JPS58145082A - Arrester ground-fault preventing unit - 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 The present invention relates to a lightning arrester earth fault preventer. For more details,
This device relates to a device that cuts off a ground fault circuit from the lightning arrester and at the same time displays that the lightning arrester is out of order in order to avoid accidents such as power outage due to the leakage when the lightning arrester breaks down due to some circumstances and leakage current occurs.

In order to prevent damage to distribution lines, distribution equipment, etc. due to lightning strikes or abnormal surges, lightning arresters are usually installed in distribution systems. However, if the arrester is damaged by lightning that exceeds its withstanding capacity or deteriorates due to wind and rain, current may leak from the arrester and cause a ground fault, causing an accident such as a power outage. In order to prevent such accidents, it is desirable to equip the lightning arrester with a device that interrupts the ground fault circuit of the arrester when a ground fault current occurs.

In Japan, the ungrounded type is normally used as a high-voltage distribution line system. The ground fault current flowing in this method's ¥M, 1s path is extremely small (approximately 100 m) compared to the grounding method.
A to 15 A), and for this reason, many conventional lightning arresters and ground fault preventers, which can also be applied to non-grounded types, use an operating system that utilizes the explosive energy of explosives.

Its structure and operating principle will be briefly explained with reference to FIGS. 1 and 2.

A lightning arrester side terminal (8) is attached to the center of the upper surface of the inorganic insulation mantle (8), and 7 langes (8a) are provided below the terminal (8).
A capsule medicine cylinder (7&) is loaded inside a cylindrical resistor (5) electrically connected to the cylindrical resistor (5), and the upper surface of the capsule medicine cylinder (7&) is connected to the 7 flange (8a) with a resistance gap (6). It is configured to form parallel to the body.

The lower part of the capsule medicine m (7&) containing the gunpowder (7) is sealed by a plug (7b), and the lower end of the plug (7b) is connected to the ground side, which is provided so as to penetrate through the center of the bottom of the insulating cover (4). The insulating cover (4) is connected to the terminal (9) and is fitted under the inorganic insulating jacket (8).

While the lightning arrester (1) is operating normally, the resistor (5)
Since the resistance value of is high, no current flows through the resistor (5), and the lightning current flows through the discharge gap (
6) The lightning arrester and ground fault preventer will not operate due to discharge between the two. When an abnormality occurs in the lightning arrester, a leakage current flows through the resistor (5) and the resistor generates heat, which causes the internal pressure of the capsule to rise rapidly, causing the insulating jacket (8) to detach and disconnecting the arrester circuit. It indicates an abnormality in the lightning arrester.

In this manner, conventional earth fault preventers use explosives to operate with a minute current, and the explosive energy of the explosives is used as a thrust to separate the casing, that is, to separate the lightning arrester line.

However, since it uses gunpowder, special care must be taken in terms of safety, there are significant restrictions on manufacturing and handling, and it is disadvantageous in terms of price.

In view of the above-mentioned current situation, the inventors of the present invention have conducted extensive research to provide a ground fault preventer that can quickly interrupt a ground fault circuit by sensing minute currents without using explosives.
No. 1 A hot-melt adhesive is used to lock the components of the housing, and the hot-melt adhesive is melted by the heat generated by the resistor due to the earth fault current, thereby releasing the engagement between the components. The present invention has been completed based on the discovery that the two components of the housing can be easily and safely separated in response to a small electric current with the help of a separation promoter.

In other words, the present invention comprises: a housing consisting of two hollow bodies with one end open; two terminals disposed facing each other in the cavity of the housing; and spaced apart from the inner wall surface of the hollow bodies. a resistor provided and connecting both terminals; a pair of discharge electrodes forming a discharge gap inside the resistor in parallel with the resistor; an inner wall surface of the hollow body and the resistor; This invention relates to a lightning arrester ground fault preventer comprising a hot melt adhesive that fills a part or all of the space of the hollow body and adhesively fixes the two hollow bodies, and a separation promoter that applies a force to separate the two hollow bodies.

Next, embodiments of the lightning arrester earth fault preventer of the present invention will be described in detail based on the drawings, but the present invention is not limited to such embodiments.

FIG. 3a shows a schematic vertical sectional view of an embodiment of the earth fault preventer of the present invention, and FIG. 4 shows a partially exploded perspective view thereof. This embodiment basically consists of two cylindrical hollow body casings (11) and (b) with one end open.
A cylindrical resistor (c) connects the lightning arrester side terminal 08), a grounding side terminal Q→, both terminals, and a discharge gap 06) is formed inside the resistor (b) in parallel with this. Connect the ground terminal (to the spring that presses I→) to the discharge electrode (alpha), to the metal plate contact for holding the resistor (to the metal plate contact for holding the resistor)
, and two +-things (11), a hot melt adhesive ψ0 filled in the space between the inner wall of (b) and the resistor θ5).

