DE102008064794B3 - Spark gap arrangement for higher rated voltages - Google Patents

Abstract

A spark gap arrangement for higher rated voltages, wherein at least two spark gaps (1, 2) having opposite electrodes are connected in series and located in a spark gap housing (112), one of the spark gaps is passive and one of the spark gaps is active, d. H. triggerable, as well as with an overcurrent protection device for use as a lightning current carrying mains arrester, characterized in that the spark gaps (1, 2) have a flameproof enclosure (21) with at least one pressure equalization opening (6) and a distance of the main electrodes (8; ) of the passive spark gap (2) bridging insert (13) consists of a low-resistance material which is strongly nonlinear behavior at current load with respect to the falling residual voltage, on the upper side of the spark gap housing (112) a wiring support (800) is arranged with a trigger circuit, the Spark gap housing (112) on its upper side a trough-like recess (114), the overcurrent protection device includes a series circuit of a plurality of fuse elements, wherein a first part of the series circuit on one side of the wiring substrate (800) consists of a mechanical series composite (900) and in the muldena a recess (114) is arranged, wherein a second. Part of the series connection on a second, the first opposite side of the wiring substrate (800) is located, consists of a mechanical parallel connection and at least one of the fuses of the mechanical parallel composite has a firing pin as a mechanical trigger, wherein the mechanical parallel composite surrounded by a protective housing (700) is, wherein by the wiring substrate (800), the trough-shaped recess (114), the spark gap housing (112) and the protective housing (700) isolated portions are formed against contamination and flashovers.

Description

The invention is based on a spark gap arrangement for higher rated voltages, wherein at least two spark gaps having opposite electrodes are connected in series and located in a spark gap housing and at least one of the spark gaps is active, ie. H. triggerable, as well as with an overcurrent protection device for use as a lightning current carrying mains arrester, according to the preamble of patent claim 1.

A series circuit of two spark gaps for the limitation of surges in low-voltage systems, consisting of three electrodes, wherein for the creation of each spark gap, two of these electrodes are each opposite to a surface and are held apart by an insulating layer, is from DE 39 14 624 C2 previously known. The local spark gaps have a very different inherent capacity, whereby the response voltage of the overall arrangement is determined essentially by the spark gap with the smaller capacity.

From the DE 42 40 138 A1 a Ausblasende spark gap is previously known, in which in series with a short spark gap with insulation material one or more spark gaps are connected in series with low-resistance material. In this case, the spark gap with the insulating material defines the response voltage of the overall arrangement.

At the lightning current carrying multiple spark gap after EP 1 381 127 A2 is assumed by several, connected in series partial spark gaps, the partial spark gaps, with the exception of the lightning current event case first responding spark gap are connected by impedances, so that they switch through successively. The second and the further spark gaps are connected via the impedances directly to a common reference potential. With the spark gap presented there, the response voltage should be reduced. For this purpose, a trigger voltage is applied to at least the electrodes of one of the partial spark gaps, by means of which the partial spark gap is forced to switch through.

Similar arrangements with several partial spark gaps are in the WO 2007/003 706 A1 and the US Pat. No. 4,860,156 B1 for high voltage applications.

From the DE 10 2004 006 988 A1 is a spark arrestor overvoltage protection element with at least two located in a pressure-tight housing main electrodes and a Zündhilfselektrode known, wherein in the housing volume, a functional assembly is housed for reducing the Ansprechspannung. This functional module comprises a series connection of a voltage-switching element, an impedance and an isolating distance, so that a simplified, quasi-integrated starting aid is created.

In summary, it belongs to the known state of the art to make spark gaps suitable for use at higher rated voltages by series connection. A simple series connection leads to triggerable spark gaps in addition to the considerable costs to restrictions in terms of protection level and the coordination of the arrester and usually requires an additional complex potential control.

From the DE 199 14 313 A1 is the hedge of a starting aid a spark gap previously known. In this case, fuses or reversible fuses are used. The melting of the fuse is used with the aid of electronic circuits for optical, acoustic and / or electronic display.

After the fuse has responded, the spark gap should be able to exert a redundant protective function with an increased protection level without an ignition aid. Derivation of a display function from the shutdown behavior of fuses is beyond the DE 38 31 935 A1 , of the DE 197 51 470 A1 or the DE 32 28 471 A1 previously known.

The US Pat. No. 6,157,529 A discloses the interruption of a circuit by means of the disconnection of a fuse and a holding coil of a switch.

Ignition aids, as in the DE 199 14 313 A1 described, are also used in combination arresters. With these arresters, the starting aid itself can be designed as an independent overvoltage protection device, which activates the short-circuit element, generally a spark gap, only at the risk of its own overload via a trigger function. A combination arrester is for example in the DE 198 38 776 C2 shown.

