VVG cable(a), also known as power wire VVG(a), also known as cable VVGng a, is a flame retardant wire that is used for the transmission and distribution of electricity, which occurs in stationary installations that have an electric current frequency of 50 Hz and a rated voltage of up to 660 or 1000 V. is extremely widely used - it is used in any climatic conditions, at high altitudes, in water - in fact anywhere, unless, of course, it is damaged. This subtype is especially often used in places where there is an increased risk of a fire - for example, in enterprises working with flammable or explosive components.
Decoding of VVG(a) cable
The marking allows us to understand in more detail what this cable is. Here is its decoding: “VVG” means “vinyl-vinyl-naked,” which refers to the presence of two layers of polyvinyl chloride, as well as the absence of a specialized protective layer. Well, “ng”, if used in marking, means that the cable, in the event of a fire hazard, will not spread combustion. The letter “a”, very often placed in brackets, means the category of non-propagation of combustion according to. In particular, this means that even when laid in bundles, these cables do not propagate combustion, while traditional VVGs can “boast” of this only when laid individually. This letter should not be confused with the “a” that is placed before the abbreviation and means that the cable is not copper. In this case it is definitely copper. Often ls, frls, frlsltx, frhf are added to the marking, but in essence this is one cable.
Technical characteristics of VVGng (a)
U VVGng A a number of parameters can vary. For example, this may be the form factor of the cores (which can be round, triangular or flat), their number (from 1 to, as a rule, 5), their sections (from 1.5 mm 2 to 50 mm 2, and sometimes even more), nominal diameter (directly dependent on cross-sections), weight (from several tens of kilograms to several tons per kilometer). The permissible current can vary from 21A to several hundred, depending on both the type of cable and its location. As you can see, there are a great many variations of this product, so before you buy a cable, you need to study in detail the description of its specific brand; it is this description that will save you time and nerves in the future. The price, again, varies depending on the complexity and size of the cable. But in comparison with other types of VVG, the cost remains at approximately the same level. But any cost is very justified, because the cable will serve you under proper operation conditions for more than thirty years, five of which, as a rule, will be under warranty.
Traditional Russian brands of cable and wire products usually have letter designation and have a transcript.
Cables
VVG and AVVG
The first letter A means the material of the core. A - aluminum, absence of the first letter - copper
- IN- the first letter B stands for insulation material. B - polyvinyl chloride (PVC);
- IN- the second letter B is the cable sheath material. B - PVC;
- G- naked, i.e. There are no additional protective layers (armor, etc.) on top of the shell.
VVG-P
The capital letter P after the main mark means a flat cable design.
VVGng(A)-LS and VVGng(A)
ng(A)-LS and ng(A) means performance in terms of fire safety indicators.
- If there is no ng designation, the cable is intended for single installation;
- ng- flame retardant when laid in groups;
- ng-LS- flame retardant with low smoke and gas emissions;
- ng-HF- flame retardant, do not emit corrosive gaseous products during combustion and smoldering;
- ng-FRLS- flame retardant, fire resistant, with low smoke and gas emissions.
The letter (A) means that the cable has the index “flame retardant according to category A.
NYM
The German mark is therefore designated in Latin letters.
- first letter N- Normenleitung - the cable is made according to German standards (VDE);
- second letter Y- Isolierung der Adern aus Polyvinylchlorid -PVC insulation;
- third letter M- Mantelleitung - with a protective shell.
According to the design of current-carrying conductors:
- cool- single-wire core;
- pl- multi-wire core.
for GOST R 53769-2010:
- O- single-wire core;
- m- multi-wire core;
- To- round core;
- With- sector or segment core;
- N- zero core;
- P.E.- grounding conductor.
Example: NYM 3x1.5ok (N,PE) - with three conductors with a cross-section of 1.5 sq. mm, single-wire round conductors, with a neutral conductor and a grounding conductor.
Wires
PVS
- P- the wire;
- IN- PVC insulation;
- WITH- connecting.
SHVVP
- Sh- cord;
- IN- PVC insulation;
- IN- PVC shell;
- P- flat design.
Which does not spread combustion. In short, the VVGng decoding indicates this property with the last letters “ng”. This wire is usually used in power distribution or transmission. Due to this feature cable VVGng 3x1.5 , excellent for laying in bundles. Its almost complete versatility makes it possible to use it in different climatic conditions - from frosty northern to hot tropical climates. This cable is most often used where there is a high risk of fire - enterprises where they work with explosive or flammable components.
