DE202007006934U1 - Plug-in surge arrester - Google Patents

Abstract

Plug-in surge arrester with a housing (1) for receiving the arrester element (5), which via conductive Connector (4; 6) on plug contacts (4b; 6b), the housing bottom penetrate, connected, being between a connection of the arrester element (5) and the associated connector (4; 6) has a thermal, formed under spring bias Lot-separation point (4e) is, as well as with a on the solder separation point (4e) acting, the biasing force transmitted separating block (2) and a status display (2d), characterized in that a the conductive connector (4) comprises a switching tongue (4c) whose Tongue end passes into a solder pad (4d) and the tongue (4c) has a current-sensitive predetermined breaking point (4e) or current-sensitive Properties, wherein this predetermined separation point or current sensitivity (4e) at least formed or present in the area of the biasing force is.

Description

The The invention relates to a pluggable surge arrester with a casing for receiving the arrester element, which via conductive connectors on plug contacts, penetrate the caseback, is connected, wherein between a terminal of the arrester element and its associated Connector a thermal, spring-biased solder joint is formed, and with a force acting on the solder separation point, transmitting the biasing force Abtrennbock and a status display, according to the preamble of the claim 1.

For different Requirements and network configurations are different wiring measures with regard to the arrangement of surge arresters necessary to match the specifics of each application have to.

in the Low voltage network will be at various interfaces of the installation Lightning and surge arresters used according to the lightning protection zone concept. This coordinated and coordinated units then dominate all types of transient overvoltages up to the more energetic loads with a direct lightning discharge.

By an interconnection of the respective surge arresters matched to the network configuration with the outer conductors or the energetic one Lines with the neutral conductor or the local earth results adapted to the respective network form protection concept, both in terms of optimum protection as well as failure safety is designed. Single circuits for low voltage networks are in the DIN VDE 0100 part 534 explained.

For the wiring TT systems use a so-called 3 + 1 circuit, at the three live-in outer conductor are interconnected to the neutral conductor, while between the neutral conductor and the local Earth (PE / protective conductor system) arranged another, so-called N / PE arrester is.

in the Case of lightning overvoltage the line arrester and the N / PE arrester, so that the resulting resulting lightning current on the discharges that the system for disposal places, divides. As a rule, these are the outer conductors against the local ones Earth. As a result, the lightning current is distributed in about the same Sharing on the outer conductor, during the entire current from the outer conductors over the N / PE arrester against the local Earth drains off. This means that the N / PE arrester on the total current and the Arresters in the outer conductors only for the respective partial flows are to be interpreted.

by virtue of these multiple load cases that mainly the N / PE arrester it can not be ruled out that this arrester may be in switched state, ie where it has its protective function exercises, overloaded becomes.

A beginning overload makes himself first in the form of a warming noticeable. Here the arrester is in a condition that he over one certain time without consequential damage. Becomes exceeded this time or the temperature reaches values that pose a fire hazard can, it is proposed to make a defined shutdown, in particular in interior applications of the arrester.

When As a result of a heavy load, the arrester can be mechanically destroyed. since e.g. first only the live ones Heat parts in fractions of a second. This can lead to a by annealing come from connections, whereby ultimately the arrester housing thermal destroyed or even can be shattered by the resulting arc.

Around Following error for the explained loading cases ruled out is one on the application case or the destructive behavior of the N / PE arrester matched protective device necessary that the current-carrying Part of arrester in case of overload disconnects and a safe electrical isolation against the ensures occurring voltages.

For example come here so-called thermal separation devices used, which usually include a Lotstelle. When the melting temperature is exceeded of the solder finds an opening the contact connection instead.

According to the state The technology is currently Gas discharge or spark gaps used as N / PE arrester. This has the advantage of being for the normal Operating condition compared to varistor discharge, as shown on the Side of the outer conductor Find a great application Insulation resistance can be achieved.