The state of the art with regard to special embodiment of encapsulated, pressure-resistant executed, non-hermetically sealed and rotationally symmetrical high-performance spark gaps is still on the DE 10 2007 015 931 A1 and the DE 10 2006 034 404 A1 The latter also includes an overcurrent protection device for use in surge protection devices with an additional mechanical release, designed as a firing pin.

The generic GB 2 179 214 A shows an overvoltage protection arrangement on the basis of the series connection of a triggerable and a non-triggerable spark gap.

From the foregoing, it is therefore an object of the invention to provide a further developed spark gap arrangement for higher rated voltages, wherein at least two, opposing electrodes having spark gaps are connected in series and one of the spark gaps active, d. H. Triggerable is executed. Regarding the response and the coordination, only the triggerable, d. H. active spark gap of the overall arrangement dominate. When line sequencers occur, the arrangement should act like a conventional series of spark gaps.

The arc voltage is composed of the partial voltages of the two spark gaps and it is divided even after the current zero crossing the recurrent mains voltage on the spark gaps. This means that between the triggered and the passive, d. H. not active spark gap to secure a load-dependent division of functions.

The object of the invention is also to provide an overcurrent protection device for use in overvoltage protection devices based on spark gaps with higher rated voltages in the range of 440 V to 760 V and more, in combination with a mechanical trigger for a display and fuses for overload protection , The possibility should be created, using geometrically identical housing, display and mounting parts at different voltage levels to make an economical and functional meaningful design of the active parts, so that an easy adaptability to different uses and applications is given.

The object is achieved by a spark gap arrangement according to the feature combination according to claim 1, wherein the dependent claims represent expedient refinements and developments.

In the series connection according to the invention spark gaps are used, which are located in a flameproof enclosure and which have at least one pressure equalization opening. Furthermore, a distance of the main electrodes of the spark gap bridging insert is provided, which consists of a low-resistance material. This material behaves strongly under current load with respect to the decreasing residual voltage nonlinear.

In a first embodiment variant, the series connection is formed from two physically separated spark gaps, one of the spark gaps being triggerable and the second spark gap being passive.

The spark gaps preferably used are rotationally symmetrical. The respective opposing main electrodes comprise a main electrode with Gasumlenkkanal. With regard to the basic construction of the spark gaps used, reference is made to the teaching according to the patent DE 10 2005 024 658 B4 directed.

Between the opposing main electrodes of the at least one passive spark gap, the bridging, low-impedance insert already mentioned is arranged as a preferably rotationally symmetrical part with a cylindrical opening delimiting the arc combustion chamber. The main electrode opposite the main electrode with the gas deflection channel has a nose portion or a projection which dips into the cylindrical opening, with the wall coming into contact with it. It is understood that the nose portion is to be formed in its outer contour complementary to the shape of the cylindrical opening.

The low-resistance material of the insert preferably has a cold resistance of <100 ohms.

The insert has in one embodiment, a hollow cylindrical shape and is located with one end face over the entire surface of the main electrode with Gasumlenkkanal.

Furthermore, there is the possibility that the preferably hollow-cylindrical insert, in each case with one of its end faces, is in contact with one main electrode in each case over its entire surface.

In this embodiment, the flashover between the main electrodes takes place only after a comparatively longer period of time or at very high pulse currents, which is of particular interest when the residual voltage of the spark gap is to be above the rated voltage for a plurality of pulse-shaped discharges in order to prevent a Netzfolgestrom ,

The clear distance between the respective main electrodes of the spark gaps is substantially greater than that which can be found in the known state of the art in corresponding series circuits, and is at least about 5 mm.

The pressure equalization openings are basically in the axial direction of oriented rotationally symmetric spark gaps and point away from each other to prevent unwanted exposure of functionally important parts.

Between the rotationally symmetric part with cylindrical opening and the main electrode with nose section, in a further embodiment, a transition part may be provided which has a higher resistance value relative to the insert, but is conductive.

The geometric shape of the insert can be subjected to changes in the radial and / or axial direction for adjusting and varying the current density, so that in the preferred rotationally symmetrical basic construction and a desired modular structure by replacing the insert various electrical parameters can be realized.

In an arrangement of two spark gaps in a common, pressure-resistant housing, a common central main electrode is preferably provided, which in this case is insulated from the jacket encapsulation.

The pressure compensation openings are designed axially and opposite in the region of the external contact of the respective main electrode as channels of small cross section for the slow pressure reduction of the already cooled gas. Also based on the design of the pressure equalization channels and the meandering deflection of the gas flow is to the patent application DE 10 2007 015 931 A1 directed.

