JPH05199636A - Arrester for distribution line - Google Patents

Abstract

PURPOSE:To suppress potential rise and to protect distribution facility against dielectric breakdown. CONSTITUTION:In a distribution line where an overhead earth-wire is stretched on the top of a pole 1, the overhead earth-wire 2 is stretched while being insulated electrically from the pole 1 and a pair of arrester conductors 3, each having upper end electrically connected with the overhead earth-wire 2 and a grounded lower end for passing the lightning current from the overhead earth-wire 2 to the ground, are laid in parallel with the pole 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning protection device for a distribution line, and more particularly to a lightning protection device which allows a lightning current flowing into an overhead ground wire of a distribution line to efficiently flow into the ground through a lightning conductor. ..

[0002]

2. Description of the Related Art A distribution line has a low insulation level and a lightning surge withstand voltage of about 100 kV. Therefore, mainly the induced lightning is dealt with by installing an overhead ground wire, a lightning arrester, a lightning protection PC and the like. However, as for the direct strike lightning, the lightning surge voltage is as large as about 300 kV, so that it is difficult to prevent the power failure of the distribution line and the insulation breakdown of the equipment due to the direct strike. For this reason, in areas where frequent lightning strikes occur, the burden of securing spare parts for restoration and arranging workers becomes excessive, which hinders the execution of normal operations.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and it is an object of the present invention to suppress an increase in the potential of a distribution pole and to protect distribution equipment from dielectric breakdown.

[0004]

A lightning protection device for a distribution line is provided in a distribution line having an overhead ground wire 2 installed on the top of a distribution pole, and the overhead ground wire 2 is electrically insulated from the distribution pole 1. And the upper end is electrically connected to the overhead ground wire and the lower end is grounded to allow the lightning current flowing into the overhead ground wire 2 to flow to the ground.
Were arranged in parallel along the distribution pole 1.

[0005]

According to the lightning protection device for the distribution line having the above structure,
The lightning current flowing into the overhead ground wire of the distribution line is passed through the lightning conductor 3 to the ground. Therefore, the potential increase of the distribution pole 1 due to the lightning current is suppressed, and the insulation breakdown of the distribution equipment is prevented.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a front view of a lightning protection device for a distribution line according to an embodiment of the present invention. The lightning protection device is mainly composed of a distribution pole 1, an overhead ground wire 2 and a lightning conductor 3.

The power distribution pole 1 is a pole-type power pole, and has an upper arm 4 on its top and a lower arm 4'on its lower part. The upper arm 4 is made up of an overhead ground wire support metal fitting 4a and a pair of lightning conductor lowering arms 4b, which are integrated into a band to distribute the power pole 1
Installed on. The lower arm 4'has a pair of turnbuckles 4b 'for tensioning the lightning conductor 3. Further, a spring 9 is incorporated in the turnbuckle 4b 'to absorb tension fluctuations and vibrations of the lightning wire 3 and prevent loosening.

The overhead ground wire 2 is a bare wire installed on the top of the power distribution pole 1, and generally, a galvanized steel stranded wire or a single copper wire is used. The overhead ground wire 2 is an overhead ground wire fitting of the upper arm 4
It is drawn through a pin insulator 5 fixed to 4a, and the overhead ground wire 2 is erected by the pin insulator 5 in a state of being electrically insulated from the distribution pole 1 and the upper arm 4.

The lightning conductor 3 is a covered wire whose upper end is mechanically and electrically connected to the overhead ground wire 2 by a branch sleeve 7 and whose lower end is grounded. A hard copper stranded wire is used. Preferably. The branch sleeve 7 is connected to the overhead ground wire 2
Is a galvanized steel stranded wire, lightning conductor wire (hard copper stranded wire;
Since it is a different metal from Cu), it is necessary to prevent the electrolytic corrosion of the connection part. In the present embodiment, an H-shaped compression branch sleeve as shown in FIG. 4 is used as a device capable of coping with this, but the branch sleeve may be of C type.

