EP1338064A2

EP1338064A2 - Compact arrangement for multipole, surge-proof surge arresters and encapsulated surge arrester for the same

Info

Publication number: EP1338064A2
Application number: EP01990442A
Authority: EP
Inventors: Georg Wittmann; Edmund ZÄUNER; Peter Zahlmann; Arnd Ehrhardt; Bernhard Krauss; Michael Waffler; Stefan Hierl
Original assignee: Dehn and Soehne GmbH and Co KG
Current assignee: Dehn SE and Co KG
Priority date: 2000-11-28
Filing date: 2001-11-27
Publication date: 2003-08-27
Anticipated expiration: 2021-11-27
Also published as: EP1338064B1; WO2002045224A3; AU2002229570A1; WO2002045224A2; US20040160723A1; US7271992B2

Abstract

The invention relates to a compact arrangement for multipole, surge-protected surge arresters, comprising internally wired, encapsulated series gaps which are arranged essentially in parallel in a housing. Said series gaps have opposite-lying, projecting contact surfaces which are connected to outer terminals and inner contact bars or bridges. The arrangement also comprises an electronic control or trigger circuit which is located on a wiring support. The housing is provided with dividing walls and has a trough shape, the resulting housing chambers accommodating the series gaps and the terminals. An insulating plate with openings into which spring contact elements are introduced is provided on the housing trough which opens upwards. Located above said insulating plate is the wiring. The spring contact elements create the electrical connection between contact points on the underside of the wiring support and the cover of one of the series gaps, respectively. The invention also relates to an encapsulated surge protector, comprising a series gap arrangement with two metallic main electrodes lying coaxially to each other and at least partially overlapping each other and having connections in opposite directions. Said main electrodes form an arc chamber in conjunction with at least one insulation part. According to the invention, at least one of the main electrodes has an inner expansion chamber and a trigger electrode extending preferably radially or axially rotationally symmetrically is provided at least in the area of an outer insulation part.

Description

Compact arrangement for multi-pole surge current-proof surge arresters and encapsulated surge arresters therefor

description

The invention relates to a compact arrangement for multi-pole surge current-resistant surge arresters with internally wired, encapsulated spark gaps arranged essentially parallel in a housing, the spark gaps having opposite, protruding contact surfaces which are connected to external connection terminals and internal contact rails or bridges, and with an electronic control or trigger circuit located on a wiring carrier, according to the preamble of patent claim 1, and an encapsulated surge arrester, in particular for use in such a compact arrangement according to the preamble of patent claim 19.

Multi-pole surge arresters are known which are surge-proof up to 100 kA and which contain several encapsulated spark gaps in one housing, but not in a 3 + 1 circuit.

In a so-called 3 + 1 circuit, the outer conductors L1, L2, L3 are connected to N and the N conductor is in turn connected to PE. In the case of such embodiments of multipole surge arresters in a housing, an internal wiring level change is therefore required if all conductors (L1, L2, L3 and N) are to be excluded from one side. If such internal wiring is implemented using an additional bridge, at least two further screw or welded connections are required for electrical contacting. Due to the fact that such a bridge is exposed to a very high mechanical load with the mentioned possible surge currents in the range around 100 kA, appropriate dimensioning and mechanical design must be ensured.

Another problem with the embodiments of multi-pole diverters with a change of wiring levels is that, if possible, no additional installation space for the bridge itself should be used in order not to change the external dimensions of the housing or to use standard housings which also are suitable for other applications.

Likewise, for reasons of installation space minimization, the trigger circuit or a control circuit is to be integrated in the housing, the electrical connection points having to be designed with a view to the assembly and production expenditure.

In low-voltage networks, so-called N-PE spark gaps are used to protect against overvoltages between the N and PE conductors. These spark gaps must have a very high surge current discharge capability up to 100 kA 10 / 350μs, especially for protection against direct lightning strikes.

Encapsulated spark gaps with such a power are known for example from DE 196 04 947 Cl, DE 198 18 674 AI or DE 298 10 937 Ul. These spark gaps have a protection level of> 2.5kV.

However, spark gaps with lower protection levels are required in certain applications. The use of trigger circuits is expedient to meet these requirements. Powerful N-PE spark gaps, which also have an additional effective trigger electrode with consistently high performance, are not yet available. The high current load, the associated high material burn-up, the high dynamic loads caused by current forces, pressure, energy and temperature place considerable structural demands on encapsulated arresters.

Surge arresters with coaxial electrode arrangements, which are advantageous on the production side due to the given rotational symmetry, have been disclosed, for example, in EP 0 840 413 AI or EP 0 771 055 AI. There, an electrode is insulated on both sides through a tube, which simultaneously represents the outer electrode and the housing jacket. The insertion of an additional trigger electrode is not possible or only with difficulty. In addition, an additional electrode would be arranged directly in the burning area of the arc and thus influence the burning behavior of the arc and be subject to severe erosion. According to DE 35 28 556 AI or EP 0 242 688 B1, coaxial electrode arrangements are formed by one-sided protrusion of a stick electrode into a tubular electrode. In the case of the solutions cited, the introduction of a third electrode is not provided and is also difficult to implement. Furthermore, in the event of the ignition of, in particular, high-current or long-lasting arcs, there is a risk that they will emerge from the coaxial electrode area and permanently damage the encapsulation of the spark gap. Existing cavities outside of the preferred combustion chamber cannot be used for pressure relief or as an expansion space, since the heat transfer to the insulation material of the housing wall is extremely ineffective.

Encapsulated spark gaps with a coaxial electrode arrangement are previously known from US Pat. No. 3,849,704, but also from DE 198 17 063 AI.

According to DE 198 17 063 AI, the electrode spacing increases with increasing distance from the rollover point. The aim here is to achieve an arc hike with an arc extension to increase the extinguishing capacity in the case of line follow current. However, the extension of the arc inevitably leads to higher energy conversions and higher temperature and pressure loads that are unnecessary and also undesirable, particularly with N-PE spark gaps.

The overvoltage protection elements cited also have no third electrode for triggering. The prior art cited above also shows no expansion spaces in which the heated gas can be effectively cooled after or during the load. However, such a measure is very important, in particular in the case of encapsulated N-PE spark gaps, since the pressure load, the arc tension and thus the energy conversion and the temperature load can be kept to a minimum.

From DE 100 08 764 AI, in turn, an overvoltage protection device is known which has coaxial main electrodes which can be triggered. The electrodes are connected from the same side in order to bring about a directed movement of the arc to a baffle plate within the spark gap. However, this leads to an extension and division of the arc, which is intended to support the extinguishing of line follow currents. As already explained, the extension of the arc is not expedient for N-PE spark gaps. Furthermore, the known spark gap has no suitable expansion spaces which allow the hot gases to cool down. The resulting high pressure thus causes an undesirable increase in the arc voltage and stresses the housing of the spark gap unnecessarily in mechanical terms. The pressure load can only be reduced through large outlet openings, which are already effective when arcing occurs. However, there is a risk of undesired leakage of electrically conductive gases.