The external trigger circuit for igniting the active spark gap is guided on the trigger electrode of this active spark gap and on the electrical end connection points of the series connection.

With the proposed spark gap arrangement, it is possible to standard standard spark gaps in encapsulated, pressure-resistant design with pressure equalization openings for higher nominal voltages through series connection, in a simple basic variant, only a single triggered spark gap is connected in series with a single passive spark gap. In the teaching of the invention, the necessary follow current limiting is achieved by increasing the arc field strength due to the pressure increase or in combination with the arc cooling by flowing the arc within encapsulated spark gaps. The distances between the main electrodes are at least 5 mm. The low-resistance material of the insert is located within the passive spark gap directly in the region of the arc channel and radially or completely limits the wall-stabilized arc.

The material bridging the distance between the main electrodes of the passive spark gap has a cold resistance of less than 100 ohms and behaves strongly non-linearly at current load with respect to the falling residual voltage. H. the voltage drops in spite of further increasing current. The material used can briefly cause pulsed currents of several kA without lasting damage until overturning. The resulting residual voltage is well below 2 kV. The height and the duration of the residual stress can also be set or influenced by influencing the current density distribution in the material itself, by the geometric design of the insert or else by a functional subdivision from a plurality of materials.

The passive spark gap does not affect the response, coordination and residual voltage behavior of the entire series connection. The subdivision into partial spark gaps reduces the thermal and dynamic load on each single spark gap and there are many design options. The performance of the series-connected lightning arrester is improved in terms of follow current limiting, lightning current carrying capacity and aging. Compared to a series connection of two triggerable arresters, there is the advantage that both space and costs for the second or multiple ignition units can be saved. In a conventional series connection of triggerable spark gaps namely either a simultaneous ignition must be done, which makes high demands on the spark gaps, the trigger circuit and the potential control, or the trigger circuit must be able to compensate the Zündverzugszeiten the individual spark gaps, since usually trigger circuits only one time and energy provide limited ignition pulse. By using one or more passive spark gaps in the embodiment of the series connection according to the invention, the costs for additional ignition circuits can be saved.

Based on the presented basic design of the series connection of spark gaps, it is possible to produce arresters for 440 V as well as for 760 V voltages. The arrester has a passive spark gap for the 440 V level and a triggerable spark gap connected in series with a trigger circuit.

For devices with higher voltage, two triggerable spark gaps are connected in series. The corresponding trigger circuits are described in the embodiment Control board available. The other means such as fuse elements and the display units are identical, ie there are no significant differences between the arresters 440 V / 760 V.

A basic idea of the invention resides in dividing the fuse elements for the spark gap arrangement, in particular fusible elements, into a series connection of a plurality of fuses which, in addition to the electrical connection, are partly in a mechanical series connection and partly in a mechanical parallel connection. By thus made division of the fuse arrangement arise various possibilities of geometric design and thus for optimal space utilization in otherwise used standard housings.

The division also allows a large variance in terms of residual voltage behavior, rollover protection, current limitation, the actual performance and the necessary distances to vulnerable other components, in particular a trigger circuit.

As already stated, according to the invention a series connection of a plurality of fuse elements is provided which form a geometrically predetermined, mechanical and electrical connection.

This series circuit has a mechanical and electrical parallel composite of fusible elements, wherein at least one of the fuses of the parallel compound comprises a firing pin as a mechanical trigger for actuating a function display.

A first part of the series combination is located on one side of a wiring substrate, in particular a printed circuit board, and a second part of the series compound is located on a second, the first opposite side of the wiring substrate.

The first part of the series composite comprises at least two cylindrical individual fuses, which are mechanically and electrically connected by a conductive cylinder on the end faces and connecting caps present there. This mechanical and electrical connection with the aid of the conductive cylinder takes place only in the area of the mechanical connection caps, so that the insulation and separation distances are maintained.

The composite of the cylindrical individual fuses with the conductive connecting cylinder may be coated by an insulating material, in particular by a shrink tube.

The second part of the series network comprises the already mentioned parallel network, wherein the parallel network is predominantly surrounded by a protective housing to which further functions, which are described below, can be assigned.

The connection caps of the fusible elements of the parallel connection are electrically and mechanically connected and merge into a connection extension, which in each case allows mounting on the wiring carrier.

The free ends of the individual fuses of the first part of the series composite also have connection caps with Lötfähnchen or tab-like continuations.

To adapt to the nominal voltage ranges, it is possible to replace one or more of the individual fuses or fusible elements by a conductive, in particular metallic, geometrically diameter-matched cylinder. The cylinder may also have a predetermined impedance.

