KG - Flexible power cables with copper stranded conductors with rubber insulation in a rubber sheath
KG - Flexible power cables with copper stranded conductors with rubber insulation in a rubber sheath.
KG - Flexible power cables with copper stranded conductors with rubber insulation in a rubber sheath.
Power flexible cables with copper conductors (KG) - features, design, application, characteristics
KG cable is designed for connecting mobile machines and mechanisms to networks with alternating voltage up to 660 V and frequency up to 400 Hz or with direct voltage up to 1000 V.
The current-carrying core of the KG cable is round, copper, necessarily multi-wire, class 5 of flexibility.
The separating layer is a synthetic film. In the absence of rubber adhesion, it is allowed to apply insulation without a film.
The insulation is made of insulating rubber. The color of the insulation lived solid. It is allowed to use a distinctive color in the form of a longitudinal strip. The insulation of the grounding conductor is only yellow-green or marked with the number 0. The flexible cable (KG) with a zero conductor is marked with the additional letter "n". In this case, the insulation of the neutral core is blue. In the absence of a neutral conductor, the blue color can be used as a distinctive color for any conductor, except for the ground conductor. For one- and two-core cables, the color of the cores is not standardized. For cables with 2-3 main cores and 1-2 auxiliary cores, the letter "c" is added to the name.
Twisting of insulated cores with a pitch of no more than 16 twist diameters.
A synthetic film, talcum powder or similar material is applied over the twisted strands. If the cores do not stick together with the sheath, it is allowed to manufacture without a film.
The sheath is made of hose rubber. In single-core KG cables, the insulation and sheath can be replaced by an insulating-protective sheath.
Operating temperature range - from -40 to +50 0 C
The warranty period of operation is 6 months from the date of commissioning, but no later than 12 months from the date of manufacture. Service life - 4 years from the date of manufacture.
The minimum bending radius is 8 cable diameters.
Maximum allowable temperature core heating +75 0 С.
The construction length of the KG cable with a cross section of the main conductors is 35 sq. mm. inclusive - at least 125 m, with a cross section of 50 sq. mm. - 150 m.
Variants of climatic version of flexible cable (KG):
HL - cold-resistant, for operation in regions with a cold climate. Operating temperatures - from -60 to +50 0 C. Insulation is made of cold-resistant hose rubber.
T - tropical, for operation in regions with a tropical climate. Operating temperatures from -10 to +55 0 C. The shell is made of antiseptic rubber. The cores are made from copper wire tin-plated or tin-lead solder, with a tin content of at least 40%.
Table data:
| Number and nominal section of conductors, mm 2 | Nominal cable outer diameter, mm | Estimated weight of 1 km of cable, kg |
| Cables brand KG | ||
| 1 x 2.5 | 6.7 | 80 |
| 1x4 | 8.0 | 110 |
| 1x6 | 9.0 | 150 |
| 1 x 10 | 11.1 | 230 |
| 1 x 16 | 12.4 | 310 |
| 1 x 25 | 14.6 | 450 |
| 1 x 35 | 16.4 | 590 |
| 1x50 | 19.0 | 820 |
| 1x70 | 21.5 | 1090 |
| 1x95 | 24.3 | 1400 |
| 1 x 120 | 27.7 | 1730 |
| 1 x 150 | 30.1 | 2070 |
| 1 x 185 | 32.7 | 2490 |
| 1 x 240 | 35.3 | 3150 |
| 1 x 300 | 40.1 | 3910 |
| 1 x 400 | 43.4 | 4980 |
| 2 x 0.75 | 8.2 | 90 |
| 2 x 1.0 | 8.5 | 100 |
| 2 x 1.5 | 9.4 | 130 |
| 2 x 2.5 | 11.2 | 190 |
| 2x4 | 13.5 | 280 |
| 2x6 | 15.5 | 380 |
| 2 x 10 | 21.2 | 680 |
| 2 x 16 | 23.7 | 920 |
| 2x25 | 28.4 | 1340 |
| 2 x 35 | 31.2 | 1680 |
| 2x50 | 38.0 | 2450 |