DE-AS 12 82 153 presents a spark gap which has a so-called expansion and reflection space. The reflection space should press the arc into the expansion space through the pressure that arises when the arc is ignited, in order to protect the ignition point against excessive burn-up and on the other hand the arc to extend, so that the extinguishing behavior of the spark gap is improved.

From the above, it is therefore an object of the invention to provide a further developed compact arrangement for multi-pole surge current-resistant surge arresters with internally wired encapsulated spark gaps with a trigger circuit arranged essentially in parallel in a housing, which can also be used for a so-called 3 + 1 circuit and which can be produced in a particularly cost-effective manner.

This part of the object of the invention is achieved with a compact arrangement for multi-pole surge current-resistant surge arresters according to the features of patent claim 1, subclaims 2-18 comprising at least expedient refinements and developments.

Furthermore, it is an object of the invention to provide a further encapsulated surge arrester with a

Specify spark gap arrangement, which in particular as N-

PE arrester can be used in a compact arrangement.

The surge arrester should meet the essential requirements, namely a high insulation capacity and a very high surge current discharge capacity, and there should be the possibility of using a third electrode

Surge arrester triggerable.

This part of the invention is solved with an encapsulated surge arrester according to the features of patent claim 19, the following subclaims comprising at least expedient refinements and developments.

According to a basic idea of the invention, it is assumed that a housing has a trough shape with internal partition walls, the housing chambers formed in this way receiving the individual spark gaps and the respective connection terminals. An insulating plate is provided on the housing trough which is open at the top and has openings into which spring contact elements are inserted. Furthermore, the wiring carrier for the electronic control or trigger circuit is located above the insulating plate, the spring contacts establishing an electrical connection between contact points on the underside of the wiring carrier on the one hand and the outer jacket of one of the spark gaps on the other.

The wiring carrier is preferably a copper-clad printed circuit board, the contact points on the underside of this printed circuit board being designed as solder pads of larger area.

The printed circuit board comprises lateral, preferably cranked connection lugs, which can be electrically and mechanically connected to the inner contact rails, which are located in the respective housing chambers. As a result, not only the desired electrical contacting but also a mechanical locking of the insulating plate containing the spring contact elements is achieved. Separate fasteners for the insulating plate itself can be omitted.

The underside of the insulating plate preferably has sleeve-like extensions in the area of the openings, which are cut at an angle to the longitudinal axis, so that on the one hand the spring contact elements are secured against falling down and on the other hand a conductive section of the latter is exposed. In the lower section, which is not cut, the sleeve-like extension is closed in order to accommodate preferably used cylindrical compression springs, which on both sides of the respective openings, i.e. protrude upwards and downwards over the gate.

If the encapsulated spark gaps have a substantially cylindrical shape, the chamfer of the sleeve-like extensions is in the form of a segment of a circle and is complementary to the cylindrical spark gap housing. Opposite the respective sleeve-like extensions, at least one further locking extension is formed on the insulating plate, which is adapted to the shape of the housing with its side oriented toward the respective spark gap, so that the insulating plate adjusts itself when it is put on, which further simplifies the assembly effort.

The top of the insulating plate has molded spacer cams that are supported against the underside of the circuit board. This minimizes unwanted force effects on the soldering points of the electronic components on the circuit board and undesired voltages and forces on the circuit board. In this sense, the distance cams are arranged distributed over the outer circumference of the top of the insulating plate.

The housing and the insulating plate are preferably plastic injection molded parts, i.e. in particular the insulating plate with the sleeve-like extensions and the distance cams is in one piece.

A proposed wiring level swap bridge for a 3 + 1 circuit has an essentially Z-shape with two short, oppositely directed and one longer connecting leg, the attachment and electrical

Contacting via a fit, essentially based solely on positive locking, is realized.

Existing protruding contact areas on the spark gaps are used to achieve the attachment and contacting of the wiring level swap bridge via these quasi bolts. The longer connecting leg of the wiring level swap bridge can be provided with an insulation jacket.

Fitting bores or cutouts are made in the short legs, which correspond to the external dimensions of the respective projecting contact surfaces of the spark gap. Furthermore, the material thickness of at least the short legs is substantially the same or a small amount less than the height of the contact surface projection of the respective spark gap. The wiring level swap bridge is then arranged in the outer housing of the surge arrester so that the long leg runs in the space between two of the spark gaps or between two chambers.

For internal connection and for receiving external terminals, the contact rails required for this purpose are designed as metallic angle elements in one embodiment of the invention, a first angle leg being non-positively connected to the respective projecting contact surface of the spark gap and a positive fit being provided in the housing via this leg. A second angle leg receives the external terminals mentioned or is used to attach them.

The first angle leg of the contact rails is connected via a screw connection to the respective contact surface of the spark gap, the bore provided there having an internal thread being used for this.

The screw connection, as mentioned above, also serves to secure the respective short legs of the wiring level swap bridge. Accordingly, there is no further screw connection or a similar contacting measure for changing the wiring level, e.g. across the contact rails, necessary.

In a three-phase arrangement of the multi-pole surge arrester with neutral conductor, one of the contact rails connects three of the four spark gaps on one of the long sides of the housing. The contact rail provided on the opposite longitudinal side of the housing is designed either as a single rail per spark gap or as a contact rail which has insulating sections. This contact rail, which has individual contact rails or the insulating sections, receives the phase or neutral conductor terminals. For the PE connection, a further contact rail is provided with at least one outer terminal, which is connected to the fourth spark gap.

The wiring level swap bridge extends between the third phase spark gap and the neutral conductor spark gap and is electrically contacted there accordingly.

The wiring level swap bridge preferably consists of a conductive flat material, in particular copper.

As mentioned above, chambers formed in the housing accommodate the spark gaps, the longitudinal sides of the housing comprising grooves or slots which serve to guide and fasten the contact rails.

One of the chamber walls can be designed to receive at least a portion of the wiring level swap bridge.

In the area of the short legs of the wiring level swap bridge, tongue-like features or projections are arranged or provided, which in the assembled state form a counter-bearing directed toward the respective first angle leg of the contact rail, so that extension forces of the wiring level swap bridge occurring during surge current flow can be safely absorbed.

In the resultant current flow of a 3 + 1 circuit with a change of wiring level, the swap body is arranged in such a way that electrical forces caused by current flow cancel each other out in the sense of compensation, which represents a further essential advantage of the invention.

Since the wiring level swap bridge is contacted directly on the spark gap packets via holes in the bridge, no additional mechanical connections are necessary. The preferred fit and the additional securing of the fit clamping by means of the contact rails creates an optimal electrical as well as mechanical African design without increasing the installation space and thus changing the external dimensions of the multi-pole surge arrester housing.

The preferred stacking arrangement of spark gaps lying in a first level, an insulating plate located above and the printed circuit board with the electronic circuit arranged above this reduces the installation space in the desired manner. The insulating plate not only fulfills the task of electrical insulation, but also serves as

Carrier element of preferably cylindrical compression springs, which serve for the electrical contacting or connection of the control or trigger circuit with the spark gaps located in the first level. An outer cover then completes the overall arrangement and ensures contact safety and protection of the assembly.

