Overvoltage protection device

Abstract

The invention relates to an overvoltage protection device having at least one trigger spark gap for connection between a first line and a reference potential and a spark gap arrangement for connection between the reference potential and a ground connection, the trigger spark gap having an ignition circuit, the overvoltage protection device according to the invention thus has a relatively low protection level, such that the spark gap arrangement has a first spark gap with a first electrode and a second electrode and at least one second spark gap with a first electrode and a second electrode, the second electrode of the first spark gap and the first electrode of the second spark gap are at a common potential such that the first spark gap and the second spark gap are connected in series, and the ignition circuit which can trigger the spark gaps is connected to the common potential of the second electrode of the first spark gap and the first electrode of the second spark gap of the spark gap arrangement.

Description

Technical Field

[0001] The present invention relates to an overvoltage protection device having at least one triggerable spark gap for connecting between a first conductor and a neutral conductor, and a spark gap device for connecting between the neutral conductor and a protective conductor, wherein the triggerable spark gap has an ignition circuit. Background Technology

[0002] Overvoltage protection devices are known from the prior art in various forms and are used to protect electrical equipment or lines from overvoltages that may be caused, for example, by lightning strikes, switching operations, or faults in technical facilities. Depending on the choice of discharger and the anticipated environmental impact, the necessary measures for protecting the power supply of equipment and facilities are divided into two to three levels. Here, the overvoltage protection devices for each level differ in terms of dissipation capacity and protection level.

[0003] Class 1 overvoltage protection devices (often also called surge protectors) typically have a discharger based on a spark gap voltage switch, as the spark gap can dissipate high overvoltages and conduct large currents. However, because spark gaps have relatively high response voltages, and therefore relatively high protection levels, they are usually connected to an ignition circuit (trigger circuit) that ignites the spark gap at lower voltages. Such spark gaps connected to or having an ignition or trigger circuit are referred to herein as triggerable spark gaps.

[0004] Various mechanisms for spark gap ignition are known. Besides high-voltage ignition using a high-voltage pulse, the applicant has for many years used a resistive ignition element for spark gap ignition (see EP 1 566 868B1). The resistive ignition element is connected to a first electrode on one side and to a second electrode on the other side via a voltage-limiting element, such as a varistor. Furthermore, the resistive ignition element is spatially connected to the arc combustion chamber of the spark gap. When a corresponding overvoltage occurs, current flows first through the resistive ignition element to the adjacent electrode. This current through the ignition element causes a discharge on its surface, thereby generating ionized gas in the ignition region adjacent to the ignition element within the arc combustion chamber, which diffuses within the arc combustion chamber. This results in a decrease in the breakdown voltage of the spark gap, thus igniting the spark gap.

[0005] The ignition or triggering circuit of a spark gap typically also includes a voltage switching element, particularly a gas discharge tube, to achieve an insulating gap in the ignition or triggering circuit. The use of a gas discharge tube here ensures that the overvoltage protection device maintains a specific insulation strength. If such a triggered spark gap is connected in series in the overvoltage protection device, the required ignition voltage for the gas discharge tube in the ignition circuit will be added accordingly due to the series connection of the ignition circuit, thereby correspondingly increasing the protection level of the overvoltage protection device.

[0006] For example, this approach is disadvantageous in classic n+1 circuits, where each phase line (L) and neutral line (N) has a protection path with a trigger spark gap, as this significantly improves the protection level in the protection path between phase line L and protective line PE (L-PE protection path). In practice, for overvoltage protection devices with a 230 / 400 V power supply, the protection level of the L-PE protection path is typically 2.5 kV.

[0007] To dissipate high overvoltages, multiple spark gaps are also used, often referred to as stacked spark gaps due to their structure. These multiple spark gaps consist of multiple electrodes and multiple insulating devices arranged between each electrode, such that each pair of electrodes has an insulating device with an opening in the middle, thus forming a single spark gap between the two electrodes. These electrodes are typically designed as circular or rectangular graphite disks, with corresponding annular or frame-like insulating devices arranged between them. These insulating devices can be in the form of insulating films or disks made of plastic.

