JP5088917B2 - Low voltage lead-in wire - Google Patents

Description

  The present invention relates to a low-voltage lead-in wire used for power supply in a section from a low-voltage distribution line to a building, and particularly relates to a low-voltage lead-in wire excellent in tracking resistance and handling properties.

  Among electric wires and cables used for power supply, two or more twisted wires or wires are used as outdoor low-voltage lead-in wires that are installed or used between the low-voltage distribution line and the customer's building. There is a flat DV electric wire arranged in parallel, and the one using vinyl chloride resin as an insulator is common.

  Conventionally, in each insulated electric wire twisted by such low-voltage lead-in wires, the insulators covering the conductors have been made of different colored resins so that they can be identified. If these insulators are made of a resin other than black, that is, a resin that does not contain carbon, these insulators have a smaller ultraviolet blocking effect than black insulators that contain carbon, and oxidation. Deterioration is likely to occur, and cracks due to deterioration were likely to occur under sunlight. As cracks and scratches in the insulator progress, the conductor is partially exposed.

  On the other hand, in such an insulated wire, when the surface of the insulator is wet or fouled, a leakage current flows along the surface of the insulator, the surface is locally dried along with the evaporation of moisture due to the generated Joule heat, and the electric resistance is high. As a result of the generation of the part, the electric field becomes irregular, and a local micro discharge with a small light emission called scintillation occurs, and a part of the insulating material is decomposed by the heat accompanying this discharge to generate carbides. Sometimes occurred. This phenomenon is more likely to occur when dust containing salt accumulates on the wire surface.

  When a tracking phenomenon occurs in two or more low-voltage lead-in wires, the carbide generated from the insulator has a high conductivity, so the leakage current between each insulated wire flows through it, and the electric field concentrates in this vicinity, scintillation, The carbide generation process is promoted and the carbide grows further. Eventually, the insulated wires are covered with a highly conductive carbide, and a leakage current always flows.

  When there is a conductor exposed portion due to cracks or scratches on the surface of the insulator in the portion where the insulated wires of the low-voltage lead-in wire are close to each other, the carbide is grown by the tracking phenomenon in the vicinity of the conductor exposed portion. When appropriate moisture is supplied to the surface of the insulator due to light rain, drizzle, mist, condensation, etc., scintillation (spark discharge) occurs, and arc discharge between conductor exposed portions is induced. When the deterioration of the insulator progresses to a state where the arc discharge is continuously generated, the conductor is softened and melted by the heat of the arc discharge, cannot withstand the installation tension, and is disconnected.

  In order to prevent the deterioration of the low-voltage lead-in wire, an insulating layer made of black resin containing carbon is disposed outside the insulator of a predetermined color that covers the conductor to prevent deterioration of the insulator. Japanese Patent Laid-Open No. 2002-324443 discloses an example of a low-voltage lead-in wire that can identify the wire by the color of the insulating layer on the cut surface.

  On the other hand, with regard to the tracking phenomenon, research and development has been conducted to ensure tracking resistance. In recent years, various types of electric wires that can prevent the conductive part from being generated on the surface of the insulator and prevent the insulator from being deteriorated due to the tracking phenomenon. An example of a low-voltage lead-in wire that has been proposed and invented by the present inventor is disclosed in Japanese Patent Application Laid-Open No. 2005-149759.

In this conventional low-voltage lead-in wire, the surface of the insulator is formed in a continuous state having a cross-sectional shape in which a plurality of protrusions are provided at predetermined intervals in the circumferential direction, and the wires are twisted and spaced apart from each other. The insulation creepage distance is increased and tracking resistance is improved, and there is almost no possibility of arc short-circuiting between exposed parts of conductors due to scratches and cracks in the insulator, reducing the risk of ignition and disconnection accidents. Have
JP 2002-324443 A JP 2005-149759 A

  The conventional electric wire is configured as described above. In the case of the former low-voltage lead-in electric wire shown in Patent Document 1, although it is strong against deterioration due to ultraviolet rays, various factors other than ultraviolet rays can be used as an insulator. Scratches and cracks may occur, and the progress of these may cause partial exposure of the conductor. Cases where this conductor exposed part is formed are: (1) When a flying object such as tin hits the electric wire due to a strong wind such as a typhoon, and (2) the wound is caused by contact with an adjacent tree, etc. When entering, (3) When accidentally scratching by dragging the wire at the time of construction, (4) When the insulator is scraped by friction due to contact with other wires after construction, (5) Due to thermal deterioration There are cases where the insulator hardens and cracks occur.

