The industry does not stand still. Old technologies are brought to perfection, new ones are born. Every day the number of electric tools and household appliances operating from a 220/380 V network. Accordingly, it becomes necessary to use a unified, standard cable that could be used to connect electrical appliances to the network. Looking ahead, we note that it is.

The specific choice is influenced by features and operating conditions. It is important to choose the most durable, electrically and fireproof cable with increased flexibility and a long service life. In addition to PVS, the best option for household appliances, there are other, less popular types of wires.

However, the PVA can be operated at AC voltages up to 380 V, which is the ideal value for domestic use. Of the advantages, plasticity should be highlighted, which is affected by the minimum bending radius. This allows you to maintain the integrity of the insulation, reduce the risk of breaking the internal conductors.

Purpose and application of PVA

In general, the purpose of the cable can be judged on the basis of the last letter of the marking - “C”, which stands for “connecting”. It turns out that the product is intended for switching electrical appliances with each other or connecting to a network.

PVA wire is operated mainly at home. It can be used to create several products:

• extension;
• switching of electrical devices;
• arrangement of temporary lighting systems.

Often the cable can be found on various manufacturing enterprises where medium power equipment is switched, including lathes, power units and control terminals. PVA wire for domestic and industrial use differs in the number and cross-sectional area of ​​\u200b\u200bthe cores. A wide variety of options allows you to find desired model in accordance with the requirements and operating conditions put forward.

PVA marking decoding

Decrypting PVS is quite simple:

• the letter "P" indicates that this product is a "wire";
• the letter "B" means that the cores and the sheath are protected by "polyvinyl chloride" (vinyl) insulation;
• "C" - cable "connecting" (purpose).

There are other wire options. For example, often on the shelves of stores you can find the marking of PVC. Many people mistakenly believe that this is an identical cable, although in fact the conductors of this model are parallel to each other. As a result, the wire turns out to be oval in cross section, and installers call it “flat”.

Any cable/wire must be marked on the outer surface. In addition to the letter designations, there can be various numbers on the PVA shell:

• the first digit is used to indicate the number of cores, so the number will always be an integer - 2, 4, 5, 8, etc .;
• the second digit indicates the cross-sectional area of ​​\u200b\u200ban individual core - 0.25, 0.75, etc. (measured in sq. mm).

It will be much easier to understand when considering examples. Suppose you saw a cable marked PVA 4 × 0.75. Deciphering the value, we get “a connecting wire with PVC insulation and four cores with a cross section of 0.75 sq. mm each. If the product is marked PVS 2 × 2.5, then this cable is a flat type of PVA with two cores and a cross section of 2.5 square meters. mm each.

There is a more complex marking when “PVA 4 × 0.5 + 1 × 1.0” is indicated on the cable. This wire has four cores with a cross section of 0.5 square meters. mm and one additional - 1.0 sq. mm.

Important! In accordance with GOST, small deviations are allowed between the actual and nominal values ​​​​of the cross-sectional area of ​​\u200b\u200bthe wire. Thus, this value may be less or more than the declared one, while the electrical resistance should be the same as indicated in technical passport. This is the main technical parameter!

Varieties

PVA can be divided into several varieties depending on the methods of operation and design. We are talking about internal and external, as well as copper and aluminum wires.

More details about each PVS option:

1. The external cable consists of at least three conductors, denoting phase, zero and ground. Such a wire can be used to connect transformers and switchboards.
2. The internal one also consists of three cores, but is mainly used inside residential and industrial premises.
3. Copper PVA is characterized by low resistance, elasticity and high strength.
4. These indicators are not worse than those of an aluminum cable. It is much cheaper, but is considered obsolete technology.

The cost of a particular cable depends on several parameters:

• section;
• manufacturer;
• terms of Use;
• the number of meters in the bay;
• technical performance;
• distance to the manufacturer (how much money was spent on transportation).