| 2x70 | 42.2 | 3170 |
| 2x95 | 47.2 | 4040 |
| 2 x 120 | 50.7 | 4800 |
| 2 x 150 | 57.5 | 6050 |
| 3 x 0.75 | 8.9 | 110 |
| 3 x 1.0 | 9.1 | 120 |
| 3 x 1.5 | 10.1 | 160 |
| 3x2.5 | 12.0 | 230 |
| 3x4 | 14.5 | 350 |
| 3x6 | 16.6 | 460 |
| 3 x 10 | 22.3 | 840 |
| 3x16 | 25.4 | 1130 |
| 3x25 | 30.4 | 1660 |
| 3x35 | 34.0 | 2150 |
| 3x50 | 39.5 | 2970 |
| 3x70 | 44.7 | 3930 |
| 3x95 | 50.6 | 5100 |
| 3 x 120 | 54.4 | 6150 |
| 3 x 150 | 63.0 | 7870 |
| 4 x 1.0 | 10.1 | 160 |
| 4 x 1.5 | 11.1 | 200 |
| 4x2.5 | 13.2 | 290 |
| 4x4 | 16.0 | 420 |
| 4x6 | 18.4 | 590 |
| 4x10 | 24.3 | 1000 |
| 4x16 | 27.8 | 1400 |
| 4x25 | 33.7 | 2100 |
| 4x35 | 37.7 | 2730 |
| 4x50 | 43.8 | 3700 |
| 4x70 | 49.7 | 5000 |
| 4x95 | 56.6 | 6500 |
| 4 x 120 | 62.0 | 8120 |
| 4 x 150 | 69.2 | 9880 |
| 5 x 1.0 | 11.1 | 190 |
| 5 x 1.5 | 12.2 | 240 |
| 5x2.5 | 14.5 | 350 |
| 5x4 | 17.8 | 530 |
| 5x6 | 20.5 | 720 |
| 5x10 | 26.8 | 1250 |
| 5x16 | 30.9 | 1700 |
| 5x25 | 37.4 | 2600 |
| 5x35 | 44.5 | 3440 |
| 5x50 | 50.1 | 4580 |
| 5x70 | 54.5 | 5870 |
| 5x95 | 63.3 | 7820 |
| 5 x 120 | 67.0 | 9360 |
| 2 x 0.75 + 1 x 0.75 | 8.9 | 110 |
| 2 x 1 + 1 x 1 | 9.1 | 120 |
| 2 x 1.5 + 1 x 1.5 | 10.1 | 160 |
| 2 x 2.5 + 1 x 1.5 | 11.8 | 220 |
| 2 x 4 + 1 x 2.5 | 13.9 | 310 |
| 2 x 6 + 1 x 4 | 16.3 | 440 |
| 2 x 10 + 1 x 6 | 21.0 | 740 |
| 2 x 16 + 1 x 6 | 25.0 | 1070 |
| 2 x 25 + 1 x 10 | 30.0 | 1550 |
| 2 x 35 + 1 x 10 | 32.4 | 1890 |
| 2 x 50 + 1 x 16 | 37.9 | 2600 |
| 2 x 70 + 1 x 25 | 42.7 | 3400 |
| 2 x 70 + 1 x 35 | 42.7 | 3400 |
| 2 x 95 + 1 x 35 | 48.0 | 4500 |
| 2 x 120 + 1 x 35 | 54.4 | 5800 |
| 2 x 150 + 1 x 50 | 57.5 | 6510 |
| 3 x 2.5 + 1 x 1.5 | 13.2 | 280 |
| 3 x 4 + 1 x 2.5 | 15.5 | 400 |
| 3 x 6 + 1 x 4 | 18.0 | 560 |
| 3 x 10 + 1 x 6 | 23.5 | 950 |
| 3 x 16 + 1 x 6 | 27.6 | 1300 |
| 3 x 25 + 1 x 10 | 33.1 | 1950 |
| 3 x 35 + 1 x 10 | 36.5 | 2400 |
| 3 x 50 + 1 x 16 | 42.4 | 3400 |
| 3 x 70 + 1 x 25 | 47.7 | 4500 |
| 3 x 95 + 1 x 35 | 53.9 | 5810 |
| 3 x 120 + 1 x 35 | 59.1 | 7280 |
| 3 x 150 + 1 x 50 | 64.9 | 8630 |
| 3 x 150 + 1 x 95* | 68.3 | 7500 |
| 3 x 150 + 1 x 120* | 68.3 | 7800 |
For laying lighting and electrical networks, connecting various equipment, special wires and cables are used that can not only conduct current, but also withstand any load. Manufacturers today offer wires and cables that are made from different materials(aluminum and copper), may or may not have a protective sheath and are used in different conditions. The most commonly used power cables with copper conductors: they are practical, versatile and affordable. We propose to talk about this type of cables in this article: we will consider their structure, features and applications.
The structure of a flexible power cable with copper conductors.
A cable with copper conductors of different brands has almost the same structure, they may differ in the materials used for protection and other elements.
Any cable of this type must have a conductive core (1), which is made of copper. It can be multi-wire, that is, it can consist of several copper wires. Like cables, wires are round.
Flexible stranded copper cable can be made in several cross-sectional options: from 0.75 to 10 square millimeters. It is worth noting that the conductive cores in it are twisted from copper wire, which is usually tinned with a tin-lead alloy or simply tin.
The flexible power cable with copper conductors must be insulated (2). It is made of special insulating rubber, the thickness of which is determined by state standards.
Also, the cable uses a twist, which is a few insulated and twisted cores. Some manufacturers use a core and additional rubber fillings in it, fibrous materials and PVC plastic can also be found.