The surge arrester further developed according to the invention is based on a coaxial construction of at least partially overlapping metallic main electrodes which have oppositely directed connections. The main electrodes enclose an arc combustion chamber in connection with at least one insulation part. According to the invention, at least one of the main electrodes has an inner expansion space and a trigger electrode, which preferably runs radially or axially rotationally symmetrically, is provided in the region of the insulation part.

The first main electrode is preferably designed as a rod electrode with a cavity, the latter being in communication with the arc combustion chamber via openings on the flow side.

In the connection area of the second, hollow cylindrical outer main electrode there is another expansion space.

The expansion spaces can have a minimized pressure compensation opening, which is preferably formed in the area of the connections. In one embodiment of the invention, the rod electrode is centered and held with its end remote from the connection via a further insulation part within the surrounding, second main electrode.

The second insulation part has return flow channels to the expansion space of the second main electrode.

Both expansion spaces can be connected on the flow side by at least one insulating channel.

A respective response voltage can be predetermined in a targeted manner by varying the radial distance between the coaxially arranged, partially overlapping electrodes.

At least one of the electrodes has a shoulder facing the arc combustion chamber or a step for a staggered response behavior and reliable extinguishing capacity even if the triggering fails.

According to the invention there is also the possibility of making the arc combustion chamber divisible by means of a peripheral web applied to the stick electrode.

The main electrodes can have groove-shaped contours, webs and / or cams to minimize burn-off on their surface facing the arc combustion chamber.

The second main electrode surrounding the first main electrode can represent an essential part of the encapsulation.

The first and / or second insulation part can have at least one peripheral web to support air breakdowns. In a pressure-tight embodiment of the surge arrester, an extinguishing gas filling is preferably provided.

The arrangement according to the invention of two electrodes embodied one inside the other in a coaxial position erosion-resistant material with opposite connections, the main electrodes having internal expansion spaces, a configuration is created which allows the insertion of a rotationally symmetrical third so-called trigger electrode. The overall arrangement has a high insulation capacity with a correspondingly high surge current discharge capacity and is therefore particularly intended for use as an N-PE spark gap.

The invention will be explained in more detail below with the aid of exemplary embodiments and with the aid of figures.

Here show:

Figure 1 is a view of the trough-like housing with individual chambers and spark gaps located therein as well as the not yet finally positioned insulating plate.

2 shows a view of the arrangement with the insulating plate positioned and the circuit board above it and not yet fastened;

3 shows a plan view of a multipole surge arrester with recognizable spark gaps, contact rails and the wiring level swap bridge;

4 detailed representations of two surge arresters each with a recognizable constructive mechanical arrangement of the wiring level swap bridge;

Fig. 5 is a view of the underside of the circuit board of the control or trigger circuit with solder island contact points.

6 shows a sectional illustration through a surge arrester with a coaxial electrode structure;

Fig. 7 is a similar representation as disclosed in Fig. 6, but with a gradation of an inside of the second Main electrode to create a staggered response;

8 shows a sectional illustration of a surge arrester with a stepped design of the second main electrode for reducing the distance in the entire arc combustion chamber and with an additional radial insulation section for reducing the erosion, in particular of the trigger electrode; and

9 shows a sectional illustration of a surge arrester with a trigger electrode which is arranged adjacent to the second main electrode in the axial direction.

1, 6 chambers are provided in the plastic housing which accommodate the surge arresters or spark gaps 1 to 4. Terminals 12 and fastening screws 13 can also be seen.

An insulating plate 25, which has a plurality of sleeve-like extensions 26 on its underside, is placed on the upwardly open housing trough. These sleeve-like extensions serve to receive a cylindrical compression spring 27 (see also FIG. 2).

In the case of spark gaps 1 to 4 in a form with a cylindrical metallic outer housing, the sleeve-like extensions 26 are cut or cut out in a segment of a circle, as a result of which part of the cylindrical compression spring 27 is exposed.

The lower end portion 28 of the sleeve-like extensions 26 is closed, thereby preventing the respective cylindrical compression springs 27 from falling out downwards.

It is thus, as can be seen in FIG. 1, the chamfer of the sleeve-like extensions 26 is designed like a segment of a circle and is complementary to the cylindrical spark gap housing. Opposite the respective sleeve-like extensions 26, at least one further locking extension 29 is formed on the underside of the insulating plate 25. Further extensions 30 in the edge region of the underside of the insulating plate secure it against undesired displacement.

On the top of the insulating plate 25 there are molded spacer cams 31 in the outer edge area which, in conjunction with the cranked connecting lugs 32 which are located on the printed circuit board 33, cause undesirable tension forces on the soldering support points for the electronic components on the printed circuit board 33 or on the printed circuit board prevent yourself.

With reference to Fig. 2, the aforementioned printed circuit board 33 is to be arranged above the insulating plate 25, the upper ends of the cylindrical compression springs 27 coming into contact with specially designed solder contact points on the underside of the printed circuit board, so that an electrical connection to the spark gaps is ensured.

The diameter of the contact points 34 is equal to or larger than the diameter of the cylindrical compression springs or the upper end of this contact spring 27. The typical flat conical shape of a soldering point in connection with the flexibility of the respective cylindrical compression spring leads to one

Centering and secure contacting even if there are unavoidable tolerances with regard to the position and embodiment of the connecting lugs 32 and their fastening by means of screws 13. The size relationships between the contact points 34 on the one hand and the other soldering pads 35 for fastening the electronic components on the printed circuit board 33 can be seen in FIG. 5, which also shows the connecting tabs 32 arranged on the side.

With multipole surge arresters in a 3 + 1 circuit, if the desired clamping is required, there is a need for an internal wiring level change, for which a speaking bridge between one of the phases and the neutral conductor is required.

The practical implementation of a multi-pole surge current-proof surge arrester in a 3 + 1 circuit can be seen in FIG. 3. The individual surge arresters 1 to 4 are located in individual chambers 5 of the plastic housing, the contact rail 7 being provided on one of the longitudinal sides of the housing and electrically connecting the surge arresters 1 to 3.

Individual contact rails 8 to 11 are provided on the opposite side of the housing 6. These individual contact rails each take a pair of outer terminals 12 (see also Fig. 4).

The contact rail 7 or the individual contact rails 8 to 11 are electrically connected to a projecting contact surface 14 of the respective spark gaps 1 to 4 via a screw which is received by a bore with an internal thread in the projecting contact surface 14.

The necessary wiring level swap bridge 15, which has an essentially Z-shape, is located with its longer connecting leg between the spark gap arresters 3 and 4.

In the exemplary embodiment according to FIG. 3, a shape 16 is provided in the corresponding chamber partition wall 17 for guiding at least the long leg of the wiring level swap bridge 15.

