JPH0544789Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is a water-injection charging deterioration method in which electricity is applied to a power cable made of plastic or rubber insulation, etc., with water injected into the wire core, and the state of deterioration of the cable is investigated. This relates to the test terminal section.

[Prior Art] Conventionally, as a test method to examine the deterioration characteristics of plastic or rubber-insulated power cables when water gets into them from the terminals, etc., a wire core of an appropriate length is immersed in a water tank, excluding both ends. Water injection deterioration tests have been carried out in which the deterioration state of cables is investigated by applying a current between the conductor and the ground while injecting water into the wire core from the terminal section.

For this purpose, it is necessary to form an end portion at the wire core end portion that facilitates water injection into the wire core and allows confirmation that the inside of the wire core is constantly flooded.For example, as shown in FIG. A terminal portion like this was formed.

That is, the insulator at the end of the wire core 10 is stripped off to expose the conductor 11, and the lead wire 1 is attached to the end of the conductor 11.
2, attach the cable insertion part 21 to the end 14 of the insulator 13 with the rain cover 20 in the opposite direction,
A sealing portion 30 for fixing the insertion portion 21 to the end portion 14 of the insulator 13 and making it watertight is formed using self-fusing tape 31, vinyl insulation tape 32, or the like. When injecting water into the wire core 10, the end portion of the wire core 10 is held vertically, and after water is injected into the rain cover, a voltage is applied to the lead wire 12. Water infiltrates into the wire core through the gap between the conductor and the insulator and the gap between the strands of the stranded conductor 11.

[Problems to be solved by the invention] By the way, in the above-mentioned terminal section for water injection charging deterioration testing, the water stored in the water injection device evaporates quickly, especially when water immersion charging is carried out at high temperatures (e.g. 80°C). When doing this, there was a problem in that electricity supply had to be stopped constantly and water had to be replenished.

This invention solves the above-mentioned problems, and makes it easier to use power cables with plastic or rubber insulation.
The purpose is to provide a terminal section for water injection charging deterioration testing that requires less frequent water injection.

[Means for Solving the Problems] In order to achieve the above-mentioned purpose, this invention installs a water injection tool made of an insulating material from its insertion part into the end of the power cable core with the terminal conductor exposed. Insert,
In the terminal part for a water injection charging deterioration test of a power cable, which is formed by fitting and sealing the insertion part to an end of an insulator, the water injection tool has an insertion part, a water storage part, a lid part, and a water injection part connected together. The insertion part has an inner diameter approximately equal to the outer diameter of the insulator of the power cable core, and the water storage part has a bottom part connected to the insertion part and a body part with a wide cross section. The other end of the lid connected to the water injection part, which is the boundary with the water injection part, has a water injection hole that doubles as a lead wire insertion hole and has a narrower cross section than the body to the extent that the charging lead wire can be inserted therethrough. , the water injection part has a wider cross section from the water injection hole toward the opening end, and at least the body of the water storage part is formed of a transparent material or a translucent material. It is.

Furthermore, instead of the water injection hole that also serves as a lead wire insertion hole at the boundary between the lid and the water injection part, a lead wire insertion hole may be provided separately from the water injection hole.

[Function] Most of the evaporated water in the water injection charging deterioration test terminal section of the power cable configured as described above hits the upper lid section, is cooled down, becomes water droplets, and returns to the water storage section in the water injection device. Therefore, the rate of water loss due to evaporation is much slower than in conventional systems, and the frequency of water injection can be significantly reduced.

Moreover, the water injection part has a wide opening, making it easy to inject water.Furthermore, in the case of outdoor tests, natural rainwater flows in, so water is replenished under conditions closer to natural conditions, and artificial water injection is avoided. When the need for will become less and less.

Furthermore, at least the body of the water storage section is made of a transparent or semi-transparent material so that the remaining amount of water can be seen through it, making it easy to check the remaining amount.

In addition, in the above-mentioned water injection device for the terminal portion of the power cable water injection charging deterioration test, it is preferable that the insertion portion and the water storage portion are formed integrally for watertight reasons. The water injection part may be a main body and a lid part, a lid part and a water injection part, or each may be provided separately so that they can be attached and detached.