[0008] To influence the ignition behavior of a multiple spark gap, prior art describes control circuits with multiple passive control elements. For example, DE 197 42 302 A1 discloses a multiple spark gap consisting of multiple individual spark gaps connected in series, wherein, except for the first individual spark gap that responds during discharge, the other individual spark gaps are connected through a hierarchical resistor network, thereby sequentially turning on these individual spark gaps. Each individual spark gap has a resistor connected in parallel, and the resistors of all individual spark gaps are connected in series with each other and grounded. To ensure that the response voltage of the multiple spark gap does not exceed a maximum value of 4 kV, the spacing between the two electrodes of the first individual spark gap should be chosen to be relatively small.

[0009] Capacitors, especially capacitors, are also commonly used as control elements in the case of multiple spark gaps. Each capacitor is in contact with an electrode via a terminal, and all capacitors are electrically connected to each other and to the second terminal of the multiple spark gap, thus forming a capacitive voltage divider that concentrates the applied voltage across a single spark gap. If this single spark gap is ignited, the total voltage, which reduces only the arc voltage of the first ignited single spark gap, is applied to the next single spark gap, thereby sequentially energizing these single spark gaps.

[0010] Compared to a single spark gap, the advantage of a multiple spark gap lies in its improved follow current suppression capability. The ability to suppress follow current increases with the number of individual spark gaps. However, at the same time, the response voltage of a multiple spark gap also increases with the number of individual spark gaps. Therefore, while a multiple spark gap composed of multiple individual spark gaps offers high follow current suppression capability, its protection level is often too high for low-voltage applications. Summary of the Invention

[0011] Therefore, the present invention is based on the following objective: to describe an overvoltage protection device as described at the beginning, which has at least one triggerable spark gap and a spark gap device with the lowest possible protection level.

[0012] This objective is achieved in the case of an overvoltage protection device having the features described at the beginning of claim 1. According to the invention, the spark gap device of the overvoltage protection device includes: a first spark gap having a first electrode and a second electrode, and at least one second spark gap having a first electrode and a second electrode, wherein the second electrode of the first spark gap and the first electrode of the second spark gap are at a common potential, such that the first spark gap and the second spark gap are connected in series. Furthermore, an ignition circuit capable of triggering the spark gap is connected to the common potential of the second electrode of the first spark gap and the first electrode of the second spark gap of the spark gap device.

[0013] Therefore, the overvoltage protection device according to the present invention has a spark gap device having at least two spark gaps connected in series, wherein the at least one ignition circuit capable of triggering the spark gap is connected to the common potential of the two spark gaps, i.e., the connection point between the second electrode of the first spark gap and the first electrode of the second spark gap of the spark gap device.

[0014] Therefore, a part of the spark gap device, namely one of the spark gaps in a spark gap device consisting of two spark gaps, is part of the ignition circuit that can trigger the spark gap. This leads to the possibility that a gas discharge tube does not need to be arranged in at least one ignition circuit that can trigger a spark gap, because the implementation of the insulation gap in the ignition circuit is undertaken by the spark gap of the spark gap device.

[0015] According to a preferred embodiment of the overvoltage protection device according to the invention, the spark gap device is designed as a multiple spark gap (Mehrfachfunkenstrecke). The second electrode of the first spark gap and the first electrode of the second spark gap, which are at a common potential, are here formed by the common electrode, thereby connecting the common electrode to the ignition circuit that can trigger the spark gap. In the simplest embodiment, the multiple spark gap here consists of only three electrodes, and therefore only two single spark gaps or two spark discharge gaps (Überschlagstrecke), wherein the middle electrode serves as the common electrode of the two single spark gaps, connected to the ignition circuit that can trigger the spark gap or becoming part of the ignition circuit.

[0016] If such overvoltage protection devices are used in an n+1 circuit, a triggerable spark gap can be used in the path between the phase line L and the neutral line N, and multiple spark gaps can be used in the path between the neutral line N and the protective earth line PE. The at least one triggerable spark gap, in addition to the first and second electrodes, also has the two main electrodes, a trigger electrode, and / or a resistive ignition element. If the triggerable spark gap is ignited by means of the resistive ignition element as described above, an additional ignition electrode can be provided in addition to the resistive ignition element. This additional ignition electrode is arranged on the second side of the resistive ignition element opposite to the first electrode and connected to the resistive ignition element.

[0017] According to another preferred embodiment of the overvoltage protection device according to the invention, the at least one ignition circuit capable of triggering a spark gap includes a voltage-limiting device, which may be, for example, a varistor. This voltage-limiting device, particularly the varistor, advantageously has a disconnection device (Abtrenneinrichtung) by which it protects the voltage-limiting device from damage. This disconnection device is particularly a thermal disconnection device, which disconnects the ignition circuit and thus interrupts the current flowing through the voltage-limiting device when it overheats.