Fibrous materials can be antiseptic coated - such cables are made for use in tropical climates. We also note that the insulated cores that are present in the twist can be of different colors. At the same time, in all cables (two or more cores) there must be a guide core and a counting core (they are marked with a color), and auxiliary ones (6) may also be present.
In some brands of cables, there is also a special separating layer (4), which is made of polyethylene terephthalate film. It is applied on top of the twisted cores.
Any power cable with copper conductors must have a sheath, which is made of special hose rubber. It can be different: for example, for a tropical climate, the cable is made using antiseptic rubber, and for other climatic conditions, cold-resistant rubber can be used. The thickness of such a rubber sheath should not be less than 1.3 mm if the cable diameter under the sheath does not exceed 10 mm, and 1.8 mm if the cable diameter is greater than 10 mm.
It should also be noted that the cable design contains a screen (7), which is applied over the insulation of the cores, armor (9) from a steel continuous spiral, etc.
Features and technical characteristics.
The manufacturer recommends using a power cable with copper conductors to connect mobile mechanisms to electrical networks that have a voltage of up to 660 V and a frequency of 400 Hz. They can also be used in networks with a constant voltage not exceeding 1000 V. There are also brands of cables that are suitable for networks with high voltage.
When using the cable, it is worth remembering the rules for its use. It is allowed to bend, but the bending radius can be different - for some it should not exceed 6, and for others - 8 diameters of the cable used. The temperature at which such a power cable is allowed to be used can vary from -40 to 50 degrees Celsius. For some brands, these temperature values \u200b\u200bmay be different, for example, special cables are produced for tropical conditions or, conversely, frost-resistant, capable of withstanding various low temperatures.
The method of twisting the cores in the cable also matters - they must be twisted only in the right direction. Moreover, if the cores have a cross section equal to or more than 16 mm 2, then they must be twisted around a special rubber core.
We also note one more feature that concerns cables with only one core. Manufacturers often leave only one shell that performs both insulating and protective functions. The thickness of such a universal sheath is usually equal to the total thickness of the sheath and insulation.
The use of power cables with copper conductors of different brands and cable marking features.
Depending on the type of cable, it can be used to connect to networks with different voltages - from 380 to 660 and even 3000 V.
Cables marked "T" are recommended by the manufacturer for use in tropical climates at air temperatures up to 60 degrees Celsius and relative humidity 98%. Such wires and cables do not fail in warm and humid climates, they do not oxidize or deteriorate over time.
Multi-wire cables with copper conductors, for which rubber is used for insulation, are usually used to connect any mobile and stationary mechanisms to electrical networks with a voltage of not more than 660 V at a frequency of 400 Hz, or with a constant voltage of up to 1000 V. Climatic conditions in which they can be used such cables are indicated in the marking with the letters "T" and "HL". They may have a zero core - its presence is indicated by the letter "H". If the cable has auxiliary cores, then the marking will also contain the letter "B". These features should be taken into account when using a cable with different mechanisms.
As for the use of cables of different brands, we note that manufacturers offer separate versions for different purposes. So, the power copper flexible cable shielded brand GRSE is designed for mining equipment. It can be used to connect the mechanisms of combines, cutters and other equipment. The mains voltage for them should also not exceed 660 V. There are also special cables designed for steep fall routes (GRSHEP), self-propelled cars (GRE), etc.
IN welding machines for arc welding for connecting electric holders, for connecting mobile mechanisms to the network, cable brands are used that have the designations KOG-1 and KG (for different climatic conditions). To connect mechanisms to networks with a voltage of 6 kV, the brands KGE, KShVG, KShVGD, KShVGDM, etc. are recommended. They are also produced for different climatic conditions; special heat-resistant rubber can be used in their production. For example, such cables are used to connect the mechanisms of excavators, as well as other mobile mechanisms.
But for stationary cable laying, KShVGT-10 is usually used. This brand can be connected to networks with alternating voltage up to 10 kV. But for a standard voltage of 220 V, a cable of the ShRBE brand is usually used - a mine cable with rubber insulation and shielding. It can be used, for example, for drilling tools and other mechanisms.
It is necessary to distinguish between cables that are designed for indoor or outdoor use. So, on the street, but in a place protected from direct sunlight, you can choose a cable of the VVG brand, in the air - NRG, and for rooms - VRG or NYM. All of them are available in different sizes, with one, two, three or four cores. They are used for laying electrical networks, connecting stationary and mobile equipment, as well as for other purposes.