As can be seen particularly clearly from the upper part of FIG. 4, a fitting hole is made in the short leg 18 of the wiring level swap bridge 15, which is matched to the outer dimensions of the projecting contact surface 14 of the respective conductor 1 to 4.

Thus, the respective short leg 18 can be brought into positive engagement with the projecting contact surface 14, the Final fixing is then carried out with the aid of a corresponding contact rail, as is evident in the lower part of the figure in FIG. 4.

The material thickness of at least the short legs 18 is substantially equal to or less than the height dimension of the contact surface projection 14 of the respective spark gap 1 to 4.

The wiring level swap bridge 15 preferably consists of a flat copper material which can be provided with an insulation sheath 19 (see FIG. 4) at least in a partial area.

The contact rail 7, but also the individual contact rails 8 to 11, are designed as metallic angle elements, a first angle leg 20 being non-positively connected to the respective projecting contact surface 14 of the respective spark gap. Via this leg 20, a form fit or a corresponding hold in the housing 6 can be achieved at the same time, which has corresponding grooves or similar recesses for this.

A second angle leg 21 carries the connecting terminals 12. The first angle leg 20 is via a screw connection

(see Fig. 4) connected to the respective contact surface 14 of the respective spark gap. This screw connection can simultaneously secure the respective short leg 18 of the wiring level swap bridge 15, as is shown in the lower right part of FIG. 4.

Tongue-like features or projections 22, which are arranged or introduced in the region of the short legs 18 of the wiring level swap bridge 15, are oriented in the assembled state toward the respective first angle leg, so that a counter bearing is then created which can absorb electrodynamic forces in the event of a surge current ,

In particular, this counter bearing counteracts an extension of the bracket when the current flows. In the case of an essentially at least section-wise U-shape of the contact rails 8 to 11 or 23 for the PE connection, a third tongue angle leg 24 (see upper part of FIG. 4) serves as a cable fastening pressure plate. This third tongue angle leg 24 is essentially opposite the second angle leg 21.

FIGS. 6-9 are based on a first main electrode 41 and a second main electrode 42, the electrodes in the regions 45 having an electrical connection. This connection can be realized for example by means of a screw connection.

The first main electrode is preferably designed as a rod electrode, which has a cavity 47 in the interior. This cavity 47 represents an internal expansion space.

The cavity 47 is connected to the arc combustion chamber 48 by at least one opening 49.

The first main electrode 41 projects partially into the tubular region of the second main electrode 42 in a coaxial arrangement. Specifically, this overlap area represents the desired coaxial structure.

Due to the cup-shaped design of the second main electrode 42, this can directly form part of the encapsulation of the entire spark gap, so that the outlay is reduced in terms of technology, but also in terms of materials.

To improve the guidance and adjustment, it is possible to arrange an insulation part 44 between the first main electrode 41 and the second main electrode 42. This insulation part 44 then simultaneously delimits the arc combustion chamber 48 in the axial direction.

The insulating part 44 preferably has suitable openings or through-flow channels 410, so that an additional cavity 47 is connected to the arc combustion chamber 48 within the second main electrode 42.

In order to now completely encapsulate the electrode arrangement and to further limit the combustion chamber, a (first) insulation part 43 is arranged between the first main electrode 41 and the open end of the main electrode 42.

A solution in which the encapsulation takes place outside the main electrode arrangement and in which the arc chamber is not directly delimited by insulation parts is also within the scope of the invention.

The insulation part 43 now has an additional third electrode 46 for triggering the main section between the first and second main electrodes. This electrode or a plurality of electrodes 46 can be arranged in a rod-shaped, pin-shaped, but also ring-shaped manner.

In a preferred embodiment, a disc electrode is used which is aligned coaxially with the first and second main electrodes.

The spark gap described is preferably pressed or screwed with additional insulation in a pressure-resistant metal housing.

The force is applied in the direction of the axis of symmetry. In order to largely decouple the arcing paths of the spark gap along the insulation parts 43 and 44 from the action of force during the joining process, these parts extend in the radial direction from the axis of symmetry. In this way it is ensured that an influence on the response voltage of the spark gap remains low both by the joining process and by thermal stress on the insulation parts under pressure.

The operation of the arrangement will be explained below. When the spark gap is triggered, one or more ignition sparks 411 are ignited by the trigger electrode 46 to one or both of the main electrodes 41 and / or 42.

The arc 100 then ignites between the main electrodes 41 and 42. In the case when the spark gap is designed without a trigger electrode 6, the arc 100 is formed by means of a sliding discharge along the insulation paths 43 or 44 or else by an air breakdown between the main electrodes 41 and 42nd

After ignition, the arc 100 is located in the arc combustion chamber 48 and can rotate around the first main electrode 41 in accordance with the coaxial arrangement within this chamber. At the time of the arc ignition, an overpressure arises within the combustion chamber 48 due to the heating of the gases present. This overpressure would lead to an increased mechanical load on the parts and, in addition, an increase in the arcing voltage, which leads to an unnecessarily high energy conversion within the spark gap and thus also to high thermal loads.

The excessive heating of all parts in the combustion chamber would also make it difficult to extinguish the arc. To avoid these negative phenomena, the expanding gas is provided with at least one additional cavity 47 as an expansion space within the spark gap, which is not directly exposed to the arc. After ignition of the arc, the heated gas can flow out into the expansion chamber 47 via the openings or channels 49 or 410 mentioned. Due to the large volume there, the large heat capacity and the large surface area of the metal electrodes, the heated gas within these cavities is immediately cooled and relaxed. The pressure increase, the arc burning voltage and the energy conversion within the combustion chamber are thus kept to a minimum.

6 is based on an embodiment of separate expansion chambers 47, but there is also the possibility that

PJ tr P- a ιQ Φ ω P- α j 3 Φ N φ HN a σ oo tr * co tr rt 3 d: a H s 3 tr d Φ 3 φ Φ Φ O 3 3 φ P d M φ O: P - i, P Φ = Φ P- PJ Ω PJ O o Φ P- tr tr Φ 3 Φ Φ Φ o P- a P s: P Φ ω a ω P 1 a ιQ 3 P- tr P- 3 P Φ P r ιQ ^ Q P- rt ^ r Φ P p tr P- tr ^ 3 op: CO P • ö J ιQ Ω> o 00 φ P- ¹ a ιQ 3 Φ p- Φ P ω tf P a

Φ P- Ω P 3 "rt ιQ P P Φ tr σ Ω P- G Ω tr oo Hl M> 00 φ rt 3 - a P- M Φ P- Φ Φ

PJ ιQ tr PJ P Φ P- Φ Hi 00 tr Ω tr 3 ^" rt d 3 PJ d φ φ P 3 XP 3 P 3 et • Ω P" tr Φ Ω J Φ Φ 3 ^ Φ Φ P- P 3 Φ o 3 - "3 N P- s: P sQ P- Ό Φ a oo P DJ tr Φ Φ P tr J 3 P- P- P- f P 3 Ω Φ .V? P φ φ ad 3 Φ Φ 3 PJ P - Φ ς d iQ P- 3 φ Φ P rt 3 rt 3 Φ co 3 ^" Ω Φ rt a PPP ≤ 3 α P P- 3 Ω 3 ^ PJ π 3 Ω Φ 00 a P- P Φ Φ P- Ω a Φ? T 3 P 3 a P- 3 3 3 oo 3 ^{^} PJ 3