Design

A modern PVA wire consists of several copper wires intertwined with each other, having a separate insulation of high-quality polyvinyl chloride. Additionally, all cores are protected by a PVC sheath. The standard cable has a round sectional shape, although the PVC model, as mentioned above, will have an oval one. Insulating materials may include various additives that give them additional protective functions (for example, the product does not support the combustion process).

Each copper core includes a large number of copper wires. When twisting each, a dense tourniquet is formed. In accordance with GOST, the class of lived in PVS must be at least the fifth. Such a standard automatically regulates the minimum thickness of the wires from which a separate core is formed.

If the cross section of each core in the cable is 1 sq. mm, then the diameter of the wires used should not be lower than 0.21 mm.

According to the standards prescribed in GOST, the wire can be produced in the following versions: with two, three, four or five cores. The cross-sectional area varies between 0.75-16 square meters. mm. Thicker varieties of cable are produced in specialized factories and are necessary for industrial use.

Parsing GOST, you can find another important rule: in PVA, the strands are twisted in the left direction, however, the density is so high that no filler is used.

When choosing an insulating sheath, manufacturers try to use materials different colors which simplifies installation tasks. Individual cores can be colored blue, brown, red, yellow or even yellow-green. The phase conductor is usually marked in brown or red, zero - in blue or blue, ground - double, yellow-green. The overall sheath, under which all the cores are located, can have an arbitrary color (for example, black).

The top, outer layer is a PVC sheath, which is applied using the extrusion method. In the process of single laying, the protective layer does not support combustion. Due to its plasticity, the sheath fills any gaps formed between the cores, due to which the wire becomes round in shape. The maximum eccentricity value is 10%.

Colors

The world has adopted standards according to which manufacturers usually paint the cores of conductors depending on their number, as well as the presence or absence of grounding.

The table below shows these standards:

If any two colors are placed through a slash, then the right to choose a specific one remains with the manufacturer.

Depending on the color of the insulation, the cores have a unique purpose:

• blue color - neutral conductor;
• yellow-green - grounding;
• black or brown - phase.

Important! Often the phase core is painted in White color, which is also acceptable according to international standards.

Operating conditions and specifications

An important condition for the operation of PVA wires of any model is the content in the operating temperature range, which ranges from -35 to +40 gr. Celsius. If you follow this rule and exclude mechanical damage, the cable will last for ten years.

Due to the high technical and operational characteristics, PVA significantly outperforms the wires of other brands. However, there is one drawback - the price. However, the reasons for the higher cost are quite obvious.

We list the main technical parameters prescribed in GOST:

1. For production, cores with a flexibility class of at least the fifth are used. In accordance with this requirement, the cross section of the wires used in the formation of the core is selected. For example, 0.21 sq. mm each for cable with conductors of 1.0 sq. mm or 0.26 sq. mm for 2.5 sq. mm.
2. The specific thickness of the insulating layer for an individual core and the entire wire as a whole depends on their cross section. For cores, the thickness range is 0.6-0.8 mm, for sheath - 0.8-1.2 mm. Choosing given value, you need to focus on the electrical resistance specified in GOST.
3. The operating temperature range of PVA-wire is from -35 to +45 gr. Celsius (for some versions below - from -25 to +40). The maximum allowable value when heating the cable is +70 gr. Celsius, while installation must be carried out at a temperature of at least -20 gr. Celsius.
4. The PVC sheath does not support combustion, but may crack due to exposure to extremely low or high temperatures.
5. The service life in accordance with GOST, with strict observance of the conditions, is at least six years.
6. There should be no visible defects on the wire sheath, including bulges or dents. It is important to ensure that free space between the cable cores, and if necessary, use additional materials as a filler. In this case, the sheath is removed from the cores easily, without any difficulty.

Feature of PVA installation for laying in the ground and outside

The first thing you should pay attention to is that PVA wire is not intended for underground installation. If this is absolutely necessary, then the product should ideally be hidden inside a double-walled pipe. When laying cables outdoors, you must use corrugated pipes attached to walls and other surfaces of stationary objects. In this case, be sure to carry out grounding.