The polyvinyl chloride insulator used for the former low-voltage lead wire is superior in workability such as lead-out, but has the property of being easily scratched and easily worn, and is resistant to tracking. Because the performance is remarkably inferior, when conductor exposed parts due to scratches occur in the portions of the twisted wires that are close to each other, the insulator further deteriorates due to the tracking phenomenon that occurs in a wet state, and the conductor is exposed. There was a problem that the rate at which arc discharge occurs between the portions and the wire breaks is extremely high.
In addition, in the former former low-voltage lead-in wire, since the outermost layers of the twisted wires are all the same color insulators with weather resistance, there is a problem that it is difficult to identify each wire in appearance. It was.

  On the other hand, the latter latter low-voltage lead wire shown in Patent Document 2 is excellent in tracking resistance, but in order to ensure performance, an insulator made of a material that emphasizes tracking resistance is provided for each of the wires twisted together. Since they are used uniformly, the color tone of each electric wire is the same, and it is necessary to use the difference in the protrusion shape on the surface of the electric wire for identifying the core. However, identification by surface shape requires familiarity, and has a problem that there is a considerable risk of erroneous identification.

  The present invention has been made to solve the above-mentioned problems, and can improve the tracking resistance and prevent ignition and disconnection accidents due to the discharge phenomenon between the insulated wires, and easily recognize each color by visual recognition. An object of the present invention is to provide a low-voltage lead-in wire that can identify an insulated wire.

  The low-voltage lead-in electric wire according to the present invention is a low-voltage lead-in electric wire formed by twisting a plurality of insulated wires, except for all of the insulated wires, or one provided only with a black or gray insulator around the conductor. The remaining insulated wires are each provided with two layers of insulators of an inner layer and an outer layer made of a predetermined material around the conductor, and the outer layer insulators have excellent tracking resistance and are made different for each insulated wire. One or a plurality of color band portions for identifying the wire cores, which are arranged in different colors and / or arrangement forms, are continuously arranged in the longitudinal direction on a part of the surface with a thickness smaller than the outer layer thickness, while the remaining portions are arranged. It is made of a material having excellent weather resistance and tracking resistance in black or gray different from the color band part, and the insulator of the inner layer is at least different from the part other than the color band part in the insulator of the outer layer. Color and other insulated Both the inner insulating body is made is different from the predetermined color from each other.

  Thus, according to the present invention, the insulation of each insulated wire in the low-voltage lead-in wire has an inner and outer two-layer structure, and most of the outer layer is made of a material excellent in weather resistance and tracking resistance, and on the outer layer surface side. A color band that enables identification of the wire core is disposed in part, and an insulator that can identify the wire core is disposed in the inner layer, so that the insulated wire has an unprocessed appearance and an inner layer when the insulator is processed. Since the core can be visually identified in any exposed state, the core core is recognizable significantly, making it possible to reliably identify and prevent identification errors. Conductors are exposed, connected, laid, or inspected. In addition to improving the various workability of the wire such as confirmation, the tracking resistance as the lead-in wire can be improved, and the discharge caused by the tracking phenomenon and the resulting carbonization of the insulator are unlikely to occur. I lost it almost extending from or cracks in the arc short-circuiting between the exposed conductor portion is enhanced reliability by reducing the risk of fire or accidental disconnection.