[0018] According to another preferred embodiment of the overvoltage protection device, a control circuit is provided for controlling the ignition behavior of the spark gap device. This control circuit has multiple control elements connected to the electrodes of the spark gap device. The control elements of this control circuit can, in particular, be impedances or capacitors. By using the appropriate control circuit, the response voltage of the spark gap device can be optimized, and thus the overall protection level of the overvoltage protection device is reduced. The number of control elements preferably corresponds to the number of spark gaps in the spark gap device.

[0019] The overvoltage protection device according to the invention is particularly advantageous when used in an n+1 circuit. The overvoltage protection device thus has n triggerable spark gaps for connection between the conductors and the neutral line, respectively. For example, if the overvoltage protection device is used in a 5-Leiter system comprising three phase lines (L1, L2, and L3), a neutral line N, and a protective earth line PE, then the overvoltage protection device has three triggerable spark gaps for connection between the three phase lines (L1, L2, L3) and the neutral line N. Furthermore, the overvoltage protection device also includes a spark gap device having at least two spark gaps, particularly a corresponding multiple spark gap, for connection between the neutral line N and the protective earth line PE. The n ignition circuits of these n triggerable spark gaps are here respectively connected to the common potential of the two spark gaps of the spark gap device or the common electrode of the multiple spark gaps.

[0020] In situations where electrical isolation between phase lines is required in a conductor system with multiple phase lines, it is meaningful, according to embodiments of the invention, to arrange voltage switching devices, particularly gas discharge tubes, in at least n-1 ignition circuits with n triggerable spark gaps. For example, if the conductor system has three phase lines, it is therefore unnecessary to arrange voltage switching devices in all three ignition circuits with three triggerable spark gaps; rather, it is sufficient to have voltage switching devices in two of the three ignition circuits.

[0021] However, if voltage switching devices are arranged in all n ignition circuits with n triggerable spark gaps, it is possible, with proper parameter design (Dimensionierung) of the voltage switching devices, to make the protection level for all n phase lines in the protection path LN the same.

[0022] A variation of the aforementioned implementation scheme of the overvoltage protection device may also be: n ignition circuits for n triggerable spark gaps have a common voltage switching device, specifically a common gas discharge tube. This common gas discharge tube then has not just two electrodes, but (n+1) electrodes, which are respectively connected to the n triggerable spark gap ignition circuits. The additional electrodes of the gas discharge tube, which, along with the other electrodes, form spark discharge gaps, are here connected to the connection point or common potential of the two spark gaps in the spark gap device. Attached Figure Description

[0023] Specifically, there are various possibilities for extending and designing the overvoltage protection device according to the present invention. Please refer to the dependent patent claims and the following description of several embodiments in conjunction with the accompanying drawings. In the drawings: Figure 1 A circuit diagram of an overvoltage protection device for an n+1 circuit in a 5-wire system, according to the prior art, is shown. Figure 2 A circuit diagram of an embodiment of an overvoltage protection device for an n+1 circuit in a 3-wire system according to the present invention is shown. Figure 3 A simplified diagram of a spark gap device with multiple spark gaps is shown, representing an overvoltage protection device design. Figure 4 A circuit diagram of a first embodiment of an overvoltage protection device for an n+1 circuit in a 5-wire system according to the present invention is shown. Figure 5 A circuit diagram of a second embodiment of an overvoltage protection device for an n+1 circuit in a 5-wire system according to the present invention is shown, and Figure 6 A circuit diagram of a third embodiment of an overvoltage protection device for an n+1 circuit in a 5-wire system is shown. Detailed Implementation

[0024] Figure 1 shows a circuit diagram of an overvoltage protection device for a 5-wire system according to the prior art. This 5-wire system has three phase wires, for which three connection possibilities are provided on the overvoltage protection device 100. In the circuit diagram, these connection possibilities are labeled L1 for the first conductor, L2 for the second conductor, and L3 for the third conductor. Furthermore, the 5-wire system also has a neutral wire and a protective conductor; in the circuit diagram, their connection possibilities are labeled N for the neutral wire and PE for the protective conductor.

