JP2018133239A - Lightning arrestor with separation function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact lightning arrestor with a separation function that conforms to revised JIS, has high current interrupting capability, and can be easily installed in a distribution board.SOLUTION: A lightning arrestor element 12 is accommodated in one end side of a housing 14, and an internal space 23 is formed and a partition wall portion 25 protruding into the internal space 23 is provided on the other end side of the housing 14, a fuse wire 29 connecting the lightning arrestor element 12 and a terminal metal fitting 32 attached to the housing 14 is bent so as to bypass the partition wall portion 25, a separation spring 31 for urging the elastic force in a direction to separate the fuse wire 29 from the lightning arrestor element 12 is provided in the housing 14 and silica sand 40 is sealed in the internal space 23 of the housing 14.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a lightning arrester with a separation function having a function of separating from a power supply line when a short circuit failure occurs due to deterioration of characteristics of the lightning protection element.

  Generally, there is a lightning arrester as a device for protecting an electrical device from a lightning surge. The power arrester is inserted and connected between phases of the power line. For this reason, a power supply voltage is always applied to the above-described lightning arrester.

  For this reason, the lightning arrester only has a low resistance only at the moment when a lightning surge enters, and it must be maintained as a resistor having a resistance value close to infinity even if the lightning arrester fails, or it must be separated from the power line. I must.

  The present applicant has previously proposed a lightning arrester with a separation function having a function of separating the lightning arrester from the power supply line (see, for example, Patent Document 1).

  When the frequency of lightning surge is increased and the characteristics of the lightning protection element deteriorate, the resistance value of the lightning protection element is not infinite and becomes low. As a result, Joule heat is generated by the applied voltage, and the lightning protection element becomes high temperature due to the Joule heat.

  In the lightning arrester with the separation function disclosed in Patent Document 1, the lightning arrester is separated from the power line by dissolving the low melting point solder due to the temperature rise of the lightning arrester.

JP2015-73419A

  By the way, the lightning protection element has a risk that the lightning protection element is short-circuited. If such a short-circuit state continues, there is a risk that a large current flows, causing a fire or a failure to peripheral equipment.

  In order to avoid such a danger, the revised JIS requires that the lightning arrester be quickly separated from the power line when the lightning arrester enters a state called a short-circuit mode in which a large current exceeding the specified current flows. Yes.

  Therefore, the above-described separation function is required in the revised JIS for the internal separator built into the lightning arrester as in Patent Document 1 and the external separator externally attached to the lightning arrester. That is, even if the lightning protection element fails, it is necessary not to be in a short-circuit state, and when separating, it is necessary to be able to quickly separate even with a current of 100 A or more.

  On the other hand, a lightning arrester having an internal separator as in Patent Document 1 does not conform to the revised JIS, and the lightning arrester can be quickly connected from the power line in a short-circuit mode in which a large current exceeding the specified current flows through the lightning arrester. It is difficult to separate.

  On the other hand, since a number of breakers are attached to the distribution board to which the lightning arrester is attached, there is not much room for the lightning arrester occupation area in the distribution board. Therefore, when an external separator is externally attached to the lightning arrester, it is not easy to attach an external separator such as a large current fuse holder in the distribution board.

  In particular, in a three-phase power supply system, when an external separator is externally attached to a lightning arrester, the number of appliances increases, and it is remarkable that there is a space limitation on the installation of the external separator. Therefore, there is a demand for a small lightning arrester having an internal separator.

  Therefore, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to comply with the revised JIS and have a large current interruption capability and can be easily installed in a distribution board. It is to provide a lightning arrester with a small separation function.

  As a technical means for achieving the above-mentioned object, the lightning arrester with a separation function according to the present invention accommodates the lightning arrester element on one side of the casing, forms an internal space on the other side of the casing, A partition wall that protrudes into the space is provided, and the fuse wire connecting the terminal fitting attached to the housing and the lightning arrester is bent so as to bypass the partition wall, and an elastic force is applied in the direction of separating the fuse wire from the lightning arrester. A separating spring is provided in the housing, and an arc extinguishing filler is enclosed in the internal space of the housing.