If you need to create overhead line power transmission using PVA-wire, then choose a cable exclusively with copper conductors. In this case, the distance between the beginning and the end of the route should be minimal. Hidden wiring from PVA cable is unacceptable (it cannot be hidden under plaster).

Despite the fact that the cable is characterized by a short service life (for electrical wiring six years in the house is really not enough), it can be used when laying under the screed. This option is appropriate if you want to save money on buying a better and more durable wire. Due to a set of unique properties and protection against dust and moisture penetration, PVA can be used in rooms with increased level humidity.

Additional isolation of a product by means of thermoshrinkable tubes is possible. However, even this option will not save the PVA cable, which cannot be operated directly in water, since the insulation will still accumulate moisture. Since the gasket cable lines under stretch ceiling refers to a hidden variety, then the PVA wire in this case is again unacceptable.

Advantages and disadvantages

From positive qualities PVC wires can be distinguished:

• copper is a light metal, so the whole structure as a whole is characterized by a minimum weight;
• possibility of application in electrical networks with a voltage of 220/380 V;
• increased flexibility, allowing the product to be laid in sharp curves requiring tight bend radii.

The disadvantages of PVA are related to handicapped laying (hidden wiring is unacceptable, laying underground). In general, due to the round shape of the cable, even with a strong desire to organize concealed wiring you will face great inconvenience. Finally, the cost of PVA is higher compared to its counterparts.

PVS cable in comparison with VVG

In terms of technical and operational characteristics, VVG is superior to PVA-wire, however, these models have different purposes. When organizing electrical wiring in a house, apartment, on industrial facilities it is best to use a VVG cable, since this is precisely its main purpose.

PVA is used where VVG is inappropriate, and can spoil the big picture. Or in any other situations when it is inconvenient to operate the VVG cable due to its more high rigidity. For example, it will be difficult to imagine the VVG used for switching microwave oven, iron or hair dryer. It looks ridiculous, extremely irrational, so in this case there is no alternative to PVA.

VVG also cannot be used when arranging a temporary street lighting, designing extension cords for connecting lawn mowers, cords for switching boilers and expansion tanks. Thus, to compare VVG and PVA according to technical parameters- inappropriate, since these conductors are designed to solve completely different problems.

How to choose a PVC wire

The first thing you should pay attention to when choosing any electrical cable or wire is the number and cross section of the cores, selected in accordance with the operating conditions. It is necessary to select PVS depending on the power of electrical devices that will be switched through it to the network. The presence or absence of a grounding conductor is important, allowing you to connect the appliance and the ground loop. For example, when laying a network industrial use you need to use PVS with four cores. At least, that's how it is written in the rules of the PUE.

When inspecting the goods, make sure that there are no defects on the insulation, its proper quality. Test it for strength, since the insulation should not be damaged or torn from touch. Otherwise, the cable will not last long, and even be dangerous.

Each manufacturer must submit a sample of their wire. Studying it, make sure that the individual core is twisted correctly. Judge about poor quality stands for the presence of spots, breaks, different colors and other defects that are visible to your eye. On the marking, you can see not only the number of cores and their cross-sectional area, but also learn about the percentage of copper.

To ensure safe and energy efficient operation electrical equipment, it is important to choose a suitable PVC wire. If in the process of choosing a product you encounter any difficulties, then seek help from professional installers or store consultants. However, you should not believe every word of the latter. Ideally, you should study the basic information regarding PVS and, armed with knowledge, go shopping.