P- iQ tr O et Φ Ω Hl? P ^• d rt tr φ 3 Φ 00 O d α σ P- φ P ιQ a J P- 3 3

3 H Φ P Φ co tr a P, O: Φ 00 o P ^J 3 a 3 d P Φ <fV Φ Φ Φ HO a pj: Φ

N Φ N a r + Φ Φ P- P 3 P a J H a N Φ sQ P d φ d 00 σ P Φ 3 Φ P

Φ P- Φ d P Φ P P iQ P rt 3 et φ H2 M 3 φ s; 3 Ω Ω Ω 3 3 d co P Φ 3

CO P- P φ a P IQ Φ oo P- Φ P Φ P P- 3? ? P rt ιQ P- P a α P Q rt vQ Ω et P- "G tc φ 3 T3 rt P- N Φ P ω *. PJ PJ PJ O: d 3 LQ P P PJ: ^ Φ

Φ d rt tr Φ Φ O: σ PJ PP> s: LQ Ω Ω P ¹ Ω tr d εo Φ N 3 dddos: 3

PP "P 3 ^* Φ d φ ω Φ 3 3" tr P- et P- φ ^" • _^ tr tr 00 Φ d Φ 00 Ω Ω 3 3 Φ rt fu: iQ Φ tr rt P TJ PO Ω PJ PJ oo oo P φ oo φ PJ iQ PP o .V? R Φ rt M rt co Φ P- CO φ co rt φ 3 tr Ω Hi rt Ω O φ PJ 3 J ^. ^ Da Φ 3 ^* P 00 PJ PJ Ω PJ

PJ P- P Ω co a Ό Hi hi P- φ ^" rt P- tr a P- 3 NJ P- Φ Φ 3 N PJ sQ Φ d .fe.? E" 3

Φ PP Φ tr co P- PJ d ιQ rt P ιQ Φ 3 Φ Φ 3 et a iQ P- P- P Φ P- ¹ Φ P- 00 ^ 1 et Φ ιQ

P- 3 c Φ Φ P P P- a Φ P § 3 3 et PJ φ c • 3 Ω N P tr P rt uQ P-

3 Φ Ω and P P? Φ rt Φ O d P 3 P 3 tr σ d oo • P- J Φ P- a oo P tr Φ N Φ co d Φ P P SS 3 a Ji. J O a σi dd P co Φ a i Φ PJ P 00 Φ

Φ co Φ rt PP ιQ P- CD a Φ sQ Φ iQ PH Φ p- d PJ: rt Φ o Φ P- 3 d OP rt G Φ t P-> O: ιQ co Φ sQ φ P P- 3 "> a ^ σ P 3 Ω rt NP P- P Ω 3 3 H

N tr P- PJ 3 d P φ et 00 Q co Φ ω ad 3 Φ C φ φ? N d φ tr LQ P- CO tr Φ rt P co d PP Ω Φ rt rt Φ P- PC 3 tr d W 3 P- S PJ P ¹ 3 ^ 00 DO oo a Φ

PJ P Φ rt P- P P Φ tr P PJ Φ φ PJ a P- 3 rt 3 O: Ω P- d P- LQ d Φ O: P- J-. P 3

P o P d Ω d Φ φ Ω J tr P a co d 00 iQ P PJ rt tr 00 Ω 3 P- H Pi Φ π rt 3

Ό 3 3 ^* rt 3 P? Hi J rt P- φ Ό O Ω P- H ¹ ιQ 3 ^" a tv ω PJ Hi Φ

P- PJ ιQ ιQ rt- N T-5 Hi Φ Hi P d O Φ 00 rt) ad: a 3 ^{^} iQ d; P- P ^J φ Φ Φ rt 00 3 LQ tr ω rt o P Φ dd Po O Φ Φ 3 Ω Φ P- tr φ rt tr 00 φ 3 P 3 rt d Φ N p- P r + P ω a PP P- a 3 sQ tr Φ m P- Φ φ a Φ Φ P- oo P- d 3 N s; 3 P-

, d Ω φ iQ LQ P ιQ φ> d P- 3 Φ o P J-. Φ PJ P? Ω Ω <rt P 3 iQ Φ. a Φ

3 P ^J P Φ a rt 00 = ε tr a et 3 φ? V 3 sQ co NP dd tr 0J Φ P 00 t £! Φ P- • _^ PJ ιQ DJ P a H. Φ Φ N Hi P rt P- Φ Ω Hi S 3 00 oo P Φ tr 3 iQ PJ Ω φ Hi P- Φ P- P φ P Φ PJ sQ P 00 00 tr c H ιQ P- a O: tr s: Ω φ Hi rt 3 3 dr

P Hi P- ¹ P Ω tr a P- P- Ω P- O P- PJ H 3 3 PP Φ Hl P- Φ 00 d: <! Φ P-co

Φ Φ P ^J Φ rt t? P tr Φ a φ 3 PJ: a rt dd 3 Hi 3 Φ o P Φ Φ rt φ

PJ P ^> T 3 t- ¹ ? Φ 3 Φ P φ tr φ P et ιQ 00 3 rt tr P aa PP P- Φ

P H- a Φ Φ P- P Φ P- Φ 3 rt Φ rt rt a Φ Φ dd Φ aa Φ Hi 3 3 P- a co - € P Φ P- P- rt f Ω ^ a "*« σ Φ 3 PP 3 rt d Φ P-: O Φ 3 d

Ό Φ OP ω rt Φ 51 3 rt P ^' o PJ φ s; (-3 • tr a Φ ιQ sQ Φ PP 3 sQ PP PJ P

P P a Φ rt h O P- P rt o P P P- P 3 C Φ Φ P- Φ 3 Ω Φ Φ Φ a 3 Ω

P- P_ Φ P d a co a rt O d P Hl Po P Φ O a 3 P P Ω P? - tr 3 3 3 CO a tr

Ω Φ P CO P Φ G a P a 00 o a 3 Ω Φ sQ Hi tr o S a d rt Φ

3 "3 PJ Φ sQ 00 φ π Φ Φ iQ P- H 3 - P TJ O f 3 J a PJ D 3 Φ P Φ r" * P P- co ii Ω P- 3 Φ 3 Φ ιQ d co aoo J rt P- PP a ιQ P-

O rl- Hi 2 oo p- 3 PJ PJP Φ 3 rt Φ 3 φ co ia a P rt Φ Φ P d P- NP d 0- po P: Φ rt Φ 3 rt 3 a P P- oo P- Φ Φ P. P Ω Φ N φ d Φ

