WO2007093572A1

WO2007093572A1 - Surge arrester having at least one arresting element, for example a varistor

Info

Publication number: WO2007093572A1
Application number: PCT/EP2007/051318
Authority: WO
Inventors: Peter Zahlmann; Edmund ZÄUNER; Sascha Ludewig; Richard Daum; Georg Wittmann; Florian Gaeck
Original assignee: Dehn + Söhne Gmbh + Co. Kg
Priority date: 2006-02-13
Filing date: 2007-02-12
Publication date: 2007-08-23
Also published as: RU2008135716A; DE102006037551B4; ATE413684T1; JP5050147B2; CN101361145A; RU2407087C2; DE502007000217D1; JP2009527072A; EP1854109A1; DE102006037551A1; EP1854109B1; CN101361145B

Abstract

The invention relates to a surge arrester having at least one arresting element, for example a varistor and a disconnection apparatus, in order to disconnect one pole or all poles of the arresting element or elements from the power supply system, with the disconnection apparatus comprising a solder point (11) which is included in the electrical connecting path within the arrester, with a moving conductor section (12) or a moving conductive link (22) being connected via the solder point (11) to the arresting element on the one hand, and with the conductor section (12) or the link (22) being connected on the other hand to an electrical external connection of the arrester, and furthermore having a spring (15) which produces a prestressing force, with the force vector relating to them acting directly or indirectly on the conductor section (12) or the link (22) in the disconnection apparatus. According to the invention, a blocking element (17) which can be tripped thermally blocks the moving conductor section (12) or the moving conductive link (22) with regard to the prestressing force vector, so that the solder point (11) of the disconnection apparatus is not subject to any permanent load on the force side.

Description

description

Surge arrester with at least one diverting element, for example a varistor

The invention relates to a surge arrester having at least one

Discharge element, for example, a varistor and a separator from device to one or the Ableitelemente one or all poles to disconnect from the network, the separating device comprises a solder joint, which is integrated into the electrical connection path within the arrester, wherein on the solder joint, a movable conductor section or a movable conductive bridge is connected to the diverter element on the one hand and the conductor section or the bridge on the other hand to an electrical outer terminal of the arrester, and furthermore comprising a biasing force generating spring, wherein the relevant force vector acts directly or indirectly on the conductor section or the bridge in the separation direction, according to the preamble of patent claim 1.

Überspannungsabieiter, also in plug-in design, belong to many years to

State of the art. For pluggable surge arresters is assumed by a lower part with contact receptacles and an upper part with insertable into the contact receptacles contact pins and arranged between these contact pins Überspannungsableitelement, preferably varistor.

In the lead to Überspannungsableitelement a solder joint is arranged as a thermal fuse in which one of the soldered supply line parts with a, this supply line in the direction away from the soldering biasing spring is in communication.

The supply line can be designed as a flexible, rope-like conductor, but here problems occur at high surge currents.

Due to the surge current problem has been proposed according to EP 0 905 839 B 1, to connect the spring-biased supply line through a bridge, while both ends are in contact with other supply lines via solder joints. The lead part, which is movable, has inherently rigid properties and can be made with a relatively large cross-section of highly conductive material. This results in a high surge current resistance. Due to the intended two interruption points a particularly safe separation of the surge arrester is to be effected by the network.

In a further development of the teaching according to EP 0 905 839 Bl, it is provided that the bridge considered in cross section double L-shaped. The two supply line sections connected by the bridge can be arranged relatively far apart in this way. It is also previously known to provide the bridge according to EP 0 905 839 Bl at one end with a web on which a spring which generates a prestressing force is fixed.

In addition, there is the possibility of pluggable surge arresters after

EP 0 905 839 B1 to provide an optical defect display, comprising an opening arranged in the end face of the opening and a movably mounted in the interior of the upper part of the lever, which extends from the region of the opening into the path of movement of the conductive bridge and the first, in the region of Opening end carries a signal plate. The signal plate has, on its surface facing the opening, a marking which is typical for the corresponding operating state. The marking can be moved by the bridge at the ÖffnungsDbewegung taking into account the existing lever from a non-visible through the opening in a viewable position.