The main advantage of rubber insulated cables is their flexibility, which allows smaller bend radii during installation. However, in terms of electrical parameters, such cables are significantly inferior to power cables with impregnated paper or plastic insulation. In addition, the insulating sheaths of cables lose their elastic properties over time; their physical, mechanical and electrical parameters decrease due to rubber aging. Rubber aging can occur under the influence of various factors ( heat, the presence of ozone, oxygen, light, etc.) and is a consequence of the oxidative degradation of the rubber contained in the rubber. All this does not currently allow the production of cables with rubber insulation for high voltages. In particular, in practice, the maximum operating voltage of cables with rubber insulation does not exceed 35 kV, although some foreign companies produce cables with ethylene-propylene rubber insulation for voltages of 66 and 110 kV.
1 - current-carrying core; 2 - isolation; 3 - a layer of rubberized tape; 4 - filling; 5 - a layer of rubberized tape; 6 - soft layer; 7- armor; 8- protective cover
Studies show that the cause of the breakdown of cables with rubber insulation is the destruction of rubber by ozone, which occurs in the cable during the ionization of air inclusions. Therefore, to create cables high voltage it is necessary to use semi-conductive screens on the core and insulation, as well as ozone-resistant rubber.
The most promising rubbers for high voltage cables are rubbers based on butyl rubber and ethylene propylene rubber. Molecules of butyl rubber have a linear structure and contain a small amount of double bonds. Ethylene propylene rubber also has a linear structure, and double bonds are completely absent in it. This explains the high ozone resistance of rubbers based on these rubbers.
Power cables with rubber insulation are made with a lead sheath without armor or armored with an outer cover, with a core cross section of up to 500 mm 2, they are used for fixed laying in installations with voltages up to 660 V AC and up to 1000 V direct current. Brands, applications and laying conditions power cables with rubber insulation are given in table. 0.
Rubber insulation is made from a continuous layer of rubber or from rubber bands, followed by vulcanization. Power cables with rubber insulation are used in networks alternating current voltage up to 1 kV and direct current voltage up to 10 kV.
The bulk of power cables with rubber insulation are low-voltage cables. Rubber insulated power cables are usually understood as power cables intended for fixed laying. However large group rubber insulated flexible cables are also designed for the transmission and distribution of electricity and are essentially power cables. Rubber insulated power cables manufactured in Russia are designed for fixed laying in 660 V AC or 1,3,6 and 10 kV AC and DC networks.
The cables have copper or aluminum current-carrying conductors of round shape with a cross section from 1 to 500 mm 2 . The insulation is made of insulating rubber; a sheath of lead, polyvinyl chloride or hose rubber is applied over the insulated cores. If necessary, the cables have reinforcing covers and protective covers of the usual design.
660 V AC (1000 V DC) cables can be one-, two-, three-, or four-wire (Table 2)
Power cables with rubber insulation
Brand of cable with cores |
Characteristics of shells and protective cover |
Application area |
|
aluminum |
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Lead sheathed with rubber insulation, without protective covers |
Indoors, in channels |
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In PVC sheath with rubber insulation, without protective covers |
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In a non-combustible rubber sheath with rubber insulation, without protective covers |
Indoors, in channels |
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Lead sheathed with rubber insulation, armored with two steel bands with a protective outer cover |
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PVC sheathed with rubber insulation, armored with two steel bands, with a protective outer cover |
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In a rubber non-combustible shell with rubber insulation, armored with two steel tapes, with a protective outer cover |
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In a PVC sheath with PVC insulation, armored with steel tapes, with a protective outer cover |
In the ground, if the cable is not subjected to significant tensile forces |
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In plastic sheath with PVC insulation, armored with steel tapes, with an outer cover of PVC hose |
In tunnels, channels, ground, if the cable is not subjected to significant tensile forces |
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In a PVC sheath with polyethylene insulation, armored with steel tapes, with a protective outer cover |
In the ground, if the cable is not subjected to significant tensile forces |
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660 V Rubber Insulated Cable Range
Number of cores |
Cross-section of conductors, mm 2 |
|
4...240 2,5..240 |
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AVRG.ANRG |
4...300 2,5...300 |
|
SRV, SRBG, VRBn, VRBG, NRB, NRBG |
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ASRB, ASRBG, AVRB, AVRBn, AVRBG, ANRB, ANRBG |
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Note. Two- and three-core cables can be made with an additional ground or neutral conductor
The thickness of the insulation, depending on the voltage and cross-section of the conductors, is 1 ... 2.5 mm. These cables are available in both lead and PVC and rubber sheaths. Stranded cables to obtain a triangular shape have a filling of the inter-core space with rubber bundles, and sometimes with unimpregnated cable yarn or staple fiberglass. Over twisted cores, as well as over the insulation of single-core cables, a tape made of polyethylene terephthalate film or rubberized fabric is usually applied, which plays the role of a separator that prevents the migration of components from the hose, reducing the electrical parameters of the insulating rubber (soot, sulfur, etc.) and accelerating its aging .
