Choosing a wire for home wiring

On how correctly chosen the wire size for wiring depends on the future performance of equipment and the safety of your home. Yes, electricity is not only light, heat and comfort, but also dangerous matter, if the wiring is faulty or does not correspond to the load used. Therefore, when choosing the type of wire, first of all, you need to focus on quality and safety.

Choosing a cable for wiring

Electrical wiring consists of cables, wires and fasteners between them. A wire is a single conductor, covered, depending on the place of use, with an airtight, nonmetallic sheath, winding or braid made of various materials.

The cable consists of several wires combined under a single sheath.

Marking of wires

The wires differ from each other:

1. The material is copper, aluminum, aluminum copper.
2. The type of shell.
3. The cross section of the wires is from 0.35 to 70 mm2 and more.
4. Insulation.
5. Rated voltage.
6. Number of cores.

The name of the wires is an abbreviation in which the initial symbols of the materials from which they are made, the number of wires and the sectional area are encrypted. For example, under the label AVVG 4 * 2.5 hides an aluminum cable with 4 conductors in vinyl insulation, covered with a vinyl sheath and not having armor. Usually such cables are called bare. When the cable is made of copper, the letter "A" no. For ordinary premises, the most commonly used cables are the following brands:

• VVG - round or flat wire for rooms with normal humidity. Copper conductors, single core. Modification VVGng - non-combustible, does not propagate combustion during installation in bundles. Execution of VVGng-LS is the same, but with low smoke emission. These types of cables are the safest of all. The number of lived in the cable - from 1 to 4;
• AVVG - a round or flat cable for laying in rooms with normal humidity. Aluminum conductors, single core. It is not subject to burning. The number of lived in the cable - from 1 to 4;
• NYM is a non-combustible round cable with single core copper conductors. Analogue of domestic cable VVGng;

  The NYM-labeled cable is a high-quality flexible cable with copper conductors sheathed in PVC

• PVC cable - a round cable with multi-conductor copper conductors;
• SHVVP - flat cable with copper stranded conductors. The maximum cross-section of cable ShVVP - 0.75 mm2.Used to connect electronics and home appliances.

Table: PVC power cables with rubber insulation

Selection criteria for wire

An insulated electric wire is suitable for a flat,designed for domestic use and designed for a voltage of 220–380 volts, and it happens:

1. Copper. Currently, copper cable is most often used, since the resistance of copper is less, respectively, such a wire can pass more current and provide more power. Also, the copper wire is durable and strong, easily amenable to tinning, soldering and welding using the most affordable tools. The minus of copper is that it is rapidly oxidized, as well as high cost. In addition, if the connection is not obscure, then it will eventually conduct the current worse and begin to warm up.
2. Aluminum. It is a chemically more active material and is lighter than copper. But his conductivity is two times lower. Aluminum is welded only in inert gas and soldered using solder and flux. And it only connects with aluminum - through bolts and nuts. In the process of assembling joints( except welding), stripping and lubrication is required. Aluminum and copper cannot be directly connected, since the point of contact will quickly collapse. Therefore, these two wires are connected only through the terminal block or the third metal. The cost of aluminum wire is several times lower than that of copper.

Wires and cables are single-core and stranded. For hidden wiring, single-core wire is more often used, since it is rigid, therefore it cannot be bent multiple times. Stranded wire is soft and well withstands numerous bends, so it is suitable for open wiring and use as a cord to connect electrical engineering. The main rule is to stay on one material and make all the wiring out of it.

Multicore cable withstands bends and takes the form of complex surfaces well.

Video: Which cable to choose for wiring

Calculation of cable section

Proper choice of wire size for home wiring is extremely important, because the consequences of incorrect calculation can have such consequences, which should be 100.a, 17cost unnecessarily expensive;

To avoid such problems, before installing the wiring, you need to correctly calculate the cable section, taking into account the indicators of current strength, power consumption of electrical devices and the length of electrical lines.

Power Calculation

Any cable has a rated power for which it is designed, provided that 80% of electrical devices are connected. Why exactly 80%?Yes, because all 100% of consumers are rarely included at the same time. To determine the load, the power of all electrical appliances to be used is calculated first. The sum of these values ​​plus 20% of the stock will determine the parameters of the input cable entering the house. However, it is not at all necessary that the rest of the wiring be just as powerful. Simply put the cable on the terminal block, and from it through the machines put the wires of the required value into the room. For example, high-power appliances such as a washing machine is best connected to a separate line. The formula for calculating the wire for an apartment is as follows: Ptotal =( P1 + P2 + P3 +. .. + Pn) * 0.8, where P1, P2. .. Pn is the unit power in kW, the coefficient 0.8 is just those 80%.

Typically, the cable is put on the input of the machine, and then diverges on consumers

Consider an example.

1. Suppose when calculating it turned out that the total power consumption is 14 kW.According to the formula, multiply this figure by a factor of 0.8 and get a figure of 11.2 kW - this will be the actual load.
2. We look at the special table and select the appropriate value in the corresponding column. For a voltage of 220 V, the number 11 for a single-phase network will suit us. Conclusion - the cross section of the wire should be 6 mm2.

Table: calculation of the cross-section of a copper cable for power and current with open wiring