For gas discharge arresters are a variety of solutions known, which have a shorting bar, the thermally triggered is bridged and the arrester. One such condition is in the case of an N / PE arrester in the low voltage network for safety reasons but not desired.

From the foregoing, it is an object of the invention to provide a further developed pluggable Surge arrester with a housing for receiving the arrester element, which is connected via conductive connector on plug contacts, which penetrate the housing bottom, indicate, the arrester ensures an effective and defined shutdown both in moderate and in heavy overloads.

The solution the object of the invention is carried out according to the combination of features Claim 1, wherein the dependent claims at least expedient embodiments and represent further education.

According to the invention is one the conductive connector designed so that it has a switching tongue includes or goes into such a tongue whose tongue end a Having solder pad.

The Tongue is over it In addition, current-sensitive, e.g. by a predetermined breaking point, this predetermined breaking point in the field of biasing force of a known separation block is trained.

Farther is an intervening according to the invention Lotkontaktstelle and the arrester element arranged electrically and thermally conductive coupling plate, which has a Lotfortsatz.

The Tongue end of the tongue has a cross-sectional shape, the is suitable to partially enclose the Lotfortsatz in Abtrennrichtung, so that only a defined, quite low Lotmenge with nevertheless safer Lotverbindung is added.

Of the Lotfortsatz the coupling plate is as a pin and the tongue end as complementary thereto Shell, gutter or groove formed.

At the Abtrennbock is inventively a nose-shaped trailer molded or arranged, the free end in the region of the predetermined breaking point of the Tongue with this in mechanical contact.

in the Separation case moves the nose-shaped trailer in the separation point into and suppresses this one maybe resulting arc.

Of the Separating block in turn is guided pivotably over a pin bearing in the housing.

The Coupling plate has at its the Lotfortsatz opposite Page a surface contour on, which is complementary to the corresponding contact surface of the arrester element, so that a safe, simple mechanical and electrical connection ensured between these parts becomes.

About the Choice of geometry and / or the material of the coupling plate can be adjust the thermal response of the separation point, i. it becomes the heat flux density from the interior of the arrester element to the thermal monitoring point or specifically influenced by Lotstelle. This influence allows ever according to installation situation and network conditions as well as performance the used Ableiterelements a design of the sensitivity or inertia the separation arrangement.

At least the conductive connector with tongue is made of a single stamped stamped part. This stamping stamping part also has the associated, the caseback penetrating plug contact.

in the Area of the tongue can complement a Tension spring can be integrated, which consists of a spring clip or a Bimetallic or a memory metal strip exists.

Of the Another conductive connector is preferably also as a punch-stamped part with Made of plug contact, said connector has a large contact area has, which in the frictional connection with the corresponding contact surface of Arrester element is located.

Of the other conductive connector has resilient properties and supports against the wall of the housing from. For a uniform contact pressure to ensure based on the arrester element are at least in the area of the housing with support function reinforcing ribs or the like constructive training provided.

The Conductor element may be preferred as a gas arrester with opposite, structured contact surfaces be formed, these contact surfaces a. concave shape exhibit.

In In this case, the coupling plate is opposite to the Lotfortsatz area convex.

Of the inventive surge arrester is preferred in a surge protector for installation between the neutral conductor and the grounding system of a low-voltage system used, the basic principle of the invention also applies to others Applications of surge arresters transferable is.

As already stated, an essential feature of the invention is a combination of a solder separation point as thermal monitoring and a predetermined separation point with adapted properties in Ableiterstoßstrompfad as additional Current monitoring or power shutdown.

The Lot separation point monitors while the heat, at moderate overload through the contacts transfers to the connections, and switches off the biased switching tongue as soon as the warming has melted the solder used.

The power Management however, considered the special behavior of the arrester when overloaded by surge current. In this case, that would be Lotüberwachung way too slow and would do not provide adequate protection. By a corresponding designed feed line, i. a special embodiment of the cross section and / or Modeling the feeder, similar a fuse is guaranteed that the separating device sufficiently fast and with appropriate breaking can be configured.

