Surge protection device

Abstract

Shown and described is an overvoltage protection device (1) with a device base (2) and at least one plug part (3) which can be plugged onto the device base (2), wherein the device base (2) has a base housing (20) with a recess (21) for receiving the plug part (3), plug contacts (4) and conductor connection terminals (5) connected to the plug contacts (4), wherein the at least one plug part (3) has a plug housing (30), an overvoltage protection element (6) arranged in the plug housing (30) and mating plug contacts (7) corresponding to the plug contacts (4) and which are electrically conductively connected to the overvoltage protection element (6), wherein the plug contacts (4) and the conductor connection terminals (5) are arranged in the base housing (20), wherein openings (23) are formed in the upper side (22) of the base housing (20) facing the recess (21), through which Mating plug contacts (7) can be inserted into the corresponding plug contacts (4),and wherein conductor insertion openings (26) are arranged in the front (24) and the rear (25) of the base housing (20), through which the conductor connection terminals (5) are accessible. , The surge protection device is particularly reliable even when higher voltages are applied because an air and creepage distance extension is formed in the area of ​​the openings (23) and / or in the area of ​​the conductor insertion openings (26).

Description

The invention relates to an overvoltage protection device, having a device socket and at least one plug part that can be plugged onto the device socket, wherein the device socket has a socket housing with a recess for receiving the plug part, plug contacts and conductor connection terminals connected to the plug contacts, and wherein the at least one plug part has a plug housing, an overvoltage protection element arranged in the plug housing and mating plug contacts corresponding to the plug contacts, which are electrically conductively connected to the overvoltage protection element. The plug contacts and the conductor connection terminals are arranged in the socket housing, wherein openings are formed in the upper side of the socket housing facing the recess, through which openings counter plug contacts can be inserted into the corresponding plug contacts. In the front side and the rear side of the base housing, conductor insertion openings are arranged, through which the conductor connection terminals are accessible for the connection of a corresponding conductor.Overvoltage protection devices are used extensively in different embodiments for protecting electrical circuits, installations, machines and devices. Depending on the application and the protection level, the overvoltage protection devices have different overvoltage protection elements and different designs. In this case, spark gaps, gas-filled surge arresters and varistors and combinations of these components are used in particular as overvoltage protection elements.In practice, such overvoltage protection devices are frequently designed as plug-in device combinations with a device base as the lower part and at least one plug part as the upper part. Frequently, a plurality of overvoltage protection elements are arranged in an overvoltage protection device, which are differently interconnected depending on the intended purpose and installation location. This applies in particular to overvoltage protection devices which are used in 3-phase systems in which a plurality of plug parts are plugged onto a device base.In known overvoltage protection devices, the device base, which can be mounted on a support rail, for example, serves for connection to the electrical lines. To install such an overvoltage protection device, which is intended to protect, for example, the phase-conducting conductors L 1, L 2, L 3 and the neutral conductor N and, if applicable, also the ground conductor PE, corresponding conductor connection terminals for the individual conductors are provided on the device base. In the known overvoltage protection devices, the device base is approximately U-shaped, wherein the conductor connection terminals for the phase conductors and the neutral conductor are arranged on one of the two legs and the conductor connection terminals for the ground conductor are arranged on the other leg. The socket housing of the device socket has a recess, the dimensions of which are adapted to the external dimensions of the plug part, so that a plug part can be inserted into the recess and locked therein. As a rule, a plurality of plug parts, each having at least one overvoltage protection element, are inserted next to one another in a base housing. The width of the device socket then corresponds to a corresponding multiple of the width of a plug part.For simple mechanical and electrical contacting of the device socket with the plug part in which the actual protective element is arranged, the device socket has plug contacts connected to the conductor connection terminals, for example plug sockets, and the plug part has corresponding mating plug contacts, for example plug pins, so that the plug part can be plugged onto the device socket and the mating plug contacts can be inserted into the