3 Φ α "rt Φ 3 o P- PJ Φ 3 P rt 3 P P- t- ¹ <! .V d P

0- P P? V P- N σ P- P o? V a Ω Φ P- • φ D PJ P- o PJ 3 oo P- d PJ ιQ Φ φ 3 tr a 3 tr PJ Φ? 3 Φ o Φ P- d M Ω P d PJ PJ: 3 o

CO CO P 3 f 00 P- O 3 rt 3 3 Φ P- 3 P- 3 P P- tr CO Ω rt 3 a o Ω ιQ 3 Φ tr d a 3 3 3 P- P Ω Φ et <ιQ tr N Φ Φ

3 P ^J ~> P- d φ 3 Φ • PJ Φ φ tr 3 1 o P- PP

P- O rt P 3 ιQ oo Ω PP Φ a P- tr et P s: a σ 3 ^" dad 1 P- Φ Ω

P- 2 P- 3 P- 3 Ω 3 "

Φ 1 Φ Φ at tr

co co IV ⁾ IV ⁾ cπ o Cπ o CJi O cπ s: H da rt ι-3 P- P- co D Φ oo d N a P- a 3 ^{^} d M tr? Ω 03 N fa • ^ σ> Φ GP J- ^ oo tu

Φ P 3 Φ Φ P 3 3 rt d P- Φ 3 Φ Φ P P- Φ 3 3 Φ Φ Φ s: Φ d P- tr P 3 Φ n rt φ

P P- tr P P- P- Φ P 3 tr P- P co Φ P- et rt P- P- Φ P P- Φ P 3 Φ co P Ω P P- aq Φ sQ φ tr ¹ s Ω tr tr Φ Ω tr rt Φ rt P- Φ 00 P- f 00 PJ φ 3 "tr d Φ

Φ ^ Q Pi - _" « iQ P- P- Φ tr Φ 00 rt tr ^ Φ Φ Φ PO d Ω P- Ω 3 P φ rt P- P- et 3 Ω φ

3 φ PJ P Φ P Ω oo P- rt φ 3 d co 3 3 00 13 3 Φ p Ω 3 ^ Φ P 3 tr N Ω Φ a for P-

P 00 P- a P φ 3 ^{^} a rt et P- φ 3 o rt Ω Ό rt P- N 3 ^* Φ P P- co Φ tr P tr Φ 3

? d rt ιQ PJ Φ 3 rt PJ PJ pj: rt? P ω s: tr Φ 3 Φ 3 ιQ rt O Φ o a Φ

O: 3 Φ ιQ ε tr d 00 tr et P- - φ a 13 P- P- d P Φ P- a PJ and others P P- a 3 φ tr Φ PJ 3

3 ^ et Φ Φ tfl o co Φ P- iQ 3 Φ PP Φ 3 00 00 rt φ Φ Φ Φ P Φ _^ P- Φ P d

3 -> P tr fT Φ sQ P <Q rt a 00 P Φ a a iQ Ω P- P P 00 P Ω fV P 3 Hl>

Φ tr Φ Φ rt P Φ P- PJ PJ rt Φ Ω ^" ιQ sQ oo df rt s: Φ asd

3 a p- P Φ 3 oo Ω oo P- tr - P - a P- a P- Φ Pl rt a 3 Φ " _^ Φ p- 3 PJ P co

^ P- Φ Φ o P- tr O tr et 3 Φ tr Φ P- Ω Φ Φ 00 Φ P Φ P- vQ P- P sQ co a G Hi φ P- fr 3 a Ω P et Φ φ a Ω Φ 3 Φ 3- ω a rt P P- P Φ Φ a 3 a Φ • Ö d 3 PJ a tr rt o Φ tr Φ PJ et ω P- P-? P- a φ J LQ LQ d P- PJ Φ s: P P a

PJ PJ rt P P • 3 rt sQ φ tr Φ φ φ ^ 3 <P- Pi P- sQ d> 3 3 tP 3 P- φ Ω

3 O 3 3 3 P- φ - P rt tr d Φ Ω Pi tr φ 3 3 PJ Φ co PJ 00 Ω tr a fV T} a PJ Öd p- P O N P- φ. _ φ o ι-3 3 co P tr Φ rt P a 00 tr 3 rt Ω oo tr Φ a

Φ φ <φ H- φ rt PJ 3 φ P P- PP tr P - rt tr Φ M d Ό 3 ^J s; Φ d tr φ s: tr P Φ

P- co o Φ P- d co P- a Ω α P- s: Φ P- Φ Φ PJ 3 rt 00 3 N P PJ: Φ tr Hi Φ Φ P

3 rt a tr P ι-3 3 3 SQ tr P- sQ P- 3 sQ 3 P- Φ P- sQ ≤. φ 3 P- Φ d • n 2! P a 3 φ P d Φ a P PJ et Φ sQ P ιQ oo rt o 3 Ω Φ Ω iQ rt 3 3 P- o rt P- P- H

Φ PH <! P- P- fr rt Φ a φ .r co Φ rt 3- φ Ό tr P- P- 3 ¹ P- Φ sQ sQ rt Φ 3 rt P

OÖ tr Ω PJ d Φ sΩ J Φ Φ ^ i P rt Ό PP Φ 3 PJ 00 rt oo iQ P a • iQ rt P- φ rt 3 ^" ω 3 00 <Q 3 P> P d φ PJ 00 Φ P- co 3 3 tr rt Φ O Φ Φ Φ J-. PJ J rt P- LQ φ Φ rt? v φ Φ 3 P- 3 3 P- s; 3 rt Ω rt 3 ω Φ P PJ PPP ¹ -J dd Φ s iQ

P- 3 P- φ rt P P PJ tr co? 3 Φ 3 P? V Φ a d Ό P- 3 d) Pi Hl 3 φ Φ

3 3 rt P- Φ a P rt Φ 3- P d Φ Φ 3 Φ 3 PN tc 3> 3 aa φ • 3 P et S2 o> H ¹ P- P- d 3 Φ a 3 Ω P iQ φ ad 0 d 3 J P- J P- N Φ

P o 3 s: 3 3 Φ φ PJ 3 Hl oo P- Φ ιΩ? aa 00 Ω P- P d 3 00 tr P 3 00 iQ pj:> rt O P- 00 o? 00 d ιQ d rt rt 3 oo Φ d Φ ^» ^ 00 3 ^* Φ Ό ιQ Ό tr Ω Φ φ 3 Φ

Ω -> rt P ≤: P rt φ Hi Φ 3 P oo PP d rt <! oo <rt P PJ: "a H 3 P- O fr tr J Hi a Φ a PP 3 s Φ a rt sQ Ω 3 Φ Φ Φ φ Φ a Φ 3 Φ 00 00 Hi P rt et d J P- 3 oa Ω φ s: Φ Φ 3 ^* CO? V P- PPPH ¹ Φ Ω iQ a P o Ω PJ a P