  In the lightning arrester with a separation function according to the present invention, when the temperature of the lightning protection element rises due to deterioration of the lightning protection element, the fuse wire is disconnected from the lightning protection element by the elastic force of the disconnection spring. Also, when the fuse wire reaches a blown state in a short-circuit mode in which a large current exceeding a specified current flows, the fuse wire is disconnected from the lightning protection element by the elastic force of the disconnect spring. An arc discharge occurs when the fuse wire is disconnected from the lightning protection element or blown.

  In the present invention, by providing a structure in which the fuse wire connecting the terminal fitting of the housing and the lightning protection element is bent so as to bypass the partition wall, the arc discharge discharge path can be lengthened when arc discharge occurs. The arc discharge can be extinguished quickly.

  Further, by filling the arc extinguishing filler in the internal space in which the fuse wire is accommodated, the arc discharge can be extinguished quickly by cooling the discharge plasma when the arc discharge occurs.

  From the above, even in the short-circuit mode that conforms to the revised JIS and a large current exceeding the specified current flows in the lightning arrester, the large current can be cut off quickly and easily in the distribution board. A small lightning arrester that can be attached can be realized.

  In the present invention, it is desirable to have a structure in which a contact switch that detects and sends out the deterioration state of the lightning protection element by the action of the elastic force of the separating spring is provided in the housing.

  If such a structure is adopted, the separation operation status of the lightning arrester can be notified to the outside by a contact switch. In other words, the deterioration information of the lightning protection element can be sent to the external device by this contact switch.

  The casing in the present invention is preferably made of a resin material in which a glass fiber is contained in a nonflammable resin and has a thickness that can withstand the pressure increase in the internal space due to deterioration of the lightning arrester.

  By adopting such a structure, even if the pressure rises in the internal space of the housing due to the occurrence of arc discharge, the thickness of the resin material constituting the housing is increased, so that the housing is not damaged. It can be prevented in advance.

  In the present invention, a structure in which a reinforcing plate is attached to a lid that closes the internal space of the housing is desirable.

  If such a structure is adopted, even if the pressure rises in the internal space of the housing due to the occurrence of arc discharge, it is possible to prevent the thin lid from being damaged by the reinforcing plate.

  According to the present invention, the fuse wire connecting the terminal fitting of the housing and the lightning arrester is bent so as to bypass the partition wall, and the arc extinguishing filler is enclosed in the internal space in which the fuse wire is accommodated. Thus, when arc discharge occurs, the arc discharge can be quickly extinguished.

  As a result, even in the short-circuit mode that conforms to the revised JIS and a large current exceeding the specified current flows in the lightning arrester, the large current can be cut off quickly and installed easily in the distribution board. A small lightning arrester that can be used.

It is the perspective view which looked at the lightning arrester from the separator side in embodiment of this invention. It is the perspective view which looked at the lightning arrester from the lightning arrester element side in embodiment of this invention. (A) is the perspective view which looked at the lightning protection element from one surface, (B) is the perspective view which looked at the lightning protection element from the other surface. (A) is the perspective view which looked at the housing | casing from the separator side, (B) is the perspective view which looked at the housing | casing from the lightning protection element side. It is an assembly disassembled perspective view which shows the state which removed the cover body of the lightning arrester. FIG. 6 is an assembled perspective view showing a state where the lid of FIG. 5 is attached. FIG. 2 is a perspective view showing a state after the separating operation in the lightning arrester of FIG. 1. It is an assembly exploded perspective view which shows the lightning arrester which connected three lightning arresters. It is an assembly completion perspective view which shows the lightning arrester which connected three lightning arresters.

  An embodiment of a lightning arrester with a separating function according to the present invention (hereinafter simply referred to as a lightning arrester) will be described in detail below with reference to the drawings.

  As shown in FIGS. 1 and 2, the lightning arrester 11 of this embodiment has a non-linear current-voltage characteristic that exhibits low resistance to surge voltages and high resistance to normal power supply voltages. A lightning protection element 12 (metal oxide varistor) mainly composed of (ZnO) and a separator 13 having a structure to be described later are accommodated in a resin casing 14, and the lightning protection element 12 and the separator 13 are integrated. It has a structure.

