JPS61273808A - Conductor anticorrosion type power cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to the improvement of conductor corrosion-resistant type cables, which are installed outdoors overhead, among resin-coated pipe cables.

[Prior art] This type of resin-coated outdoor overhead power cable has been used in large quantities. However, in recent years, when rainwater, etc. enters the conductor from the terminal connection, etc., corrosion of the conductor occurs, and due to the interaction between this corrosion and the stress applied to the conductor, the conductor may break and the entire cable may become disconnected. It has become clear.

In order to improve this point, we use so-called watertight wires in which the entire conductor is filled with a watertight compound to prevent rainwater from entering through the terminal connections.

Some types of conductors with improved corrosion resistance compared to conventional types have already been put into practical use. Figure 2 shows a cross-sectional view of an example of a watertight electric wire. In the figure, the conductor is made of stranded wires,
1 indicates the center strand, 2 indicates the first layer of strands twisted on the center strand 1, 3 indicates the second layer, and 4 indicates the strand. Indicates l,
5 is a watertight compound, which is filled inside and outside the conductor in the insulating layer 5.

On the other hand, a cable has been proposed in which a corrosion inhibitor is mixed in a single-layer resin, and when rainwater or the like enters, the corrosion inhibitor is eluted from the resin, thereby preventing corrosion of the conductor.

[Problem to be solved] However, when using the above-mentioned water wire, if the cable is struck by lightning, it will melt if it is a normal conductor.
In contrast, water-tight wires contain water-tight compounds, and cables break instantly.
Heat capacity...54. , is large and may not melt instantly, causing the cable to break unexpectedly at a later date, which poses a safety problem.

In addition, when a corrosion inhibitor is mixed into the resin of the insulating layer, when water enters the conductor, the corrosion inhibitor will dissolve into the water and exert a corrosion-preventing effect on the conductor, but the same effect will be applied to the outside. Corrosion inhibitors are released, especially in overhead cables used outdoors, due to exposure to rain.
Before water seeps into the conductor, most of the corrosion inhibitor is released to the outside, creating a risk of pollution problems and reducing the corrosion protection performance of the conductor when water seeps into the conductor afterwards. There are dangers such as: Furthermore, depending on the type and amount of corrosion inhibitor, it may affect the electrical performance of the cable itself.

1 [Object of the invention] The present invention improves these points and improves 1 safety 1 long term 7 points 5 15.1. The object of the present invention is to provide a conductor corrosion-resistant carved cable with improved reliability of corrosion-proof performance during overhead line installation.

[Means to solve the problem] *E46. -Oh. -0°. , 9.6-ゎ ; The feature is that a corrosion-preventing resin is provided on the central strand forming the conductor and the first layer of strands or one of the strands.
"The detailed explanation of the present invention is shown in FIG. 1.
2. Some parts are indicated by the same reference numerals.

A resin layer 5 containing a corrosion inhibitor is formed between the central strand 1 of the copper conductor made of stranded wires and the first layer 2 of the strands immediately above the strand 1 . A second layer 3 of strands is formed on the outer periphery of the first layer 2 of strands, and an insulating layer 11 is formed on the outer periphery by resin extrusion.
is formed.

As the copper corrosion inhibitor used in the present invention, various commercially available corrosion inhibitors including benzotriazole or modified products thereof can be used.

As the resin component, commercially available general-purpose resins such as polyethylene, ethylene vinyl acetate copolymer (EVA resin), ethylene ethyl acrylate copolymer (EEA resin), and ethylene propylene rubber can be used.

Furthermore, the resin composition containing a corrosion inhibitor may also contain an antioxidant, a lubricant, a filler, etc., or may be blended with carbon black to impart electrical conductivity, if necessary. Further, in order to prevent discoloration of the conductor in the initial stage, a corrosion inhibitor may be separately applied to the conductor.

Examples will be described below.

[Example: A water-soluble pencil was placed on a copper wire with an outer diameter of 2 mm.
EVA resin containing 2% Riazole is extruded and coated to a thickness of 0.4 mm to form the center line of the conductor, and on top of that, six copper wires with an outer diameter of 2 mm are placed in the first layer and the second layer! Two wires were stranded one after another, a 0.3% benzotriazole trichloride solution was added dropwise to the whole, and the strands were dried to obtain a copper stranded wire conductor of "Goms".

A polyethylene insulating layer with a thickness of 25 mm was extruded on this conductor to obtain a 6 kV, 80 m5" OE cable. This cable was used at the same time as a normal 8 kV, GO-■8 OE cable in the equipment shown in Figure 3. The following corrosion test was conducted using

That is, the length 1 of the sample cable S in FIG. 3 is 30 cm, and with both ends cut, I 00 in the test container
Immerse PP- in NHsOH, keep the container tightly closed, equip with a syringe needle I for air removal, and incubate at room temperature.
Time, one day heat cycle of 8 hours at 60°C, stage surface A as shown: 1 day at 20 cm, stage B: lOc
This is an accelerated corrosion test conducted for 1, 2, 4, and 8 weeks each using a 6-day completion cycle.

As a result, black corrosion was observed on the conductor surface of the ordinary OE cable after one week, but no corrosion was observed on the conductor surface of the OE cable according to the present invention until four days later, and very slight corrosion was observed after eight weeks. Only slight corrosion was observed.

As is clear from the examples described above, it has become clear that the conductor corrosion-resistant cable according to the present invention can provide a good conductor corrosion prevention effect.

Furthermore, it shows good results in terms of fusing characteristics during lightning strikes and long-term corrosion prevention effects for the reasons mentioned above.

The above description has been made of a case in which a resin containing a water-soluble copper corrosion inhibitor is formed on the center strand of a conductor, but for example, when copper strands are twisted in multiple layers on the center strand of a conductor. , the number of wire layers is n+IF! I (where n = 1 +
2 +3 ・), a similar corrosion-preventing effect is produced even if a resin layer containing a water-soluble copper corrosion inhibitor, for example, made of EVA, is provided on the n-th layer, but the corrosion inhibitor is not applied to the outside. Considering the elution of the resin layer, the more the resin layer is provided on the outer layer, the larger the amount is required, so there is a concern that the fusing characteristics will deteriorate.

Therefore, it is desirable that the resin layer is provided at the center wire or between inner layers close to the center wire.

[Effect] As explained above, in the present invention, a water-soluble corrosion inhibitor is contained between the center strand of the stranded wire constituting the conductor and the first layer of strands, or one of the layers of strands. A resin layer is provided,
The amount of this resin layer is smaller than the watertight compound that is filled into watertight electrical wires.

Because of this, the increase in heat capacity of the cable is small, and the effect on the fusing characteristics during lightning strikes is minimal.

Furthermore, since the resin containing the corrosion inhibitor is present inside the conductor, there is no risk of the corrosion inhibitor being extracted by rain or the like even during long-term overhead lines, and the conductor exhibits a corrosion-preventing effect.

[Brief explanation of the drawing]

FIG. 1 shows a cable according to the invention in cross section. FIG. 2 shows a conventional watertight cable in cross section. FIG. 3 is an explanatory diagram of the test container. DESCRIPTION OF SYMBOLS 1... Center strand, 2... 1st layer of strands, 3... 2nd layer of strands, 4... Insulating layer, 5... Watertight compound.

Claims (1)

[Claims] (1) A resin layer containing a water-soluble copper corrosion inhibitor is provided between the central strand of a copper conductor made of stranded wire and the first layer of strands directly above the strand, or between any arbitrary strand layers; A conductor corrosion-resistant power cable characterized in that an insulating layer is provided on the copper conductor.