P- H. d oo dad Φ Φ d-? Ϊ P Φ P- 00 13 Φ 3 ^{^} Hi Φ P - P- P- 3 "Ω 3 O s Φ 3 φ 3 Φ 3 P P- P ¹ Φ P * rt a PJ 3 3 ^* PJ «: fV ω iQ Φ π J PJ ^{^} dad P- a iQ et 3 ro ^ Ω 3 ^" Φ P- 3 oo Φ o ιQ rt Ω Ό Φ P- "rt Hi Φ 3 φ

3 ι 3 d Φ Φ Φ N ^" Φ d Φ 3 rt P- rt 3 d P PJ Pl Φ P- rt 3 ιQ ιQ Φ aad φ 3 PP 00: 3 Φ P- φ d P rt Φ ω 3 0 φ 3 ^ P fr O 4- »

3 • P- P P a rt oo o 3? oo rt P ι-3 3 Φ Φ 3 rt sQ a P- 3 d P- rt 3 a H a cn a co tr Φ sQ Φ et tr tr a φ Φ rt P ιQ Ω 3 co P φ rt d 3 sQ P oo Φ 00 φ

P- Ω • a P- Φ P- Φ o 3 φ 3 00 3 • P- •? • d CO 1 3 V ιQ o rt P o P s: φ - PJ P- tr p- 3 tr Φ rt co P- iQ φ a f rt ιQ Φ Φ a Φ H Φ

00 PJ tr 3 Φ rt 3 rt Φ rt Ω Φ O sQ D3 O Φ rt Φ P ¹ tr 3 P Φ P- ^ 1 J Pi P- φ Hi Φ a Φ tc P aa P "P- PJ Φ Φ φ P - P P- 3 ^" N co d H" d rt P 00

P rt P- Φ tjd oo 3 «PJ PJ PJ Φ 3 <Q P P- tr φ o rt d a rt P d-> 3 P- P- rt

Φ P P P- Φ d d P 3 Ω a Φ 00 φ ω ^ 3. 3 • P- P ιQ t-o J-- fr O sQ td 3 Φ φ Ω Cd P * ü 3 3 f PJ G sQ Ω? T 3 d a Φ Φ 4 ^ Φ 3 sQ a

P d 3 tr Φ a rt \ - ~ a Φ a tr Φ 3- P- φ 3 at ^"1 Ω PJ <! 3 ω Φ P- φ iQ co tu 3 P Φ Φ PJ P- oo d Φ 3 PJ Φ σ P? P- 4 ^ daf P Φ a oo 00 P Φ

3 y hi p? a Φ 3 P * d φ o 00 P P P- φ φ φ r Pi Φ Φ oo P d rt rt Φ

3 left PJ Φ PJ Φ p- • _^ Φ Pi N Φ Ω? .V rt 3 P- PJ 3 rt d rt for PPPH ^ for PJ H "3 3 P Ω fr Φ pi d tr o J d Φ d co s P- 00 rt 3 Φ d = Ω Φ Φ Φ d

PJ 3 3 3 tr d rt PP 00 tr Ό 3 3 3 a σ rt O: 3 rt P- d P 3 ^* Ω Ω ^ 3

3 rt i Φ <3 P a P- PJ 00 PJ 3 ιQ P- rt P iQ P P- rt Φ N? \? ^ Et? ^

3 P- a PJ P o O a O Φ ιQ iQ rt d N o Φ Φ Φ Ω P rt φ Φ Φ P Φ φ Φ Φ 3 P tr a 3 LQ φ 00 d = d rt 00 φ Ω P- Ω 3 ^" <! tr • P- O 3

P h P 3 3 1 3 N Φ Φ 3 1 3 3 Φ Φ P-? Ω V o PJ 3 N a 1

3 rt φ P- φ s; P a a P- 3 3 Φ 3 Φ 3 P φ d φ

P rt PJ 1 Φ Φ 1 Φ 3 PP »3 1 3

through fire, temperature or pollution until the emergency arises. Such a mode of operation can also be implemented with two completely independent and separate combustion chambers.

Fig. 8 shows a similar arrangement as Fig. 7, but here the paragraph or the step is extended so far that there is a significant reduction in the distance in the entire arc combustion chamber 48 between the first and second main electrodes 41/42. An additional axial insulation section 413 also reduces the erosion on the insulation part 43 and the trigger electrode 46, since direct contact of these parts with the arc 100 can be avoided. Of course, this insulation section 413 can also be provided independently of the step 412 as in an embodiment according to FIG. 6.

An arrangement in which the trigger electrode 46 is arranged downstream of the second main electrode 42 in the axial direction is shown in FIG. 9.

This arrangement ensures both the protection of the trigger electrode against excessive burn-up and a reduction in the response voltage without triggering. Furthermore, the trigger energy required can be reduced to a minimum with this arrangement. The ignition spark which arises when the trigger circuit triggers between the trigger electrode 46 and the second main electrode 42 can in particular contact the first main electrode 41 when the insulation part 414 projects minimally into the combustion chamber 48 and the distance between the main electrodes 41 and 42 is shorter. As a result, the insulation gap between the main electrodes 41 and 42 is bridged suddenly and the trigger energy is limited to a minimum.

In the arrangement according to FIG. 9, partial insulation of the main electrode 41 within the combustion chamber 48 along the axis of symmetry and adjacent to the insulation parts 43 and 44 can be provided to protect against the signs of burn-off on the respective ones Isolation parts or on the trigger electrode may be useful.

To support the desired arc rotation and to avoid excessive deposition of melting material, one or more circumferential contours, e.g. can be formed or inserted as grooves or attached webs.

Individual knobs or other increases to control the response voltage are also included

Air breakthroughs or to control the combustion behavior can be realized.

To support air breakdowns, the

Insulation parts 43 and 44 may additionally be provided with at least one peripheral web (not shown) projecting into combustion chamber 48.

Show reference list

1 to 4 surge arresters or spark gaps

5 chamber 6 plastic housing

7 contact rail

8 to 11 individual contact rails

12 connecting terminal

13 screw 14 protruding contact surface of the spark gap

15 interchangeable wiring levels

16 formation

17 chamber partition

18 short legs of the wiring level swap bridge

19 Insulation jacket

20 first angle leg

21 second angle leg

22 tongue-like shapes or projections 23 PE clamps

24 tongue angle legs

25 insulating plate

26 sleeve-like extension

27 cylindrical compression spring 28 lower end portion of the sleeve-like extension

29 locking extension

30 more extensions

31 distance cams

32 connection lug 33 circuit board

34 contact point

35 solder islands

41 first main electrode

42 second main electrode 43 outer insulation part

44 inner insulation part

45 connections

46 trigger electrode

47 expansion room Arc combustion chamber openings, flow channels, ignition sparks, arc, step or step, axially extending insulation part, insulation part protruding

Claims

claims

1.Compact arrangement for multi-pole surge current-resistant surge arresters with internally wired encapsulated spark gaps arranged essentially in parallel in a housing, the spark gaps having opposite, protruding contact surfaces which are connected to external connection terminals and internal contact rails or bridges, and with an electronic one on one Control or trigger circuit located in the wiring support, characterized in that the housing has a trough shape provided with dividing walls, the housing chambers formed in this way receiving the spark gaps and the connecting terminals, on the upwardly open housing trough an insulating plate having openings is provided in the spring contact elements are inserted, is still located above the insulating plate of the wiring carrier, the spring contact elements being an electrical connection between contact points on the underside of the ver wire carrier and the jacket each create one of the spark gaps.