The solder joint, which holds the bridge under spring biasing force, has a solder with a defined melting point. The melting point is chosen so that it is not yet reached with heat energies that the arrester can absorb undamaged. The solder joint thus remains effective as long as the surge arrester is undamaged but is released at higher heat energies.

[009] In compliance with the maximum requirements of the standard regulations

Operating temperature inside such Überspannungsabieiter relatively low melting solders must be used. Such solders are only limited able to absorb mechanical forces, in particular shear forces.

The latter, in turn, means that the spring biasing force, which acts on the bridge and the corresponding solder joint, is subject to a narrow limitation. However, limited spring force is detrimental to rapid separation of the rigid bridge member, especially if there is no immediate penetration of the solder joint due to the eutectic behavior of the solder.

From the foregoing, it is therefore an object of the invention to provide a weiterentD wound Überspannungsabieiter with particular thermal separation device from which shows a very safe low-arc separation behavior in case of failure and has a high long-term stability, especially with regard to the solder joint of the thermal separation point. The solution of the object of the invention is achieved by a Überspannungsabieiter in its definition according to feature combination according to claim 1, wherein the dependent claims represent at least expedient refinements and developments.

Accordingly, the basic idea of the invention is that in addition a thermally actuable blocking element blocks the movable conductor section or the intended movable conductive bridge with respect to the permanently acting prestressing force vector so that the soldering point of the separating device is not subjected to permanent force-side loading.

By this additional e.g. Lotformteil is given a lock, which is subject to unlocking on reaching the set melting temperature, so that the prestressed spring then activates the separation device.

The sensitive solder joint of the electrical isolation device is not permanently one

Spring force or spring preload exposed. With this in mind, it is now possible to simplify the design of mechanical assemblies, i. to correct and optimize the spring, the release lever and the respective lever ratios.

In particular, according to the invention, there is the possibility of allowing large spring forces to take effect, which realize rapid movement during the actual separation. Under these conditions, the breaking capacity of the separating device in the case of becoming active this is significantly improved.

In one embodiment of the invention, the thermally triggered

Locking element on the one hand in an Abwinklungsbereich of the conductor section and on the other hand counteracted on the arrester housing or a housing partition wall of the arrester and standing with the arrester in thermal, heat-conducting contact.

In a further embodiment of the invention blocks the thermally triggered locking element as a bolt-like part of the movement of a lever translation, which is arranged between the spring and the conductor section.

The thermally actuable blocking element can be made as a preformed part from a low-melting solder or be manufactured in such a way.

The properties of the solder for the thermally-releasable blocking element, regardless of electrical parameters, can be determined solely from the mechanical point of view, e.g. high tensile strength, can be selected.

[019] In the embodiment, the movable conductor section can be designed as a spring tongue be, so here is a further support of the separation movement in case of failure is given.

[022] The leverage can be associated with an optical defect indicator to signal the failure or failure state of the diverter element.

Of course, there is the possibility of resorting to the

HebelD translation or the movement of the conductor section to activate a telecommunications contact.

In one embodiment of the invention, the movable conductor section is a

Punched-bent part, which has a molded external connection, in particular in the form of a plug-in contact. Thus, this part can be manufactured inexpensively and easily assembled without much effort.

In a preferred embodiment of the invention, the

Activation temperature of the blocking element is less than the melting point of the solder joint. Thus, the blocking element function is lifted when the temperature rises in the critical area, so that the further movement of the temperature in case of failure, the separation movement is freely triggered or can take place.

[026] If, for example, a lever transmission ensures that the

Reaching the activation temperature of the blocking element, a lever part travels a first way to get into abutment with the conductor section or the bridge, then this distance traveled can be used to trigger a telecommunications contact or an optical display, which signals that a critical Temperature increase took place in order to indicate in this way that it is expedient to replace the surge arrester.

