JPH036112Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a structure in which a cable installed in a tunnel is subjected to moisture-proofing treatment at the floor-penetrating portion of the cable on its route to a substation, power receiving station, or the like.

[Conventional technology]

In the part where the cable laid in the tunnel rises toward the substation or power receiving station, the humidity inside the tunnel is extremely high, and the route leading from the part where the cable rises to the substation acts like a chimney. The humid air in the tunnel is sucked in and condenses on the cable terminal, causing dust particles to adhere to the cable terminal, causing creeping discharge from the cable terminal to the cable bracket or cable penetration, which is an unfavorable condition for preventing electric shock and maintaining equipment. be.

For this reason, some kind of moisture-proofing treatment has conventionally been applied to cable through holes, and one example of this is as shown in FIG.
A cable insertion hole 32 is bored in the cable insertion hole 32, the Bakelite plate is divided around the cable insertion hole 32, and the cable 2 is sandwiched between the Bakelite plates 31 to support the cable 2 and cover the through hole 34.

[Problem that the invention attempts to solve]

In the above structure, a gap remains between the cable insertion hole 32, the abutting part between the cable end part 35 and the sleeve of the end part 25, and the abutting part of the divided Bakelite plate 31. As the size increases, moisture inside the tunnel rises through the gap, which condenses on the cable terminal 35 or the live part due to the drop in outside air, and dust particles adhere to this, deteriorating the insulation condition and causing folds to form from the live part. Moisture passes through the surface of the mantle and is discharged to the ground through the Bakelite abutment part with dust particles attached.

[Purpose of invention]

In view of the above points, this idea was developed to prevent moist air from rising inside the tunnel, in other words, to prevent condensation on the power receiving room (substation room) side. ) to prevent creepage discharge from the live parts of the cable terminals from occurring, and to improve maintenance and safety.

[Means to achieve the purpose]

In order to achieve the above object, in this invention, in the moisture-proof structure of the part where the cable laid in the tunnel rises to a substation or power receiving station, there is a A bowl-shaped cover that airtightly covers the opening is attached, a cable passes through the cover airtightly from the tunnel, a terminal portion is provided at the end thereof, and this terminal portion or the cable is connected to the peripheral partition wall of the through hole via a support. This is what I supported.

[Effect]

In the moisture-proof structure configured in this way, the cover completely prevents moist air from rising inside the tunnel and entering the substation room (power receiving room), so dew condensation does not form on the cable terminals. Moreover, since the cover is bowl-shaped, the creeping surface from the cable terminal to the floor becomes long, and creeping discharge from the live part of the cable terminal to the floor (earth) does not occur.

In addition, since the terminal section or cable is supported by the bulkhead, even if an external force is applied to the cable from the substation side, which is the terminal section side, that force is blocked by the bulkhead via the support and transmitted to the cover. Never.

〔Example〕

Embodiments of this invention will be described below with reference to the accompanying drawings FIGS. 1 to 4.

As shown in FIGS. 1 and 2, a cable 2 rising from a tunnel 1 reaches a substation 4 through a cable through hole 3 in a floor A that serves as a partition wall. Cable 2 has
A terminal portion 5 is provided at the exit of the cable through hole 3, and the cable 2 is held by a bracket 6 attached to a channel C provided in the cable through hole 3, as shown in FIG. Note that the cable 2 is branched into each phase before passing through the cable through hole 3.

The cover 12 covering the cable through hole 3 has a bowl shape as shown in FIGS.
It has a flange 9 that abuts on the periphery and can be divided into two in the horizontal direction, and a notch S is provided from the central cable insertion hole 11 to the left and right cable insertion holes 11', and the divided portion t and the notch are provided. A member 12a, 1 is provided with opposing flanges 10 in the portion S.
2b from the left and right sides of the rising cable cores 2a, 2b, 2c, tighten the ribs 13 of the cable insertion holes 11, 11' with the tightening rings R, and divide the member 1 into two.
2a and 12b are combined by tightening screws and nuts through the presser plate 14 into screw holes drilled at appropriate locations in the flange 10, and the flange 10 at the notch S is similarly tightened with screws and nuts, with the top open. It is.