plug contacts in the process. The plug-in capability of the overvoltage protection element arranged in the plug part makes it possible to replace the plug part in the event of a fault or during revision or maintenance work, without the conductors connected to the conductor connection terminals of the device socket having to be disconnected.The object of the present invention is to provide an overvoltage protection device described at the beginning which ensures reliable use even at higher voltages applied.This object is achieved in the overvoltage protection device described at the beginning with the features of claim 1 in that an air and creepage distance extension is formed on the base housing in the region of the openings for the plug contacts and / or in the region of the conductor insertion openings. The air and creepage distance extensions formed on the base housing achieve an extension of the corresponding air and creepage distance between two adjacent contacts, that is to say either between two plug contacts or between two conductor connection terminals. Since the base housing is generally made of plastic and is frequently produced by injection molding, the individual air and creepage distance extensions can be realized directly during the production of the base housing, so that no additional manufacturing step is then required.Preferably, an air and creepage distance extension is formed in each case both in the region of the openings for the plug contacts and in the region of the conductor insertion openings. As a rule, in this case corresponding air and creepage distance extensions are formed in the region of all openings for the plug contacts and also in the region of all conductor insertion openings. However, embodiments are also possible in which an air and creepage distance extension is formed only in the region of the openings for the plug contacts or only in the region of the conductor insertion openings, or air and creepage distance extension is not formed in the region of all openings for the plug contacts or not in the region of all conductor insertion openings.According to a preferred embodiment, the air and creepage distance extensions formed in the region of the openings for the plug contacts are each formed as encircling collars. A collar surrounds the associated opening in the upper side of the base housing and projects into the recess. If the plug part is plugged onto the socket part, a mating plug contact dips through the collar and the opening in the upper side of the socket housing into the corresponding plug contact, with the result that the mating plug contact is also surrounded by the encircling collar. The collar thus extends starting from the associated opening in the opposite direction to the insertion direction of the plug part into the recess in the base housing. The configuration of the individual collars extends both the air plug and the creepage distance between two adjacent plug contacts, which are each accessible through the collars or the openings surrounded by the collars, without the dimensions of the device base and thus also of the overvoltage protection device as a whole increasing.The plug contacts can each be designed as a type of contact tulip in which the individual contact arms can have a curved shape. In this case, more than two contact arms can also be formed, which together form a plug contact or a contact tulip. Likewise, the individual contact arms of a plug contact can be slotted, whereby individual contact fingers are formed, which together form a plug contact. The mating plug-in contacts can then be designed, for example, as contact pins or also as contact blades. Preferably, the plug contacts and / or the mating plug contacts are designed to be resilient in order to enable a sufficiently high contact force in the inserted state of the plug contact and mating plug contact.The air and creepage distance extensions formed in the region of the conductor insertion openings to the conductor connection terminals are preferably realized in that the conductor connection terminals are arranged set back to the corresponding front side or rear side in the base housing. As a result, the length of the channel formed by the conductor insertion opening can be extended from the outside of the socket housing to the conductor connection terminal without the corresponding outer dimension of the socket housing being increased. This is advantageous since the overvoltage devices frequently have certain, predetermined external dimensions. These cannot be easily increased as a rule, since the overvoltage devices are usually mounted together with other protective devices on a support rail and installed in a switch cabinet, where the space available is generally limited.It has been stated at the outset that in the overvoltage protection devices in question, a plurality of plug parts are generally plugged onto a device base. In such overvoltage protection devices, the device base has a width that corresponds to the sum of the widths of the individual plug parts. In the case of an overvoltage protection device having, for example, four plug parts, wherein the individual plug parts each have the same width, the width of the device base is