For assembly, fix the lightning arrester side terminal (b) to the casing 0υ, and in contact with the terminal α8), insert a resistor (]0) into which a discharge electrode ◇η is fitted at one end and a metal plate contact (b) at the other end. The resistor (b) is preferably cylindrical in order to form a discharge space inside, but it is preferable to use a means that prevents the hot melt adhesive 11) from filling the discharge space, such as a cylindrical inner casing. (not shown) may be provided inside the resistor, it may be rod-shaped. The resistor) is fixed away from the inner wall of the casing θ1) to form a space filled with hot melt adhesive.

A ground side terminal (14) is provided with a hole in the center of the bottom of the casing, and an electrode (b) is integrally formed therein.
into the hole). A coil spring is provided between the terminal 0 → 7 langes (c) and the bottom of the casing (b), and this spring is used as a separation promoter during separation.

Casings (11) assembled as above
, (B) so that the electrode (E) penetrates the hole e4 in the center of the metal plate contact (19), and push it forward against the spring until the open ends of both casings come into contact.

At that time, the periphery of the metal plate contact (19) is the casing 02)
It is preferable that it be in slidable contact with the inner wall surface of or face to face with a slight gap. Next, hot melt adhesive C21) is injected into the space formed by the casing 01), (b) and the resistor (151) through the injection port (25a), and the hot melt adhesive overflows from the overflow hole (25a). Once started, stop injecting and casing 03)
, (b) are glued and fixed to assemble the earth fault preventer.

In this operation, if the lightning arrester (not shown) is operating normally, only lightning current will not flow from the lightning arrester, and if lightning current flows, the discharge gap 06) will be discharged to eliminate the lightning current. Cause a ground fault.

If an abnormality occurs in the lightning arrester and a small leakage current flows from the distribution line, no discharge will occur in the discharge gap 06),
The leakage current passes through the resistor) and causes a ground fault. At that time, the resistor (
B) generates heat due to leakage current and melts the hot melt adhesive (C) that adheres the casings α1) and (B). When the hot melt adhesive () melts, the force of the spring () causes the terminal (0→7 lunge) to push the metal plate contact (to), separating the casing (b) from the casing 0υ, and connecting the terminal (b) to the contact. (To) and disconnect the ground fault circuit. The casing (casing 02 detached from 10) hangs down, indicating that an abnormality has occurred in the lightning arrester.

The shape of the housing is not limited to a cylindrical shape, but may be box-shaped, spherical, or the like. Furthermore, as shown in FIG. 3b, the inner surface of the housing can be shaped so that only the part filled with hot melt adhesive forms a space between it and the resistor.
In that case, a smaller amount of adhesive is required and the housing can be made smaller. The material may be any insulating material, and may be an inorganic or organic insulating material, but thermoplastic resins such as vinyl resins are preferred because they are easy to mold and are inexpensive.

When using the cylindrical housing shown in Figures 1 and 2, the size is 32 mm in outer diameter and 41 mm in height, but it can be made even smaller by appropriately selecting resistors, springs, hot melt adhesive, etc. It is also possible to convert

Furthermore, as a method of connecting the terminal to the lightning arrester, the case where the terminal 08) is connected to the lightning arrester has been described, but conversely, there is no problem if the terminal 04j having the spring (c) is connected to the lightning arrester.

The shape and material of the discharge electrode may be any conventionally used one.

The hot melt adhesive may be appropriately selected depending on the magnitude of the ground leakage current expected in the event of a failure of the lightning arrester. Specific examples include Dumilan (modified ethylene-vinyl acetate copolymer, trade name of Takeda Pharmaceutical Co., Ltd.), Atomer (modified polyolefin adhesive, Mitsui Petrochemical Co., Ltd.)
(trade name), Evaflex (a modified product of ethylene-vinegar 1[nil copolymer, trade name of Mitsui Polychemicals]), or blends of these with resins such as polyethylene, etc., but are limited to only these. It's not something you can do.

In the present invention, the gap between the casing and the resistor is made small, and only the joint between the two casings is tapered as shown in Figure 3b to make it easier for hot melt adhesive to enter. The type and position of the promoter can be changed in various ways. Another embodiment of the earth fault preventer of the present invention will be described below.
The same parts as in the embodiment shown in the figures are denoted by the same reference numerals, and their explanation will be omitted.

The embodiment shown in a schematic vertical cross-sectional view in FIG. (c) is formed and closes the open end of (c) on the casing together with a metal plate contact (19).

A predetermined number of 9 through holes are formed in the 7 rung portion (c). The open end surface of the casing is provided with the same number of protrusions as the through holes. FIG. 6 shows a sectional view taken along the line (A) in FIG. 5.

Assembly is carried out by inserting the protrusion into the through hole () and injecting hot melt adhesive (c) through the injection port (c). The operation is similar to the embodiment shown in FIG. 3, in which the hot melt adhesive is melted by the heat generated by the resistor (), and the casing (c) and the terminal 0→ are detached by the force of the spring ().

When constructed as in this embodiment, assembly is extremely simple.