[027] Compared to previous thermal separation devices, the

Biasing force, which is preferably generated with a spring arrangement, assume a higher value compared to the possible continuous load of the solder joint in order to ensure the desired very fast separation movement of the conductor section or the conductive bridge in case of failure.

The invention will be hereinafter an embodiment and under

With the help of figures will be explained in more detail.

[029]

[030] FIG. 1 shows a first exemplary representation of the solution according to the invention with a solder preform, which is located in the disconnection frame in thermal contact with a varistor disk,

[031] FIG. 2 shows an embodiment in which the solder preform of the blocking element acts directly on or is arranged on the conductor section and via an abutment in the

Housing partition, and [032] Figures 3 and 4 show a third embodiment of the invention with two stages

Load or defect indicator. [033] In the illustrations according to FIGS. 1 and 2 is of a pluggable

Surge arrester with a base part assumed. This base part 1 has a rear recess with means for DIN rail mounting 2. [034] In the space formed by the two legs of the U-shaped base part 1, the actual surge arrester 3 is inserted. Appropriate

Plug contacts 4 on the surge arrester 3 engage in contact recesses 5 in

Base part 1 a. An encoding 6 on the one hand in the base part 1 and on the other hand in

Surge arrester 3 prevents the insertion of incorrect or inappropriate

Arrester. The surge arrester 3 has in its interior the actual arrester (not shown), e.g. a varistor disc. [036] The varistor disk located behind the partition wall 7 has two

Connections. A first terminal 8 is connected to the left-side plug contact 4 via

Ladder part 9 in connection. [037] A second terminal 10 is passed through the partition wall 7 and connected there via a solder joint 11 with a movable conductor section 12. [038] The movable conductor section 12 is arranged in the right side

Plug contact 4 via. [039] A lever-like cut-off block 13 has an optical top side

Defect indicator 14 on. [040] A first end of a spring 15 engages adjacent to the optical defect indicator 14, wherein the second end of the spring 15 is fixed in the region of the dividing wall 7. Thus, the spring 15 causes a biasing force via the disconnecting block 13 and the plunger 16 on the movable conductor portion 12 and thus the solder joint 11. [041] The thermally-releasing blocking element 17, e.g. designed as a solder preform, sits in

Abtrennbock 13 and locks it like a bolt on a corresponding counter-bearing in the partition 7. By the thermally triggered blocking element 17 of the force vector of

Clamping force blocked, so that the soldering 11 of the separating device is not exposed to a permanent force-side load. The surge arrester 3 also has a housing 18 with a window 19 with respect to the optical defect display 14. In the embodiment of FIG. 2 is assumed by a similar construction as explained for Fig. 1.

However, here the thermally releasable blocking element 17 is not located as a locking pin in the separation block, but in the region of the movable conductor portion 12 and symbolized by the reference numeral 20.

Also in this embodiment prevents the thermally triggered

Locking element, that the biasing force of the spring 15, the solder joint 11 permanently applied with the result of undesirable tensile or shear forces. Only when the melting temperature of the solder preform 20 is reached, the force path is released and it can be carried out in a known manner with further temperature increase after reaching the solder temperature with respect to the solder joint 11 of the separation process.

As can be seen from FIGS. 1 and 2, the movable conductor section 12 can be manufactured in one piece with the right-hand plug-in contact 4 as a stamped and bent part and used to facilitate assembly.

Figs. 3 and 4 show a third embodiment of the invention with two-stage load or fault indication.

FIG. 3 illustrates the state in which no critical ther-dynamic loads have yet occurred for the surge arrester and in which the blocking element 17 has not yet been triggered.

FIG. 4, on the other hand, shows the state after release of the blocking element 17.