The upper end portion of the lightning conductor 3 is connected by the branch sleeve 7 as described above, and the lightning lead wire 3 is drawn through the pin insulator 5 (see FIG. 2 for details) fixed to the end portion of the upper arm member 4. There is. Then, the armor 4b for pulling down the lightning conductor is attached to the tension insulator 6
(Refer to FIG. 3 for details) and is retained by the retention clamp 8 attached thereto. Subsequently, the lightning conductor 3 is arranged in parallel with the distribution pole 1 from the detention clamp 8 and is retained by the detention clamp 8'which is attached to the lower arm 4'through the tensile insulator 6 '. ..

The detention clamps 8 and 8'have a structure in which a wedge having teeth that bite through the covering material of the lightning conductor 3 to cut into the conductor is incorporated (FIG. 5), and the covering is not peeled off only by tightening the bolt. It is designed to be held in. Therefore, no special tools are required, and no waterproof / insulation treatment is required.
Also, when the tension increases, there is no worry of slipping because the biting force increases due to the effect of the wedge. Furthermore, since the wedge and the clamp body are insulated, electric shock due to induction etc. is prevented, and since the tooth part of the wedge is covered with a waterproof compound, rainwater may enter the wire coating. Absent. If, after mounting the clamp, an insulating cover that also serves as a waterproof is used together, these effects are further improved.

The tension of the lightning conductor 3 is set to a tension of about 100 kgf by the turnbuckle 4b 'in order to prevent shaking and vibration due to the wind, and the tension fluctuation is prevented by the spring 9.
Further, in order to secure an insulation separation from the power distribution pole 1 and the power line supporting arm, the distance between the lightning conductor 3 and the power distribution pole 1 is set to about 30 cm. For this reason, it is not necessary to install a supporting device for steadying between the detention clamps 8 and 8 ', so that there will be no obstacles when the lightning conductor 3 is used as a lifting safety device, as will be described later. become.

[0013]

The upper end is electrically connected to the overhead ground wire 2,
Since the pair of lightning conductors 3 whose lower ends are grounded are arranged in parallel along the power distribution pole 1, the lightning current flowing into the overhead ground wire 2 efficiently flows into the ground through the lightning conductor 3. Therefore, the potential rise of the power distribution pole 1 is reduced, power failure due to lightning can be suppressed, the power distribution equipment can be protected from dielectric breakdown, and the reliability of power supply can be greatly improved.

Further, since the pair of lightning conductors 3 are arranged in parallel along the power distribution pole 1, the lightning conductors can be used as guides for the lifting safety device at the time of work, so that installation of a separate lifting safety device is omitted. can do.

[Brief description of drawings]

FIG. 1 is a front view of a lightning protection device for a distribution line according to an embodiment of the present invention.

FIG. 2 is a front view of a pin insulator.

FIG. 3 is a front view of a tension insulator.

FIG. 4A is a front view of an H-shaped compression branch sleeve, and FIG. 4B is a side view of the same.

FIG. 5 (a) is a front view of the tension clamp, and FIG. 5 (b) is an X of (a).
-X sectional view, (c) is also a plan view.

[Explanation of symbols]

1 distribution pole 2 overhead ground wire 3 lightning conductor wire 4 upper arm 4a overhead ground wire support metal fitting 4b armor for pulling down lightning conductor 4'lower arm 4b 'turnbuckle 5 pin insulator 6, 6'strength insulator 7 branch pick -Bus 8,8 'Straining clamp 9 Spring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Yamauchi 2-242 Fukuike, Tenpaku-ku, Nagoya, Aichi (72) Inventor Takaho Iida 943, Hongo, Fukuju-cho, Hashima-shi, Gifu Prefecture (72) Hideaki Kikuchi, Kanagawa Prefecture Asahi Denki Co., Ltd. 475 Hisamoto, Takatsu-ku, Kawasaki City

Claims (1)

[Claims] 1. An overhead ground wire installed on the top of a distribution pole (1)
In the power distribution line having (2), the overhead ground wire (2) is installed while being electrically insulated from the power distribution pole (1), and the upper end is electrically connected to the overhead ground wire (2). Then, a pair of lightning conductors (3) for grounding the lower end and flowing the lightning current flowing into the overhead ground wire (2) to the ground are arranged in parallel along the distribution pole (1). Lightning protection device for distribution lines.