EP1338064B1 - Compact arrangement for multipole, surge-proof surge arresters and encapsulated surge arrester for the same - Google Patents

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

The invention relates to a compact arrangement for multi-pole surge current proof with in a housing substantially parallel, internally wired, encapsulated spark gaps, the spark gaps having opposite, protruding contact surfaces, which are connected to external terminals and inner contact rails or bridges, and with an electronic , located on a wiring carrier drive or trigger circuit according to the preamble of patent claim 1.

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

In a so-called 3 + 1 circuit, the outer conductors L1, L2, L3 are switched against N and the N conductor again against PE.
In such embodiments of multi-pole surge arresters in a housing so an internal wiring level change is required if all conductors (L1, L2, L3 and N) to be excluded from one side.

If such an internal wiring is realized by an additional bridge, at least two further screw or welded connections for electrical contacting are required. Due to the fact that such a bridge is exposed to a very high mechanical load in the mentioned possible surge currents up to the range of 100 kA, care must be taken for a corresponding dimensioning and mechanical design.

Another problem with the embodiments of multi-pole arresters with wiring level change is that, if possible, no additional space for the bridge itself should be taken in order not to change the outer dimensions of the housing or to use standard housing, which also for others Applications are suitable.

Likewise, for reasons of space minimization to integrate the trigger circuit or a drive circuit in the housing, wherein the electrical connection points are to be formed with a view to the assembly and manufacturing costs.

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 capability up to 100 kA 10/350 μs, in particular for protection against direct lightning strike.

Encapsulated spark gaps with such a performance are for example from DE 196 04 947 C1 . DE 198 18 674 A1 or DE 298 10 937 U1 previously known. These spark gaps have a protection level of ≥ 2.5kV.

In certain applications, however, spark gaps with lower protection levels are required. To realize these requirements, the use of trigger circuits is expedient. 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 erosion, the high dynamic loads due to current forces, pressure, energy and temperature make significant design demands with encapsulated arresters.

Surge arresters with coaxial electrode arrangements, which are on the production side due to the given rotational symmetry of advantage, have been described for example in the EP 0 840 413 A1 or EP 0 771 055 A1 disclosed. There is an electrode isolated on both sides passed through a tube, which simultaneously represents the outer electrode and the housing shell. The introduction of an additional trigger electrode is not possible or only with difficulty. In addition, an additional electrode would be arranged directly in the focal region of the arc and thus affect the burning behavior of the arc and subject to a strong burn. According to DE 35 28 556 A1 or EP 0 242 688 B1 become coaxial
Electrode arrangements formed by a one-sided intrusion of a rod electrode into a tube electrode. In the cited solutions is the introduction a third electrode not provided and difficult to realize. Furthermore, in the ignition of particularly high-current or long-lasting arcs the risk that they escape from the coaxial electrode area and damage the encapsulation of the spark gap lasting. Existing cavities outside the preferred combustion chamber can not be used for pressure relief or as expansion space, since the heat transfer to the insulation material of the housing wall is extremely ineffective.

From the US 3,849,704 , but also the DE 198 17 063 A1 are encapsulated spark gaps with coaxial electrode arrangement previously known.
According to DE 198 17 063 A1 the electrode spacing increases with increasing distance from the flashover point. The aim here is to achieve an arc migration with arc extension to increase the extinguishing capacity at Netzfolgestrom. The extension of the arc, however, inevitably leads to higher energy conversions and stronger temperature and pressure loads, which are unnecessary in particular in N-PE spark gaps and beyond undesirable.
Nor do the cited overvoltage protection elements have a third electrode for triggering. The above-cited prior art 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 especially in N-PE spark gaps in encapsulated design, since so the pressure load, the arc voltage and thus the energy expenditure and the temperature load can be limited to a minimum.

From the DE 100 08 764 A1 In turn, an overvoltage protection device is known, which has coaxial main electrodes which are triggerable. The connection of the electrodes takes place from the same side in order to effect 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 to support a deletion of Netzfolgeströmen. The extension of the arc is, as already stated, not suitable for N-PE spark gap. Furthermore, the known spark gap has no suitable expansion spaces, which allow cooling of the hot gases. The resulting high pressure causes an undesirable increase the arc voltage and claimed the housing of the spark gap in mechanical terms unnecessary. Reducing the pressure load can only be achieved by means of large outlet openings, which are already effective during arc formation. However, there is a risk of undesirable leakage of electrically conductive gases.