The Combined separation unit is compact and consists of a single element consisting of line infeed, break point and solder joint or Lotschalter composed, the Lotschalter directly to the component to be monitored, in the present case preferably a gas discharge spark gap is located.

The Invention is based on an embodiment and with the aid of figures will be explained in more detail.

in this connection demonstrate:

1 a view of the pluggable surge arrester with removed protective cap and thus recognizable internal structure and

2 a detail according to 1 with tongue, solder pad and breaking point in the area of the biasing force on a nose-shaped trailer of the separation block.

As shown 1 the surge arrester consists of a housing 1 , At the housing 1 is a visible surface 1a for a status display, wherein a shape 1b represents a stop for this status display.

This status display 2d is at a severance block 2 as well formed as the separation block 2 a nose-shaped trailer 2 B includes.

The overall arrangement, as in the 1 is shown, leaving the plug contacts 4b and 6b surrounded by a cap, which has a viewing window corresponding to the visible surface 1a has.

The plug contacts 4b and 6b serve for contacting in a lower part (not shown) on which the line feed of the outer terminals is made.

These two outer plug contacts 4b and 6b lead into the interior of the case 1 and contact there on both sides of the arrester element 5 ,

According to embodiment, both contact pieces / connectors 4 and 6 in one piece as a punching, drawing or embossing part of a predominantly resilient and yet highly conductive material, for example copper beryllium, made at the ends or expression of each contact springs the plug contacts 4b and 6b form. Furthermore, a contact clip 6a on such a connector which provides an electrical connection to the arrester element 5 produces on the front side.

One of the connectors is formed as a combined separator. This connector consists of a central rail 4 , their expression 4c the line feed to the arrester element 5 and at the same time forms a switching tongue.

At the end of the tongue is a solder pad 4d at a moderate load of the arrester element 5 at the contact 5a melted by heat transfer and with a switching movement of the switching tongue 4c causes the spaced shutdown.

The switching movement of the tongue 4c results from a spring preload, which indirectly via the Abtrennbock 2 a bias on the expression or the tongue 4c and thus on the solder pad 4d exercises.

By the rotary movement of the separation block 2 leads the severed tongue 4c a correspondingly fast switching movement over a large opening travel and thus provides a secure separation between the arrester element 5 and the one by the tongue 4c ago formed line feeder ago.

At the same time, that of the separation block 2 executed rotational movement in its final position 1b in the viewing window 1a displayed so that outwardly this switching position of the Abtrennbocks 2 based on its display area 2d is recognizable as a triggering state. The end of the spring 4 is on the one hand in the benchmark 4a the connector and the other in the benchmark 2c at the separation block 2 attached.

For the interruption of the circuit in case of heavy overload affects the formed by expression tongue 4c , by the required Liche current-sensitive Solltrennstelle 4e located in the cable train formed by them. The then occurring mechanism of the switching movement is the same as in the case of Lotabtrennung, so that here, the optical state detection is effective. The separation point / breaking point 4e is located in the lower third and not directly at the end of the tongue 4c ,

When separating movement, the separation block pushes 2 by its rotational movement between the point of separation, which is carried out as a result of the separation, so that a potentially resulting switching arc is effectively interrupted immediately after its formation. This is possible because of the severance block 2 with its molded nose-shaped trailer 2 B directly above the current-sensitive breaking point 4e is positioned, presses on this and moves in their separation into the space inside.

As already explained, the bias for the switching tongue 4c by a spring 3 produces its one fixed point at the upper end of the contact piece 4a Has. The train created by the spring then acts on the divider block 2 at the point of attack 2c , in turn, on the pivot bearing 2a of the severance block 2 acts and allows the desired rotational movement.