thus four times the width of a plug part.In an overvoltage protection device having a plurality of plug parts, according to a preferred embodiment additional connection elements are arranged in the base housing, each of which is assigned to a conductor connection terminal and is electrically conductively connected to the latter. A connection element provided in addition to a conductor connection terminal enables the electrical connection of a second conductor to the conductor connection terminal or to the conductor connected thereto. For this purpose, openings are formed in the front side or the rear side of the base housing, via which openings the connection elements are accessible. The additional connection elements can be designed in particular such that a conductor can be connected to them in each case, which conductor has a fork shoe at its stripped end. Preferably, the connection elements are each formed integrally with the conductor connection terminal or are part thereof.In order that an extension of the air and leakage path is also provided between two additional connection elements arranged next to one another in such an overvoltage protection device, ribs are formed on the front side and the rear side of the base housing, which ribs are each arranged laterally next to an opening for the connection element. The ribs extend parallel to the insertion direction of the plug part into the recess in the base housing and thus perpendicular to the width direction of the base housing and also perpendicular to the insertion direction of a conductor to be connected to the additional connection element.According to a further advantageous embodiment of the overvoltage protection device according to the invention, which enables an additional extension of the air and creepage distance, at least one frame part is provided, which can be fastened to the front side and / or to the rear side of the base housing. The frame part has a plurality of wall elements which surround at least the individual conductor insertion openings. The frame part can have, for example, four wall elements and be of rectangular configuration, wherein a frame part encircling in this way surrounds a conductor insertion opening in the assembled state. By means of a frame part arranged on the front side or on the rear side of the base housing, there is thus an additional extension of the channel from the outer side of the frame part to the conductor connection terminal and thus an additional extension of the air and leakage path between two adjacent conductor connection terminals. Preferably, a frame part, in addition to the outer wall elements, also has inner sections which project at least partially into an associated conductor insertion opening.If the overvoltage protection device has the above-described additional connection elements, the frame part is preferably designed such that the wall elements of the frame part at least partially enclose not only a conductor insertion opening, but also the opening assigned to the additional connection element. Since the additional connection element is electrically connected to the conductor connection element, no wall element has to be arranged between the conductor insertion opening and the opening for the additional connection element.The frame part described above is preferably designed as a separate housing part from the base housing, which is fastened to the base housing. For this purpose, at least one holding element is formed on the frame part and at least one holding element corresponding thereto is formed on the front side and / or on the rear side of the base housing. Webs or ribs, for example, can be provided as retaining elements, which can be inserted into corresponding recesses or grooves. The holding elements can also be designed such that they latch with one another, so that a frame part can be latched on the front side or on the rear side of the base housing. As retaining elements, latching noses or latching pins can then be provided, for example, which can be inserted into corresponding latching recesses or latching openings.The individual conductor connection terminals can be designed, for example, as a screw connection or as a spring force clamping connection, so that a conductor to be clamped to a conductor connection terminal is clamped against a busbar section by means of a screw or a clamping spring. The busbar section is connected to an associated plug contact, so that a connected conductor is electrically connected to an overvoltage protection element in the corresponding plug part when the plug part is plugged onto the base part.If the individual conductor connection terminals are designed as screw connections, then a screw shaft is formed in the base housing for the individual screw connections, by means of which shaft the respective screw of a screw connection can be actuated. In such an embodiment of the overvoltage protection device or the base part, at least one cover is preferably arranged on the base housing, which can be moved, in particular pivoted, from a first position, in which the screw shafts are accessible, into a second position, in which the screw shafts are not accessible. In the second, closed position of the