  As shown in FIGS. 3A and 3B, the lightning protection element 12 has a substantially square shape and has a structure in which the element element is covered with an insulating material. On one surface of the lightning protection element 12, the power application side electrode plate 15 is extended to form an electrode fitting 16 [see FIG. The insulating material is partially removed on the other surface of the lightning protection element 12, and the ground electrode plate 18 is exposed through the opening 17 (see FIG. 1A). In this embodiment, the square lightning protection element 12 is illustrated, but a round lightning protection element or the like may be used, and the shape thereof is arbitrary.

  The housing 14 is a resin molded product made of a resin material in which glass fibers are contained in a non-combustible resin. As shown in FIGS. 4A and 4B, the housing 14 has a two-layer structure for accommodating the lightning protection element 12 and the separator 13. The two-layer housing 14 is provided with a partition wall 19 at a boundary portion between one side and the other side.

  A recess 20 for accommodating the lightning protection element 12 is formed on one side of the housing 14 [see FIG. A notch 21 for leading the electrode fitting 16 of the lightning protection element 12 to the outside is formed in a part of the periphery of the recess 20. An outer wall portion 22 is formed on the other side of the housing 14 [see FIG. An inner space 23 for accommodating the separator 13 is formed in the outer wall portion 22. The outer wall portion 22 is thick on the entire outer periphery of the inner space 23.

  The partition wall portion 19 of the housing 14 is provided with a window portion 24 penetrating between the recess 20 and the internal space 23 so as to correspond to a portion where the electrode plate 18 of the lightning protection element 12 is exposed. A partition wall 25 is integrally formed in the vicinity of the window 24 so as to protrude from the outer wall 22 and the partition wall 19 to the internal space 23.

  The partition wall part 19 is not necessarily required. When the partition wall portion 19 is not provided, the other surface of the lightning protection element 12 (see FIG. 3A) can be used as a partition wall portion. In this case, the partition wall portion 25 may be formed so as to extend integrally from the periphery of the outer wall portion 22.

  The outer wall 22 has a slit 26 for mounting a terminal fitting 32 (see FIG. 1), a notch 27 for inserting a fuse tension wire 30 (see FIG. 1), and an external connection line (not shown). ) Is provided in the notch 28.

  As shown in FIG. 2, the lightning protection element 12 is accommodated in a recess 20 located on one side of the housing 14. The lightning protection element 12 is fixed to the partition wall 19 of the recess 20 by an appropriate means such as an adhesive. The electrode fitting 16 of the lightning arrester 12 is led out from the notch 21 of the recess 20.

  As shown in FIG. 1, the separator 13 includes a fuse wire 29 made of a copper alloy, a fuse tension wire 30 made of an insulating material, and a disconnecting spring 31 made of an elastic material. Via the fuse wire 29 of the separator 13, the electrode plate 18 of the lightning protection element 12 exposed from the window portion 24 of the partition wall portion 19 and the terminal fitting 32 attached to the outer wall portion 22 of the housing 14 are connected. ing.

  That is, one end of the fuse wire 29 is electrically and mechanically connected to the electrode plate 18 of the lightning protection element 12 through the window portion 24 of the partition wall portion 19 by the low melting point solder 33. The other end of the fuse wire 29 is electrically and mechanically connected to a terminal fitting 32 that is fitted and fixed to the slit 26 of the outer wall portion 22. The fuse wire 29 has a shape bent in a dogleg shape so as to bypass the front end surface of the partition wall portion 25.

  The separation spring 31 has a band plate shape and is disposed outside the outer wall portion 22. The cut-off spring 31 has a curved base 34 screwed to the outer periphery of the outer wall 22, and a straight tip 35 extending from the base 34 is disposed in parallel along the outer periphery of the outer wall 22.

  One end of the fuse tension wire 30 is inserted into the cutout 27 of the outer wall portion 22 and is fixedly attached to the separation spring 31. The other end of the fuse tension wire 30 is hooked and locked near the bent portion 36 of the fuse wire 29. In this way, the fuse wire 29 is in a state of being pulled by the fuse pulling wire 30 by the pulling force of the separating spring 31.

  A contact switch 37 is disposed in the vicinity of the distal end portion 35 of the separation spring 31 outside the outer wall portion 22. The contact switch 37 is fixed to the housing 14. The contact switch 37 detects the deterioration state of the lightning protection element 12 by opening the lever 43 and sends it to an external device.