The spring preload force thus engages over the disconnect block 2 on the tongue 4c and thus on the solder pad 4d on the one hand and the current-sensitive predetermined breaking point 4e on the other hand. An additional support for this bias is possible in that in the expression of a tension spring is integrated, which may for example consist of a spring clip or preferably made of a bimetal or memory metal strip. These metals or combinations of metals are selected so that at least two stable, temperature dependent positions or shapes can be assumed. This effect is used according to the invention such that the tongue learns increasing pressure in the switching direction with increasing temperature and thus takes place in addition to the spring force, a bias increase, which positively influences the switching process and the switching speed. In addition, this combination for generating the bias voltage increases the reliability of the triggering of a switching operation, so that a redundancy or emergency running feature is present in the event that one of the mentioned systems fails or has only a limited effect.

The solder pad, the tongue 4c with the arrester element 5 is designed and adjusted so that the separation takes place safely and at a time when there is no thermal damage from a superheated discharge element 5 to be foreseen or given.

This point is determined by the choice of the solder, wherein also the described mechanical bias provides a significant proportion. Furthermore, the Lotmenge at the Lotstelle 4f and optimized the heat distribution at the solder pad.

The solder contact point 4d is shaped so that it takes up only a limited amount of solder. This is the end of the tongue 4c narrow and half-chapped. In order to achieve optimum heat distribution, only highly thermally conductive metals or metal alloys or coatings are used at least in the area of the solder pad.

The further connector or the further contact piece 6 is shaped so that it has supports 8th in the housing or housing half part 1 , which is intended for receiving the components, a contact pressure on the bracket 6a on the contact surface 5b of the arrester element 5 exercises. These supports 8th For example, consist of webs, which at the same time the strength of the Gehäusehalbteils 1 increase, so that a continuous contact pressure is ensured by a corresponding rigidity of the housing.

Through the supports or bars 8th in the bearing housing half part 1 become the two contact pieces or connectors 4 . 6 led and held in their position. At the same time inner webs or formations in certain areas act as insulation for the contact pieces.

The invention essential coupling plate 7 allows through their choice of materials and geometric design to influence the heat flux density from the inside of the spark gap / GDT to the thermal monitoring point (solder pad) targeted.

These Influencing allows depending on the installation situation and network conditions as well as on performance the spark gap / GDT used a sensitivity setting, i.e. the response of the separation arrangement.

So is it possible in principle by a poorly thermally conductive material, e.g. Iron or an unfavorable one geometric design in the form of an elongated conductor with small cross-section, a relatively insensitive thermal separation device perform. This measure leads to in the explained Case the heat flux density reduces and thus the time to reach the melting temperature is enlarged at the solder pad.

In the opposite case, it is possible by using a very good conductive material for the coupling plate 7 as well as by appropriate geo metric design with large cross section and short lengths to increase the heat flux density with the result that the separation device responds faster.

2 shows the thermo / current sensitive area of the switching tongue 4c , Here is also the groove profile, from which the tongue 4c is formed, recognizable.

In the area where the nose-shaped trailer 2 B of the severance block 2 on the tongue 4c rests, is a hole as a current-sensitive breaking point 4e educated.

This hole saves the bottom of the grooved profile, while the side parts or legs of this profile are at least largely preserved. This results in a narrowing of the cross section, which already kinks in the heating phase under the influence of the bias of the Abtrennbocks and thus both the separation and the arc extinction by the Abtrennbock 2 favored.

The expiring end of the tongue 4c consists of a hollow end piece 4d (Lotkontaktstelle), which led outward Lotfortsatz 5a in the form of a form-fitting surrounding in the form of a connecting pin in the separation direction, that the switching movement of the switching tongue 4c when melting the solder in the direction of the bias of the separation block 2 he follows.

These parts form the thermosensitive region of the separating device, ie the one on the heating of the arrester 5 responding.

The tail 4d is using a fusion solder 4f soldered to the Lotfortsatz, the Lotmenge on the Lotfortsatz 5a is limited.