[Embodiment] FIG. 1 is a longitudinal sectional view showing a first embodiment of this invention. 10 is a wire core of a cross-linked polyethylene insulated cable, 11 is a conductor exposed by stripping off the insulation at the end, 12 is a lead wire for charging attached to the conductor, 13 is an insulator, and 14 is an insulator. It is the end of the body. 20 is a water injection device made of transparent or translucent polyethylene. Reference numeral 21 denotes an insertion portion of a water injection tool inserted into the end portion 14 of the insulator 13, and has an inner diameter approximately equal to the outer diameter of the insulator. Reference numeral 22 denotes a water storage portion of the water injection device, 23 a lid portion, 24 a water injection portion, and 25 a boundary portion between the lid portion and the water injection portion, forming a water injection hole that also serves as a lead wire insertion hole.

Further, 30 fixes the water injection tool 20 to the wire core 10,
Insulator 13 of wire core 10 and insertion part 21 of water injection tool 20
This is a sealing part for sealing the interface with the holder, and is finished by wrapping a self-fusing tape 31 and then wrapping a vinyl tape 32.

FIG. 2 is a longitudinal sectional view showing the second embodiment. The difference from the first embodiment is that a water injection hole 26, which is the boundary between the lid part 23 and the water injection part 24, is provided near the edge of the lid part, and separately, a lead wire insertion hole 27 is provided in the center of the lid part. The rest of the structure is the same as that of the first embodiment, and is shown using the same symbols as in FIG.

Compared to the first embodiment, the lead wire insertion hole 27
Water vapor leakage will increase slightly due to the additional installation, but water injection will be much easier.

[Effects] As described above, in the power cable water injection charging deterioration test terminal of this invention, most of the injected water hits the upper lid and is cooled down, becoming water droplets and flowing into the water reservoir of the water injection device. Since the water is refluxed, the rate of water loss due to evaporation is much slower than in conventional systems, making it possible to significantly reduce the frequency of water injection.

Moreover, the water injection part has a wide opening, making it easy to inject water.Furthermore, in the case of outdoor tests, natural rainwater flows in, so water is replenished under conditions closer to natural conditions, and artificial water injection is avoided. There is almost no need for this, and it has the effect of greatly saving labor.

Furthermore, since at least the body of the water storage section is formed using a transparent or semi-transparent material, the remaining amount of water can be seen through, making it easy to predict when water will need to be poured.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional views of an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view of a conventional example. 10...Cable core, 11...Conductor, 12
... Lead wire, 13 ... Insulator, 20 ... Water injection tool, 23 ... Lid of water injection tool, 24 ... Water injection part of water injection tool, 25 ... Water injection hole that also serves as lead wire insertion hole
26...Water injection hole, 27...Lead wire insertion hole, 30
...Sealing part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Insert a water injection tool made of an insulating material from its insertion part into the end of the power cable core with the terminal conductor exposed, and insert the insertion part into the end of the insulator. In the terminal part for water injection charging deterioration test of a power cable which is fitted and sealed in The water storage part has an inner diameter approximately equal to the outer diameter of the insulator of the power cable core, and the water storage part has a bottom part connected to the insertion part and a body part with a wide cross section, and a lid part connected to the body part. The other end, which is the boundary with the water injection part, is formed with a water injection hole that also serves as a lead wire insertion hole and has a narrower cross section than the body part, to the extent that the charging lead wire can be inserted therethrough. For a water injection electrification deterioration test of a power cable, the cross section is wider from the water injection hole toward the open end, and at least the body of the water storage portion is formed of a transparent or semitransparent material. Terminal section. (2) Insert a water injection tool made of an insulating material through its insertion part into the end of the power cable core with the terminal conductor exposed, and fit and seal the insertion part to the end of the insulator. In the terminal section for water injection charging deterioration test of a power cable, the water injection tool is composed of a hollow body in which an insertion section, a water storage section, a lid section, and a water injection section are arranged in series, and the insertion section is arranged outside the insulator of the power cable core. The water storage part has a bottom part connected to the insertion part and a body part with a wide cross section, and the lid part connected to the body part has an inner diameter approximately equal to the water injection part. The water injection part has a water injection hole whose cross section is narrower than the body, and an insertion hole for the charging lead wire, and the water injection part has a wider cross section from the water injection hole toward the opening end, and at least the water storage part has a cross section that is narrower than the body. 1. A terminal section for a water injection charging deterioration test of a power cable, characterized in that a body section of the section is formed of a transparent material or a translucent material.