When installing power supply lines and household electrical wiring, it is difficult to do without high-quality cable products that guarantee long-term operational reliability of the routes being laid. VVG wire is one of the most common product samples that meet the basic requirements of the PUE in terms of arranging cable networks. It is distinguished by its resistance to destructive influences, characteristics suitable for the stated purposes, and a quite acceptable price per running meter.
Application area
Electric cables VVG are widely used for laying, replacing or current repair of various types of electrical wiring, as well as for organizing individual branches from overhead lines. Most often, the need for an electric cable VVG arises in the following cases:
- when connecting power supply from transformer substations to residential buildings and input devices of industrial facilities;
- in a situation where you need to lay a single-phase or three-phase cable line from a high-voltage outlet to a specific private house, for example;
- for wiring internal electrical networks (electrical wiring) at objects of various categories;
- when laying wiring in medical and childcare facilities (in this case, special non-combustible modifications are used).
As a special case of its use, the electrical wiring of city apartments can be considered.
VVG electric cables are not intended for laying directly underground, since there are no samples in armored protection in their line. To assess the scope of the chosen model, it is enough to understand its labeling, which reflects all the necessary information.
Design features and specifications
When considering the features of the composition of cable products, it is important to know that it is classified according to the following main features:
- real conditions of installation and operation;
- number and cross-section of VVG cable cores;
- the degree of protection against destructive factors.
In accordance with the first of them, these products are subdivided into samples intended for installation indoors or outdoors (outdoors).
In the case of their external laying, it is imperative to use special protective structures: metal sleeves, as well as steel pipes or trays.
According to the number of insulated copper conductors included in them, there are two, three, four, 5 and 6 cores. The section varies widely (from 1.5 to 250 sq. Mm).
When describing the characteristics of cable products, in addition to the indicators already listed, the maximum permissible current per core is necessarily mentioned. Its value corresponds to the value of the characteristic cross-section for VVG, corrected for the number of conductors. In terms of the degree of protection, these products are represented by samples in the usual design and wires, characterized by increased resistance to destructive influences.
A high degree of protection is achieved through the use of double insulation: each of the cores separately and a common outer shell.
The service life of products of this class, according to the current GOST, is at least 30 years. Sometimes the specifications indicate the length of the cable stored in standard round coils.
Decoding of marking and possible modifications
When familiarizing with cable products of the VVG brand, attention, first of all, is drawn not so much to the appearance as to the marking. It contains data on the material and cross-section of current-carrying conductors, as well as detailed information on the type of insulation of the inner and outer sheath. The decoding and application of the VVG base wires have a direct connection, which manifests itself in the following:
- the absence of the letter "A" in the first position means that pure copper was used as the material of the veins;
- two "B" symbols indicate that the sheaths of the individual cores and the external general insulation are made on the basis of durable polyvinyl chloride;
- the letter "G" in the next position indicates that the cable does not have protective armor, such a product is not allowed to be used for laying underground;
- the letter "T", added to the main designation through a hyphen, indicates the tropical version of this model.
The symbols following the basic designation should be understood as variants of execution, differing in some technical parameters.
To accurately decipher the brand of the VVGN wire, for example, you will need to know the meaning of the last character "H", indicating a special modification of this product. As an example of designation, consider a sample of VVG-T 3x25-0.66 cable.
- this is a model of a VVG cable made in a tropical version;
- the product itself contains three monolithic veins;
- the section of each of them is 25 mm2;
- this brand of cable is designed to operate at an effective voltage not exceeding 0.66 kV.
Lists of possible cross-sections of conductors, depending on their number and operating voltage, are given in special tables placed in thematic sections of the Internet.
Non-combustible version of VVG
Fire safety marking is expressed in the presence at the end of the prefix from the symbols "NG" indicating that this sample of the cable belongs to non-combustible versions. During production, special ingredients are added to its shell, which contribute to the damping of combustion.
The VVGNG multi-wire cable and its modification with the LS badge are a kind of non-combustible type that produces a minimum of smoke when smoldering and does not emit toxins at all. Such products remain operational for a long time and are used in emergency lighting systems and places with increased requirements for fire safety.
Another type of cable products under the designation VVGNG HF is characterized by the fact that it does not contain halogen substances (including chlorine) in its sheath. And the product of the VVGNG FRLS brand belongs to a modification that is characterized by maximum resistance to open fire in conditions of group laying. Its ability to resist an open flame with minimal smoke generation is due to the presence of a special mica component in the outer protective shell.
The shape of the cores and the sheath of the cable
According to the shape of the sheath, cable products are divided into flat and round samples. As an example, consider the VVGP NG wire, the decoding and application of which is associated with the following features:
- the designation indicates that this is a flat power wire with two or three cores;
- APG wire is used for laying in hard-to-reach places;
- with this brand of cable, it is easier to route with a large number of flat bends.
In all other modifications, the shape of the shell is standard (round).
According to the configuration of the cross-section of individual copper conductors, the known VVG samples are divided into products with round and segment buses.
Any modification of the VVG cable is protected from the outside by a polyvinyl chloride sheath that does not support combustion with a single laying. In the case of group use of cable products of this brand, it is necessary to choose models that have the prefix "NG" in their designation.For all other uses of products of this class, special marking is provided, added to the main designation through a hyphen.