Two- and three-core cables (with the exception of armored ones) with a cross section of up to 16 mm 2 inclusive can be made flat, i.e. laid parallel in the same plane. When laying cables in the ground, as well as indoors, if the cable is not subjected to significant tensile forces, the protective covers of the cables must include two armored tapes. If mechanical impacts are minimal during cable laying, then armored covers are not used. Cable sheaths can be made of oil-resistant, flame-retardant rubber.
Cables for voltages of 3, 6 and 10 kV are made only single-core. The thickness of the insulation, depending on the cross-section of the core, is within 1.8 ... 3.8 mm for 3 kV cables and 3 ... 4 mm for 6 kV cables. Cables for a voltage of 10 kV are produced only with large sections (240, 300 and 400 mm 2) and have an insulation thickness of 5 mm.
Table 2. Number of conductors and sections of cables with rubber insulation(GOST 433-73)
Cable brand |
Number of cores |
Variable 660 (constant 1000), V |
Rated direct cable voltage, V |
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3000 | 6000 | 10000 |
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Nominal cross-section of conductors, mm 2 |
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AVRG, ANRG |
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AVRG, ANRG |
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SRBGt, ASRBGt |
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SRBG, ASRBG |
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SRP, SRBG, VRBn, VRB, VRBG. PRB. RRBG |
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ASRB, ASRBG. AVRB, AVRBN |
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AVRBG, A NRB, ANRBG |
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Note. Two- and three-core cables can be made with an additional ground or neutral conductor.
The thickness of the lead sheath is in the range of 1 ... 2 mm, the thickness of the sheath made of rubber is 1.2 ... 3.5 mm, and that of polyvinyl chloride is 1 ... 2.6 mm.
Depending on the type of rubber used, the long-term operating temperature of the cables is 65 and 90 °C.
Power cables with rubber insulation for fixed laying are marked according to the same principle and with the same letters as power cables with paper insulation, with the addition to the brand of the letter P, the presence of which indicates that the cable has rubber insulation, and the letter H, indicating that the cable sheath is made of oil-resistant nayrite rubber.
For example, an SRG brand cable has a copper core, rubber insulation and a lead sheath; AVRB brand cable has an aluminum core, rubber insulation and a PVC sheath armored with two steel tapes with a protective outer cover; NRB cable has a copper core, rubber insulation, a nayrite rubber sheath and appropriate protective and reinforcing covers.
Power cables with rubber insulation for non-stationary laying include a large group of cables for various purposes, however, the bulk of these cables are flexible cables for voltages up to 660 V. Cables are designed to connect mobile mechanisms to AC or DC voltage networks. Cable conductors are copper, of varying degrees of flexibility; number of main conductors 3. Four-core cables are used for grounding when necessary. In addition, individual brands of cables have one or two auxiliary cores. The cross section of the main conductors is 0.75 ... 150 mm 2, grounding - from 0.75 ... 50 mm 2, auxiliary - 1.5 ... 10 mm 2. Ground conductor insulation - yellow-green. Insulated cores of 4...6-core cables are twisted around a round or profiled rubber core. A rubber sheath is applied over the twisted cores, which can be oil-resistant and flame-retardant.
Cables with a conductor cross section of 6 mm 2 or more must be resistant to bending at an angle of ±n / 2 rad at a nominal tensile force of 49 N. The diameter of the rollers on which the bend is made, depending on the cross section of the conductors, can be from 200 to 600 mm; number of bends - at least 4000 ... 12000. Cables with a cross section of the main conductors up to 4 mm 2 inclusive must be resistant to multiple kinks through the system of rollers under current load and withstand at least 30,000 kink cycles. A number of cables of this type must be resistant to crushing forces (no more than 8 kN). Long-term operating temperature of cables +75 °С. Depending on the type of materials used, the frost resistance of cables ranges from -10 to -60 °C.
During the operation of cables, tensile forces should not exceed 19.6 N per 1 mm 2 of the total cross section of all cores. The bending radius of cables during installation and operation is within 5 ... 10 cable diameters (depending on the type of cables).
There is a large group of specialized flexible rubber insulated power cables with certain design features. These include, in particular, highly flexible shielded cables on AC voltage up to 660 V with isolated neutral, intended for connection of a mine drilling power tool; cables for tower cranes designed to connect equipment for controlling mechanisms, signaling equipment and other devices to an alternating current network at an alternating voltage of up to 660 V; mine cables designed to connect mobile machines and mechanisms to the network for alternating voltage of 1140 V on the main conductors and 220 V on the auxiliary ones. A feature of mine cables is the presence of flexible screens made of conductive rubber.