The DE-AS 12 82 153 presents a spark gap that has a so-called expansion and a reflection space. The reflection space is intended by the pressure generated during the arc ignition, the arc specifically press into the expansion chamber, on the one hand to protect the ignition from excessive burn and on the other hand to extend the arc, so that the quenching behavior of the spark gap is improved.

From the CH 679 715 A1 is a generic compact arrangement for multi-pole surge current resistant Überspannungsabteiter according to the preamble of claim 1 previously known. This known arrangement has a housing with substantially parallel, internally wired, encapsulated spark gaps. The spark gaps have opposite, protruding contact surfaces, which are connected to outer terminals and contact rails. In addition, a drive or trigger circuit is provided and the housing has a partitioned trough shape to receive the spark gaps.

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

The object of the invention is achieved with a compact arrangement for multi-pole surge current resistant surge arrester according to the features of claim 1, wherein the dependent claims 2 - 18 include expedient refinements and developments.

According to one aspect of the invention is based on a housing having a trough shape with inner partitions, wherein the housing chambers thus formed receive the individual spark gaps and the respective connection terminals.

On the upwardly open housing tray, an insulating plate is provided, which has openings, are inserted into the spring contact elements.

Furthermore, the wiring carrier for the electronic drive or trigger circuit is located above the insulating plate, wherein the spring contacts produce an electrical connection between contact points on the underside of the wiring substrate on the one hand and the outer sheath one of the spark gaps on the other.

Preferably, the wiring carrier is a copper-clad circuit board, wherein the contact points are executed on the underside of this circuit board as a larger area solder pads.

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

The Isolierplattenunterseite has in the region of the openings preferably sleeve-like projections, 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 exposed. In the uncut lower region, the sleeve-like extension is closed to receive preferred cylindrical compression springs inserted on either side of the respective apertures, i. up and down over the gate free or protrude.

If the encapsulated spark gaps have a substantially cylindrical shape, the gate of the sleeve-like projections is formed like a circle segment and complementary to the cylindrical spark gap housing.

The respective sleeve-like projections opposite at least one further Arretierungsfortsatz is integrally formed on the insulating plate, which is adapted to its respective spark gap side oriented to the housing shape, so that the insulating plate when placing itself adjusted, whereby the assembly effort is further simplified.

The top of the insulating plate has molded spacer cams, which are supported against the underside of the circuit board. Undesirable force effects on the solder joints of the electronic components on the printed circuit board as well as undesirable stresses and forces on the printed circuit board are thereby minimized. In this sense, the distance cams are arranged distributed over the outer circumference of the top of the insulating.

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

A dedicated 3-to-1 wiring plane swap bridge has a substantially Z-shape with two short, oppositely directed and one longer interconnecting legs, the attachment and electrical contacting being realized via a fit substantially only positive-fit ,

Existing protruding contact surfaces on the spark gaps are used to achieve the fastening and contacting of the wiring plane swap bridge via these quasi bolts. The longer connection leg of the wiring plane swap body may be provided with an insulation sheath.

In the short legs fitting holes or recesses are introduced, which correspond to the outer dimension of the respective protruding contact surfaces of the spark gap.

Furthermore, the material thickness of at least the short legs is substantially the same or a small amount smaller than the height dimension of the contact surface projection of the respective spark gap. The wiring level swap body is then in the outer casing of the surge arrester arranged so that the long leg in the space between two spaces of the spark gaps or between two chambers.

For internal connection and for receiving external terminals, the contact rails required for this purpose are formed in one embodiment of the invention as metallic angle elements, wherein a first angle leg frictionally connected to the respective projecting contact surface of the spark gap and is given over this leg a positive fit in the housing. A second angle leg receives the aforementioned external terminals or serves to attach this.

The first angle leg of the contact rails is connected via a screw connection with the respective contact surface of the spark gap, for which purpose the bore provided there with internal thread is used.

The screw connection, as mentioned above, at the same time serves to secure the respective short legs of the wiring level swap body. Thus, there is no further screw connection or similar contacting action for the wiring plane change, e.g. beyond the contact rails, necessary.

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

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

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, with the housing longitudinal sides comprising slots or slots serving to guide and secure the contact rails.

One of the chamber walls can be designed for the leading reception of at least one subsection of the wiring plane interchange bridge.

In the region of the short legs of the wiring plane interchange tongue-like forms or protrusions are arranged or provided, which form in the assembled state a directed to the respective first angle leg of the contact rail counter bearing, so that occurring at surge current stretching forces of the wiring plane swap body can be safely absorbed.