The members 12a and 12b of the cover 12 are made of synthetic resin and manufactured by various methods such as taping method and molding method, and since they are flexible and can be easily deformed, cable cores 2a, 2b, 2c, etc. The insertion work is easy.

Further, if the presser plate 14 is made of a hard insulating material such as a hard vinyl chloride plate, and packing is used when the collar 10 is tightened, the air shielding properties will be improved.

The cover 12 is airtightly attached to the periphery of the through hole 3 by screwing the channels C and C', which are fitted onto the periphery of the through hole 3 and fixed with bolts through a packing 18 at the bottom, through a presser plate 19. It will be done. Channel C also serves as support for terminal section 5.

As described above, a mounting method that does not require work such as welding or drilling, and does not use a welder, electric drill, etc., is effective during live wire work. However, if the work is not a live wire work, the cover 12 may be screwed directly to the floor A via the holding plate 19.

Further, as shown in FIG. 4, if the floor A is composed of a striped plate given by the channel C, and the through hole 3 is formed by hollowing it out, the channel C
The auxiliary channel _C1 may be screwed to the auxiliary channel C1, and then the cover 12 may be attached in the same manner as described above. Further, as shown in the figure, when there are two cables 2 and six cable cores, the cover 12 may be divided as appropriate and the divided surfaces may be similarly secured with screws via a holding plate.

The above-mentioned cover 12 is installed through the insertion holes 11 and 1.
This is done after the cable cores 2a, 2b, 2c are inserted through the cable cores 1', 11', and the holding plate 14 may be tightened either before or after the cover is attached.

The moisture-proof structure configured as described above is based on the cover 12.
This completely prevents moisture from rising from the tunnel, keeps the area above the cover 12 dry, prevents condensation from forming on the cable terminal, and prevents dust from adhering to the cable terminal. Coupled with the longer creeping surface from the live part to the floor (earth), creeping discharge is less likely to occur.

Incidentally, even if the cover 12 is attached to the conventional example shown in FIG. 5, the structure of the present invention can be obtained, and its functions and effects can be obtained.

[Comparative example]

In order to confirm the effect of this invention, 22KV400mm ²
When a 3-core twisted cross-linked polyethylene cable was laid as shown in Figures 1 and 5, and the rated voltage was applied with the inside of the tunnel in a superhumidified state, the cable of the present invention shown in Figure 1 showed creeping discharge and terminal part. No dew condensation was observed, but dew condensation and creeping discharge were observed in the prior art device shown in FIG.

〔effect〕

As explained above, according to the present invention, the moisture-proof cover can completely stop moisture, and the cable terminals and the floor can be kept dry.
Creeping discharge is less likely to occur, and the maintenance and security of installed cables and substations (power receiving stations) can be ensured.

Furthermore, since the cable or its terminal portion is supported by the partition wall, the cover is not damaged and the above effects can be obtained for many years.

Further, since the cover is shaped like a bowl, there is an advantage that the end portion inside the through hole can be avoided.

[Brief explanation of the drawing]

Fig. 1 is a cutaway front view of one embodiment of the moisture-proof structure of this invention, Fig. 2 is a left cut side view of Fig. 1, Fig. 3 is a bottom view of the cover of Fig. FIG. 5 is a cutaway side view of the embodiment, and FIG. 5 is a cutaway front view of the conventional example. 2...Cable, 2a, 2b, 2c...Cable core, 3...Cable through hole, 5...Terminal part, 9
...Tsuba, 11, 11'...Cable insertion hole, 12
...cover, S...notch, A...floor.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a moisture-proof structure for the part where a cable laid in a tunnel rises from a substation or power receiving station, the opening is airtightly covered around the periphery of a through-hole in a bulkhead at the rising part. A bowl-shaped cover is attached, a cable passes through the cover airtight from the tunnel, a terminal part is provided at the end thereof, and this terminal part or the cable is supported on the peripheral partition wall of the through hole via a support. Features a moisture-proof structure for the cable rising section. (2) The moisture-proof structure for a cable rising portion according to claim 1, wherein the cover is made of flexible synthetic resin.