PVA 3x1.5


PVA 3x2.5


PVA 3x4
Application area:
Wire with flexible copper conductors, intended for connection electrical machines and appliances for household and similar use electrical network, for electrical appliances and power tools for home care and repair, washing machines, refrigerators, small-scale mechanization for gardening and horticulture and for the manufacture of extension cords.
Connecting wire with twisted copper conductors with PVC insulation and PVC sheath for voltage up to 380 V for 380/660 V systems

Design
Conductor - copper or tinned copper, round, stranded
Insulation - PVC
Stranding - insulated cores are twisted without filler. Insulated conductors of five-core wires can be twisted around the core
The sheath is made of PVC plastic compound. The sheath in the wires is applied to fill the gaps between the cores, giving the wires a round shape.

Specifications

• The specific electrical resistance of the PVA cable cores to direct current at a temperature of 20 ° C Ohm * mm 2 / m, not less than - 0.01724.
• Rated current loads, A no more:
  with a core cross section of 0.75 mm 2 - 6.0;
  with a core cross section of 1.0 mm 2 - 10.0;
  with a core cross section of 1.5 mm 2 - 16.0;
  with a core cross section of 2.5 mm 2 - 25.0.
• Temperature operation environment from -25°С to +40°С
• Maximum working temperature conductors - 70°C
• Bending radius - not less than 40 mm
• Do not spread fire
• Mold resistant wires
• Service life - at least 10 years

Section options

PVA 2x0.75	PVS 2x1.0	PVA 2x1.5	PVA 2x2.5	PVA 3x0.75	PVS 3x1.0	PVA 3x1.5	PVA 3x2.5	PVA 3x4	PVA 3x6
PVA 4x0.75	PVS 4x1.0	PVA 4x1.5	PVA 4x2.5	PVS 4x4	PVA 5x1.0	PVA 5x1.5	PVA 5x2.5	PVS 5x4	PVA 5x6.0

Connecting moving objects to transformer substations or voltage distribution networks requires the use of flexible conductors. The use of mobile power plants mirrors this challenge. The situation can be aggravated by the presence of water, spilled emulsions, oils at the installation site. Conditions are not always external environment allow the use of conductors with plastic vinyl or polyethylene protection here.

Rubber insulation of copper conductors, rubber sheath allows you to effectively use the KG cable where it is impossible to use anything else. The class of flexibility makes it unique for connections in hard-to-reach places with aggressive environments.

The article will introduce this conductor, its characteristics, parameters. Other cables of this group of materials are shown in an overview.

The general principles of design and the main parameters of the KG brand cable, models and brands based on it, are established by GOST 24344-80 “Cables for non-stationary laying”. Modern products produced on the basis of TU 16.K73.05-93 and TU 3544-078-21059747-2011 (for 660 and 380 volts, respectively).

Location of the main structural elements the base instance of the CG group in the section looks like this:

1. Copper round stranded conductors, quantity from 1 to 6. Flexibility class 5;
2. Separating synthetic film, may be absent if the insulation material does not stick to copper:
3. Layer of isolation from electrotechnical rubber RTI-1. The thickness depends on the cross section, the number of cores;
4. Separating layer of a film twisted together with a step of no more than 16 diameters, insulated cores. May be absent if the insulation does not adhere to the sheath;
5. Protective sheath made of hose rubber RSHT-2, RSHTM-2, RSHN-1. The thickness is different, depending on the number and cross section of the cores. Can be made for cold or tropical areas. The sheath and insulation of single-core cables can be combined into one layer of RTISH rubber, at least two layers of insulation thick.

Marking table

Cable marking is performed as standard using an alphanumeric code. From left to right:

• K - cable
• Characteristics or design features. The letters given in the table may be missing;
• G - flexible;
• Through a hyphen climatic version;
• Through a space, the product size: number of cores, multiplication sign, nominal cross section in mm 2.