In the resulting current flow of a 3 + 1 circuit with wiring plane change, the swap body is arranged so that current flow-related electrical forces cancel each other out in the sense of compensation, which represents a further significant advantage of the invention.

Due to the fact that the contacting of the wiring level swap bridge takes place directly at the spark gaps through holes in the bridge, no further additional mechanical connections are necessary. The preferred fit and the additional securing of the Passklemmung by means of the contact rails creates an optimal electrical and mechanical construction, without the space is increased and thus change the outer dimensions of the multi-pole surge arrester housing.

The preferred stack arrangement of lying in a first plane spark gaps, an insulating plate located above and arranged above this circuit board with the electronic circuit reduces the space in the desired manner. In this case, the insulating plate fulfills not only the task of electrical insulation, but serves as a carrier element of preferably cylindrical compression springs, the electrical contacting or connection of the control or trigger circuit with in the first this arranged printed circuit board with the electronic circuit reduces the space in the desired manner. The insulating plate not only fulfills the task of electrical insulation, but serves as a carrier element of preferably cylindrical compression springs, which serve the electrical contact or connection of the control or trigger circuit with the spark gaps located in the first plane. An outer cover then completes the overall arrangement and ensures the contact safety and protection of the assembly.

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

Fig. 1

eine Ansicht des wannenartigen Gehäuses mit Einzelkammern und darin befindlichen Funkenstrecken sowie die noch nicht endgültig positionierte Isolierplatte;

Fig. 2

eine Ansicht der Anordnung mit positionierter Isolierplatte und darüber befindlicher, noch nicht befestigter Leiterplatte;

Fig. 3

eine Draufsicht auf einen mehrpoligen Überspannungsableiter mit erkennbaren Funkenstrecken, Kontaktschienen und der Verdrahtungsebenen-Wechselbrücke;

Fig. 4

Detaildarstellungen von jeweils zwei Überspannungsableitern mit erkennbarer konstruktiver mechanischer Anordnung der Verdrahtungsebenen-Wechselbrücke und

Fig. 5

eine Ansicht der Leiterplattenunterseite der Ansteuer- oder Triggerschaltung mit Lotinsel-Kontaktpunkten.

Hereby show:

Fig. 1

a view of the trough-like housing with individual chambers and spark gaps therein and the not yet finally positioned insulating plate;

Fig. 2

a view of the arrangement with positioned insulating and overlying, not yet mounted circuit board;

Fig. 3

a plan view of a multi-pole surge arrester with detectable spark gaps, contact rails and the wiring level swap body;

Fig. 4

Detailed representations of two surge arresters each with recognizable constructive mechanical arrangement of the wiring level swap and

Fig. 5

a view of the PCB bottom of the drive or trigger circuit with Lotinsel-contact points.

According to Fig. 1 6 chambers are provided in the plastic housing, which accommodate the surge arrester or spark gaps 1 to 4. To recognize are still terminals 12 and mounting screws 13th

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

In spark gaps 1 to 4 in a form with a cylindrical metallic outer housing, the sleeve-like extensions 26 are cut or recessed circular segment, whereby a portion of the cylindrical compression spring 27 is exposed.
The lower end portion 28 of the sleeve-like projections 26 is closed, whereby it is prevented that the respective cylindrical compression springs 27 can fall down.

So it's like in the Fig. 1 it can be seen, the gate of the sleeve-like extensions 26 formed like a circle segment and complementary to the cylindrical spark gap housing.

The respective sleeve-like projections 26 opposite at least one further Arretierungsfortsatz 29 is integrally formed on the underside of the insulating plate 25.
Further extensions 30 in the edge region of the underside of the insulating plate secure them against undesired movement.

At the top of the insulating plate 25 formed in the outer edge region spacer cam 31 are present, which in conjunction with the bent terminal lugs 32 which are located on the circuit board 33, undesirable stress forces on the soldering pads for the electronic components on the circuit board 33 and on the circuit board prevent yourself.

Recalling Fig. 2 is above the insulating plate 25 to arrange the aforementioned printed circuit board 33, wherein the upper ends of the cylindrical compression springs 27 come with specially trained Lotkontaktpunkten on the underside of the circuit board, so that an electrical connection is ensured to the spark gaps.
The diameter of the contact points 34 is equal to or greater than the diameter of the cylindrical compression springs or the upper end of this contact spring 27. The typical flat conical shape of a Lotpunkts leads in Connection with the flexibility of the respective cylindrical compression spring for centering and secure contact even if there are unavoidable tolerances with respect to the position and embodiment of the terminal lugs 32 and their attachment by means of screws 13. The size ratios between the contact points 34 on the one hand and other solder pads 35 for mounting the electronic components on the circuit board 33 are the Fig. 5 removable, which also shows the laterally arranged terminal lugs 32.