In addition, the low-voltage lead-in wire according to the present invention is such that the outer layer insulator has a thickness of a black or gray material portion positioned inside the color band portion of 0.1 mm or more as necessary. is there.
As described above, according to the present invention, the thickness of the black or gray material portion inside the color band portion is ensured, and sufficient weather resistance is ensured regardless of the presence of the color band portion. Even if the material is inferior in weather resistance, a black or gray outer layer is present at a sufficient thickness below the color band part, and even if the color band part deteriorates and disappears, As an insulator, weather resistance that can withstand long-term outdoor use can be secured, cracking due to deterioration is difficult to occur, and even when it is impossible to identify the core by color band, the insulator on the outer layer can be peeled off The color of the inner insulator can be confirmed, and the wire core can be properly identified to prevent connection errors.

Further, in the low-voltage lead-in wire according to the present invention, the inner layer insulator is formed of the same material having the same color as that of the color band portion, if necessary.
As described above, according to the present invention, the inner layer insulator has the same color and the same material as the color layer of the outer layer, so that the inner layer insulator has the same tracking resistance and flame resistance as the outer layer side. As a result, the tracking resistance and the like of the entire insulator can be improved, and the correspondence between the insulator of the inner layer and the color band portion becomes obvious at a glance, and the wire core can be properly identified without error. Furthermore, the electric wire manufacturing process can be simplified because only two types of constituent materials can be used for the insulator.

  In addition, the low-voltage lead-in wire according to the present invention is a low-voltage lead-in wire formed by twisting a plurality of insulated wires, and includes only one of all the insulated wires or a black or gray insulator around the conductor. The remaining insulated wires, except for, are provided with two layers of insulators consisting of an inner layer and an outer layer each made of a predetermined material around the conductor, and the outer layer insulator is black or gray and has excellent weather resistance and tracking resistance. The wire core identification mark that is distinguishable from the black or gray material color and is made different for each insulated wire is repeated in the longitudinal direction continuously or at predetermined intervals. The inner layer insulator has a predetermined color which corresponds to the mark in the outer layer insulator in a one-to-one relationship and is different from the inner layer insulators of other insulated wires.

  As described above, according to the present invention, the insulation of each insulated wire in the low-voltage lead-in wire has an inner and outer two-layer structure, the outer layer is made of a material excellent in weather resistance and tracking resistance, and a wire core is formed on the outer layer surface side. A mark that enables identification of the wire is arranged, and an insulator capable of identifying the wire core is arranged on the inner layer, and the wire core is either in the unprocessed appearance of the insulated wire or in the exposed state of the inner layer when processing the insulator. Can be identified visually, significantly improving the recognizability of the wire core, making it possible to ensure reliable identification without causing misidentification, and various workability for electric wires such as conductor exposure, phase confirmation during connection, installation or inspection. In addition, the tracking resistance as a lead-in wire can be improved, and the electric discharge caused by the tracking phenomenon and the resulting carbonization of the insulator are less likely to occur. Almost eliminated to lead to arcing short circuit between output portion is enhanced reliability by reducing the risk of fire or accidental disconnection.

Also, low pull-in wire according to the present invention, if necessary, the insulator of the outer layer, 30 to a metal hydroxide to 100 parts by weight of olefin or rubber-based resin in proportions of 150 parts by weight It is made of material.
As described above, according to the present invention, an olefin-based or rubber-based resin is used as an insulator, and a metal hydroxide is blended in an appropriate ratio to provide high insulation performance, thereby improving tracking resistance. It is possible to prevent the formation of a conductive path on the surface, and even if the insulator is flawed or cracked, the risk of arc discharge between the exposed portions of the conductor is low, and ignition and disconnection accidents are less likely to occur. Furthermore, even if the insulator is burnt, the crystal water of the metal hydroxide is ejected, exerting a fire extinguishing action that takes away the generated Joule heat and dissipates it to the surroundings, making the insulator difficult to burn, and ejecting crystal water It is possible to prevent the progress of the tracking phenomenon by suppressing the growth of the carbide that becomes the conductive path by blowing away the carbide with the momentum of the evaporation gas.