In a preferred embodiment, the wiring carrier has an elongate, rectangular shape with screw connection lugs attached to the narrow sides.

The first part of the series composite is at a longitudinal outer edge, with this substantially laterally terminating, located on the wiring carrier.

The second part of the series composite, containing the parallel connection, is arranged essentially at right angles to the longitudinal axis of the first part of the series combination on the wiring carrier.

The protective housing is open to the longitudinal edge of the wiring substrate, to allow an exit of the firing pin and an operative connection of the firing pin towards a spring-biased indicator slide.

The protective housing has on its upper side facing away from the wiring substrate a color-coded indicator surface or an indicator surface extension, which is integrally formed on the housing. In this way, based on a viewing window in a cap or an outer housing, which reveals a view of the top of the protective housing, a functional state can be displayed by a slide either the view of the top releases or blocks this view.

It therefore has the protective housing on the one hand, the function of the isolation of the parallel compound and is for the purpose of retaining elements in the event this fuse is triggered. Furthermore, the housing serves for the aforementioned formation of an indicator surface or the reception of an indicator surface extension.

The wiring carrier is preferably mountable on the upper side of a housing, wherein the housing accommodates in its interior an arrangement of surge arresters, in particular spark gaps. This arrangement of surge arresters, in particular spark gaps is in series connection.

One of the spark gaps of the device is triggerable, in which case the trigger circuit is on the wiring carrier.

The housing for receiving the spark gaps has on its upper side over a longitudinal edge a trough-like recess, in which the first part of the series compound dips, in order to effect a protective and insulating function of the first part of the series compound.

The overall arrangement of housing-mounted spark gaps, located on the top of the housing wiring substrate with electrical elements and the series circuit of a plurality of fuses is surrounded by an insulating cap, the cap having the aforementioned window for detecting the functional state with respect to the indicator surfaces.

The overcurrent protection device is characterized by a modular design with selected fuses for series connection to cause easy adaptation to different rated voltages.

The display slider, which is spring-biased and can be released from the firing pin of the parallel connection, has a display surface which releases or obscures a color-deviating indicator surface, in particular the indicator surface of the top of the protective housing.

Furthermore, the display slider has an extension, which extends in the longitudinal direction beyond the narrow side of the wiring substrate, in order to interact there with a telecommunications contact in operative connection.

The usable in the series circuit of the overcurrent protective device fuses consist of inexpensive to produce individual fuses, each z. B. for a voltage level of 250 V.

For the first part of the series connection, at least two of the fuses are connected together by a precisely fitting cylinder. The cylinder may preferably be a metal cylinder, which in addition to the electrical connection also takes over the mechanical fixing and the necessary mechanical stabilization of the corresponding part of the series connection. The number of connection elements is smaller by this type of connection than in a simple series connection of individual electrical fuses, each z. B. connected by soldering to a circuit board.

The distance between the remaining connection elements or end caps of the fuses is considerable, which makes it easier to maintain separation distances and significantly reduces the risk of bridging.

The preferred arrangement of the above-described series connection on the underside of the wiring substrate provides sufficient separation distances on the wiring substrate and space on the component side, d. H. the opposite side, on the one hand on the volume savings and on the other hand by avoiding critical approximations between the overload-endangered elements and the protective device.

The first part of the series connection is separated at the top by the board from the components of the ignition circuit and on the bottom by the trough-like expression of the housing. This results in a quasi a complete insulating enclosure of the protective device. This prevents in the event of an error Berußung that may occur, and it will protect the separation sections of the ignition circuit when the release of gas or plasma from the fuse from flashovers.

The parallel component arrangement representing the second part of the series arrangement is preferably designed as in the DE 10 2006 034 404 A1 described.

The fuses used as fuses of the parallel connection and also of the series combination preferably have the same fusible conductor at maximum rated voltage. This ensures an almost simultaneous response of all fuses for adiabatic loads and loads in which the axial heat dissipation dominates over the radial heat output.

The characteristic of the series connection of the fuses thus corresponds to a partial area fuse. The dimensions of such a series connection are considerably smaller with comparable switching capacity than individual fuses, z. B. for a nominal voltage of 690 V.

In addition to the above-mentioned space saving allows the division of the fuse into several subunits and a very flexible arrangement of the individual functional units with respect to the position and location with respect to the wiring substrate.

At desired lower rated voltages, one or more fuses of the series assembly can be replaced by a simple metallic cylinder. In addition to the cost reduction, this also leads to a reduction of the residual voltage and thus supports the desired basic function of the arrester. By a two-sided arrangement of metal cylinders in addition to a real fuse in a series combination also the current force effect can be reduced to the fusible conductor, whereby higher pulse currents can be supported.