In multi-pole surge arresters in 3 + 1 circuit arises with a corresponding desired clamping the need for an internal wiring plane change, for which a corresponding bridge between one of the phases and the neutral is required.

The practical design of a multi-pole surge-proof surge arrester in 3 + 1 circuit leaves Fig. 3 detect. The individual surge arresters 1 to 4 are located in individual chambers 5 of the plastic housing, wherein the contact rail 7 is provided on one of the housing longitudinal sides, which connects the surge arresters 1 to 3 electrically.

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

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

The necessary wiring plane interchangeable bridge 15, which has a substantially Z-shape, is located with its longer connecting leg between the spark gap arresters 3 and 4.

According to the embodiment Fig. 3 is to form the leading receiving at least the long leg of the wiring plane changing bridge 15 a molding 16 in the corresponding chamber partition wall 17 is present.

Like from the Fig. 4 In the upper part of the image particularly clearly recognizable, a fitting bore is introduced in the short leg 18 of the wiring plane changing bridge 15, which is tuned to the outer dimensions of the projecting contact surface 14 of the respective arrester 1 to 4.

Thus, the respective short leg 18 can be brought into positive engagement with the projecting contact surface 14, wherein the final fixing is then carried out with the aid of a corresponding contact rail, as in the lower part of the picture Fig. 4 becomes clear.

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

Preferably, the wiring plane changing bridge 15 consists of a flat copper material, which at least in a partial area with an insulation sheath 19 (see Fig. 4 ) can be provided.

The contact rail 7, but also the individual contact rails 8 to 11 are formed as metallic angle elements, wherein a first angle leg 20 is non-positively connected to the respective projecting contact surface 14 of the respective spark gap. About this leg 20, a positive connection or corresponding support in the housing 6 can be achieved at the same time, which has corresponding grooves or the like recesses.

A second angle leg 21 carries the terminals 12th
The first angle leg 20 is connected via a screw connection (see Fig. 4 ) connected to the respective contact surface 14 of the respective spark gap. This screw can simultaneously secure the respective short leg 18 of the wiring level change bridge 15, as shown in the picture below right below Fig. 4 is shown.

Tongue-like forms or projections 22, which are arranged or introduced in the region of the short legs 18 of the wiring plane swap body 15, oriented in the mounted state towards the respective first angle leg, so that then an abutment is formed which can absorb electrodynamic forces in the surge current case.
In particular, this counter bearing counteracts stretching of the bracket during the flow of current.

In a substantially at least partially U-shape of the contact rails 8 to 11 or 23 for the PE connection is a third tongue-angle leg 24 (see the upper part of the picture Fig. 4 ) as a cable fixing pressure plate. This third tongue-angle leg 24 is substantially opposite to the second angle leg 21.

LIST OF REFERENCE NUMBERS

1 to 4

Surge arresters or spark gaps

5

chamber

6

Plastic housing

7

contact bar

8 to 11

Single contact rails

12

terminal

13

screw

14

protruding contact surface of the spark gap

15

Wiring levels-swap

16

formation

17

dividing wall

18

short leg of the wiring level swap

19

insulation enclosure

20

first angle leg

21

second angle leg

22

tongue-like forms or protrusions

23

PE terminal

24

Tongue angle leg

25

insulation

26

sleeve-like extension

27

cylindrical compression spring

28

lower end portion of the sleeve-like extension

29

Arretierungsfortsatz

30

further extensions

31

spacer cams

32

terminal lug

33

circuit board

34

contact point

35

solder pads

Claims (18)