[0025] The known overvoltage protection device 100 has an n+1 circuit connection scheme (Anschlussschema) in this example, where protection paths with triggerable spark gaps 110, 120, and 130 are respectively implemented between the n = 3 phase lines L1, L2, and L3 and the neutral line N. Furthermore, a protection path with a triggerable spark gap 140 is also formed between the neutral line N and the protective earth line PE. These triggerable spark gaps each have an ignition circuit 150, where the ignition circuit in the prior art typically has at least one series circuit consisting of a varistor and a gas discharge tube.

[0026] In the 3+1 circuit of the known overvoltage protection device 100 shown, the protection path (L-PE protection path) between phase lines L1, L2, L3 and the protective earth line PE has two triggerable spark gaps, for example, triggerable spark gaps 110 and 140 for the L1-PE protection path, connected in series. Therefore, the ignition circuit for the L-PE protection path consists of two ignition circuits 150 connected in series, which results in a corresponding increase in the ignition voltage required for the gas discharge tubes arranged in the ignition circuit 150, and thus a corresponding increase in the protection level of the overvoltage protection device 100 for the L-PE protection path. In practice, for a 230 / 400 V power supply voltage, the protection level of the L-PE protection path in the overvoltage protection device 100 is typically 2.5 kV.

[0027] Figure 2 is a circuit diagram of a first embodiment of an overvoltage protection device 1 for a three-wire system according to the present invention. The three-wire system has a phase wire (first wire), to which the overvoltage protection device 1 provides connection possibilities marked L1 in the circuit diagram. Furthermore, the three-wire system has a neutral wire and a protective conductor, whose connection possibilities are marked N for the neutral wire and PE for the protective conductor in the circuit diagram.

[0028] The overvoltage protection device 1 also has an n+1 circuit connection scheme, which is 1+1 circuit in this example. A protection path with a triggerable spark gap 10 is implemented between one of the phase lines L1 and the neutral line N. Furthermore, a protection path is also implemented between the neutral line N and the protective earth line PE, but this protection path does not have a triggerable spark gap; instead, it has a spark gap device 40 with two spark gaps 41 and 42 connected in series. The first spark gap 41 has a first electrode 411 and a second electrode 412. Correspondingly, the second spark gap 42 also has a first electrode 421 and a second electrode 422. The second electrode 412 of the first spark gap 41 and the first electrode 421 of the second spark gap 42 are connected to each other, so that the two electrodes 412 and 421 have a common potential.

[0029] Unlike existing overvoltage protection devices 100, the ignition circuit 14 that triggers the spark gap 10 is connected to the connection point 43 between the second electrode 412 of the first spark gap 41 and the first electrode 421 of the second spark gap 42, i.e., connected to the common potential of these two electrodes 412 and 421. Since the first spark gap 41 of the spark gap device 40 is part of the ignition circuit 14 that triggers the spark gap 10 in the L1-N protection path, the gas discharge tube is eliminated from the need to arrange it in the ignition circuit 14. Here, the insulation gap in the ignition circuit 14 is achieved by the first spark gap 41 of the spark gap device 40.

[0030] The triggerable spark gap 10 shown in Figure 2, in addition to the two main electrodes, namely the first electrode 11 and the second electrode 12, also has a trigger electrode 13 connected to the ignition circuit 14. Accordingly, the trigger electrode 13 can also be referred to as the ignition electrode. Furthermore, the ignition circuit 14 also has a voltage limiting device 15, which is arranged between the trigger electrode 13 and the connection point 43 between the two electrodes 412 and 421. The voltage limiting device 15 is preferably designed as a varistor with a thermal disconnect device 16, wherein the thermal disconnect device protects the varistor from damage under intense heating.

[0031] Figure 3 shows a simplified diagram of a spark gap device 40 designed as a multiple spark gap for overvoltage protection device 1. In its simplest form, the multiple spark gap has only three electrodes 411, 44, and 422, which constitute two spark gaps 41 and 42. The first spark gap 41 is formed by the first electrode 411 and the intermediate common electrode 44. Correspondingly, the second spark gap 42 is formed by the common electrode 44 and the second electrode 422. Each electrode 411, 422, and 44 can be designed as a thin disk made of graphite or carbon. If the spark gap device 40 is designed as a multiple spark gap, the ignition circuit 14 that triggers the spark gap 10 is connected to the common electrode 44 of the first spark gap 41 and the second spark gap 42.