Through the use of the above-mentioned impedance-affected cylinder and the requirements for the switching capacity of the actual fuse can be reduced, since the prospective short-circuit current is limited by the impedance.

The invention will be explained below with reference to exemplary embodiments and with the aid of figures.

Hereby show:

1 a series connection of a triggered spark gap and a passive, ungetriggered spark gap as discrete elements in each flameproof enclosure;

2 an exemplary geometry of a passive spark gap, as used for the series connection;

3 a further embodiment of a geometry of a passive spark gap, as used in the series connection;

4 a particularly space-saving arrangement of a triggered and a passive spark gap in a common, metallic flameproof enclosure with opposite pressure equalization holes in the form of channels of small cross-section,

5 and 6 a representation of the first part of the series of fused elements;

7 a plan view of the housing with enclosed spark gaps and recognizable trough-like recess at the top of the housing;

8th a side view of an arrangement with housing and wiring support, which includes, inter alia, the trigger circuit and the overcurrent protection device;

9 a representation similar to that after 8th , but in perspective and

10 a representation of the series connection of the spark gaps in the housing 112 ,

The 1 shows a series connection (sectional view) of a triggered spark gap 1 (active spark gap) and an ungetriggered (passive) spark gap 2 ,

The trigger circuit 3 the active spark gap 1 has a connection 4 on that with a connection 5 a main electrode 8th the passive spark gap 2 communicates. Another connection of the trigger circuit 3 leads to the main electrode 8th the active spark gap 1 that also trigger the trigger through insulation 20 , led out of the flameproof metallic encapsulation 21 has.

Pressure relief openings 6 the spark gaps 1 and 2 and the gas flow direction 7 (Arrow) within the spark gaps 1 and 2 are oriented opposite.

Both spark gaps 1 and 2 each have several independent vents 6 to better control the flow and to effectively cool the gases produced during the ignition and burning of the arc. Each one of the main electrodes 8th has an opening 22 , which forms part of a Gasumlenkkanals, in the pressure equalization holes 6 passes.

The triggerable spark gap 1 has two main electrodes, namely the main electrode 8th and 9 , as well as an auxiliary electrode 10 that with the trigger contact 20 is in electrical connection.

Furthermore, the spark gap 1 at least one isolation route 12 on, extending between the main electrodes 8th and 9 this spark gap is located.

Also the passive spark gap 2 has two main electrodes 8th and 9 on. One as a spacer 13 trained insert between the main electrodes 8th and 9 the passive spark gap is preferably made in one piece from a very low-resistance material. With a preferred geometry of da = 15 mm, di = 5 mm and h = 5 mm results in a test current of a few mA, a cold resistance of <100 ohms.

The spacer 13 is preferably designed as a hollow cylinder and lies according to the illustration 1 with one of its front sides over the entire surface of the main electrode 8th on. In the interior of the insert 13 , ie the existing there cylindrical opening, protrudes a nose portion 23 the main electrode 9 into it, resulting in a radial contact with the insert or the spacer 13 results.

The spacer 13 is to avoid flashovers in the contact area between the nose portion 23 the main electrode 9 and the plate-shaped electrode holder 14 against this over the part 15 isolated.

The immersion depth of the nose section 23 the electrode 9 in the spacer 13 increases with the desired level of performance of the arrester and decreases with increasing erosion resistance of the electrode material. The immersion depth is in this case dimensioned so that both the axial erosion of the nose electrode 9 as well as the radial erosion of the spacer 13 not to an insulating separation path between the parts 13 and 9 leads. After the response of the spark gap 1 At momentum load, a current flows up to several kA across the spacer 13 until the path between the electrodes 8th and 9 the passive spark gap 2 is overturned. Due to the non-linear behavior of the material of the spacer 13 Only a small residual stress on the material of the spacer 13 generated, which does not increase the protection level of the entire arrester.

Due to manufacturing and material tolerances, soiling or extreme stress but contact problems or a change in the rollover behavior of the spacer 13 occur, which may result in undesirable effects on the residual voltage of the arrester. This can be due to high demands on the level and duration of the residual voltage of the arrester by one in the trigger circuit 3 integrated overvoltage fine protection and by the type of contact, which includes the passive spark gap can be compensated.

For reproducible manufacturing and material properties or not particularly high stresses and / or lower demands on the protection level, the contacting of the trigger device between the two spark gaps, so only at the terminals of the spark gap 1 , respectively.