Letter designations design features, properties, applications, reflected in the marking, are shown in the table:

Peculiarities	Description	Litera
Flexibility	Power flexible	KG
	Increased flexibility	KKE
	Particularly flexible	COG
Design	With screens for each core, with a common screen over twisted cores	E
	core	With
	With reinforcing elements	At
The form	flat	P
Heat resistance	for a long time allowable temperature core heating over 75°C	T
Core construction	The cores of cables intended for operation in areas with a tropical climate are made of copper wire tinned or coated with a tin-lead alloy with a tin content of at least 40%	L
Climatic modification, through a hyphen	For cold climates, operating temperature range -60 ÷ +50°С.	HL
	Tropical version, for work in conditions high humidity and temperatures in the range of -10 ÷ +55°С, provides protection against damage to the insulation by mold and fungus spores	T through a hyphen
fire hazard	Oil resistant flame retardant rubber	H

It is applied to the outer surface of the shell by any indelible method except for embossing.

Design and operating conditions

The wide range of models in this family provides wide opportunities choice of brand for application in specific conditions.

Cable brand	Design	Operating conditions
KG	Basic (with copper stranded conductors with rubber insulation in a rubber sheath)	For bends with a radius of at least 8 cable diameters, at an ambient temperature of -40 to +50°C when exposed to solar radiation
KG-HL	With rubbers for cold climates	The same, at ambient temperature from -60 to +50°С
KG-T	Tinned copper stranded with tropical rubbers	The same, at ambient temperature from -10 to +55°C, with resistance to mold fungi
KGN	In an oil-resistant shell that does not propagate combustion	At bends with a radius of at least 8 cable diameters, with the possibility of oil getting on the sheath, at an ambient temperature of -30 to +50°C
KKE	stranded increased flexibility	For bends with a radius of at least 5 cable diameters, at an ambient temperature of -50 to +50°C when exposed to solar radiation
CPSU	With highly flexible conductors and profiled core	The same, with the possibility of impact and crushing loads on the cable

conductor

The core is made by twisting a large number copper wires, the diameter of which does not exceed 0.5 mm at the largest sections of the core. This design, together with the increased elasticity of the rubber insulation, sheath, provides the KG cable with increased flexibility. This greatly expands the scope of its application.

The nominal cross section of the conductor determines the value of the active electrical resistance of the conductor. The less resistance, the more admissible current. Accordingly, the greater the allowable power will be included. The number of conductors of some models, their cross-sectional interval:

Cable brand	Number of cores
	major	grounding	auxiliary
KG, KG-T, KG-HL, KGN	1	-	-	2,5 - 120
	2&Z	-	-	0,75 - 120
	2 and 3	1	-	0,75 - 120
	2 and 3	-	1	2,5 - 70
	2 and 3	-	2	2,5 - 70
	4 and 5	-	-	1,0-25
KKE	2	-	-	0,75 - 70
	2 and 3	1	-	0,75 - 70
KPGS, KGPSN	3	1	-	2,5 - 120
	3	1	1	2,5 - 6,0
	3	1	2	4,0 - 50
COG-1	1	-	-	16- 150
CGE	3	1	-	10- 150
	3	1	1	10- 150
KShVGT-10	3	3	-	25 - 150

Protection material and thickness

The size of the insulation layer ensures that the ability to prevent electrical breakdown between the two wires remains unchanged. The voltage can exceed the value of the nominal operating voltage during emergency surges many times. Heating the conductor with a flowing current can also affect the condition of the rubber. The sheath provides electrical strength, mechanical protection. Insulation thickness of some grades of the KG group, mm:

Nominal section of the main conductors, mm 2	Insulation	Sheath for cables
		single-core	stranded
0.75	0.8	-	1,3- 1,5
1	0.8	-	1,3- 1,6
1.5	0.8	-	1,5- 1,8
2.5	0.9	1.4	1,7-2,0
4	1	1.5	1,8-2,2
6	1	1.6	2,0 - 2,5
10	1.2	1.8	3,1 -3,6
16	1.2	1.9	3,3 - 3,9
25	1.4	2	3,6 - 4,4
35	1.4	2.2	3,6 - 4,5
50	1.6	2.4	4,5 - 5,0
70	1.6	2.6	4,8 - 5,0
95	1.8	2.8	5,0-5,3
120	1.8	3	5,0 - 5,3

