JPH0129762Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a low-pressure arrester, and more particularly to a low-pressure arrester in which visibility is improved by eliminating the visual directionality of a display section that indicates that a lightning arrester element has deteriorated.

Some low-pressure arresters are equipped with a lightning arrester element such as ZnO having a non-following current characteristic and a display section that indicates when the element has deteriorated. This low-voltage arrester has a lightning arrester element made of ZnO or the like in a bell-shaped insulator, and a display part is fixed to the earth electrode of the element by soldering.When the soldered part melts, the display part is elastically applied. It has a structure in which the element protrudes from the arc, and is further provided with an arc extinguishing part so that the short circuit current can be cut off even if the element deteriorates rapidly due to lightning strikes or the like.

In the above configuration, when the lightning arrester element deteriorates and its insulation resistance drops to a predetermined level, the leakage current exceeds the predetermined value, the solder melts, and the display part protrudes, making it possible to accurately determine the deterioration of the element. Furthermore, even if a relatively large short-circuit current flows, it can be reliably interrupted.

However, in the case of conventional low-voltage arresters, the display part is provided so as to protrude from the bottom of the bell-shaped insulator, so if the installation position changes depending on the tension of the distribution line, The visibility of the display section may deteriorate because the display section cannot be checked from below.

The present invention was developed in view of the above, and in order to always maintain good visibility of the element deterioration display section regardless of the installation position with respect to the power distribution line, and at the same time to make the shape compact, To provide a low-voltage arrester in which a conductor is connected to both axial ends of a shaped arrester.

The low pressure arrester of the present invention will be explained in detail below.

FIG. 1 shows an embodiment of the low-voltage arrester of the present invention, and as shown in the figure, the arrester 1 is connected between a line-side conductor 2 and a ground-side conductor 3.

Figures 2A and 2B are explanatory diagrams of the internal state of the arrester of the present invention when the arrester element is in normal operation and when the deterioration indicator is in operation, respectively. An outer frame 4 made of a formed transparent insulator (for example, polycarbonate, etc.), and a transparent insulator fitted into an opening of the outer frame 4 formed coaxially around the outer periphery of the terminal 3a of the ground side conductor 3. It has a cap 5 (for example, made of the same material as the outer frame 4), and a lightning arrester element 6 having non-follow current characteristics such as ZnO connected to the line-side conductor terminal 2a inside the outer frame 4. One end of a rod-shaped fuse 7 is connected to the ground side electrode of the element 6 with a low melting metal such as solder (hereinafter simply referred to as solder 8), and the rod-shaped fuse 7 is connected to the arc extinguishing sand 1 in the arc extinguishing chamber 9.
It is buried in 2.

The arc extinguishing chamber 9 is formed by a pair of opposing disc members 10a, 10b made of conductive plates such as brass, a spacer 11 disposed between the pair of disc members 10a, 10b, and these members. A hole 1 formed in the center of the element-side disk member 10a is made of arc-extinguishing sand 12 filled in a space.
The tip 7a of the fuse comes into contact with the ground side electrode of the element 6 through 0c, and is connected by solder 8. A fuse insertion hole 10d is formed in the center of the ground side disk member 10b, and a communication hole 13a communicating with the insertion hole 10d is formed in the element side end surface of the connecting member 13. The head of the fuse 7 is locked at the inner peripheral edge of the communication hole 13a as shown. Spring 15 is spring retainer 1
4 and the connecting member 13 inserted and seated in the insertion hole 14a of the retainer 14, and is compressed and held between the retainer 14 and the disk member 10b. The fuse 7 is fixed to the element 6 with solder 8 while resisting the tensile force of the spring 17 toward the ground side.

The connecting member 13 is made of a hollow, substantially cylindrical conductor, and is inserted into the insertion hole 14a of the retainer 14, and is seated with the locking protrusion 13c locked by the peripheral edge of the insertion hole 14a. . At the ground side end of the connecting member 13, there is an outer peripheral surface of the ground side conductor terminal 3a,
An elastic terminal 13b connected in a sliding relationship is formed, and the elastic terminal 13b is formed with, for example, an elongated slit-like notch (not shown) to make elastic contact with the outer periphery of the ground side conductor terminal 3a.

Reference numeral 16 indicates a cylindrical window-perforated sleeve (for example, four non-directional windows are formed in the circumferential direction) made of, for example, a transparent material, and the window-perforated sleeve 16
is supported at one end by the inner surface of the cap 5, while the other end is in contact with a compression spring 17 disposed around the outer periphery of the spring retainer 14, and is connected to the ground side disc member 10b. The compression spring 17 is kept compressed. From the track side conductor 2 to the outer frame 4,
A cover 18 is provided from the ground conductor 3 to the cap 5 to maintain watertightness and airtightness.
Reference numeral 16a indicates a window portion of the window sleeve 16. Reference numeral 19 is a watertight and airtight member made of an elastic material.

In the above configuration, as shown in Fig. 1, the line side and ground side terminals can be connected to both axial ends of the elongated cylindrical arrester 1 made entirely of a transparent insulator, so that it can be installed in a stretched state of the distribution line. Regardless of changes in posture, the display section can be checked from any direction, providing excellent visibility, and the shape can be made compact. For example, when the insulation resistance of the ZnO element 6 is maintained at a predetermined value or higher, the fuse 7 is connected to the element 6 as shown in FIG. Based on the deterioration of the solder 8, when the leakage current flowing from the line side conductor to the element to the ground exceeds a predetermined value, the solder 8 melts and becomes unable to resist the expanding force of the spring 15, resulting in the phenomenon shown in Fig. 2B. The deterioration display part protrudes like this. Retainer 14 and spring 15
If the display is colored red, for example, the deterioration indicator can be checked very easily.

The arc extinguishing chamber 9 can cut off the short circuit current even if the element 6 suddenly deteriorates due to a lightning strike or the like.

Since the inside of the arrester is completely sealed, it has excellent watertightness and prevents deterioration of the ZnO element, and the entire outside of the arrester is completely insulated, so there is no risk of electric shock.

As explained above, according to the low-voltage arrester of the present invention, since conductors are connected to both axial ends of the elongated cylindrical arrester, the visibility of the element deterioration display section can be improved regardless of the installation orientation with respect to the distribution line. It is possible to maintain the structure while at the same time achieving a compact shape.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the low-pressure arrester of the present invention, and FIGS. 2A and 2B are explanatory views of the internal state of the arrester of the present invention when the arrester element is operating normally and when the deterioration indicator is operating, respectively. Explanation of symbols, 1...Arrester, 2...Line side conductor, 2a...Terminal, 3...Grounding side conductor, 3a...
...Terminal, 4...Outer frame, 5...Cap, 6...Surge arrester element, 7...Fuse, 7a...Tip, 8
... Solder, 9... Arc extinguishing chamber, 10a, 10b...
Disc member, 10c...hole, 10d...insertion hole, 11...spacer, 12...arc-extinguishing sand, 13...
...Connection member, 13a...Communication hole, 13b...Elastic terminal, 14...Spring retainer, 14a...
Insertion hole, 15...Spring, 16...Window sleeve, 16a...Window part, 17...Compression spring, 1
8...Cover, 19...Watertight and airtight member.

Claims (1)

[Claims for Utility Model Registration] A lightning arrester element having a non-following current characteristic, and a display unit that displays deterioration by melting a low alloy metal for fixing when the element deteriorates and ground leakage current reaches a predetermined level. , in a low-voltage arrester equipped with an arc-extinguishing part that cuts off a short-circuit current when it flows through the element, wherein the display part is housed in a cylindrical transparent body that has no visual directionality. Features a low pressure arrester.