section of the power consumption (how to implement right choice Wires, you will learn from this material) - this is the key to the fact that the power supply will function correctly and efficiently.

Wiring Materials

As a rule, the installation of wiring in a private house or apartment is made using three-core wires. Moreover, each vein is separate isolation, they all have different colors - brown, blue, yellow-green (standard). He lived - this is exactly the part of the wire, which flows current. It can be both single-robes and multi-proper. In some brands, the wire is used cotton braid over the lived. Materials for making lived wires:

1. Steel.
2. Copper.
3. Aluminum.

Sometimes you can meet combined, for example, a copper wire of a multi-boiler with several steel conductors. But these were used to carry out a field telephone connection - a signal was transmitted over copper, and the steel was used for the most part for fastening to supports. Therefore, in this article, there will be no conversation about such wires. For apartments and private houses, the copper wire is perfect. It is durable, reliable, characteristics are much higher than at cheap aluminum. Of course, the price of the copper wire bite, but it is worth mentioning that his service life (guaranteed) is 50 years.

Brand wires

For laying wiring, it is best to use two brands of wires - WDGNG and VG. The first has the ending "-ng", which indicates that the insulation does not burn. It is used to carry out electrical wiring inside structures and buildings, as well as in the ground, outdoors. Stably works in the temperature range -50 ... +50. Guaranteed service life - at least 30 years. The cable can be with two, three or four cores, the cross section of each - in the range of 1.5 ... 35 square meters. mm. Pay attention to the fact that it is necessary to calculate the cross-section of the wire for power consumption and length (in the case of a long line).

Carefully look at the fact that before the name of the wire there was no letter "A" (for example, AVVG). This suggests that inside the veins are made of aluminum. There are also foreign analogues - a NYM brand cable having a round shape complies with standards adopted in Germany (VDE0250). Copper veins, insulation is not susceptible to burning. The round shape of the wire is much more convenient if you need to install through the wall. But for conducting wiring indoors it turns out more conveniently flat domestic.

Wires of aluminum

They have a little weight, and most importantly, low cost. Therefore, it will be useful for those cases when you need to lay long lines by air. If all the work is competent and correctly, you will get an ideal air line, since aluminum has one huge advantage - it is not susceptible to oxidation (unlike copper). But often, the wiring from aluminum was used in homes (as a rule, in older). The wire used to get it easier, and he cost a penny. It should be noted that the calculation of the cross section of the power consumption (the features of this process are known to each electrician) is the main stage in creating a project of the power supply of the house. But you need to pay attention to one feature - the cross section of the aluminum wire must be greater than copper to withstand the same load.

Table for calculating the cross section

It is also necessary to mention that the maximum allowable current load is much smaller than for copper. The table below will help calculate the cross section

Wiring section depending on the type of wiring

There are two types of installation of electrical wiring in homes - open and closed. As you understand, you need to take into account this nuance when carrying out calculations. Hidden mounted inside overlaps, as well as in grooves and canals, in pipes, etc. Closed wiring has higher demands, since it has a lower cooling capacity. And any wire with long-term exposure of high load heats up very much. Therefore, in the case when you calculate the cross section of the wire for power consumed, the effect on heating is necessarily taking into account. It is also necessary to take into account the following parameters:

1. Long current load.
2. Loss of voltage.

With an increase in the wire length, the voltage decreases. Consequently, to reduce voltage losses, it is necessary to increase the cross section of the live wire. If we are talking about a small house or even the room, then the value of the loss is extremely low, they can be neglected. But if the long line is calculated, it will not go from it. After all, the calculation of the cross-section of the wire for power consumed (the effect of length is very large) depends on such a parameter as the length of the line.

Calculation of power wires

So, you will need to know the following characteristics:

1. The material from which cable veins consist.
2. Maximum power consumption.
3. Supply voltage.

Note that when the temperature is leaking, the temperature is raised and the allocation of some heat. Moreover, the amount of heat is proportional to the entire power, which is dissipated on a piece of electrical wiring. If you choose an incorrect cross section, there will be excessive heating, and the result may be deplorable - ignition of electrical wiring and fire. Therefore, it is worth carrying out the accurate calculation of the cross section of the power consumption. Risk factors are too big, and there are many of them.

Optimal parameters

Optimal sections:

1. For wiring sockets - 2.5 square meters. mm.
2. Lighting group - 1.5 square meters. mm.
3. High-power electrical devices (electric stove) - 4-6 square meters. mm.

At the same time, pay attention to the fact that the copper wires can withstand the following loads:

1. Wire of 1.5 square meters. mm - up to 4.1 kW (current load - 19 amps).
2. 2.5 square meters. mm - up to 5.9 kW (by current - up to 27 amps).
3. 4-6 square meters. mm - more than 8-10 kW.

Therefore, with an increase in the load, you will always have a fairly large reserve.

Conclusion

Now you know how to calculate the cross section of the wire for power consumed (the definition of important characteristics and other small factors are now known to you). Based on all the above data, you can independently, without resorting to the help of professionals, draw up a power plan for your home or apartment.