The height and duration of the current through the spacer 13 as well as the rollover behavior, in addition to the material properties of this part, also by controlling the current density and the current distribution in the spacer 13 to be influenced. In addition to influencing the residual stress, this can also be used to control the power conversion, the burnup and the thermal load on the spark gap and in particular of the insert 13 be used. The main electrodes 8th and 9 the passive spark gap 2 can with respect to the spacer 13 be completely or partially isolated.

The 2 shows an exemplary geometry as a cross-sectional representation of a passive spark gap. Again, there are two opposing main electrodes 8th and 9 available. The electrodes are insulated in a metallic encapsulation 21 located.

The main electrodes shown 8th and 9 can over the insert 13 be isolated, but the breakdown voltage of the insulation must be well below the desired protection level and below the residual voltage of the trigger circuit.

As an alternative to insulation, there is a defined transition area with a thin and opposite to the spacer 13 high-resistance, but electrically conductive layer 16 possible. Both measures described require a higher current density at the quasi-channel inside of the designed as a hollow cylinder spacer 13 and lead to an accelerated rollover behavior. In addition, a pre-ionization in the isolated or high-impedance range is effected.

The spacer 13 can also be varied in the circumference of the hollow cylinder in both the radial and in the axial direction with respect to the electrical conductivity. As a result, in addition to the control of the electric current density in the spacer 13 also effects of thermal insulation against the electrodes 8th and 9 be effected. In addition, the variation of the materials in the discharge channel can serve the function division or be used to influence the temperature and pressure resistance and the better aging quality and to reduce the burnup.

The 2 shows here, for example, a substantially only axial function distribution. In contrast to the representation after 1 are according to 2 the electrodes 8th and 9 in terms of metallic encapsulation 21 isolated.

The 3 shows a further embodiment of a possible geometry in cross-sectional view for the passive spark gap 2 ,

At this spark gap 2 meant a flashover between the main electrodes 8th and 9 first take place at a comparatively long period of time or very high pulse currents.

This is of particular interest when the residual voltage of the spark gap 2 should be at a plurality of pulse-shaped discharges above the rated voltage in order to prevent a Netzfolgestrom.

For this purpose, the spacer 13 on both sides of the entire surface with the respective main electrodes 8th and 9 contacted to a largely homogeneous current density within the spacer 13 to effect. In addition, increases in the electric field strength, in particular in the rollover area can be avoided.

With the help of 4 Let us illustrate a basic embodiment of two spark gaps in a cross-sectional view, which are located within a common metallic encapsulation 21 are located.

Both spark gaps have a common center electrode 9 , which compared to the flameproof enclosure 21 is isolated. In the area of the passive spark gap 2 However, it is a low-resistance connection to the main electrode there 8th available. In contrast to the representation after 1 in which at both spark gaps 1 and 2 in each case a main electrode directly to the metallic shell 21 in contact, at least at one of the spark gaps 1 and 2 as shown by 4 Both main electrodes opposite the jacket or the encapsulation 21 isolated.

As shown 4 this is at the passive spark gap 2 the case. Alternatively, the spark gap can also 1 or also both spark gaps with insulating main electrodes 8th and 9 be executed. The isolation of the main electrodes 8th and 9 is against an insulating interruption of the pressure-resistant metallic shell 21 preferred due to a better overload behavior. The spark gaps accordingly 4 own as well as in 1 shown, opposite venting and pressure equalization holes or channels 6 ,

The main electrodes point at both spark gap 1 and 2 each at least a distance of substantially 5 mm. The pressure in the discharge area, which of the insert 13 is completely or partially enclosed, is up to several 100 bar for pulse and follow current discharges. For prospective net sequence currents in the range of> 500 A to several kA, pressures of at least 10 bar are achieved.

To control the operating voltage and to ignite the spark gaps no complex and overload-endangered, external, additional capacitive or resistive voltage control is required, which would also need to be tuned over the entire relevant frequency range. The illustrated series circuit of two spark gaps can basically be extended as desired.

The series connection of a spark gap with insulation and a quasi-shorted spark gap has compared to two spark gaps, each with isolated separation distance per se the disadvantage that only one separation section provides an immediate consolidation after the current zero crossing. The instant solidification voltage is in the range of about 300 V. When using such a spark gap at higher operating voltages, especially at voltages above the instant solidification voltage, there is a risk of reignition. In order to be able to work with only one insulation distance, despite this disadvantage, the effect is used that the spark gaps used make use of the pressure increase that forms to delete the secondary current. By using the pressure to extinguish the follow-on current, even after the current zero crossing, in particular with a gradual pressure reduction, it is possible to make the relatively high pressure effective for increasing the dielectric strength of the separation gap. The voltage resistance after the current zero crossing can thus be increased proportionally with the pressure increase, whereby reignifications are avoidable. This surprisingly allows the use of the proposed spark gap combination even at nominal voltages well above the instantaneous consolidation voltage for a separation line.