7 and 8 show schematic longitudinal cross-sectional views of another embodiment of even more compact construction. In the embodiment shown in FIG. 7, a weight Oll is used as the separation promoter instead of a spring. The structure of the casing (to) is the same as that of the casing (1υ) of the embodiment shown in Fig. 3. In this embodiment, the electrode (e) on the ground side terminal 04) is connected to the metal plate contact (b). Although it is integrally formed, an electrode (E) may be integrally formed on the terminal 0→, similarly to the embodiment shown in FIG. Inside the other casing (toward), only terminals are disposed on the bottom surface. A weight 6υ is attached to the outside of the casing to adjust the separation of the casing. When the weight of the casing (to) is appropriately selected, the weight OD is not necessary. That is, the separation promoter in this example is the dead weight of the casing.

To assemble, put both casings together so that the terminal 0→ and the metal plate contact are in close contact, and then inject the hot melt adhesive Qυ from the injection port. The operation is shown in Figures 6a and 5.
This embodiment is the same as the embodiment shown in the figure, except that instead of the spring, the weight 0υ or the weight of the casing acts as a separation promoter.

The embodiment shown in FIG. 8 has the same internal structure of the housing as the embodiment shown in FIG. 7. In this embodiment, seven rung parts 07) and (07) are provided around the closed ends of both casings (07) and (07), respectively, and a spring (07) is engaged with these parts to wind the housing. It is distinctive in that it has a

Assembly and operation are the same as the embodiment shown in FIG. 7, except that instead of a weight, a spring (2) acts as a separate promoter. Note that the spring (to) may be attached after assembling the housing.

Although the earth fault preventer of the present invention has been described above in detail based on the drawings, the locations at which internal structures such as resistors and electrodes are separated are not limited to those embodiments, and may be designed in various ways. Can be changed. Furthermore, the earth fault preventer of the present invention may be installed between a power distribution line and a lightning arrester.

In the lightning arrester earth fault preventer of the present invention, by appropriately selecting the type of resistor, the size of the resistance, the type and amount of one agent (hot melt), the type and force of the separation promoter such as a spring or weight, The sensitive current and the time required for separation can be arbitrarily selected.

For example, in the embodiment shown in FIG. 3a, a cylindrical carbon resistor of 8 to 8 Ω is used as the resistor, and Dumilan D-219 (a modified product of -1-tyrene-vinyl acetate copolymer (softening point near 600) is used as the hot melt adhesive. ), Takeda Pharmaceutical Co., Ltd. (trade name)), and the results are shown in Table 1. The results are also shown in Table 1.

As is clear from Table 1, the earth fault preventer of the present invention disconnects more quickly with a smaller current.

As described above, the earth fault preventer of the present invention does not use any dangerous substances such as explosives, so it is safe and can have a simple structure. Therefore, manufacturing constraints are significantly eased, the device is suitable for mass production, and handling and installation can be performed safely and quickly. Furthermore, by appropriately selecting and combining components such as hot melt adhesives,
It can be applied to lightning arresters of any standard, from those with higher sensitivity to those with lower sensitivity than conventional ones. In addition, one of the casings is kept hanging down after detachment, so
A malfunctioning lightning arrester can be easily discovered.

[Brief explanation of the drawing]

Figure 1 is a schematic vertical cross-sectional view of a conventional lightning arrester earth fault preventer, Figure 2
The figure is a schematic circuit diagram of the ground fault preventer shown in FIG. 1, and FIG.
FIG. 6b is a partial sectional view of another embodiment of the casing used in the present invention, FIG. 4 is a partially exploded perspective view of the embodiment shown in FIG. 6a, and FIG. 5 is another embodiment of the earth fault preventer of the present invention. FIG. 6 is a schematic vertical sectional view of the example, FIG. 6 is a sectional view taken along line (A)-(A) 1il of FIG. FIG. (Main symbols in the drawing) (1): Surge arrester 0 clause: Housing (11), (B), 斡1 (C) 1 0 缝, 靏, 疡 (to): Casing αa): Surge arrester side terminal 0→: Ground Side terminal 05): Resistor 06): Discharge gap α'7), ni): Discharge electrode (goods), (to): Spring @υ; Hot melt adhesive 6υ; Weight Fig. 1 27 238 Figure 3b Figure 24 Figure 5 Figure 16; l! IF7 diagram

Claims (1)

[Scope of Claims] (1) A housing consisting of two hollow bodies with one end open; two terminals disposed facing each other in the cavity of the housing; A resistor which is provided with an opening and connects both terminals, a pair of discharge electrodes forming a discharge gap inside the resistor in parallel with the resistor, and an inner wall surface of the hollow body and the resistor. A lightning arrester for preventing earth faults, consisting of a hot melt adhesive that fills part or all of the space between the two hollow bodies and sticks them together, and a separation promoter that applies the force to separate the two hollow bodies. vessel. 2. The earth fault preventer according to claim 1, wherein the separation promoter is an elastic body. 3. The earth fault preventer according to claim 1, wherein the separation promoter is a weight.