VVGng (a) transcript
According to the markings, we can understand what kind of cable it is. “VVG” stands for “vinyl-vinyl-naked,” thereby indicating that the cable has 2 layers of polyvinyl chloride in its structure, without any armor. What “NG” means was said at the beginning of the article. “A”, which is usually indicated in brackets, means the GOST type of flame retardation.
Even when laying cables in bundles, in the event of a fire, the combustion will not spread to other wires. Ordinary VVGs cannot boast of this property, except during solo installation. One small clarification: do not confuse the letter “a”, which is placed in front of the abbreviation - this means that the wire is aluminum. In our case, copper. As you can see, there is nothing difficult in remembering the decoding of the VVGng cable.
Laying methods
Open gasket. Based on the technical characteristics, the cable can be laid over structures, as well as surfaces that are not flammable. This could be concrete, brick, plastered surface, etc. It is also possible to lay it over suspended structures, such as a cable, but it is necessary to prevent stretching or sagging of the wire.
Gasket with protection. If there is a significant threat of mechanical damage to the wire, then it is necessary to provide a protective case, for example:
- pipe;
- cable channel;
- corrugated sleeve;
- metal hose, etc.
Hidden. Laying is carried out under the plaster, in voids or in specially made grooves. In this case, mechanical damage is unlikely, but the exceptions include the voids of wooden houses. In such cases, installation must be carried out in non-flammable pipe-type cases.
In the ground. The rules do not include laying the cable without special protection, because the wire does not have armor. Installation of the wire in such cases is carried out in sealed cases (boxes) along overpasses and cable structures.
The VVGng-LS cable performs transmission and distribution electric current in permanent devices. A special feature of the VVGng-LS conductor is its increased fire protection.
Explanation of the marking: the letters “B” indicate vinyl, and “g” means open, bare. That is, two layers consist of polyvinyl chloride, there is no protective layer. Decoding of the letters “ng” - does not light up. The marking value “ls” means low smoke level. Full name VVGng(A)-LS.
- Structure and characteristics
- Types of cable
- Cable VVGng-p-LS: structure
- Application area
- Screen types
Structure and characteristics
The wire has from 1 to 6 cores, with a maximum cross-section of 240 mm². The permissible current value is 21 - 70 A. The maximum weight can be 2 tons per km, the minimum weight is 112 kg. The cost depends on the characteristics of the product. It is affected by the number of cores and the total volume.
The development of this cable was caused by the need to use it for transmitting current in flammable conditions in accordance with fire safety requirements. The main feature is the reduction of smoke during a fire.
The operating temperature varies from -50 to +50 degrees. Installation is carried out at temperatures above -15 degrees, since low temperatures damage the shell. Usage time is about 30 years.
VVGng-LS is used for networks alternating current up to 1000 volts at a frequency of 50 Hertz. The cable is used in buildings and objects; it can be laid in trays and boxes. According to fire regulations, it cannot be installed in social institutions.
Types of cable
Cable VVGng-p-LS: structure
The peculiarity of the marking is in the letter “p”, which means “flat”. The basis is made up of single-core or stranded wires, which can be round or sectored.
The insulation consists of polyvinyl chloride with high fire resistance. Its color can be white, yellow, blue, green, red, crimson, brown, black. Inside there is another extruded shell to fill the space between the cores. The weight of the VVGng-p-LS 3x2.5 wire per 1 km is 167 kg.
The VVGng-LS cable version has some advantages in terms of functionality. VVGng-LS is a round wire filled with halogen-free, non-vulcanized rubber, which ensures fire resistance. The shell consists of a special non-flammable PVC plastic compound. Thanks to these parameters it is achieved high level security.
Application area
This conductor is used for AC and DC electrical devices. Can be installed indoors or outdoors. VVGng-p-LS is often intended for offices, industrial facilities, and nuclear power plants.
Duration of use is 30 years, warranty is usually 5 years. These figures will be reliable provided that the rules of transportation, storage, installation, and operation are followed.
The minimum wire length is 450 m. VVGng-p-LS can withstand heating up to 70 degrees. The bending radius is 10 diameters for a single-core cable, 7.5 for a multi-core cable. Installation is permissible at least -15 degrees. Wire VVGng(A)-p-LS has almost 100% resistance to humidity at temperatures below 35°.
The "a" stands for aluminum. The main technical characteristics of the cable are combustion resistance, low smoke and gas levels, minimal toxicity.
Wires VVGng(A)-LSLTx are designed to distribute directed energy of alternating current up to 1 kV, direct voltage up to 1.5 kV. Used in private and apartment buildings, kindergartens, schools, hospitals, hostels, motels, clinics, train stations, museums.