Obviously, the properties must be scope-aware. For example: single, highly flexible COG-1, the main application is the connection of electrode holders welding machines. Operating conditions place high demands on mechanical strength, chemical resistance. The table below gives an idea of ​​the design features:

Another example of changing parameters with the development of a design for a specific application. The KShVGT-10 brand works mainly in AC voltage networks up to 10 thousand volts. The use of screens helps to reduce the level of mutual electromagnetic interference. The insulation layer, sheath, protective hose in total provide a sufficient value of electrical strength. Dimensions of structural elements of the KShVGT-10 structure, mm:

Rubber, in comparison with polyvinyl chloride, is less susceptible to destruction by ultraviolet radiation. This allows the KG cable to be used outdoors.

Insulation color

The color of the wires, its correct use is important when performing installation. For wires, the number of cores of which is more than two, a standard color scheme. Blue is used neutral wire. Brown, more "hot", serves as a phase conductor (for a constant voltage "plus"). Green-yellow wire is always connected protective earth. If there is no such color, the ground is connected in black. Compliance with these rules will help during installation, increase the safety of maintenance or repair.

Number of cores	Color without earth core	Coloring with residential grounding
3	blue, black, brown	green-yellow, blue, brown
4	blue, black, brown, black or brown	green-yellow, blue, black, brown
5	blue, black, brown, black or brown, black or brown	green-yellow, blue, black, brown, black or brown
6	-	green-yellow, black, blue, black, brown, black

Weight, dimensions

In connection with the use of mobile consumers for connecting, the declared weight of the product is important. For each brand, it is normalized for a length of one kilometer:

Nominal section of the main conductors, mm 2		With three main cores and residential ground marks			COG-1	CGE	KShVGT - 10
		KG, KG-HL, KG-T, KGN	KKE	CPGS, CPGS
0.75		140	140	-		-
1	-	150	150	-	-	-	-
1.5	-	190	190	-	-	-	-
2.5	70	280	280	310	-	-	-
4	100	390	400	430	-	-	-
6	130	540	570	600	-	-	-
10	210	910	990	1100	-	2000	-
16	290	1200	1300	1400	240	2300	-
25	420	1700	1900	2000	320	2900	4900
35	560	2300	2600	2600	440	3500	5800
50	760	3100	3600	3700	610	4100	6700
70	1000	4100	4800	4800	840	5600	7900
95	1300	5300	-	5500	1100	6900	9700
120	1600	6300	-	6500	1400	8100	11000
150	-	-	-	-	1700	9600	13000

The possibility of increased flexibility, allowing you to lay connections in hard-to-reach places, obliges you to know the external dimensions. The values ​​of the outer diameters of some representatives model range are given:

Nominal section of the main conductors, mm 2	Single-core grades KG, KG-KhL, KG-T	With three main conductors and an earth conductor			COG-1	CGE	KShVGT - 10
		KG, KG-HL, KG-T, KGN	KKE	CPGS, CPGS
0.75	-	10	10	-	-	-	-
1	-	10	10	-	-	-	-
1.5	-	11	11	-	-	-	-
2.5	7	13	13	16	-	-	-
4	8	16	16	18	-	-	-
6	9	18	19	22	-	-	-
10	10	23	24	25	-	41	-
16	13	25	28	30	10	44	-
25	15	30	32	34	12	46	67
35	17	35	38	38	14	50	72
50	19	42	44	45	16	54	74
70	22	45	49	49	18	63	79
95	24	51	-	53	20	67	86
120	27	56	-	58	23	72	91
150	-	-	-	-	25	78	97

Approximate scope

Fulfilling the general purpose, the KG cable and each individual model of this group has its own specific application.