[0032] Figure 4 A circuit diagram of a first embodiment of an overvoltage protection device 1 for a 5-wire system according to the present invention is shown. As described above in conjunction with FIG1, the 5-wire system has three phase wires, for which the overvoltage protection device 1 provides three connection possibilities, which are labeled L1, L2, and L3 for the first, second, and third wires in the circuit diagram. Furthermore, the 5-wire system also has a neutral wire and a protective conductor, whose connection possibilities are labeled N for the neutral wire and PE for the protective conductor in the circuit diagram.

[0033] The overvoltage protection device shown in Figure 4 also has an n+1 circuit connection scheme, which is a 3+1 circuit in this example. Protection paths with triggerable spark gaps 10, 20, and 30 are implemented between phase lines L1, L2, and L3 and the neutral line N, respectively. The N-PE protection path implemented between the neutral line N and the protective earth line PE has a spark gap device 40 with two series-connected spark gaps 41 and 42. The three ignition circuits 14, 24, and 34 of the three triggerable spark gaps 10, 20, and 30 are respectively connected to the connection point 43 between the second electrode 412 of the first spark gap 41 and the first electrode 421 of the second spark gap 42 of the spark gap device 40. Thus, the first spark gap 41 of the spark gap device 40 is a part of the corresponding ignition circuits 14, 24, and 34 of the corresponding triggerable spark gaps 10, 20, and 30 in the corresponding LN protection path. Therefore, no gas discharge tube is provided in each of the ignition circuits 14, 24, 34 (as previously described with reference to ignition circuit 14 in conjunction with FIG2), because the realization of the corresponding insulation gap in ignition circuits 14, 24, 34 is achieved by the first spark gap 41 of spark gap device 40.

[0034] Each triggerable spark gap 10, 20, and 30 has a first electrode 11, 21, 31, a second electrode 12, 22, 32, and a trigger electrode 13, 23, 33, respectively, wherein each trigger electrode 13, 23, 33 is connected to a corresponding ignition circuit 14, 24, 34. Furthermore, each ignition circuit 14, 24, and 34 is equipped with a voltage-limiting device 15 designed as a varistor, and each voltage-limiting device has a thermal disconnect device 16. Therefore, the structures of the three ignition circuits 14, 24, and 34 in the embodiment of the overvoltage protection device 1 according to FIG. 4 correspond to the structure of the ignition circuit 14 in the embodiment of the overvoltage protection device 1 according to FIG. 2.

[0035] Figures 5 and 6 show circuit diagrams of the overvoltage protection device 1 for a 5-wire system. Figure 4 Unlike the illustrated embodiment, here, voltage switching devices 17 are also arranged in each of the ignition circuits 14, 24, and 34 that can trigger spark gaps 10, 20, and 30. In this example, the voltage switching devices are designed as gas discharge tubes. By arranging such voltage switching devices 17 in the ignition circuits 14, 24, and 34, electrical isolation can be achieved between the phase lines L1, L2, and L3 that can be connected to the overvoltage protection device 1.

[0036] In principle, for n phase lines or n triggerable spark gaps 10, 20, 30, it is sufficient to arrange the corresponding voltage switching devices 17 in n-1 ignition circuits. Alternatively, instead of the three voltage switching devices 17 in the three ignition circuits 14, 24, 34 shown in Figure 5, it is equally sufficient to arrange voltage switching devices 17 in only two ignition circuits 14 and 24 respectively, and not to include voltage switching devices 17 in ignition circuit 34.

[0037] Instead of arranging gas discharge tubes separately in at least n-1 ignition circuits, a single common gas discharge tube can be used, in which the gas discharge tube no longer has only two electrodes, but n+1 electrodes. Therefore, in the embodiment according to FIG5, the gas discharge tube must have four electrodes, one of which is connected to the connection point 43 of the spark gap device 40, and the other three electrodes are connected to one of the three trigger electrodes 13, 23, 33 respectively through the varistor 15.

[0038] In the circuit diagram shown in Figure 6, the spark gap device 40 has a control circuit 45 between the neutral line N and the protective earth line PE for controlling the ignition behavior of the spark gap device 40. This control circuit has multiple control elements 46. The control elements 46 are preferably capacitors connected to the electrodes of the spark gap device 40. A first capacitor is connected to the first electrode 411 of the first spark gap 41 with its first terminal, and a second capacitor is connected to the second electrode 422 of the second spark gap 42 with its terminal. The second terminals of the capacitors are electrically connected to each other and to the connection point 43 of the two spark gaps 41, 42, and thus to the respective ignition circuits 14, 24, 34.