The used overcurrent protection device comprises a series connection of a plurality of fuse elements, which form a geometrically predetermined, mechanical and electrical composite.

A first part of the series composite comprises two individual cylindrical fuses 100 and 200 , These two cylindrical individual fuses 100 and 200 be through a conductive, preferably metallic cylinder 300 on the front sides 400 and existing connection caps 500 mechanically and electrically, z. B. connected by clamping or soldering.

The resulting composite of cylindrical individual fuses 100 and 200 with the connecting cylinder 300 is with an insulating shrink tube 600 coated (see 6 ).

The free ends of the individual fuses 100 and 200 also have connection caps 500 , but with solder flags 500a which the electric Serve connection and mechanical fixing on a circuit board, on.

The series circuit also includes a mechanical and electrical parallel composite of fusible elements, wherein at least one of the fusible elements of the parallel compound has a firing pin as a mechanical trigger. The mechanical release can be embodied as a wire-shaped release part, whereby preferably this wire of the release part is connected in parallel over a part of the entire overcurrent protection device, which has the advantage that the coordination of the current commutation and the switching capacity is limited to this part of the protection.

In a parallel connection to the entire fuse arrangement, d. H. parallel to all partial fuses, the fuse conductor of the indicator fuse would have to have full switching capability, which is possible but leads to higher costs.

In one embodiment, the fusible link of the fuse to which the indicator is connected in parallel may be provided with a minimally lower fuse integral to ensure a reliable indication even at low overloads.

Since the complete outgassing of the indicator fuse or the throwing away of parts of the indicator can be avoided only with great effort, there is basically the danger of the outer flashover of the fuse arrangement at high voltages.

To counteract this danger, the indicator part, ie the parallel connection, with an additional housing 700 (please refer 8th and 9 ) Mistake.

This case 700 blocks the external flashover and considerably reduces the danger that can arise from released indicator parts (firing pins).

Like from the 8th can be seen, is the case 700 preferably at right angles with respect to the longitudinal axis of the wiring substrate 800 arranged.

The first part of the series 900 comprising the individual fuses with connecting cylinder and protective cover, is on the underside of the wiring substrate 800 located, the second part of the series, located in the housing 700 located on top of the wiring harness 800 is arranged.

From the illustration to 9 it can be seen that the wiring carrier 800 an elongated, rectangular shape with attached on the narrow sides Schraubanschlusslaschen 110 , wherein the first part of the series composite 900 at a longitudinal outer edge, with this substantially laterally, is located.

The protective housing 700 is to the longitudinal edge of the wiring substrate 800 open, to an outlet of the firing pin therein and an operative connection to a spring-biased indicator slide 111 to enable.

The protective housing 700 owns at its from the wiring carrier 800 facing away from a color indicator surface, z. B. red, or has an indicator surface extension, extending from the housing 700 starting out.

The wiring carrier 800 is on top of a case 112 mountable, being in the housing 112 there may be a series spark gap arrangement.

The advantages of the housing construction with regard to the creation of separate, mutually isolated subregions should be made with reference to 7 to 10 will be explained below.

The shielded subregions are the upper part of the wiring substrate 800 , the groove-shaped recess 114 , the spark gap housing 112 and the fuse box 700 to watch. The area of the carrier board and the fuses is from the spark gap housing 112 protected by an insulating partition from Berußung or pollution from this area. The fuse in the groove-shaped recess 114 Thus, in addition to the impurities from the area of the wiring substrate 800 , also from the spark gap housing 112 foreclosed. It can thus neither impurities from the spark gap area nor contamination by destroyed components on the wiring substrate the switching capacity of the fuse 900 affect.

The other part of the series connection of the fuses is through the housing 700 protected for the parallel connection from being touched by the wiring support and at the same time can not cause arcing on the wiring support.

At least one spark gap of the spark gap arrangement can be triggered and the trigger circuit can be located on the wiring carrier. The contacting between the wiring carrier and the spark gap to be triggered can take place via a contact spring extending through a recess 113 in the case 112 extends ( 7 ).

Furthermore, the spark gap housing has 112 on its upper side a trough-like recess 114 into which the first part 900 of the series compound immersed to effect a protective and insulating function (see 7 and 8th ).

The overall assembly may be surrounded by an insulating cap, the cap having a viewing window for a view of the top of the housing 700 or the display slider 111 to allow.

The indicator slider 111 has a display area 115 on. This display area can, for. B. have a green color, which signals the state "OK".

If the display slider moves as shown in the illustration 9 to the left, the underlying top of the case becomes 700 , which is designed differently colored, released and signaled an error condition.