  As shown in FIGS. 5 and 6, the lid body 38 is fixed to the outer wall portion 22 of the housing 14 with screws 39. The lid 38 closes the internal space 23 of the outer wall portion 22. In the recess 41 of the thin lid 38, a metal reinforcement plate 42 is fitted together with the lid 38 screwed.

  Note that one side of the housing 14 is not provided with a lid because it is attached to a lightning arrester housing (not shown), but a lid that closes the recess 20 may be provided.

  In the case 14, the internal space 23 of the outer wall portion 22 is filled with a filler for extinguishing arc discharge, for example, silica sand 40 (shown by dotted points in the figure) mainly composed of silicon dioxide. Yes. The particle size of the silica sand 40 is effectively 500 μm or less.

  In FIG. 5, the fuse wire 29, the fuse pulling wire 30, the partition wall 25, and the like are shown so as to be visible for explanation. Further, in FIGS. 1 and 7, the silica sand 40 is not shown.

  The lightning arrester 11 having the above configuration is inserted and connected between phases of power supply lines. That is, the electrode fitting 16 of the lightning arrester 11 is connected to the power application side of the power supply line, and the terminal fitting 32 of the lightning arrester 11 is connected to the ground side of the power supply line. The operation of the separator 13 when the lightning arrester 12 is deteriorated will be described in detail below.

  If the lightning protection element 12 is normal, one end of the fuse wire 29 of the separator 13 is connected to the electrode plate 18 of the lightning protection element 12 by a low melting point solder 33 as shown in FIG. That is, the electrode plate 18 of the lightning protection element 12 is connected to the terminal fitting 32 through the fuse wire 29 by the low melting point solder 33. At this time, the fuse wire 29 is in a state of being pulled in the direction of the outer wall portion 22 by the fuse pulling wire 30 by the pulling force of the separation spring 31.

  When the lightning protection element 12 deteriorates, the lightning protection element 12 generates Joule heat with the applied voltage, and the lightning protection element 12 becomes high temperature due to the Joule heat. When the lightning protection element 12 reaches a high temperature, the low melting point solder 33 that connects the electrode plate 18 of the lightning protection element 12 and one end of the fuse wire 29 is dissolved. Thereby, since the fuse wire 29 is pulled in the direction of the outer wall portion 22 by the pulling force of the separation spring 31, the fuse wire 29 is separated from the electrode plate 18 and is cut off.

  When the lightning protection element 12 is in the short-circuit mode, the fuse plate 29 is blown to disconnect the electrode plate 18 of the lightning protection element 12 and the terminal fitting 32 of the housing 14. When the fuse wire 29 is blown, arc discharge occurs at the position of the fuse wire 29.

  As shown in FIG. 7, the remaining portion of the fused fuse wire 29 is instantaneously detached from the electrode plate 18 of the lightning protection element 12 because it is pulled by the fuse tension wire 30 due to the tensile force of the separation spring 31. . Thus, the remaining portion of the fused fuse wire 29 is pulled by the disconnection spring 31, so that the arc discharge can be quickly extinguished.

  Further, even if the fuse wire 29 is softened without being completely melted, the fuse wire 29 is completely cut by the tensile force of the separation spring 31. Further, when the low melting point solder 33 is not melted completely and is softened, similarly, the fuse wire 29 is separated from the electrode plate 18 of the lightning protection element 12 by the tensile force of the separation spring 31.

  In the lightning arrester 11 of this embodiment, the fuse wire 29 is largely bent so as to bypass the partition wall portion 25, the vicinity of the bent portion 36 is cut off, and the fuse tension wire 30 is pulled by the tensile force of the spring 31.

  Thereby, when arc discharge occurs, the discharge path (discharge interval) can be lengthened, and the arc discharge can be extinguished quickly. The partition wall 25 contributes to extinguishing the arc discharge by limiting the diffusion of the discharge plasma due to the arc discharge.

  Silica sand 40 is sealed as an arc extinguishing filler in the internal space 23 in which the fuse wire 29 is accommodated. Thereby, at the time of arc discharge generation, arc discharge can be rapidly extinguished by cooling the discharge plasma by arc discharge.