Is due to a current load of the arrester 5 a heating of the coupling plate 7 with lotus 5a , learns due to the lower mass of the deflected area of the tongue 4c As a result, the molten solder is additionally sucked from the solder pad by capillary action, so that a sudden release of the switching tongue 4c is guaranteed without training of finned solder bridges.

Claims (18)

Pluggable surge arrester with a housing ( 1 ) for receiving the arrester element ( 5 ), which via conductive connectors ( 4 ; 6 ) at plug contacts ( 4b ; 6b ), which penetrate the housing bottom, is connected, wherein between a terminal of the arrester element ( 5 ) and the associated connector ( 4 ; 6 ) a thermal spring-biased solder joint ( 4e ) is formed, as well as with a solder on the separation point ( 4e ), the biasing force transmitted separating block ( 2 ) and a status display ( 2d ), characterized in that one of the conductive connectors ( 4 ) a tongue ( 4c ), the tongue end in a solder pad ( 4d ) and the tongue ( 4c ) a current-sensitive predetermined separation point ( 4e ) or has current-sensitive properties, this nominal separation point or current sensitivity ( 4e ) is formed or present at least in the region of the biasing force. Arrester according to claim 1, characterized in that a between solder pad ( 4d ) and the arrester element ( 5 ) arranged, electrically and thermally conductive coupling plate ( 7 ) is provided, which a Lotfortsatz ( 5a ) having. Arrester according to claim 2, characterized in that the tongue end ( 4c ) has a cross-sectional shape, which is suitable, the Lotfortsatz ( 5a ) partially enclose in the separation direction. Arrester according to Claim 2 or 3, characterized in that the solder extension ( 5a ) as a pin and the tongue end ( 4c ) is designed as a shell, gutter or groove. Arrester according to one of the preceding claims, characterized in that on the separation block ( 2 ) a nose-shaped trailer ( 2 B ) is formed or arranged, whose free end in the region of the predetermined breaking point ( 4e ) of the tongue ( 4c ) is in mechanical contact with this. Arrester according to Claim 5, characterized in that in the case of separation the nose-shaped carrier ( 2 B ) into the separation point ( 4e ) and suppresses a possible arc. Arrester according to one of the preceding claims, characterized in that the disconnecting block ( 2 ) is pivotally mounted in the housing. Arrester according to one of claims 2 to 7, characterized in that the coupling plate ( 7 ) at her the Lotfortsatz ( 5a ) opposite side has a surface contour which corresponds to the corresponding contact surface of the arrester element ( 5 ) is complementary. Arrester according to claim 2 or 8, characterized in that on the choice of the geometry and / or the material of the coupling plate ( 7 ) the thermal response of the solder separation point ( 4e ) is adjustable. Arrester according to one of the preceding claims, characterized in that at least the conductive connector ( 4 ) with tongue ( 4c ) consists of a single punched-stamped part. Arrester according to claim 10, characterized in that the punching-stamping part the associated plug-in contact ( 4b ). Arrester according to one of Claims 1 to 11, characterized in that in the region of the switching tongue ( 4c ), a tension spring is integrated, which consists of a spring clip or a bimetal or memory metal strip. Arrester according to one of the preceding claims, characterized in that the further conductive connector ( 6 ) from a punching embossed part with plug contact ( 6b ), this connector ( 6 ) has a large contact area, which in the frictional connection with the corresponding contact surface of the arrester element ( 5 ) is located. Arrester according to Claim 13, characterized in that the further conductive connector ( 6 ) has resilient properties and against the wall of the housing ( 1 ) is supported. Arrester according to claim 14, characterized in that at least in the region of the housing ( 1 ) with support function reinforcing ribs ( 8th ) are provided. Arrester according to one of the preceding claims, characterized in that the arrester element ( 5 ) is a gas discharge with opposite, structured contact surfaces. Arrester according to claim 16, characterized in that the contact surfaces ( 5b ) have a concave shape. Arrester according to Claim 2 or 17, characterized in that the coupling plate ( 7 ) is formed convex on its surface opposite the Lotfortsatz.