JPS645956Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an edge turning device that takes measures to prevent wire breakage due to follow-on arcs.

A conventional power transmission/distribution line edging device uses a jumper support insulator to support the edging portion of the wire, which is held in place by a tensile insulator that is stretched in the direction of the line by holding a grounding fitting such as a cross arm. If an impact overvoltage such as a lightning surge occurs, a flash may occur between the edging part supported by the jumper support insulator and the base metal fitting of the jumper support insulator, or the electric wire may be connected to the retaining clamp that holds the wire. This can cause flash short circuit between the pin fitting of the tension insulator on the energized side and the cap fitting of the tension insulator on the grounding side, and the jumper support insulator or the tension insulator will be damaged by the arc heat of the subsequent arc. However, if the energy of the follow-on arc was large, the pin fittings of the tension insulator on the energized side would melt due to the arc heat generated by the arc, and as a result, the electric wire would break and fall to the ground. In addition, if the electric wire is a covered electric wire, if a flash short circuit occurs between the edging part of the electric wire and the base metal fitting of the jumper support insulator, the generation point of the follow-on arc will be fixed at the point where the insulation coating of the electric wire has penetrated and broken, and the edge of the electric wire will There was a drawback that the rotating part broke. Furthermore, if the insulation coating is not stripped off at the location where the wire is held by the retaining clamp, the wire will easily break when a follow-on arc occurs for the same reason as above. It is necessary to strip off the insulating coating of the electric wire so that the wire can be electrically connected, and there is also a drawback that the stripping operation is time-consuming.

The present invention was completed with the aim of providing an edge turning device that does not have the above-mentioned drawbacks and takes measures to prevent wire breakage.Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

Reference numerals 1 and 1 indicate tension insulator devices that are stretched in the direction of the track with a grounding fitting 2 such as a cross arm in between, and each tension insulator device 1
consists of tension insulators 5, 5 with cap metal fittings 4, 4 connected to the grounding metal fitting 2 with a strap 3, and a retaining clamp 6 for securing the electric wire 7 to the tension insulator 5 on the energized side, The electric wire 7 electrically connects the retaining clamps 6, 6 of both tension insulator devices 1, 1.
The edging portion 7a is supported by a bind wire 18 on the head of a jumper support insulator 8 which is vertically attached to the grounding fitting 2, and is no different from the conventional edging device for power transmission and distribution lines. There isn't. 9
is a current limiting element, and the current limiting element 10 is made of a material with non-linear voltage-current characteristics such as silicon carbide or zinc oxide. It is coated with an insulator 13 made of rubber or synthetic resin, except for the tip part of the terminal, and is attached to the band fitting 14 holding the base fitting of the jumper support insulator 8 with the ground side terminal 12. It is grounded to 2. Reference numeral 15 denotes a discharge electrode that is attached to at least one of the tension insulators 5 and the jumper support insulator 8 constituting each tension insulator device 1, respectively. It has a substantially C-ring shape with a diameter that surrounds it concentrically. Further, in the first embodiment shown in FIG. 1, a discharge electrode 15 surrounding the jumper support insulator 8 is connected to the energizing side terminal 11 of the current limiting element 9, and has a required distance between it and the edge portion 7a. The discharge electrodes 15, 1 form an air gap and surround the tension insulator 5 on the other hand.
5 is attached to the band metal fitting 16 holding the cap metal fitting of the tension insulator 5 on the ground side via an insulating support 19 made of rubber, synthetic resin, porcelain, etc.
A required air gap is formed between the discharge electrodes 15, 15 and the retaining clamps 6, 6, which are insulated from the They are electrically connected using a conductive wire 17 or the like having high electrical conductivity. The material and shape of the discharge electrode 15 are not limited as long as it is made of a conductive material; If the tension insulator 5 on the ground side is made into a C-ring shape with an inner diameter sufficient to surround it from the outside, it will have an excellent capture function for streamers generated by shock overvoltage such as lightning surges, and the C-ring If the shaped discharge electrode 15 is made of a spring material such as spring stainless steel or phosphor bronze, and its opening is made expandable, the discharge electrode 15 can be attached to the existing tension insulator 5 or jumper support insulator 8. This is preferable because it can be installed through the opening. On the other hand, in the second embodiment shown in FIG. 4, the discharge electrode 15 is attached so as to surround the tension-resistant insulator 5 on the energized side, and the discharge electrode 15 is attached to a band metal fitting 16 holding a cap metal fitting. At the same time, the current limiting element 9 attached to the discharge electrode 15 and the jumper support insulator 8 is insulated between the discharge electrode 15 and the grounding metal fitting 2 such as a cross arm by using the tension insulator 5 on the ground side. The power side terminal 11 is electrically connected to the power side terminal 11 by a conductive wire 17, and in this case, the insulating support 19 in the first embodiment can be omitted, so that the device can be expected to be simplified. Further, the electric wire 7 held by the tension insulator device 1 may be either a bare electric wire or a covered electric wire,
In the case of coated wires, the insulation coating of the wire 7 is stripped off and the core wire is held by the retaining clamps 6, as has been commonly done in the past. Alternatively, the insulating coating may be held with a retaining clamp 6 from above without being stripped off.Furthermore, in the above embodiment, one current limiting element 9 is used. However, for example, multiple current-limiting elements 9 may be connected in parallel to increase the capacity to flow an impact current such as a lightning surge, that is, discharge withstand capacity, or when used on a high voltage line, multiple current-limiting elements 9 may be connected as necessary. Current limiting elements 9 may be connected in series, and the number of current limiting elements 9 is not limited.