In the illustrations according to FIGS. 3 and 4, the thermally triggerable

Locking element 17 part of a two-stage load or DefektD display, with a hinged lever arm 28 is present, the lever arm 29 engages in a locking slide 24. This locking slide 24 is in mechanical contact with a stop 27 of a bridge actuating part 23 and blocks this bridge actuating part 23 in the state according to FIG. 3.

[051] The bridge operating member 23 is held under bias of a spring 15 and has a recess 26 in which a nose 25 of the conductive bridge 22 engages.

In the state of the blocked bridge operating part 23 due to the action of the

Locking slide 24 is, as shown in Fig. 3, detail A, a clearance between the recess 26 and the nose 25 is present, which means that the force of the spring 15 is not transferred to a critical solder joint extending between the bridge 22, the respective terminal of the diverter and the plug contact 4 is located.

So it takes the blocking element with its locking slide 24 the FedervorD voltage of the bridge actuating member 23 in the untripped condition and derives the spring biasing force. In the tripped state, however, the gate valve 24 comes out of contact with the stop 27 of the BrückenbetätiDgungsteils 23, with the result that the game as shown in detail A of FIG. 4 disappears. Only in this case, the effect of the spring 15 for generating a biasing force on the bridge operating member 23 to the bridge 22 comes into their own.

The lever arm 28 of the locking element 17 is held by a solder pin or plunger 30 as the actual thermal barrier element, wherein the melting temperature of this solder pin or Lotbolzens 30 may be smaller than the temperature of the solder, which the bridge 22 with the respective terminal of the diverter and the plug contact 4 connects.

If, for example, a thermal load of the surge arrester has occurred, which has not yet led to a malfunction of the actual diverter, but for the future performance or the exchange cycle of the trap is important, under the action of the spring 32, the lever arm 28 in a 4 transferred to the left, with the entrainment of the locking slide 24, which communicates with an optical defect indicator 14 in connection. This optical defect D display 14 then enters the area of a window, not shown, and signals the occurred thermal load.

[056] As is clear from the figurative representations 3 and 4, this takes effect

Hebelarmende 29 in a groove-shaped recess of the locking slide 24 in order to take this movement side can.

By the blocking action between the locking slide 24 and the stop 27 of the bridge actuating part 23, the bias of the spring 15 can be made very large, without causing an unwanted mechanical permanent load on the bridge-side solder joint or several solder joints located there. On the other hand, this higher bias of the spring 15 causes a very rapid opening and thus separating the diverter in the load case. Due to the arrangement of the solder pin or soldering bolt 30 directly on or in the partition wall 7 and thus in the immediate vicinity of the diverter, the heat generated in this element in the load case is passed directly to the solder pin or bolt 30, so that for a safe response of the solder material in the sense of desired thermal tripping is ensured. The bridge actuating part 23 may have a tongue 33 for receiving the spring 15, which at the same time serves to guide the bridge actuating part 23 by means of spaced guide elements 34.

[059] To facilitate the assembly, in particular, of the bridge actuation part 23 under prestressing of the spring 15, this has bores 35 which are provided on projections. If a U-shaped bracket is inserted into the bores 35, further parts, in particular the locking element 17, are independent of the mounting , Carrying out the soldering of the bridge 22 in a particularly easy way possible. Namely, in this case, the bracket not shown in the figures blocks the movement of the bridge operating member 23 by being engaged with the outer edge of the partition wall 7. In the holes 35, a soldering pin or soldering bolt 30 can also be integrated to realize the function of locking.