[0039] List of reference numerals 1. Overvoltage protection equipment 10, 20, and 30 can trigger spark gaps. 11, 21, 31 First Electrode 12, 22, 32 Second Electrode Trigger electrodes 13, 23, and 33 14, 24, 34 Ignition circuits 15 Varistors 16 Disconnection device 17 Gas Discharge Tube 40 Spark gap device (multiple spark gap) 41 First Spark Gap 411 First Electrode 412 Second Electrode 42 Second Spark Gap 421 First Electrode 422 Second Electrode 43 Connection Points 44 Common Electrode 45 Control Circuit 46 Control elements 100 Overvoltage Protection Equipment 110 and 120 can trigger spark gaps. 130 and 140 can trigger spark gaps. 150 Ignition Circuit L1 First conductor L2 Second wire L3 Third conductor N Neutral line PE protection line.

Claims

1. Overvoltage protection device (1) having at least one triggerable spark gap (10, 20, 30) for connection between a first line (LI) and a neutral line (N) and a spark gap arrangement (40) for connection between the neutral line (N) and a protective line (PE), wherein the triggerable spark gap (10, 20, 30) having a firing circuit (14), characterized in that the spark gap arrangement (40) comprises a first spark gap (41) having a first electrode (411) and a second electrode (412) and at least one second spark gap (42) having a first electrode (421) and a second electrode (422), wherein the second electrode (412) of the first spark gap (41) and the first electrode (421) of the second spark gap (42) are at a common potential, such that the first spark gap (41) and the second spark gap (42) are connected in series, and the firing circuit (13) of the triggerable spark gap (10) is connected to the common potential of the second electrode (412) of the first spark gap (41) and the first electrode (421) of the second spark gap (42) of the spark gap arrangement (40).

2. The overvoltage protection device (1) according to claim 1, characterized in that The spark gap arrangement (40) is designed as a multiple spark gap, wherein the second electrode (412) of the first spark gap (41) and the first electrode (421) of the second spark gap (42) are formed by a common electrode (44), and wherein the common electrode (44) is connected to the firing circuit (13) of the triggerable spark gap (10).

3. The overvoltage protection device (1) according to claim 1 or 2, characterized in that The at least one triggerable spark gap (10, 20, 30) has a first electrode (11, 21, 31), a second electrode (12, 22, 32) and a trigger electrode (13, 23, 33) or a resistive firing element.

4. The overvoltage protection device (1) according to any one of claims 1 to 3, characterized in that The firing circuit (14, 24, 34) of the at least one triggerable spark gap (10, 20, 30) has a voltage limiting device (15), in particular a voltage-dependent resistor.

5. The overvoltage protection device (1) according to claim 4, characterized in that The voltage limiting device (15) of the firing circuit (14, 24, 34) has a disconnection device (16).

6. The overvoltage protection device (1) according to any one of claims 1 to 5, characterized in that A control circuit (45) for controlling the firing behavior of the spark gap arrangement (40) is provided, wherein the control circuit (45) has a plurality of control elements (46) which are connected to the electrodes (411, 412, 421, 422) of the spark gap arrangement (40).

7. The overvoltage protection device (1) according to any one of claims 1 to 6, characterized in that The overvoltage protection device (1) has n triggerable spark gaps (10, 20, 30) for connection between a line (LI, L2, L3) and the neutral line (N), respectively, and The n firing circuits (14, 24, 34) of the n triggerable spark gaps (10, 20, 30) are each connected to the common potential of the second electrode (412) of the first spark gap (41) and the first electrode (421) of the second spark gap (42) of the spark gap arrangement (40).

8. The overvoltage protection device (1) according to claim 7, characterized in that A voltage switching device (17), in particular a gas discharge tube, is arranged in at least (n-1) of the n ignitable spark gaps (10, 20, 30).

9. The overvoltage protection device (1) according to claim 8, characterized in that At least n of the n ignitable spark gaps (10, 20, 30) have a common voltage switching device, in particular a common gas discharge tube.

10. The overvoltage protection device (1) according to any one of claims 2 to 9, characterized in that, The electrodes (411, 422, 44) of the multiple spark gap are designed as thin disks made of graphite or carbon.

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