Also, low pull-in wire according to the present invention, if necessary, the insulator of the outer layer, 30 to a metal hydroxide to 100 parts by weight of olefin or rubber-based resin containing a high-density polyethylene 150 parts by weight It is formed with the material mix | blended in the ratio used as follows.
Thus, according to the present invention, an olefin-based resin containing high-density polyethylene is used as an insulator, and a metal hydroxide is blended in an appropriate ratio thereto, thereby providing high insulation performance and wear resistance. In addition to the improved tracking resistance, by making the insulator excellent in scratch resistance, it is difficult to cause scratches on the surface that tends to cause moisture and dust and tends to be the starting point of discharge. It is difficult for damage to reach the conductor, which is one of the factors leading to disconnection, and further improvement in safety and reliability can be achieved. Furthermore, even if the insulator is burned, the crystal water of the metal hydroxide is ejected and given a fire extinguishing action that takes away the generated Joule heat and dissipates it to the surroundings, making the insulator difficult to burn and the ejected crystal water It is possible to prevent the progress of the tracking phenomenon by suppressing the growth of the carbide that becomes the conductive path by blowing away the carbide with the momentum of the evaporation gas.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a sectional view of a low-voltage lead-in electric wire according to the present embodiment, and FIG. 2 is a schematic perspective view of the low-voltage lead-in electric wire according to the present embodiment.
In each of the drawings, the low-voltage lead-in electric wire 1 according to the present embodiment is formed by twisting three insulated electric wires 11, 12, and 13 having a circular cross-sectional shape having the same outer diameter. The insulated wire 11 is provided with only one insulator 15 around the conductor 14, while the other insulated wires 12 and 13 are provided with two inner and outer insulators around the conductor 14, and one of the outer insulators 16 and 17. This is a configuration in which the part and inner layer insulators 18 and 19 are of a predetermined color that can be discriminated.

The insulated wire 11 is provided with a single tracking insulator 15 made of black or gray mixed with carbon black or the like and having excellent weather resistance and tracking resistance around the conductor 14 and having general tracking resistance. The configuration is the same as that of the electric wire, and detailed description is omitted.
In addition, the insulated wire 12 is covered with an inner layer insulator 18 made of a material excellent in tracking resistance around the conductor 14, and the inner layer insulator 18 is also coated with an outer layer insulation made of a material similarly excellent in tracking resistance. The structure is covered with the body 16. Furthermore, the insulated wire 13 is covered with an inner layer insulator 19 made of a material having excellent tracking resistance and a color different from that of the inner layer insulator 18 around the conductor 14, and an outer layer insulator 17 is disposed on the outer side thereof. It is the composition which is done. In these insulated wires 12 and 13, if the outer layer insulators 16 and 17 have sufficient tracking resistance, the inner layer insulators 18 and 19 may not necessarily be made of a material having excellent tracking resistance. .

  The outer layer insulators 16 and 17 are provided with color core portions 16a and 17a for identifying the cores that have different colors for the respective insulated wires 12 and 13, and a predetermined thickness that is thinner than the thickness of the entire outer layer on a part of the surface. Now, one or a plurality of wires are continuously arranged in the longitudinal direction, and the remaining portion is formed of a weather resistant material portion 16b, 17b made of a black or gray material similar to the insulator 15 of the insulated wire. is there. The total thickness of the outer layer insulators 16 and 17 is 0.2 mm or more, and the thickness of the weather resistant material portions 16b and 17b in the portion located inside the color band portion in a state of overlapping with the color band portions 16a and 17a is as follows. 0.1 mm or more, and sufficient weather resistance can be ensured regardless of the presence or absence of the color band portions 16a and 17a. That is, the color band portions 16a and 17a are inferior in terms of weather resistance compared to the weather resistant material portions 16b and 17b, and may be deteriorated and lost from the insulator surface after long-term (several decades) outdoor use. However, since the weather resistant material portions 16b and 17b are present in a sufficient thickness inside the color band portions 16a and 17a, the weather resistance necessary for long-term outdoor use as the outer layer insulators 16 and 17 is ensured. It is a mechanism that can.