2. Compact arrangement according to claim 1, characterized in that the wiring carrier is a copper-clad printed circuit board, the contact points being designed as larger solder islands.

3. Compact arrangement according to claim 1 or 2, characterized in that the printed circuit board comprises lateral connection lugs which are electrically connectable to the inner contact rails, this simultaneously resulting in a mechanical locking of the insulating plate containing the spring contact elements.

4. Compact arrangement according to one of the preceding claims, characterized in that the insulating plate underside in the region of the openings has sleeve-like extensions which are cut at an angle to the longitudinal axis, so that on the one hand the spring contact elements are secured against falling down and on the other hand a conductive portion of this is exposed ,

5. Compact arrangement according to claim 4, characterized in that the encapsulated spark gaps have a substantially cylindrical shape or such a partial shape, wherein the gate of the sleeve-like extensions is circular segment-like and complementary to the cylindrical spark gap housing or a corresponding housing part.

6. Compact arrangement according to one of the preceding claims, characterized in that the spring contact elements are cylindrical compression springs which protrude on both sides of the respective opening.

7. Compact arrangement according to claim 5, characterized in that the sleeve-like extension opposite at least one further locking extension is provided, which is adapted with its side oriented to the respective spark gap on the housing shape.

8. Compact arrangement according to one of the preceding claims, characterized in that the top of the insulating plate has molded spacer cams.

9. Compact arrangement according to one of the preceding claims, characterized in that the housing and the insulating plate consist of plastic injection molding.

10. Compact arrangement according to one of the preceding claims, characterized in that a wiring level swap bridge with a substantially Z-shape is provided with two short, oppositely directed and a longer connecting leg, fitting holes or recesses are introduced in the short legs, which the external dimension of protruding contact surfaces correspond to the spark gap, the material thickness of at least the short legs is substantially equal to or less than the height of a contact surface projection of the spark gap and the long leg extends in the space between two of the spark gaps.

11. Compact arrangement according to claim 10, characterized in that the contact rails are designed as metallic angle elements, with a first angle leg non-positively connected to the respective projecting contact surface of the spark gap and a positive fit is given in the housing via this leg, and further a second angle leg outer terminals carries.

12. Compact arrangement according to claim 11, characterized in that the first angle leg is connected via a screw connection to the respective contact surface of the spark gap.

13. Compact arrangement according to claim 12, characterized in that the screw connection simultaneously secures the respective short leg of the wiring level swap bridge.

14. Compact arrangement according to claim 10, characterized in that in a three-phase arrangement with neutral one of the

Contact rails connects three of the four spark gaps on one of the long sides of the housing, the contact rail provided on the opposite long side of the housing having or being interrupted by sections and the Phases as well as the neutral connecting terminals, a contact rail with at least one external connecting terminal is connected to the fourth spark gap for the PE connection and the wiring level swap bridge is located between the third phase spark gap and the neutral spark gap and makes electrical contact there is.

15. Compact arrangement according to claim 10, characterized in that the wiring level swap bridge consists of a conductive flat material, in particular copper.

16. Compact arrangement according to claim 10, characterized in that a chamber partition for guiding at least a portion of the wiring level swap bridge is formed.

17. Compact arrangement according to one of claims 10 to 16, characterized in that in the region of the short legs of the wiring level swap bridge tongue-like features or projections are arranged which form a counter bearing directed to the respective first angle leg in the assembled state.

18. Compact arrangement according to claim 11, characterized in that in a substantially section-wise U-shape of the contact rails, a third tongue angle leg, which lies opposite the second angle leg, forms a cable fastening pressure plate.

19. Encapsulated surge arrester with a spark gap arrangement, comprising two coaxially located, at least partially overlapping metallic main electrodes with oppositely directed connections, the main electrodes forming an arc combustion chamber in connection with at least one insulation part, characterized in that at least one of the main electrodes has an inner expansion space and that in the area of an outer insulation part there is a trigger electrode which preferably runs radially or axially rotationally symmetrically.

20. Encapsulated surge arrester according to claim 19, characterized in that the first main electrode is designed as a rod electrode with a cavity, which is connected via openings with the arc combustion chamber on the flow side.

21. Encapsulated surge arrester according to claim 20, characterized in that a further expansion space is present in the connection area of the second, hollow cylindrical main electrode.

22. Encapsulated surge arrester according to one of claims 19 - 21, characterized in that the expansion space or spaces have a minimized pressure compensation opening, which is preferably formed in the area of the connections.

23. Encapsulated surge arrester according to one of claims 20 to 22, characterized in that the rod electrode is centered and held with its end remote from the connection via a further inner insulation part within the surrounding second main electrode.

24. Encapsulated surge arrester according to claim 23, characterized in that the second, inner insulation part has flow channels to the expansion space.

25. Encapsulated surge arrester according to one of claims 21 to 24, characterized in that both expansion spaces are connected by at least one insulating channel.

26. Encapsulated surge arrester according to one of claims 19 - 25, characterized in that the respective response voltage can be predetermined by varying the radial distance between the coaxially arranged, partially overlapping electrodes.

27. Encapsulated surge arrester according to one of claims 19 - 27, characterized in that at least one of the electrodes has a shoulder directed towards the arc combustion chamber or a step for a staggered one

Response and safe extinguishing capacity even if the triggering fails.

28. Encapsulated surge arrester according to one of claims 20 to 27, characterized in that the arc combustion chamber is divisible by a peripheral web applied to the rod electrode.

29. Encapsulated surge arrester according to one of the claims

19 to 28, characterized in that the main electrodes have groove-shaped contours, webs and / or knobs on their surface facing the arc combustion chamber.

30. Encapsulated surge arrester according to one of claims 19 to 25, characterized in that the second main electrode surrounding the first main electrode forms part of the surge arrester encapsulation.

31. Encapsulated surge arrester according to one of claims 19 to 30, characterized in that the electrodes consist of erosion-resistant material, in particular tungsten copper or graphite, and the insulation parts consist of a gas-emitting plastic.

32. Encapsulated surge arrester according to one of claims 19 to 31, characterized in that the first and / or second insulation part have at least one peripheral web to support air breakdowns.

33. Encapsulated surge arrester according to one of claims 19 to 21, characterized by a pressure-tight design with extinguishing gas filling.

34. Encapsulated surge arrester according to one of claims 19 to 33, characterized in that the active forces are oriented in the direction of the axis of symmetry during the pressure-tight connection by means of pressing, screwing or the like.

35. Encapsulated surge arrester according to one of claims 19 to 34, characterized by its use as an N-PE spark gap.

36. Encapsulated surge arrester according to one of the

Claims 19 to 35, characterized by its use in a compact arrangement according to one of the

Claims 1 to 18.