To connect excavators and other mobile mechanisms to electrical networks with an isolated neutral at an alternating voltage of 6 kV, flexible four- and five-core cables with a cross section from 3 x 10 + 1x6 + 1x6 mm 2 to 3 x 150 + 1 x 50 + 1x10 mm 2 are used. The cables have screens along the core and insulation made of electrically conductive rubber. Nominal insulation thickness of main conductors 4 mm, auxiliary conductors 2.0...2.5 mm, electrically conductive screens 0.4...0.6 mm. The voltage of partial discharges in the insulation of the shielded main conductors must not be less than 9 kV, the discharge termination voltage must not be less than 6 kV. The cables are resistant to alternating bends around the rollers at an angle I am glad with a tensile force of 196 N. The diameter of the rollers on which the bend is made is 400 ... 600 mm; the number of alternating bends is 30000...40000. After such impacts, the number of wire breaks in each core should not exceed 30%. The long-term permissible maximum operating temperature of these cables is within +(75...80) °С. Minimum allowable temperature environment- (40...60) °С. The service life of flexible power cables in comparison with the service life of cables for fixed laying (20...25 years) is much less. Thus, the minimum service life of an excavator cable for a voltage of 6 kV is 3 years, and when operated using mechanisms equipped with cable receiving drums, 5 years.
For alternating voltage up to 6-10 kV, a wide range of flexible cables is also produced. general purpose designed to connect mobile machines, mechanisms and equipment to electrical networks and mobile sources of electrical energy. Cables are distinguished primarily by the degree of flexibility of the conductive core. The number of main conductors - 1 ... 3, grounding - 1 ... 2, auxiliary - 1, 2, 3, 5, 7. The nominal section of the main conductor is from 0.75 to 150 mm 2. Service life of cables - from 1 to 6 years.
The specific characteristics of power cables with rubber insulation, especially their increased flexibility, determine their further improvement and development. At present, the issue of replacing such cables with plastic-insulated cables cannot be resolved positively. Perhaps over time this problem will be solved with the introduction of a number of thermoplastic elastomers.
The range of manufactured cables and wires with rubber and plastic insulation is very wide, so below is information only about some the most important types cable products used for the transmission and distribution of electricity.
The widest group of rubber-insulated and rubber-sheathed cables is made up of general-purpose copper flexible cables designed to connect mobile mechanisms to electrical networks for a rated alternating voltage of 660 V, a frequency of up to 400 Hz or a direct voltage of up to 1000 V. In accordance with GOST 13497-77 seven brands of cables are produced. Cables are produced with 1...3 core cores, the nominal section of which can be from 0.75 to 150 mm 2 . Some cables have a ground conductor and 1...2 auxiliary conductors. The sections of the grounding conductors, depending on the section of the main conductor, are 0.75 ... 150 mm 2; the section of the auxiliary conductors is 0.75 ... 10 mm 2. Cables of the KRTP and KRPTN brands have a core that is inferior in flexibility to the cores of cables of other brands listed in Table. 0 and 1. So if the core of cables of the KRTP and KRPTN brands with a cross section of 70 mm 2 consists of 189 wires with a diameter of 0.68 mm, then for cables of the KRPG, KRPGN, KRPS, KRPSN, KRSHK brands, the same section is performed by 266 wires with a diameter of 0.58 mm each. The main conductors of the cables must be colored to distinguish them from each other, or in other ways to distinguish them. The ground conductor (except for the ground conductor of cables of the KRSHK brand) must be black or yellow-green. The average service life of cables is in the range from 2 to 4 years, and during this service life the cables must withstand from 4000 to 15000 alternating bends with a diameter of at least 200...400 mm (depending on cable brands). The long-term permissible temperature of the current-carrying conductors of the cables should be no more than 65 °C. Tensile loads on the cable should be no more than 19.6 N per 1 mm 2 of the total cross section of all cores.
Rubber insulation and sheath continue to dominate a number of special purpose cables, among which are the following:
- Cables and wires for mining and earthmoving. These cables are designed to connect various mobile machines and mechanisms, such as excavators, mine combines, mine drilling tools, etc., to electrical networks. Such cables include flexible power excavator cables for voltages of 6 and 10 kV, flexible mining cables, including those with shielded cores, flexible shielded mining cables for drilling tools.
- High voltage x-ray cables. These cables are designed to supply filament current and high voltage to X-ray tubes. The cables are designed for rectified pulsating voltage up to 150 kV or alternating voltage 55 kV.
- Cables for radio installations. Such cables are designed for mounting radio installations for alternating voltages of 380, 660 and 3000 V with a frequency of up to 400 Hz or constant 700, 1000 and 6000 V. If protection against radio interference is required, then the cables are shielded.
- Aerodrome cables. Designed for alternating voltages of 250, 660, 3000 and 6000 V. Low-voltage cables for voltage of 250 V are designed to connect airfield lights or light signs to the secondary winding of transformers, as well as cable glands transformers. Low-voltage cables for 660 V connect airfield lights that illuminate aircraft landing areas. High-voltage cables for voltages of 3 and 6 kV connect the primary windings of the transformers that feed the airfield lights into a common circuit and are used to connect to the dimmers. In addition, 3 kV cables connect high-voltage windings of transformers for aerolight signals.
