JPH043447Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a bushing through-type arrester.
In particular, the present invention relates to a bushing penetrating arrester that is easy to install and allows for miniaturization.

[Conventional technology]

As a conventional device-built-in arrester, there is one that is housed inside a switch, for example. This switch built-in arrester is placed between the fixed electrode conductor and the ground terminal of the switch. For example, by connecting the charging side and ground side terminals to the fixed electrode conductor and the ground terminal, respectively, the switch is housed within.

[Problems to be solved by the invention] However, according to the conventional arrester with a built-in switch, the conductor for the fixed electrode of the switch and the ground terminal are connected to each other by a connecting conductor whose length corresponds to the position where it is placed. Since the capacitor is housed in a predetermined position, a special installation space is required, and if the current capacity is increased, the capacitor becomes larger.

[Means for solving problems]

The present invention was developed in view of the above, and does not require any special installation space, is easy to install, and can accommodate increased voltage resistance and current capacity without increasing the size. In order to achieve this, a bushing penetrating type arrester is provided in which an arrester element is built into a molded insulator that is fitted into the bushing and positioned on the outer periphery of the bushing.

That is, the bushing penetrating arrester of the present invention has the following means.

(1) Mold insulator Consists of insulators such as epoxy and rubber.
Due to its donut shape, it can be easily fitted onto the outer periphery of the bushing. In the case of rubber, it can be easily fixed by expanding the inner wall using its elasticity and fitting it. Further, when the bushing has a groove on its outer periphery, the groove may be filled with a suitable material to make it smooth and then fixed with an adhesive.

(2) Arrester element A nonlinear non-driving element such as Z _o O is used, and multiple blocks are connected in series or parallel, housed in a molded insulator, and both terminals are connected to the equipment conductor and ground terminal. . When connected in series, the breakdown voltage can be increased due to the voltage division effect, and when connected in parallel, a large current capacity can be obtained due to the shunt effect. By combining the two, or by combining both with a series gap, an arrester with a desired rating can be obtained.

[Effect]

With the above configuration, installation is completed by positioning the molded insulator containing the arrester element on the outer periphery of the bushing inside the electrical equipment, and connecting the charging side electrode to the equipment conductor and the grounding side electrode to the earthing terminal. do.

〔Example〕

FIG. 1 shows an embodiment of the present invention applied to a switch. Bushings 2 passing through the main body 1 are provided on both sides of the switch main body 1. Bushing 2
supports a cable 3, the cable conductor being connected via a connecting conductor 4 to a fixed contact 5. A movable contact 6 is connected to and released from the fixed contact 5, and an arc extinguishing chamber 7 is formed around the movable contact 6. A bushing-through type arrester 8 is provided on the outer periphery of the bushing 2, and its charging side electrode (screw hole 26, which will be described later) is connected to the fixed contact conductor 4 via the connecting conductor 10, and the earthing side electrode (which will be described later) Grounding screw hole 3
2) is connected to the ground terminal 13 via the connecting conductor 12.

FIG. 2a shows a unit body of arrester elements, in which two arrester elements 21 and 22 are connected to an electrode plate 2.
3 are connected in series, and the arrester element 2
Other electrode plates 24 and 25 are provided on the opposite side of electrodes 1 and 22. A screw hole member 26 is fixed to the electrode plate 24 as a charging side electrode, and a discharge gap 27 described later is connected to the electrode plate 25.

FIG. 2b shows an embodiment of the through-type arrester 8 of the present invention in which the arrester element unit shown in FIG. Through hole 3
1 is formed. According to the cross section shown,
The arrester element 21 has upper and lower electrode plates 23 and 24, and is integrated with an insulator 30 so that the screw hole member 26 fixed to the electrode plate 24 is exposed on the surface, and the discharge gap part 27 is molded with a grounding screw conductor 32 protruding from it. This discharge gap portion 27 is connected to a first discharge electrode 33 fixed to the electrode plate 25 and a ground screw conductor 3.
2 and a second discharge electrode 34 connected to the first
and the second discharge electrodes 33 and 34 are provided with spacers 35
They are arranged so as to have a predetermined gap 40. Further, a shielding conductor 36 whose tip is expanded into a bell mouth shape is connected to the second discharge electrode 34, and the electric field at that portion is relaxed and the insulator 30
This prevents local electrical stress from being applied. Furthermore, since the shield conductor 36 surrounds the gap 40, the influence of electromagnetic induction caused by the current flowing through the conductor passing through the through hole 31 is reduced, and the discharge characteristics of the gap 40 can be stabilized.

FIG. 2c shows the bushing through-type arrester 8 shown in FIG.
A grounding screw conductor 32 is provided as a charging side electrode and a grounding side electrode.

In the above configuration, the bushing 2 is passed through inside the switch main body 1 of FIG. The connecting conductor 12 is connected to the earthing screw conductor 3 by means of a nut 12a.
2, the installation of the bushing penetrating arrester 8 is completed.

Figures 3a and 3b show other embodiments of the present invention, a
is one in which three arrester elements 41, 42, 43 are connected in series by electrode plates 48, 49, and the arrester function and follow-on current blocking function of the arrester elements 41, 42, 43 prevent abnormal voltage. This protects the equipment from b is the electrode plate 50,5
1, the arrester elements 44, 45, and
Arrestor element 46,
47 connected in parallel are connected in series by an electrode plate 51, and discharge gap portions 53 are connected in series by an electrode plate 52.

As is clear from the above description, since the molded insulator is arranged annularly around the outer periphery of the bushing, a large number of arrester elements can be accommodated in parallel and in series even though the shape is not very large.

[Effect of idea]

As explained above, according to the bushing penetrating arrester of the present invention, the arrester element is built into the molded insulator that is fitted into the bushing and positioned around its outer periphery, so no special installation space is required. Moreover, it can be easily attached, and furthermore, it can cope with an increase in withstand voltage value and current capacity without increasing the size.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view showing a switch to which a bushing-through type arrester of the present invention is applied. Figure 2a,
b and c are explanatory diagrams showing one embodiment of the present invention. FIGS. 3a and 3b are explanatory diagrams showing other embodiments of the present invention. Explanation of symbols, 1... Switch main body, 2... Bushing, 3... Cable, 4... Fixed contact conductor,
5... Fixed contact, 6... Movable contact, 7... Arc extinguishing chamber, 8... Penetrating arrester, 10, 12... Connection conductor, 13... Earth terminal, 21, 22... Arrestor element, 23, 24, 25...electrode plate, 2
6...Screw member, 27...Discharge gap, 30...
...Mold insulator, 31...Threaded hole, 32...Screw conductor for grounding, 33, 34...Discharge electrode, 35
...Spacer, 36...Shielding conductor.

Claims (1)

[Claims for Utility Model Registration] A molded insulator having a through hole through which a bushing is passed, and an arrester element embedded in the molded insulator and having both terminals connected to a conductor of an electrical device and a ground terminal, respectively. A bushing-through type arrester, characterized in that a bushing of an electrical device is passed through the through-hole and provided on the outer periphery of the bushing.