  From the above, even in the short-circuit mode that conforms to the revised JIS and a large current exceeding the specified current flows through the lightning protection element 12, the large current can be cut off quickly and easily in the distribution board. It is possible to realize a small lightning arrester 11 that can be attached to the device.

  At this time, the distal end portion 35 of the separation spring 31 is displaced by the elastic restoring force, so that the lever 43 of the contact switch 37 is opened and the contact switch 37 can be turned on. When the contact switch 37 is turned on, the deterioration state of the lightning protection element 12 can be detected by the output of the contact switch 37 and sent to an external device.

  The housing 14 in this embodiment is made of a resin material in which a glass fiber is contained in a nonflammable resin. Further, the outer wall portion 22 of the housing 14 is thick on the outer periphery of the inner space 23. That is, the outer wall portion 22 has a thickness that can withstand the pressure increase in the inner space 23 caused by the occurrence of arc discharge.

  As a result, even if the pressure rises in the internal space 23 of the housing 14 due to the occurrence of arc discharge, the housing 14 is made of the resin material described above and the thickness of the outer wall portion 22 of the housing 14 is increased. Therefore, it is possible to prevent the casing 14 from being damaged.

  Furthermore, in this embodiment, the reinforcing plate 42 is attached to the lid body 38 that closes the internal space 23 of the housing 14. Thereby, even if a pressure rises in the internal space 23 of the housing 14 due to the occurrence of arc discharge, the thin cover 38 can be prevented from being damaged by the reinforcing plate 42.

  In the above embodiment, the lightning arrester 11 (see FIG. 6) having a basic configuration attached to the single-phase AC circuit has been described. However, the lightning arrester 11 shown in FIG. 6 has a single-phase three-wire structure as shown in FIGS. The present invention can also be applied to an AC circuit and a three-phase three-wire AC circuit.

  In this embodiment, as shown in FIGS. 8 and 9, a case where three lightning arresters 11 are connected is illustrated. As shown in the figure, the housings 14 of the lightning arresters 11 have mounting portions 47 and 48 having through holes 45 and 46 through which the screws 44 are inserted formed on the outer peripheral edge portions of the housing 14 and the lid 38. It has a structure. In this embodiment, two attachment portions 47 and 48 of the housing 14 are provided, but the number and position of the attachment portions 47 and 48 are arbitrary.

  In this embodiment, the three lightning arresters 11 are joined, the screws 44 are inserted into the through holes 45 and 46 of the attachment portions 47 and 48 of the casing 14 and the lid 38, and tightened with the nuts 49. The lightning arresters 11 are connected and integrated.

  At this time, since one side of the housing 14 is opened in a state where the lightning protection element 12 is accommodated, a packing 50 such as a ceramic sheet is provided between the one side of each housing 14 and the adjacent lid body 38. It is effective to intervene. Thereby, it is possible to prevent moisture or foreign matter from entering the lightning protection element 12 present inside the housing 14.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 11 Lightning arrester 12 Lightning arrester 14 Case 23 Internal space 25 Bulkhead part 29 Fuse wire 31 Disconnection spring 37 Contact switch 38 Cover body 40 Filling material (silica sand)
42 Reinforcing plate

Claims (4)

  A lightning protection element is accommodated on one side of the housing, an internal space is formed on the other side of the housing, and a partition wall portion is provided to project into the internal space, and the terminal fitting attached to the housing is connected to the lightning protection device. The fuse wire is bent so as to bypass the partition wall, and a disconnecting spring is provided in the housing for biasing the elastic force in the direction of separating the fuse wire from the lightning protection element. For arc extinguishing in the internal space of the housing A lightning arrester with a separation function, characterized by enclosing a filler.   The lightning arrester with a separation function according to claim 1, wherein a contact switch that detects and sends out a deterioration state of the lightning arrester by the action of the elastic force of the separation spring is provided in the housing.   The lightning arrester with a separation function according to claim 1 or 2, wherein the casing is made of a resin material in which glass fiber is contained in a nonflammable resin, and has a thickness that can withstand a pressure increase in the internal space due to deterioration of the lightning arrester.   The lightning arrester with a separation function according to any one of claims 1 to 3, wherein a reinforcing plate is attached to a lid that closes the internal space of the housing.

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