Cable brand	Application area
KG, KG-KhL, KG-T, KGN, KPG, CPGS, KPGSN	For connecting mobile mechanisms to electric networks for rated alternating voltage up to 660V, frequency up to 400Hz or direct voltage up to 1000V
COG-1	For connection with arc welding electric holders of welding installations for a rated voltage of 220V AC with a frequency of 50Hz or DC
CGE	For connecting excavators and other mobile mechanisms to electric networks for a rated voltage of 6 kV alternating current with a frequency of 50 Hz.
KShVGT-10	For stationary and mobile laying and connection of mobile mechanisms to electric networks for a rated voltage of 10 kV alternating current with a frequency of 50 Hz

In conclusion, the values ​​of parameters, characteristics of flexible conductors of this family, not mentioned in the article, are given:

• Ambient temperature for normal operation, °С, -40 ÷ +50;
• Long-term limiting operating temperature, °С, +70;
• Electrical strength at normal conditions, not less, mOhm/km, 50;
• The insulation test of the KG base cable is carried out by applying an alternating voltage of 2.5 kV for 5 minutes;
• Bending resistance, not less, cycles, 30000.

The service life of mobile consumers with the observance of the rules of normal operation is not less than, years, 4.

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Cable KPGNT power increased flexibility

Cable KPGNT power increased flexibility

To high-flexibility cable KPGNT power is used when connecting various external power mechanisms under conditions of aggressive temperature and other influences. Kpgnt cable 3x1 5 1x1 5 has multi-wire copper conductors covered with heat-resistant rubber insulation, oil-resistant rubber is additionally used, which does not support and does not spread combustion. Also, the sheath is characterized by high tensile strength, and the cable itself is flexible and easily switched in power cabinets, shields of circuit breakers.

Scope of cable kpgnt:

The main scope of application is the connection of external mechanisms of stationary and mobile types to the main or intermediate electrical network. Operate at 400 Hz and alternating current 600 V and DC 1000 V. The cable must not be twisted, the permissible turning radius must be at least 5 cable diameters. Designed for maximum temperature conductive core up to +85 degrees.

Cable brand kpgnt

The cable of increased flexibility is branded depending on the area of ​​use. After all, there are even frost-resistant models designed for operating temperatures up to -60 degrees. All of them are designed for operation in aggressive environments: disinfectants, hot oils, large external temperatures. Accordingly, some models have a special marking: T - high temperatures, H - with a zero core, B - cable with main and auxiliary conductive cores, M - frost-resistant.

Where can I buy a wide range of KPGNT products?

In our company, you can buy all existing kpgt cables on the market. There are products designed for large negative temperatures. All presented products consist of several main conductors of various sections and a separate conductor, like zero or a ground loop. For all products, the price is available to everyone and the lowest in the region.

Attention! We sell products in bulk. We accept orders for from 20 thousand rubles. Delivery in Moscow and up to 10 km from the Moscow Ring Road is free of charge.

The article will consider all aspects of the classification of cable products by flexibility and give recommendations on practical choice products for designers and operating organizations.

The division into flexibility classes is reflected at the legislative level for both types of products by clearly indicating the norms in state standards. The need for division arose as a result of the urgent needs of industry and technology. Most standards provide for three classes of cable product flexibility. For example, a power insulated wire can be normal, increased (G) or highly flexible (OG - special flexibility), and a power cable for non-stationary laying can be flexible (G), increased flexibility (PG), special flexibility (OG).

The areas of application of a particular cable or wire, regardless of flexibility, are considered in the technical specifications and standards for the manufacture of cable products. The value of flexibility directly determines how small the bending radius can be during product operation, which should be taken into account when installing specific equipment. Example: if it is not possible to reduce the bending radius when laying, then it is necessary to use more flexible cable, the price of it, respectively, will be higher. And, of course, bending the wiring at an angle close to a straight line requires choosing the most flexible product.

According to the standards, normal flexibility allows a minimum bending radius of 8d, increased flexibility - 5d, special flexibility - less than 5d, where d is the cable diameter.

Any brand of cable product in the designation contains the degree of flexibility in the first place in the abbreviation, only after that the remaining characteristics are listed. Thus, the full designation, which includes the brand, also carries information about flexibility.