The indicator slider 111 also has an extension 116 extending longitudinally across the narrow side of the wiring substrate 800 extends to having a telecommunications contact 117 to come into operative connection.

In the area of the extension 116 has the indicator slide 111 a mandrel-like formation which receives a helical compression spring which faces the spark gap housing 112 supported to produce the necessary bias.

LIST OF REFERENCE NUMBERS

1

active spark gap

2

passive spark gap

3

trigger circuit

4

connection

5

Main contact / connection

6

Pressure equalization port

7

Gas flow direction

8th; 9

main electrode

10

auxiliary electrode

12

insulating gap

13

Insert or spacer

14

plate-shaped electrode holder

15

insulation part

16

high-resistance, electrically conductive layer

20

Isolation for trigger contact

21

metallic, flameproof enclosure

22

Opening in Gasumlenkbereich a main electrode / Gasumlenkkanal

23

nose section

100; 200

cylindrical single lock

300

connecting cylinder

400

front

500

connection cap

500a

Lötfähnchen

600

coating

700

Housing for parallel connection

800

wiring support

900

first part of the series network

110

Schraubanschlusslasche

111

display slide

112

Spark gap housing

113

Recess for trigger contact

114

trough-like recess

115

display area

116

extension

117

telecomm

180

indicating surface

Claims (8)

Spark gap arrangement for higher rated voltages, wherein at least two opposing spark gaps ( 1 ; 2 ) in series and in a spark gap housing ( 112 ), one of the spark gaps is passive and one of the spark gaps is active, ie triggerable, and with an overcurrent protection device for use as a lightning current carrying mains arrester, characterized in that the spark gaps ( 1 ; 2 ) a flameproof enclosure ( 21 ) with at least one pressure equalization opening ( 6 ) and a distance of the main electrodes ( 8th ; 9 ) of the passive spark gap ( 2 ) bridging insert ( 13 ) consists of a low-resistance material, which behaves strongly at current load with respect to the decreasing residual stress non-linear, on the upper side of the spark gap housing ( 112 ) a wiring carrier ( 800 ) is arranged with a trigger circuit, the spark gap housing ( 112 ) on its upper side a trough-like recess ( 114 ), the overcurrent protection device comprises a series connection of a plurality of fuse elements, wherein a first part of the series connection on one side of the wiring substrate ( 800 ) from a mechanical series composite ( 900 ) and in the trough-like recess ( 114 ), wherein a second. Part of the series connection on a second, the first opposite side of the wiring substrate ( 800 ) Is located, consists of a mechanical parallel compound and at least one of the fusible elements of the mechanical parallel composite has a firing pin as a mechanical trigger, wherein the mechanical parallel composite of a protective housing ( 700 ) is surrounded by the wiring substrate ( 800 ), the trough-shaped recess ( 114 ), the spark gap housing ( 112 ) and the protective housing ( 700 ) partitioned portions are formed against pollution and flashovers. Spark gap arrangement according to claim 1, characterized in that the mechanical series composite ( 900 ) at least two cylindrical fuses ( 100 ; 200 ), which by a conductive cylinder ( 300 ) on the front sides ( 400 ) and there existing connection caps ( 500 ) are mechanically and electrically connected. Spark gap arrangement according to claim 2, characterized in that the composite of cylindrical fusible elements ( 100 ; 200 ) of an insulating shrink tube ( 600 ) is coated. Spark gap arrangement according to claim 1, characterized in that the connection caps of the fusible elements of the mechanical parallel connection connect electrically and mechanically connected in each case into a connection extension, which mounting on the wiring substrate ( 800 ), in particular a printed circuit board. Spark gap arrangement according to one of claims 1 to 4, characterized in that the wiring carrier ( 800 ) an elongated, rectangular shape with attached on the narrow sides Schraubanschlusslaschen ( 110 ), wherein the mechanical series composite ( 900 ) is arranged at a longitudinal outer edge, with this laterally final. Spark gap arrangement according to claim 5, characterized in that the mechanical parallel compound at right angles to the longitudinal axis of the mechanical series composite ( 900 ) on the wiring carrier ( 800 ) is arranged. Spark gap arrangement according to one of claims 1 to 6, characterized in that the protective housing ( 700 ) to a longitudinal edge of the wiring substrate ( 800 ) is open, to an outlet of the firing pin and an operative connection to a spring-biased indicator slide ( 111 ). Spark gap arrangement according to claim 7, characterized in that the protective housing ( 700 ) at its from the wiring carrier ( 800 ) facing away from the top has a color-coded indicator surface or has an indicator surface extension.

Images