  The color band portions 16a and 17a and the weather resistant material portions 16b and 17b forming the outer layer insulators 16 and 17 are blended with a metal hydroxide in an olefin base resin containing high-density polyethylene excellent in wear resistance and scratch resistance. In addition to being less susceptible to scratches reaching the inner layer insulators 18 and 19 and the conductor 14, it is possible to reduce the factors leading to disconnection, and in addition, the tracking resistance is superior to the vinyl chloride resin provided in the olefin resin. The reliability is further improved by the nature. Since the outer layer insulators 16 and 17 are thermoplastic and non-crosslinked materials, they are recyclable and do not generate harmful gases even when incinerated. Since the heat-resistant temperature is higher than that of vinyl chloride resin, the allowable current can be increased and the wire size can be reduced.

The metal hydroxides blended in the outer layer insulators 16 and 17 are mainly magnesium hydroxide and aluminum hydroxide. When only one kind is blended, and when two or more kinds of metal hydroxides are blended together, There is. The total compounding ratio of the metal hydroxide is 30 to 150 parts by mass with respect to 100 parts by mass of the olefin base resin. When the blending ratio is less than 30 parts by mass , the flame retardancy and tracking resistance are lowered, and when it exceeds 150 parts by mass , the insulation performance and mechanical properties are degraded.

  Such metal hydroxide causes the moisture contained in the metal hydroxide to evaporate by diffusing the moisture contained in the metal hydroxide against the Joule heat generated by leakage current flowing through the moisture on the surface of the insulator 16 or the heat generated by local discharge. In addition, while being decomposed by discharge or heat, the carbides are dissipated by the gas generated at the same time, and the progress of the tracking phenomenon is suppressed. The metal hydroxide also has the effect of making the insulator 16 difficult to burn, supplements the properties of olefin-based resins such as polyethylene that are easy to burn, and is sufficiently flame retardant as an insulating material for low-voltage lead-in wires drawn into houses. Can be secured.

  In addition, when the thickness of the portion located inside the color band portions 16a and 17a among the weather resistant material portions 16b and 17b in the outer layer insulators 16 and 17 is 0.2 mm or more, sufficient weather resistance and tracking resistance are obtained. Therefore, the inner insulators 18 and 19 do not necessarily have to be made of a flame resistant material containing a metal hydroxide.

  The inner layer insulators 18 and 19 are formed of the same material having the same color as the color band portions 16 a and 17 a in the outer layer insulators 16 and 17, and have different colors for the insulated wires 12 and 13. Like the outer layer insulators 16 and 17, the inner layer insulators 18 and 19 are made of an olefin-based resin containing high-density polyethylene. The inner layer insulators 18 and 19 are hardly damaged by reaching the conductor 14, are not easily broken, and are flame resistant. Excellent tracking resistance. The colors of the inner layer insulators 18 and 19 are blue, green, brown, white, red, yellow, purple, peach, orange, beige and gray which are different from the weather resistant material portions 16b and 17b of the outer insulators 16 and 17. Etc. are adopted.

  Next, the tracking phenomenon suppression state of the low-voltage lead-in wire based on the above configuration will be described. In each of the insulated wires 11, 12, and 13 twisted together as the low-voltage lead-in wire 1, the surface insulator 15 and the outer layer insulators 16 and 17 have high tracking resistance, and the risk of causing an arc short circuit is extremely small. If dust containing moisture or salt adheres to or accumulates on the surface of the insulator 15 and the surface of the insulator 15 becomes wet or fouled, leakage current flows along the surfaces of the insulator 15 and the outer layer insulators 16 and 17. .