With this structure, when an impact overvoltage such as a lightning surge occurs in the electric wire 7, the electric wire 7 is connected between the edge part 7a supported by the jumper support insulator 8 and the discharge electrode 15 attached to the jumper support insulator 8, or Pin fitting 5 of tension insulator 5 on the voltage charging side electrically connected to electric wire 7 via retaining clamp 6
A and the discharge electrodes 15 attached to the tension insulator 5 will cause a flash short circuit, but each discharge electrode 15 is electrically connected to the current-loading side terminal of the current-limiting element 9 that is grounded to the grounding fitting 2. Therefore, the shock current flowing at that time flows from the discharge electrode 15 through the current limiting element 10 built in the current limiting element 9 to the arm which is the grounding metal fitting 2. Subsequent current that attempts to flow is blocked by the non-linearity of the voltage-current characteristics of the current limiting element 10, and a follow-on arc is not generated, thereby preventing disconnection of the electric wire 7 and damage to the jumper support insulator 8 and tension insulator 5. In addition, as described above, the current limiting element 9 blocks the follow-on current that attempts to flow after a flash fault. There is no risk of breaking the wire even if the wire is gripped by the wires, and there is also the advantage that the work of stripping off the covering, which was conventionally required, can be omitted. Furthermore, the necessary tension insulators 5 and jumper support insulators 8 of the tension insulator device 1 are provided.
Since the discharge electrodes 15 to be attached to the retaining clamps 6 and the edging portions 7a can be installed with an air gap between them, the existing insulators can be used as is even when applied to an existing edging device. This has the advantage that installation work can be done with live wires. Furthermore, the discharge electrodes 15 attached to the jumper support insulator 8 and the tension insulator 5 can be electrically connected together using the conductor 17 and then connected to the grounded current limiting element 9. Current limiting elements 9 on all of the tension insulators 5
Therefore, it is possible to provide a simple and economical edging device by reducing the number of current limiting elements 9. In addition, if the edge part 7a of the electric wire 7 and the conducting wire 17 are arranged side by side as in the illustrated embodiment, when an excessive lightning surge that cannot be captured by the discharge electrode 15 occurs, the conducting wire 17 will be discharged. Electrode 15
It is even more preferable because it can perform the same function as above, reliably capture the streamer generated from the edge portion 7a, and guide it to the current limiting element 9.

As is clear from the above description of the embodiment, the present invention is not only extremely effective in terms of the safety of transmission and distribution lines and the stable supply of power, but also facilitates the maintenance of the lines. It is of great practical value as it overcomes the shortcomings of conventional edge routing devices for transmission and distribution lines.

[Brief explanation of drawings]

FIG. 1 is a front view showing the first embodiment of the present invention;
Figure 2 is a partially cutaway plan view of the jumper support insulator section, Figure 3 is a view taken along arrow A-A in Figure 1, and Figure 4 is a partially cutaway plan view of the jumper support insulator section.
The figure is a front view showing a second embodiment of the present invention. 1: Tension-resistant insulator device, 2: Grounding fitting, 5: Tension-resistant insulator, 6: Retaining clamp, 7: Electric wire, 7a: Edge section, 8: Jumper support insulator, 9: Current-limiting element,
11: Power supply side terminal, 15: Discharge electrode.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A edging of a power transmission and distribution line in which the edging part of an electric wire held in place by a tension insulator device stretched in the line direction with a grounding fitting in between is supported by a jumper support insulator. In the apparatus, discharge electrodes 15 are attached to the required tension insulators 5 and jumper support insulators 8 constituting each of the tension insulator devices 1, respectively, by the retaining clamps 6 and the edge portions 7a of the tension insulator devices 1.
and the discharge electrode 15 is electrically connected to the current-supplying side terminal 11 of the current limiting element 9 which is grounded to the grounding fitting 2. Edge turning device with measures to prevent wire breakage. 2. The edging device provided with a measure to prevent disconnection as set forth in claim 1 of the utility model registration, in which each discharge electrode 15 is shaped like a C-ring and is disposed so as to surround the tension insulator 5 and the jumper support insulator 8, respectively.