cover, this also results in an extension of the air and creepage distances between two adjacent screws of two screw connections. In addition, a closed cover reduces the risk that moisture or dirt can enter the individual screw shafts.In particular, there are several possibilities for embodying and further developing the overvoltage protection device according to the invention. In this regard, reference is made both to the individual patent claims and to the following description of preferred exemplary embodiments in conjunction with the drawing. In the drawing, the following are shown: FIG. 1 shows a representation of a first exemplary embodiment of an overvoltage protection device, comprising a device lower part and a plurality of plug parts, FIG. 2 shows a perspective illustration of a base part of the overvoltage protection device according to FIG. 1, FIG. 3 shows the base part according to FIG. 2 in an exploded illustration, FIG. 4 shows a perspective illustration of a second exemplary embodiment of a base part of an overvoltage protection device, FIG. 5 is a perspective view of a frame part of the base part according to FIG. 4 , FIG. 6 shows two perspective representations of a third exemplary embodiment of a base part of an overvoltage protection device, and FIG. 7 shows two perspective representations of a further exemplary embodiment of an overvoltage protection device, comprising a device lower part and a plurality of plug parts.FIG. 1 shows an overvoltage protection device 1 which is embodied in multiple parts, namely has a device base 2 and four plug parts 3. The plug parts 3 can each be simply plugged onto the U-shaped device socket 2 and, for example, for the replacement of a defective plug part 3, can also be easily removed from the device socket 2 again without the lines connected to the device socket 2 having to be disconnected for this purpose. The plug parts 3 each have a plug housing 30 and the device socket 2 a socket housing 20, which latch with one another when the plug parts 3 are plugged onto the device socket 2. Four plug parts 3 can be plugged onto the device socket 2 shown separately in FIG. 2. For this purpose, the base housing 20 has a recess 21, the dimensions of which are matched to the dimensions of the plug housings 30.As can be seen from the exploded view of the device socket 2 according to FIG. 3, the device socket 2 has a plurality of plug contacts 4 and a plurality of conductor connection terminals 5 electrically conductively connected to the plug contacts 4. The conductor connection terminal 5, which in the exemplary embodiment shown are designed as screw connections, serve for connecting the electrical lines of a network to be protected to the device base 2 and thus also to the overvoltage protection device 1. The overvoltage protection elements 6 each have mating plug contacts 7 corresponding to the plug contacts 4, which are also indicated by dashed lines in FIG. 1. If the individual plug parts 3 are plugged onto the device socket 2, the individual mating plug contacts 7 are inserted into the corresponding plug contacts 4 in the socket housing 20. For this purpose, corresponding openings 23 are formed in the upper side 22 of the socket housing 20 facing the recess 21, through which openings the mating plug-in contacts 7 can be inserted into the corresponding plug-in contacts 4.In order that the lines to be connected to the overvoltage protection device 1 can be connected to the conductor connection terminals 5 arranged in the base housing 20, corresponding conductor insertion openings 26 are arranged in the front side 24 and the rear side 25 of the base housing 20. In the exemplary embodiment shown in FIGS. 1 and 2, the phase-guiding conductors L 1, L 2, L 3 and the neutral conductor N can be connected to the corresponding conductor connection terminals 5 through the conductor insertion openings 26 in the front side 24 of the base housing 20. In contrast, in the rear side 25 of the base housing 20, only two conductor insertion openings 26 are arranged, which lead to two conductor connection terminals 5 for the ground conductor PE.In the overvoltage protection device 1 according to the invention shown in the figures, in the region of the openings 23 leading to the plug contacts 4, respective encircling collars 27 are formed on the base housing 20, which collars serve as air and creepage distance extensions. As can be seen, for example, from FIGS. 2 and 3, the collars 27 protrude into the recess 21 starting from the upper side 22 of the base housing 20. The individual collars 27 thus extend, starting from the associated opening 23, in the opposite direction to the insertion direction E of the plug parts 3 into the device socket 2; the box-shaped, encircling collars 27 extend the air and creepage distances both between the two plug contacts 4 arranged in the longitudinal direction L of the device socket 2 and associated with a plug part 3 and between the plug contacts 4 arranged next to one another perpendicular to the longitudinal direction L, which are used for contacting in each case a mating plug contact 7 of two plug parts 3 plugged next to one another onto the device socket 2.In the region of the conductor insertion openings 26 to