Use of VVG wire and its technical characteristics

The technical characteristics, as well as the price-quality ratio, which the VVG wire possesses, allow it to compete on equal terms not only with domestic, but also with foreign counterparts. Given the number of varieties of this cable on the market, its scope is practically unlimited. The main thing is to choose the right section.

Scope of application

VVG wire is intended for use in household and industrial electrical circuits, with voltage up to 1000 Volts. Most often, such a wire is recommended for home electrical wiring when using hidden and open installation methods, as well as when installing behind plasterboard floors.

A limitation on the use of VVG cable is laying it under the ground, since the soft outer insulation will not be able to protect the wire from rodents or mechanical damage that may arise due to soil displacement. If it is necessary to use it for laying underground utilities, the cable should be laid in a pipe or other rigid insulation.

Fire safety markings

A full description of the properties of the cable can be drawn up by the main and additional markings. At the VVG cable, decoding begins with the presence or absence of the letter "A" at its beginning. If it is not there, then the cable is copper, otherwise it is aluminum. The letters "B" denote the insulation material: on the conductors and outside - in both cases, polyvinyl chloride is used. The last letter "G" indicates the absence of an outer armored coating - such a cable with a soft sheath is considered bare. The letter "p", if it stands after the letters VVG, means that the cable is flat - the wires in it are laid in a row, and not twisted together. Also, there are designations "T" and "UHL", which indicate the tropical performance of the insulation or designed for a temperate and cold climate.

In addition to the main letters in the cable marking, there may be additional ones indicating that the fire-fighting properties of the insulation differ from the standard ones.

• ng - shows that in the case of laying wires in one cable channel, with significant overheating of one of the wires, the insulation will not ignite, but will only smolder, protecting the adjacent wires from ignition;
• ng-ls - insulation during smoldering emits a reduced amount of smoke and carbon monoxide into the air;
• ng-hf - even if the insulation fires, a minimum amount of harmful resins and gases will be released into the air, which can have a corrosive effect;
• if the prefix "fr" is added to the above designations, this indicates the fire resistance of the insulation, which is achieved by using a mica-containing winding.

Wires can be numbered or color-coded, and manufacturers use a solid color of the wire core and a partial color when only a part of the insulation is colored, usually a 1 mm wide strip. If there are two conductive cores, then their coloring necessarily includes a blue neutral wire, and if there are three or more, then the grounding is yellow-green.

Marking of the number, location and shape of cores

After the letter designations, the cable marking contains digital ones showing the number of current-carrying conductors and their number, for example - 3 x 25 means that there are 3 separate conductors in the cable, each of which has a cross-section of 25 mm².

Four-core cables have their own peculiarity - some of their varieties are made with one core of a reduced cross-section.This is due to the fact that the neutral or ground wire does not always need the same cross-section as the phase ones, and with its decrease when installing large power grids, the savings become significant. Accordingly, the use of a smaller conductor is reflected in the marking. If a standard four-core cable is designated 4 x 2.5 mm², then the marking with one reduced core will look like 3 x 2.5 + 1 x 1.5. This indicates the presence in the cable of three conductors of 2.5 mm² and one 1.5 mm².

The next characteristic displayed in the marking is the use of single-wire or stranded conductors in the cable, for which the designations "O" - rigid or "M" - flexible wire are used. Also indicated is their shape, which can be round or sector - "K" or "C", respectively.

The full marking looks like VVG 3 x 2.5 ms + 1 x 1.5 ms (N) - 0.66 TU - how it can be deciphered, in the table in the figure:

Marking indicating single or stranded conductors, as well as their shape, need not be applied if conductors of equal cross-section are used, with an area of ​​less than 16 mm²

Specifications

Where and how you can use a particular brand of cable show its technical characteristics. The VVG electrical wire has several varieties, of which the VVGng cable is most often used, the technical characteristics of which are suitable for single and heap laying.

• The maximum voltage is 660-1000 Volts, depending on the insulation class.
• The recommended temperature for use is from -50 to +50 C °.
• It is allowed to use at air humidity up to 98%.
• The temperature that the insulation can withstand for a long time without changing its properties is 70 ° C. For a short time it can withstand heating up to 90 ° C and about 4 seconds - up to 250 ° C. Insulation ignites at temperatures of +400 and above.
• Emergency operation is allowed for 8 hours a day, but not more than a thousand hours for the entire life of the wire.
• The permissible bending radius during installation depends on the type of core - solid or multi-wire. In the first case, the bend will be the total cable diameter * 10, and in the second - the diameter * 7.5.
• The number of wires in the coil depends on the cross-section of the cores. Up to 16 mm² - 450 meters, from 25 to 70 mm² - 300 meters, and all others - 200 m.
• The estimated service life of the wire is 30 years, the warranty period is 5 years.

The above data show what a VVGng cable is and where it can be used.

For more information about the VVG cable and its use, see this video:

What to look for when choosing

Despite the complexity of fake electrical cables, it is still possible to come across low-quality products in which the insulation does not meet the standards or the cross-section of the conductors is less than that indicated on the marking. To check the insulation, it is enough to look at the presence or absence of streaks - on a good wire there will be a clean, even cut with insulation of a tight-fitting core. To check the cross-section, you can use a micrometer or the "old-fashioned" method, when the vein is folded into 10 layers and measured with a ruler. For the rest, you need to focus on the calculated indicators and choose the cable of the desired section.