Any object of the modern world, whether it is an industrial complex, a residential apartment building or the smallest private house, requires electricity. This can be achieved by laying an electrical cable to the end user.
An electrical cable is a complex structure consisting of many components that perform different functions, depending on the loads and conditions of use. It transmits energy or signals in large volumes and over long distances. It is impossible and impractical to use such bulky networks in all projects. Therefore, a lot of specialized electrical cables and wires appeared, for which markings corresponding to the purpose were introduced - letter and color.
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How to determine the purpose of a cable or wire
The letter designation of electrical wires, according to GOST, is applied by the factory to the outer side of the sheath and indicates the layout starting from the core. Thanks to this, it is easier to understand the functional features of different types of electrical cables and wires for the correct use for their intended purpose.
The color marking of electrical wires is designed for quick and easy orientation during installation work. It also greatly reduces the risk of electric shock. The color of the insulation can be white, black, brown, orange, green, yellow, red, blue, purple, gray, pink and turquoise. Each color indicates the purpose of wires and cables in AC and DC networks.
Types of electrical cables depend on the materials used for their sheath:
- rubber;
- PVC;
- polyethylene;
- paper core insulation with an outer sheath of lead or aluminum.
If necessary, the cable can be covered with several layers of insulation, including combinations of the above materials, for better tightness and reinforcement.
Types of electrical cables
Types of electrical wires and cables are classified based on the type of conductors, their cross-sectional area and diameter, conductivity, insulation, heat resistance, flexibility and application. The following is a brief description of cable brands and electrical wires.
Due to a wide range of applications and resistance to various types of exposure, including fire, temperature changes of 100 degrees (-50 ... + 50 ° C), high humidity (up to 98%), bending, tearing and aggressive chemicals, the VVG cable has proven itself .It has a copper wire (flat or round) with PVC insulation and the same sheath without the use of external protection.
Designed to transmit electricity in the voltage range of 660-1000 V. This cable is most often painted black, and the insulation of the conductive cores, due to its wide range of applications, can be painted in all colors used for marking electrical wires.
Inside the power VVG cable there can be either one or more cores (up to 5). Depending on the operating conditions, the cross section of the cores varies from 1.5 to 240 mm², and the cores themselves are single-wire and multi-wire. The cross-section of the conductor should be taken into account, since during the laying and installation of the cable, refraction is possible in the event of a strong decrease in the bending radius.
There are 4 most commonly used types of VVG power cable:
- VVGp (flat);
- VVGz (special separation of cores inside the cable using various fillers);
- AVVG (aluminum core);
- VVGng (increased insulation resistance to fire).
NYM-cable is an improved analogue of VVG, which has both advantages and some disadvantages. This abbreviation is deciphered as follows: the letter N means the name of the organization of the German Electrical Engineering Union and compliance with all necessary standards; Y - insulation material (PVC); M - the possibility of multi-purpose use.
The main characteristics are almost identical, with the exception of a smaller range of core cross-sections and a shift in temperature limits to higher values.The strands inside are exceptionally round and stranded, which adds more flexibility, but takes away the advantage of being used inside the floor or walls. Another significant drawback is its price. VVG cable is much cheaper.
KG is a cable with rubber insulation, copper conductors (from 1 to 6) of increased flexibility and an operating temperature range of -60…+50°C. This cable can be used for both AC up to 660V and DC up to 1000V. A few examples of popular applications for such a cable are the power supply of welding machines and construction cradles. There is a less flammable option.
VBBSHv is a more durable, mechanically resistant type of VVG cable with identical characteristics to the latter. Strength is achieved by wrapping galvanized steel strips on the outer sheath of the cable with an overlap so that there are no gaps between the coils of metal. In addition, the cable armored in this way is additionally placed in a PVC sleeve with an existing less flammable modification. VBBSHv-cable can be laid in the ground, pipes and outdoors.
There are the following types of electrical cables VBBSHv:
- AVBBSHv - aluminum conductors;
- VBBSHvng - less flammable cable;
- VBBSHvng-LS is a special cable with low emission of toxic substances during operation at elevated temperatures.
Description and types of electrical wires
If a cable is a complex structure of many elements, then a wire can be represented as a structural unit of a cable. Wires are used for further transmission of electricity received through cables. Electrical wires have a considerable number of types:
- winding copper or high resistance;
- output (PVKV, RKGM, runway);
- heating;
- connecting (PVA, PRS, ShVP);
- for rolling stock;
- automotive;
- communications;
- heat-resistant;
- aviation;
- installation (APV, PV1, PV2, PV3);
- isolated for overhead lines;
- uninsulated;
- mounting;
- thermoelectrode;
- for geophysical work.
Electric wire with copper single cores (two or three), PVC insulation and sheath - PBPP. Its main purpose is to power stationary light sources. Since its installation is often carried out indoors, it has a temperature range of -15…+50 °C. Withstands up to 250 V at a frequency of 50 Hz.
Not too flexible, unlike PBPPg (the letter g stands for flexibility), specially designed for indoor work with the need to repeatedly around corners and make frequent turns. This is its main and only difference - stranded wires. The wire is best suited for powering household electrical appliances.
Modification PBPP with aluminum cores is designated by the abbreviation APUNP. This is where his differences end. It should be borne in mind that such a wire, like PBPP, happens only with single cores and has a limited bending radius.
PPV is a flat single-core copper wire with PVC insulation (single) and special jumpers between the cores, used for installing an electrical network indoors, in a cable duct or corrugation. It is also used in two other versions: with a different core material - aluminum wiring APPV, as well as a single-core (single- or multi-wire) round shape - APV. Moreover, the APV wire can be of different thicknesses.
If this is an option with a single core, then the wire cross-section varies from 2.5 to 16 mm², while a wire with a core consisting of several wires can be from 2.8 to 5.5 mm thick. All these types of wires are distinguished by a wide operating range of both temperatures (-50 ... +70 ° C) and voltage (up to 450 V at a frequency of up to 400 Hz), excellent protective characteristics, due to which they can be used in the installation of power lines, lighting systems, switchboards, laid in plastic and metal boxes, voids and various pipes.
More flexible options for automatic reclosure, with a copper conductor instead of aluminum, are called PV1 and PV3. They can have single and stranded conductors, with a cross section of 0.75 and 16 mm², respectively. The bending radius must not be less than 6 diameters. It is laid in places with frequent turns, bends, used in electrical circuits of cars, switchboards.
PVA is a copper wire with several (2-5) stranded wires, insulated inside and out with polyvinyl chloride, which, in addition to protection, gives the wire a rounded shape and high density with sufficient softness. The spread of conductor cross sections is standard for PPV, but a slightly lower maximum voltage of 380 V and a frequency of 50 Hz. The factory marking of the insulation of the cores is multi-colored, and the outer sheath is most often white.
PPV is one of the most common wires in everyday life, as it is light and resistant to bending and wear (it can withstand about 3000 kinks). It is used to connect any electrical appliance, make extension cords, install sockets and lighting, and repair electrical networks. It is non-flammable in case of a single strip.
What other wires are
We can mention the existence of other types of connecting copper wires - SHVVP. Their difference lies in the tinning of stranded wires. ShVVP wires are flexible, withstand voltage up to 380 V with a frequency of 50 Hz. Due to the lack of diversity in the thickness of this wire, it is mainly used to connect lighting fixtures and power equipment that does not require high power - radio electronics, small household appliances.