Functional fire hazard of premises from 1 - 3 F.
Description of technical characteristics
Operation of the wire is possible at temperatures from -50 to +50°C, relative humidity 98%, if the temperature does not exceed 35°C. The cable can be laid down to -15°C. The permissible operating temperature is up to 70 degrees. Emergency mode provides a permissible temperature of 90 degrees. VVGng-FRLSLTx can withstand temperatures under short-second short circuit conditions of up to 400 degrees, and VVGng(A)-LSLTx up to 350 degrees in a similar situation. The weight depends on the cross-section, so 1x1.5 per 1 km of cable is 52.7 kg.
Includes:
- copper conductors;
- exturbated PVC insulation layer;
- belt insulation with increased fire resistance;
- shielded copper tapes;
- two galvanized steel strips;
- outer protective layer (hose, casing).
Installation conditions are met in accordance with the rules and regulations for the installation of electrical installations.
Carries out the transmission of electrical energy in a stationary network with a current variable load and a constant voltage of up to 1 kV.
New letters “fr” appear in the name, meaning fire resistance. The wire is characterized by long-term resistance to open fire, the time varies from 60 to 180 minutes.
The fire-resistant barrier is a mica-containing tape. The VVGng-FRLS conductor is used for power supply in both residential and industrial premises. Thanks to the materials used in the insulation and sheath, the cable has high fire-fighting properties and low toxicity.
Application of VVGng-FRLS in public place guarantees the safety of the electrical network. Group laying is possible. The cable is resistant to open fire conditions.
Operating temperature range from minus 50 to plus 50, with a humidity of 98%. A single-core wire has a minimum radius of up to 10 outer diameters, and a stranded wire has a radius of up to 7.5 outer diameters. The weight of the cable varies, for example, VVGng(A)-FRLS 2x1.5 1 kV per 1 km - 212 kg, 1x150 per 1 km - 1763 kg.
The wire has a long service life of up to 30 years.
A special type of cable is shielded VVGE, used for transmitting audio and digital signals. Due to the fact that audio and digital signals travel through the cable, it is necessary to ensure that no distortion occurs. This requires a screen adaptation. To make a shielded wire, it is covered with a screen, that is, protection.
Screen types
- Screen made of copper or aluminum foil. It covers the cable around. But this method is fragile, so it is laid in stationary conditions.
- Shielded mesh shell. These products are highly reliable, but do not provide 100% coverage of the signal wire. Manufacturers can increase the density of shielded wire, but the cost will increase.
- Spiral braided wire. The cable is flexible and stronger than foil, but the coating does not achieve great results.
Weight depends on screen type.
Judging by the emerging shortcomings of each type of screen, a double shielded cable has appeared. This may be a combination of mesh and foil or two layers of spiral braids. Drain wire is added to strengthen the shielded cable.
An important technical characteristic of a shielded cable is the thickness of the foil. Manufacturers are constantly optimizing the manufacturing process, increasing the value to 100 microns. VVGng-LS manufacturers have taken care of a wide variety of cables that transmit electric current. They have different sections, lengths, and functionality.
The VVGng(A)-LS cable is a wire that does not distribute combustion, which allows it to be used not only for transmission, but also for the purpose of redistributing electrical energy. These processes are carried out on stationary equipment characterized by an electric current frequency of up to fifty hertz and a rated voltage of up to six hundred sixty or a thousand volts. Such a cable is characterized by a very wide range of applications in various climatic zones, at impressive heights, in bodies of water - almost anywhere, if, of course, its damage is prevented. This cable is especially relevant for premises where there is a significant risk of fire - for example, at industrial facilities working with flammable or dangerous compounds.
The marking explains to us what the main characteristics of a particular cable are. Let's try to decipher it together. VVG is vinyl-vinyl-naked. This means that the product contains several layers of polyvinyl and there is no special protective layer. If you see the combination of letters “ng”, this indicates that if there is a fire danger, the cable will not support the fire. The letter “a” in brackets is a type of flame retardation in accordance with a certain GOST. This suggests that even if the cables are laid in bundles, they will not propagate combustion, whereas classic VVGs have a similar characteristic only in the case of a single installation. But be careful, if the letter “a” is located before the abbreviation, it is intended to inform the user that copper was not used to produce the cable. The letters ls, frlsltx, etc. are often added to the marking, but in reality this is a similar cable.
Different types of VVGng(A)-LS cable may differ in their characteristics. So, for example, the permissible current can range from twenty-one amperes to several hundred, it all depends on the type of cable and its location.