1. Compact arrangement for multipole surge-current proof surge arresters comprising internally wired, encapsulated spark gaps (1 to 4) essentially arranged in parallel in a housing (6), said spark gaps (1 to 4) having facing projecting contact surfaces (14) connected to outer terminals (12) and inner contact bars (7) or bridges, and comprising an electronic control or trigger circuit present on a wiring support (33), said housing (6) being trough-shaped with dividing walls (17), wherein the resulting housing chambers (5) accommodate the spark gaps (1 to 4) and the terminals (12),
   characterized in that
   an insulating plate (25) is provided on the upwardly opening housing trough, which insulating plate has openings into which spring contact elements (27) are introduced,
   moreover, the wiring support (33) is arranged above said insulating plate (25), with the spring contact elements (27) forming an electrical connection between contact points (34) on the underside of the wiring support (33) and the cover of one of the spark gaps (1 to 4), respectively.
2. Compact arrangement according to claim 1,
   characterized in that
   the wiring support (33) is a copper-clad circuit board, with the contact points (34) being formed as larger-area solder lands (35).
3. Compact arrangement according to claim 1 or 2,
   characterized in that
   the circuit board (33) comprises lateral terminal lugs (32) which may be electrically connected to the inner contact bars (7), whereby a simultaneous mechanical locking of the insulating plate (25) containing the spring contact elements (27) is hereby achieved.
4. Compact arrangement according to one of the preceding claims,
   characterized in that
   in the area of the openings, the underside of the insulating plate (25) comprises sleeve-like extensions (26) which are cut at an angle to the longitudinal axis so that the spring contact elements (27), on the one hand, are secured from dropping out downwardly, and, on the other hand, a conductive portion thereof is exposed.
5. Compact arrangement according to claim 4,
   characterized in that
   the encapsulated spark gaps (1 to 4) are essentially cylindrical-shaped or have such a partial shape, said cut portion of the sleeve-like extensions (26) being formed like a circle segment and complementarily 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 pressure springs (27) which project on both sides of the corresponding opening.
7. Compact arrangement according to claim 5,
   characterized in that
   facing said sleeve-like extension (26), at least one further locking extension (29) is provided which on its side facing the corresponding spark gap (1 to 4) is adapted to the housing shape thereof.
8. Compact arrangement according to one of the preceding claims,
   characterized in that
   the upper side of the insulating plate (25) has spacer cams (31) formed thereon.
9. Compact arrangement according to one of the preceding claims,
   characterized in that
   the housing (6) and the insulating plate (25) are made of injection-molded plastic.
10. Compact arrangement according to one of the preceding claims,
    characterized in that
    an essentially Z-shaped wiring plane change-over bridge (15) is provided including two short (18), oppositely directed connection legs and one longer connection leg, with fitting bores or recesses being formed in the short legs (18), which correspond to the outer dimension of projecting contact surfaces (14) of the spark gap, with the material thickness of at least the short legs (18) being essentially equal to or less than the height of a projection of a contact surface (14) of the spark gap (1 to 4), and the long leg extending in the spacing of the installation space between two of the spark gaps (1 to 4).
11. Compact arrangement according to claim 10,
    characterized in that
    the contact bars (8 to 11) are formed as metallic angular elements, with a first angle leg (20) being non-positively connected with the corresponding projecting contact surface (14) of the spark gap (1 to 4), and a form-fit support being provided in the housing by this leg, and a second angle leg (21) moreover accommodating the outer terminals (12).
12. Compact arrangement according to claim 11,
    characterized in that
    the first angle leg (20) is connected with the corresponding contact surface of the spark gap (1 to 4) by means of a screw connection.
13. Compact arrangement according to claim 12,
    characterized in that
    the screw connection simultaneously secures the respective short leg (17) of the wiring plane change-over bridge (15).
14. Compact arrangement according to claim 10,
    characterized in that
    in a three-phase arrangement including a neutral conductor, one of the contact bars connects three (1 to 3) of the four spark gaps on one of the longitudinal housing sides, with the contact bar (7) provided on the facing longitudinal housing side comprising insulating portions or being interrupted, and accommodating the terminals of the phase and the neutral conductor, a contact bar having at least one outer terminal being moreover connected with the fourth spark gap (4) for the PE-connection, and the wiring plane change-over bridge (15) being arranged and electrically contacted between the spark gap of the third phase and the spark gap of the neutral conductor.
15. Compact arrangement according to claim 10,
    characterized in that
    the wiring plane change-over bridge (15) consists of a conductive flat material, in particular copper.
16. Compact arrangement according to claim 10,
    characterized in that
    a dividing wall of the chamber (17) is formed to guidingly receive at least one partial portion of the wiring plane change-over bridge (15).
17. Compact arrangement according to one of claims 10 to 16,
    characterized in that
    in the area of the short legs (18) of the wiring plane change-over bridge (15), tongue-like elevations or projections (22) are arranged, which when assembled, form a counter-bearing facing the corresponding first angle leg.
18. Compact arrangement according to claim 11,
    characterized in that
    with an essentially portion-wise U-shape of the contact bars (8 to 11), a third tongue angle leg (24) facing the second angle leg (21) forms a pressure plate for cable fixation.

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