[060] List of Reference Numerals

[061] 1 base part

[062] 2 means for DIN rail mounting

[063] 3 surge arrester

[064] 4 plug contact

[065] 5 contact recess

[066] 6 coding

[067] 7 partition wall

[068] 8 first connection

[069] 9 ladder part

[070] 10 second connection

[071] 11 solder joint

[072] 12 movable conductor section

[073] 13 detachment block

[074] 14; 31 optical defect displays

[075] 15; 32 springs

[076] 16 pestles

[077] 17 thermally triggerable blocking element

[078] 18 housings

[079] 19 windows

[080] 20 blocking element in the embodiment according to FIG. 2 (solder preform)

[081] 21 second terminal according to the third embodiment

[082] 22 bridge [083] 23 bridge operating part

[084] 24 gate valves

[085] 25 nose

[086] 26 recess

[087] 27 stop

[088] 28 lever arm

[089] 29 lever arm end

[090] 30 plumb or plunger

[091] 33 tongue

[092] 34 guide elements

[093] 35 bore

Claims

claims

Surge arrester with at least one diverting element, for example a varistor and a disconnecting device, in order to disconnect the diverter element (s) one or all poles from the mains, wherein the divider device comprises a soldering point which is integrated into the electrical connection path inside the arrester; wherein via the solder joint, a movable LeiterDabschnilt or a movable conductive bridge with the Ableitelement on the one hand and the Leiterabschnilt or the bridge on the other hand connected to an electrical outer terminal of the arrester, and further comprising a biasing force generating spring, wherein the relevant force vector directly or indirectly on the conductor portion or the bridge acts in the separation direction, characterized in that a thermally actuable blocking element blocks the movable conductor section or the movable conductive bridge with respect to the biasing force vector, so that the solder joint of the A Btrennvorrichtung is exposed to any permanent forceful load.

Surge arrester according to claim 1, characterized in that the thermally triggered blocking element engages on the one hand in an angled portion of the Leiterabschnits and on the other hand is abutted against the arrester housing or housing partition wall of the arrester.

Überspannungsabieiter according to claim 1, characterized in that the thermally triggered locking element as a bolt-like part blocks the BewegungsDweg a lever translation, which arranged between the spring and LeiterD section.

Surge arrester according to one of the preceding claims, characterized in that the thermally actuable blocking element is a preformed part made of a low-melting solder.

Surge arrester according to one of the preceding claims, characterized in that the movable conductor section is designed as a spring tongue. Surge absorber according to claim 3, characterized in that the lever transmission is in communication with an optical defect indicator.

Surge arrester according to one of the preceding claims, characterized in that the movable Leiterabschnilt is a stamped and bent part, which has a molded outer terminal, in particular plug connection.

Surge arrester according to one of the preceding claims, characterized in that the activation temperature of the blocking element is smaller than the melting temperature of the solder joint.

Surge arrester according to one of the preceding claims, characterized in that the biasing force occupies a higher value compared to the possible continuous load of the solder joint, in order to ensure a very fast separation movement of Leiterabschnilts or the conductive bridge in case of failure.

Surge arrester according to one of the preceding claims, characterized in that the thermally actuable blocking element (17) is part of a two-stage load or defect indicator and comprises a hinged lever arm (28), the lever arm end (29) in a locking slide (25) engages with a stop (27) of a bridge actuating member (23) in mechanical contact, the bridge actuating member (23) is held under spring tension and a recess (26) into which a nose (25) extends into the conductive bridge, wherein the Locking element (17) with its locking slide (24) receives the spring bias of the bridge actuating part (23) in the untripped state and derived kraftseMg such that between the recess (26) and nose (25) remains a game and in the tripped state, however, the locking slide (24 ) comes out of contact with the stop (27) of the BrückenDbetätigungsteils.

[011] Surge arrester according to claim 10, characterized in that the locking slide (24) is connected to an optical defect indicator (14). Surge absorber according to claim 10 or 11, characterized in that the lever arm (28) via a solder pin or plunger (30) as a thermal

Locking element is secured. [013] Surge arrester according to claim 12, characterized in that the melting temperature of the solder pin or plunger (30) is lower than that

Melting temperature of the solder is, which the bridge (22) with the respective

Connection of the diverting element and the plug contact (4) connects. [014] Surge arrester according to one of Claims 10 to 13, characterized in that the bridge operating part (23) is connected to a further optical defect indicator (31).