  When moisture partially evaporates due to the Joule heat generated by this current, when some surfaces of the insulator 15 and the outer layer insulators 16 and 17 are locally dried, the current path is interrupted to generate a discharge, and the heat accompanying this discharge However, when the heat is applied to the metal hydroxide contained in the insulator 15 and the outer layer insulators 16 and 17, the metal hydroxide crystals Water blows out, dissipates heat, dissipates to the surroundings, makes the insulator 15 and the outer layer insulators 16 and 17 difficult to burn, suppresses the formation of carbides, and blows off the carbides with the momentum of the evaporating gas of the crystal water to be blown out To prevent the tracking phenomenon from progressing by suppressing the growth of carbides that become conductive paths.

  On the other hand, the twisted low-voltage lead-in wire 1 requires identification of the wire core for phase confirmation in inspection work, work for exposing conductors during laying, connection, etc. By making the appearance different depending on the presence or absence of the color band portion and the color of each of the electric wires 11, 12, and 13, the wire core can be easily identified based on the difference and the work can be performed. Even when the outer layer insulators 16 and 17 including the color band portions 16a and 17a are processed, the inner layer insulators 18 and 19 that are color-coded for the insulated wires 12 and 13 are exposed, so that there is no problem. The mind can be identified.

  As described above, the low-voltage lead-in electric wire according to the present embodiment has a double-layer structure for the insulated wires 12 and 13, and most of the outer-layer insulators 16 and 17 have weather resistance and excellent tracking resistance. In addition to the material portions 16b and 17b, color belt portions 16a and 17a capable of identifying the wire core are disposed on a part of the outer layer surface side, and the inner layer having excellent tracking resistance while being able to identify the wire core. Since the insulators 18 and 19 are arranged and the wire cores can be visually identified in both the unprocessed appearance of the insulated wires 11, 12, and 13 and the inner layer exposed state when the insulators are processed, the core recognition is possible. Thus, it is possible to perform reliable identification that is unlikely to cause identification mistakes, and to improve various operability for electric wires such as exposure of conductors, phase confirmation during connection, installation, or inspection. In addition, the tracking resistance of the lead-in wire can be improved, and the discharge caused by the tracking phenomenon and the resulting carbonization of the insulator are unlikely to occur. There is almost no connection to an arc short circuit, reducing the risk of fire and disconnection accidents, and improving reliability.

  In the low-voltage lead-in electric wire according to the embodiment, the color cores are identified by providing the color belt portions 16a, 17a continuous in the longitudinal direction on the partial surfaces of the outer insulators 16, 17 in the insulated wires 12, 13. However, the configuration is not limited to this, and instead of the color band portion, each outer insulation is provided with a wire core identification mark having a different shape for each insulated wire corresponding to the difference in color of the inner insulator. It can also be configured to be continuously arranged in the longitudinal direction on the surface of the body or repeatedly arranged at a predetermined interval, and by distinguishing the mark on the surface of the insulated wire, the core can be visually identified as in the above embodiment. The recognizability of the wire can be remarkably improved, and it is possible to perform reliable identification that is difficult to cause identification mistakes, and various operability for the electric wire such as conductor exposure, phase confirmation during connection, installation, or inspection can be improved.

  Further, in the low-voltage lead-in wire according to the embodiment, the insulated wire 11 is configured to include only one layer of the insulator 15 made of black or gray material. However, the invention is not limited thereto, and the conductor 14 is made of black or gray material around the conductor 14. If only an insulator is provided, the same or different insulators made of black or gray material may be arranged around the conductor in a plurality of layers. In particular, the insulated wires 12 and 13 are only black or gray material. Similarly, when the two-layer structure is used, the same manufacturing equipment as that of the insulated wires 12 and 13 can be manufactured as it is by changing the insulator material, and the manufacturing cost can be reduced.

  In addition, the low-voltage lead-in wire according to the embodiment has a configuration in which the number of insulated wires twisted together is three. However, the present invention is not limited to this, and the required number of insulated wires is appropriately determined with different appearances. It can also be set as the structure used as a low-voltage lead-in electric wire by integrating several twists or predetermined number in parallel.

