Power cables in rubber insulation are used for the purpose of transmission, redistribution electric current 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.

Rubber insulated cable structure

Difference from other wires

Cables of this type differ from other types in the following ways:

• torsion resistance;
• flexibility;
• high degree of moisture repellency;
• insulation resistance to alkaline, acidic and oily environments;

Application of rubber insulated cables

The main environment where flexible copper stranded wire in rubber insulation is used is the electrical field in various industries industry and power industry. As invariably used, they are used in mines, basements, and ships, where moisture may be present for a long period of time. Rubber cables are suitable for laying in vertical, horizontal and inclined openings in mines, and similarly in other places of application. It is possible to use it in rooms with vibration phenomena.

The rubber cable uses from 1 to 5 cores, making it possible to use it 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.

Brands of rubber insulated cables

• KG - flexible cable made from a large number of copper conductors. Flexibility is ensured by the properties of rubber; when changing the direction of the product, it does not lose resistance to tearing. In some markings, the cable may have a grounding conductor, usually blue, and if it is absent, a yellow-green one is used. Product production is established for each climate zone: temperate, tropical, arctic climates.
• KG-HL - used for temporary installation of distribution board or electrical equipment. Often used for internal connections of machine tools, control panels, assembly lines and conveyors. The braid is made of cold-resistant rubber, which makes it possible to use this cable in extremely low temperature conditions.
• RKGM - used for terminals from electrical equipment. Distinctive feature is resistance to elevated temperatures. The main voltage for which the cable is applicable is 660 V.
• RPS - 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 protected from sunlight and precipitation.

KG - Flexible power cables with copper stranded conductors with rubber insulation in a rubber shell.

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

The 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, 5th class of flexibility.

The separating layer is a synthetic film. If there is no rubber adhesion, it is permissible to apply insulation without film.

The insulation is made of insulating rubber. The core insulation color is solid. It is allowed to use distinctive colors in the form of a longitudinal stripe. The insulation of the grounding conductor is made only in yellow-green color or is marked with the number 0. A 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, blue can be used as a distinctive color for any conductor except the grounding conductor. For single- and double-core cables, the colors of the cores are 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 in increments of no more than 16 twist diameters.

A synthetic film, talc or similar material is placed over the twisted wires. If the cores do not stick to the sheath, production without film is allowed.

The sheath is made of hose rubber. In single-core cables KG, the insulation and sheath can be replaced with an insulating protective sheath.

Operating temperature range – from -40 to +50 0 C

The warranty period 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.

Minimum bending radius is 8 cable diameters.

The maximum permissible heating temperature of the cores is +75 0 C.

The construction length of the KG cable with a cross-section of the main cores is 35 sq. mm. inclusive - at least 125 m, cross-section from 50 sq. mm. – 150 m.

Climatic options for flexible cable (KG):

HL – cold-resistant, for use in regions with cold climates. Operating temperatures – from -60 to +50 0 C. The insulation is made of cold-resistant hose rubber.

T – tropical, for use 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 of copper wire tinned with tin or tin-lead solder, with a tin content of at least 40%.

Table data:

A flexible rubber-insulated cable with a rubber or plastic sheath is used to connect moving elements to the electrical network.

Flexible rubber insulated cables

Cables in this segment have a copper stranded core; ethylene propylene rubber combined with butyl rubber is used to produce insulation - these materials have increased strength. The product stands out for its special performance characteristics. It has:

• resistance to oils;
• frost resistance;
• preventing the spread of fire;
• immunity to ozone.

A rubber insulated flexible cable can be used when connecting network elements with moving elements. The cable product can withstand alternating voltage of 660 V at a frequency of up to 400 Hz, and is also capable of withstanding direct voltage within 1000 V. Can be used in conjunction with welding equipment, construction equipment, ventilation or climate control systems. Production is carried out in three types of execution:

• cold-resistant;
• tropical;

Copper cables with rubber insulation

A copper cable in rubber insulation has a twisted copper conductor core, which can be tin-plated. The product is wrapped in a layer of PET-E film. Rubber insulation belongs to the RTI-1 type and is made using butadiene, and, in some cases, natural rubber. Multicore cables are numbered or color coded and use polyester threads as a core. Such a rubber-insulated copper cable can be twisted without using a core. The shell is made of oil-resistant rubber; it does not propagate combustion, since chloroprene is used as the base.

The cable is operated in land and water conditions, as well as in rooms with natural ventilation. It is important that there is no exposure to ultraviolet radiation and precipitation. Can be used in rooms with high level humidity, where frequent condensation occurs.

Marine rubber insulated wires

There is a marine-type rubber-insulated cable, the cores of which can be shielded or armored with galvanized steel wire braid. It is used in telephone and control circuits, and can be used to connect to moving current collectors indoors and outdoors, but subject to UV protection.

Structurally, the wire consists of conductive copper wire strands. The steel braid of the product must be primed. The wire can be bent up to 5 outer radii; it can withstand 100% humidity.

Advantages and disadvantages of rubber insulated cables

Rubber insulated cable have advantages and disadvantages, the positive point is the increased elasticity achieved thanks to the rubber insulating layer. The wires are resistant to moisture and aggressive environments:

• oil;
• alkalis;
• acid.

Rubber insulated cable can withstand high temperatures in the event of short circuits. At the same time, it cannot tolerate direct sunlight; due to the rounded shapes of the current-carrying cores, an excess outer diameter is formed in comparison with products with a sector shape.