Power cables in rubber insulation used to transfer, redistribute electric current up to permanently installed machines and mechanisms consuming alternating voltage up to 660V and constant voltage up to 1000V.
The peculiarity of the cables lies in their design. Due to the use of rubber, they can be used in rooms with high humidity.
Cable structure in rubber insulation
Difference from other wires
Cables of this type differ from other types in the following:
- twist resistance;
- flexibility;
- high degree of moisture repellency;
- insulation resistance to alkaline, acid and oil environments;
Application of cables in rubber insulation
The main environment where the flexible copper stranded wire in rubber insulation is used is the electrical field in various industries and the electric power industry. As invariably used, they are used in mine, basement, ship premises, where the presence of moisture is possible for a long period of time. Rubber cables are applicable for laying in vertical, horizontal and inclined workings in mines, and similarly in other places of application. It is possible to use in rooms with the presence of vibration phenomena.
In a rubber cable, from 1 to 5 cores are used, due to which they can be used in single-phase and three-phase networks.
The quantitative indicator of the cores in the cable directly affects the purpose, conditions of use, phase, and the presence of grounding.
Types of cables in rubber insulation
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- KG - flexible cable made from a large number copper conductors. Flexibility is provided by the properties of rubber, when changing the direction of the product, do not lose resistance to tearing. In some markings, the cable may have a ground conductor, usually blue, and in its absence, yellow-green is used. Production is adjusted for each climatic zone: temperate, tropical, arctic climates.
- KG-HL - used for temporary mounting of a switchboard or electrical equipment. Often used for internal connection of machine tools, control panels, assembly lines and conveyors. The braid is made of cold-resistant rubber, which makes it possible to use such a cable in extremely low temperature conditions.
- RKGM - used for outputs from electrical equipment. Distinctive feature is high temperature resistance. The main voltage for which the cable is applicable is 660 V.
- RPSh - it is used as the main one when connecting electrical installations, radio equipment, as well as for non-traditional installation. Operation takes place in areas with a temperate climate, in rooms closed from sunlight and precipitation.
Cable KG power flexible copper, multi-wire with rubber insulation is designed for connecting mobile mechanisms to electrical networks at an alternating voltage of 660 V with a frequency of up to 400 Hz or a constant voltage of 1000 V.
Design:
Conductor - copper, multiwire, round shape, class 5 according to GOST 22483.
The separating layer is a synthetic film; it is allowed to apply insulation without a film in the absence of rubber sticking.
Insulation - insulating rubber.
Insulated cores have a distinctive color, solid or in the form of a longitudinal strip.
The insulation of the zero core is blue; if there is no neutral conductor, the blue color is used for the color of any conductor except for the grounding one.
The ground conductor is green-yellow or marked with the number 0.
The color of single-core and two-core cables is not standardized.
The colors red, grey, white and, if not combined, green and yellow are not used for core colors in multicore cables.
Twisting - insulated cores are twisted with a twisting pitch of no more than 16 twist diameters.
Separating layer - over twisted strands - synthetic film or talc or other similar material.
Sheath - from rubber hose.
In single-core, it is allowed to replace the insulation and sheath with an insulating-protective sheath.
The nominal thickness of the insulating-protective sheath is equal to the sum of the nominal thicknesses of the insulation and sheath, or twice the thickness of the insulation.
Application:
In various mobile electrical installations such as gantry crane, excavator or welding machine.
It is possible to operate in closed and open structures, in areas with a temperate climate.
Since the rubber insulation is resistant to sunlight, the cable can be used outdoors.
Specifications:
Temperature regime of cable operation: from -40° to +50° degrees Celsius.
The maximum allowable tensile load on the cable during operation: no more than 24.5 N (2.5 kgf).
Minimum allowable bending radius: - 8 external cable diameters.
Test alternating voltage of rated frequency 50 Hz (test time 5 min.): 15 kV - for the main current-carrying conductors, 2 kV - for the additional conductor.
Warranty period: 6 months from the date of commissioning, but no later than 12 months from the date of manufacture.