To withstand the given flexibility of the product, the conductors are selected according to classes from the first to the sixth according to the tables of GOST 22483, and in required quantity. The higher the core class, the more flexible cable product can be obtained from it. The material is also important, aluminum conductors can be found in cable products of less flexibility than copper ones, in particular, there are no aluminum conductors higher than the third class. As for the first and second class, aluminum or copper wire is selected based on the specified minimum number of pieces in the core. Whereas for other classes, the maximum area of ​​each individual wire is used. And the amount is obtained by dividing the area of ​​\u200b\u200bthe core by the area of ​​​​one wire:

1 class - section from 0.03 to 1000 mm2 with a minimum number of wires from 1 to 59;

2 class - section from 0.5 to 2000 mm2 with a minimum number of wires from 7 to 91;

3 class - section from 0.5 to 500 mm2, maximum diameter wires from 0.33 to 0.87;

4th class - section from 0.05 to 400 mm2, maximum wire diameter from 0.11 to 0.69;

Class 5 - section from 0.03 to 625 mm2, maximum wire diameter from 0.09 to 0.61;

6th class - section from 0.03 to 300 mm2, maximum wire diameter from 0.06 to 0.41;

Among other things, class 2 includes two types of strands, compacted and non-compacted, which also affects the minimum number of wires in them.

Example: for power cables non-stationary laying (used, for example, in power extension cords), it is stipulated that the conductive conductors must be at least the fifth class (obviously copper), further detailing is assigned to specifications for a particular brand of product. These specifications are developed by special design bureaus and are most often distributed on a paid basis. For power insulated wire the class of cores is indicated directly in the standard:

Normal flexibility - 1 class;

Increased flexibility - 2-4 class;

High flexibility - 5-6 class.

Wires PV1 - PV4 must consist of one core. At the same time, their flexibility according to GOST 6323, respectively, is as follows: normal, flexible, increased flexibility, special flexibility. And they are implemented on the veins of 1-2,2-4,3-4,4-5 classes, respectively. In this case, the choice of one or another class is determined by the cross section of the core.

So that the cores can be unmistakably distinguished from both ends of the cut piece of wiring, they are enclosed in a colored sheath. This is done in the KG brand cable (core class 5), designed to power mobile mechanisms and widely used in the production of professional 380 V electrical extension cords. Moreover, there is a preferred set of colors for each number of strands. The standard provides for separate modifications for three-phase and single-phase applications.

The qualities of a cable product depend on its constituent cores, and the requirements for composite products are described in detail in the documentation governing the manufacturing process. Cables and wires are tested for flexibility in accordance with GOST 12182. To ensure the proper dosage of loads and the choice of test equipment normative documents products are supplied with instructions for testing. According to the standards, the cable product must withstand 30,000 bending cycles.

In conclusion, I would like to give some advice on the purchase. In the process of working on a project with the agreed documentation, problems, as a rule, do not arise, since the designer unambiguously indicates the type of the required product. But when repairing old equipment, the question of replacing a failed wiring section may arise, and documentation can no longer be found. In this case, there are two ways to select the desired product:

Try to visually determine which standard the product belongs to, the chance of success is quite high, because state standards do not undergo large changes over long periods of time;

Do the design work yourself, that is, find out the operating voltage and choose the appropriate standard according to the operating conditions. After that, it is enough to conduct a visual comparison of the old sample with the selected one. With identity appearance doubts can be put aside. The nominal value is selected using a ruler, caliper, calculator and simple geometric calculations.

Finally, the flex class is determined by rolls similar to those used for flex test in standard laboratories. Comparing the minimum radius with the requirements of the regulations, it is possible to determine the class of flexibility of the product.

Depending on the extent of compliance technological requirements for a cable or wire, the price can fluctuate quite a lot. However, do not forget about economic indicators that vary greatly around the world: the amount of taxes, the wages of workers.