The KG power cable is flexible copper, multi-wire with rubber insulation, 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 direct voltage of 1000 V.

Design:

Current-carrying conductor - copper, stranded, round shape, 5th class according to GOST 22483.
The separating layer is a synthetic film; it is possible to apply insulation without film if there is no rubber sticking.
Insulation - made of insulating rubber.
Insulated cores have a distinctive color, solid or in the form of a longitudinal stripe.
The insulation of the neutral core is blue; if there is no neutral conductor, blue color is used to color any conductor except the grounding conductor.
The grounding conductor is green-yellow in color or marked with the number 0.
The colors of single-core and two-core cables are not standardized.
The colors red, grey, white and, unless combined, green and yellow are not used for coloring the cores of multi-core cables.
Stranding - insulated cores are twisted with a twist pitch of no more than 16 twist diameters.
The separating layer - on top of the twisted cores - is a synthetic film or talc or other similar material.
The shell is made of hose rubber.
In single-core ones, it is allowed to replace the insulation and sheath with an insulating protective sheath.
The nominal thickness of the insulating protective shell is equal to the sum of the nominal thicknesses of the insulation and shell or twice the thickness of the insulation.

Application:

In various mobile electrical installations, such as a gantry crane, an excavator or a welding machine.
It is possible to operate in closed and open structures, in areas with temperate climates.
Since the rubber insulation is resistant to sunlight, the cable can be used outdoors.

Specifications:

Cable operating temperature range: from -40° to +50° degrees Celsius.
Maximum permissible tensile load on the cable during operation: no more than 24.5 N (2.5 kgf).
Minimum permissible bending radius: - 8 outer cable diameters.
Test alternating voltage of nominal frequency 50 Hz (test time 5 min.): 15 kV - for the main 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

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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 of 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 are those with copper cores: they are practical, multifunctional and affordable. We propose to talk about this type of cables in this article: we will consider their structure, features and areas of application.

The structure of a flexible power cable with copper conductors.

Copper cable different brands has almost the same structure; they may differ in the materials and other elements used for protection.

Any cable of this type must have a conductor (1), which is made of copper. It can be multi-wire, that is, consist of several copper wires. Like a cable, wires have a circular cross-section.

Flexible stranded copper cable can be made in several cross-section options: from 0.75 to 10 square millimeters. It is worth noting that the conductors in it are twisted from copper wire, which is usually tinned with a tin-lead alloy or simply tin.

A flexible power cable with copper conductors must have insulation (2). It is made of special insulating rubber, the thickness of which is determined by state standards.

The cable also uses twisting, which consists of several insulated and twisted wires. Some manufacturers use a core and additional rubber filling in it; fiber materials and PVC plastic may also be found.

Fiber materials can have an antiseptic coating - such cables are made for use in tropical climates. Note also that the insulated cores that are present in the twist can be different color. In this case, all cables (two or more cores) must have a guide and counting cores (they are marked with color), and auxiliary ones (6) may also be present.

Some brands of cables also contain a special separating layer (4), which is made of polyethylene terephthalate film. It is applied on top of the twisted conductors.

Any power cable with copper conductors must have a sheath, which is made of special hose rubber. It can be different: for example, for tropical climates 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 millimeters if the diameter of the cable under the sheath does not exceed 10 millimeters, and 1.8 millimeters if the cable diameter is more than 10 mm.

We also note that the cable design contains a screen (7), which is placed over the core insulation, armor (9) made of a continuous steel spiral, etc.

Features and technical specifications.

The manufacturer recommends using a power cable with copper conductors for connecting mobile mechanisms to electrical networks that have a voltage of up to 660 V and a frequency of up to 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, you should remember the rules for its use. It can be bent, 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 ​​may be different; for example, special cables are produced for tropical conditions or, conversely, frost-resistant cables that can withstand different 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.

Let us note one more feature that concerns cables that have only one core. Manufacturers often leave only one shell, which 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.

Use of power cables with copper conductors of different brands and features of cable marking.

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 with air temperatures up to 60 degrees Celsius and a relative humidity of 98%. Such wires and cables do not fail in warm and humid climates; they do not oxidize or deteriorate over time.

Stranded cables with copper conductors, for which rubber is used for insulation, are usually used for connecting any moving and stationary mechanisms to electrical networks with a voltage of no 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 markings with the letters “T” and “HL”. They may have a zero core - its presence is indicated by the letter “N”. If the cable has auxiliary conductors, the marking will also contain the letter “B”. These features should be taken into account when using cables with different mechanisms.

As for the use of cables of different brands, we note that manufacturers offer separate versions for different purposes. Thus, shielded power copper flexible cable of the GRSHE brand is intended for mining equipment. It can be used to connect the mechanisms of combines, cutters and other equipment. The network voltage for them should also not exceed 660 V. There are also special cables designed for steep slope routes (GRSHEP), self-propelled cars (GRE), etc.

In welding machines for arc welding, to connect electrical holders and to connect mobile mechanisms to the network, cable brands are used that are designated KOG-1 and KG (for different climatic conditions). To connect mechanisms to networks with a voltage of 6 kV, 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 excavator mechanisms, 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, they usually use a cable of the ShRBE brand - a mine cable, which has rubber insulation and shielding. It can be used, for example, for drilling tools and other mechanisms.

A distinction should also be made between cables that are intended for indoor or outdoor use. So, outdoors, but in a place protected from direct sunlight, you can choose a cable of the VVG brand, outdoors - NRG, and for indoors - VRG or NYM. All of them are released 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.