  Moreover, in the low voltage lead-in electric wire according to the embodiment, the outer layer insulators 16 and 17 are configured to use an olefin base resin containing high density polyethylene in order to impart wear resistance and scratch resistance. In addition to this, when used in an environment where it is not necessary to consider much wear resistance and scratch resistance, a configuration in which a high-density polyethylene is not necessarily included and an olefin-based or rubber-based resin is formed as a material, As in the above-described embodiment, the cost can be reduced while ensuring weather resistance and tracking resistance.

  Further, in the low-voltage lead-in electric wire according to the embodiment, the color strip portions 16a and 17a and the inner layer insulators 18 and 19 in the outer layer insulators 16 and 17 are the same color in the insulated wires 12 and 13, respectively, and the wire cores are arranged. Although it is configured to be easily identifiable, in addition to this, it is possible to identify by changing the number of color band parts appearing on the surface for each insulated wire while matching the color of the color band part for all insulated wires. If the color band portion and the inner layer insulator correspond to each other in a one-to-one correspondence and can be discriminated in both the unprocessed state of the insulator and the exposed state of the inner layer, the color band portion and the inner layer insulator are the same. It does not matter if the configuration is not colored.

  In the low voltage lead-in wire according to the embodiment, the inner layer insulators 18 and 19 are formed of the same material having the same color as the color band portions 16a and 17a in the outer layer insulators 16 and 17, respectively. The inner layer insulator and the color band portion are formed of different materials as long as the colors of the inner layer insulator and the color band portion are the same or very similar and can be identified for each insulated wire. It doesn't matter.

It is sectional drawing of the electric wire for low voltage | pressure lead which concerns on one Embodiment of this invention. It is a schematic perspective view of the low-voltage lead-in electric wire according to one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Low voltage lead-in wire 11, 12, 13 Insulated wire 14 Conductor 15 Insulator 16, 17 Outer layer insulator 16a, 17a Color belt part 16b, 17b Weatherproof material part 18, 19 Inner layer insulator

Claims (5)

In the low-voltage lead-in wire that is formed by twisting together multiple insulated wires,
All of the insulated wires, or the remaining insulated wires except for one having only a black or gray material insulator around the conductor, have two layers of insulators of inner and outer layers each made of a predetermined material around the conductor. Prepared
The outer layer insulator is provided with one or a plurality of longitudinally extending color strips having a color and / or arrangement different for each insulated wire and having a thickness smaller than the outer layer thickness on a part of the surface. While being arranged continuously in the direction, the remaining part is a weather resistant material part ,
The color band part and the weather resistant material part are both made of a material excellent in tracking resistance, and the weather resistant material part is black or gray different from the color band part and has excellent weather resistance. And
The thickness of the weather-resistant material part in the portion located inside the color band part in a state of overlapping with the color band part can ensure the weather resistance necessary for outdoor use even after the outdoor use period in which the color band part deteriorates has elapsed. Thickness and
The inner layer insulator has a color that is at least different from a portion other than the color band portion of the outer layer insulator, and has a predetermined color that is different from the inner layer insulator of other insulated wires. Low-voltage lead-in wire. In the low-voltage lead-in wire according to claim 1,
A low-voltage lead-in electric wire characterized in that the outer layer insulator has a thickness of a weather-resistant material portion positioned on the inner side of the color band portion of 0.1 mm or more. In the low-voltage lead-in electric wire according to claim 1 or 2,
The low-voltage lead-in electric wire, wherein the inner layer insulator is formed of the same material having the same color as the color band portion. In the low-voltage lead-in wire according to any one of claims 1 to 3,
The outer layer insulator is formed of a material in which 100 parts by mass of an olefin-based or rubber-based base resin is blended in a proportion of 30 to 150 parts by mass of a metal hydroxide . In the low-voltage lead-in wire according to any one of claims 1 to 3 ,
The outer layer insulator is formed of a material in which a metal hydroxide is mixed in an amount of 30 to 150 parts by mass with 100 parts by mass of an olefin-based or rubber-based base resin containing high-density polyethylene. Low-voltage lead-in wire.

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