Service life (from date of manufacture): 4 years
| cable type | Outer diameter, mm | Specific gravity kg/km |
| KG 1x4 | 8,0 | 110 |
| KG 1x6 | 9,0 | 150 |
| KG 1x10 | 11,1 | 230 |
| KG 1x16 | 12,4 | 310 |
| KG 1x25 | 14,6 | 450 |
| KG 1x35 | 16,4 | 590 |
| KG 1x50 | 19,0 | 820 |
| KG 1x70 | 21,5 | 1090 |
| KG 1x95 | 24,3 | 1400 |
| KG 1x120 | 27,7 | 1730 |
| KG 1x150 | 30,1 | 2070 |
| KG 1x185 | 32,7 | 2490 |
| KG 1x240 | 36,8 | 3190 |
| KG 1x300 | 40,1 | 3910 |
| KG 1x400 | 43,4 | 4980 |
| KG 2x0.75 | 8,2 | 90 |
| CG 2x1.0 | 8,5 | 100 |
| KG 2x1.5 | 9,4 | 130 |
| CG 2x2.5 | 11,2 | 190 |
| KG 2x4 | 13,5 | 280 |
| KG 2x6 | 15,5 | 380 |
| KG 2x10 | 21,1 | 680 |
| KG 2x16 | 23,7 | 920 |
| KG 2x25 | 28,4 | 1340 |
| KG 2x35 | 31,2 | 1680 |
| KG 2x50 | 38,0 | 2450 |
| KG 2x70 | 42,2 | 3170 |
| KG 2x95 | 47,4 | 4040 |
| KG 2x120 | 50,7 | 4800 |
| KG 2x150 | 57,5 | 6050 |
| KG 3x0.75 | 8,9 | 110 |
| KG 3x1.0 | 9,1 | 120 |
| CG 3x1.5 | 10,1 | 160 |
| CG 3x2.5 | 12,0 | 230 |
| KG 3x4 | 14,5 | 350 |
| KG 3x6 | 16,6 | 460 |
| KG 3x10 | 22,3 | 840 |
| KG 3x16 | 25,4 | 1130 |
| KG 3x25 | 30,4 | 1660 |
| KG 3x35 | 34,0 | 2150 |
| KG 3x50 | 39,5 | 2970 |
| KG 3x70 | 44,7 | 3930 |
| KG 3x95 | 50,9 | 5100 |
| KG 3x120 | 54,4 | 6150 |
| KG 3x150 | 63,0 | 7870 |
| CG 4x1.0 | 10,1 | 150 |
| KG 4x1.5 | 11,1 | 200 |
| KG 4x2.5 | 13,3 | 290 |
| KG 4x4 | 16,0 | 420 |
| KG 4x6 | 18,5 | 590 |
| KG 4x10 | 24,4 | 1000 |
| KG 4x16 | 27,8 | 1400 |
| KG 4x25 | 33,7 | 2100 |
| KG 4x35 | 37,7 | 2730 |
| KG 4x50 | 43,8 | 3700 |
| KG 4x70 | 49,7 | 5000 |
| KG 4x95 | 56,6 | 6500 |
| KG 4x120 | 62,0 | 8120 |
| KG 4x150 | 69,2 | 9880 |
| KG 5x1.0 | 11,1 | 190 |
| KG 5x1.5 | 12,2 | 240 |
| KG 5x2.5 | 14,6 | 350 |
| KG 5x4 | 17,8 | 530 |
| KG 5x6 | 20,2 | 720 |
| KG 5x10 | 26,8 | 1250 |
| KG 5x16 | 30,9 | 1700 |
| KG 5x25 | 37,4 | 2600 |
| KG 5x35 | 44,5 | 3440 |
| KG 5x50 | 50,1 | 4580 |
| KG 5x70 | 54,9 | 5920 |
| KG 5x95 | 63,3 | 7820 |
| KG 5x120 | 67,0 | 9360 |
| CG 2x0.75+1x0.75 | 8,9 | 110 |
| CG 2x1+1x1 | 9,1 | 100 |
| CG 2x1.5+1x1.5 | 10,1 | 160 |
| CG 2x2.5+1x1.5 | 11,8 | 220 |
| CG 2x4+1x2.5 | 13,9 | 310 |
| KG 2x6+1x4 | 16,3 | 440 |
| KG 2x10+1x6 | 21,0 | 740 |
| KG 2x16+1x6 | 25,0 | 1070 |
| KG 2x25+1x10 | 30,0 | 1550 |
| KG 2x35+1x10 | 32,4 | 1890 |
| KG 2x50+1x16 | 37,9 | 2600 |
| CG 2x70+1x25 | 42,7 | 3400 |
| KG 2х95+1х35 | 48,6 | 4500 |
| KG 2x120+1x35 | 54,4 | 5880 |
| KG 2x150+1x50 | 58,1 | 6590 |
| CG 3x2.5+1x1.5 | 13,2 | 280 |
| CG 3x4+1x2.5 | 15,5 | 400 |
| KG 3x6+1x4 | 18,0 | 560 |
| KG 3x10+1x6 | 23,5 | 950 |
| KG 3x16+1x6 | 27,6 | 1300 |
| KG 3x25+1x10 | 33,1 | 1950 |
| KG 3x35+1x10 | 36,5 | 2400 |
| KG 3x50+1x16 | 42,4 | 3400 |
| KG 3x70+1x25 | 47,7 | 4500 |
| KG 3x95+1x35 | 54,5 | 5890 |
| KG 3x120+1x35 | 60,9 | 7280 |
| KG 3x150+1x50 | 64,9 | 8630 |
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