the conductor connection terminals 5, an air and creepage distance extension is also realized in each case in the base housing 20 shown. For this purpose, the conductor connection terminals 5 are arranged in the base housing 20 in a manner set back to the corresponding front side 24 or to the corresponding rear side 25, as a result of which the length of the channels formed by the individual conductor insertion openings 26 is extended from the outer side of the base housing 20 as far as the respective conductor connection terminals 5. This increases the air and creepage distances between adjacent conductor connection terminals 5.In the device sockets 2 shown in the figures, additional connection elements 8 are arranged in the socket housing 20, each of which is assigned to a conductor connection terminal 5 and is electrically conductively connected to the latter. Correspondingly, openings 28 are formed in the base housing 20, through which the additional connection elements 8 are each accessible. As can be seen from FIG. 2, ribs 29 are formed on the front side 24 of the base housing 20 laterally next to the openings 28 for the connection elements 8, which ribs extend parallel to the insertion direction E of a plug part 3. These ribs 29 also result in an extension of the respective air and creepage paths between two additional connecting elements 8 arranged next to one another. As can be seen from FIG. 2, the ribs 29 are arranged laterally next to the openings 28 in such a way that two ribs 29 running parallel to one another are arranged between two openings 28 arranged adjacent to one another. This results in a further extension of the creepage distances between adjacent connection elements 8.It can be seen from the exploded view of the device base 2 according to FIG. 3 that the base housing 20 is formed in two parts. It can also be seen that the individual plug contacts 4 are formed on a common busbar arrangement 9. By configuring the busbar arrangement 9, the respective connection scheme of the overvoltage protection device 1 is realized. The busbar arrangement 9 illustrated implements a 3+1 circuit in which the conductor connection terminals 5 for the PE conductor are arranged on the side of the busbar arrangement 9 facing the rear side 25 of the base housing 20, and the conductor connection terminals 5 for the neutral conductor N and the outer conductors L 1, L 2, L 3 are arranged on the side of the busbar arrangement 9 facing the front side 24 of the base housing 20.The device base 2 shown in FIG. 4 differs from the device base 2 according to FIG. 2 in that an additional frame part 40 is fastened to the front side 24 of the base housing 20. The frame part 40 shown separately in FIG. 5 has a plurality of wall elements 41, 42 which, in the exemplary embodiment shown, are connected to one another and surround a conductor insertion opening 26 and the associated opening 28 which is associated with a connection element 8 in such a way that a wall element 41 is arranged in each case between two adjacent conductor insertion openings 26, said wall element extending in the insertion direction E of a plug part 3. The individual arcuate wall elements 42 each extend above an opening 28, whereby the air and creepage distances between additional connection elements 8 arranged next to one another are further increased. Three straight wall elements 41 and one arc-shaped wall element 42 together form a closed subframe which encloses a conductor insertion opening 26 and the associated opening 28. The frame part 40 also has, in addition to the outer wall elements 41, 42 described above, inner sections 43 which project partially into the individual conductor insertion openings 26.For fastening a frame part 40 to the front side 24 of the base housing 20, the frame part 40 has a plurality of holding elements 44, with which corresponding holding elements 45 are formed on the front side 24 of the base housing 20. In the exemplary embodiment shown, the retaining elements 44 are designed as ribs and webs which engage in corresponding grooves and recesses in the front side 24 of the base housing 20.In the illustrated exemplary embodiments of the overvoltage protection device 1 according to the invention or of the device base 2, the conductor connection terminals 5 are designed as screw connections. Therefore, a screw shaft 46 is formed in the base housing 20 for each screw connection, through which the screw of a screw connection can be actuated.In the embodiment of the device base 2 shown in FIG. 6, a cover 47 is additionally arranged on the base housing 20 in the transition region from the front side 24 to the top side 22, which cover can be pivoted from a first, open position shown in FIG. 6 a into a second, closed position shown in FIG. 6 b. In the open position, the screw shafts 46 are accessible, so that the screws arranged underneath can be actuated by means of a screwdriver. In the second, closed position, on the other hand, the screw shafts 46 are covered, i.e. not accessible.If the corresponding conductors are connected to the individual conductor connection terminals 5, so that the screw connections no longer have to be actuated, the cover 47 is pivoted into the second position, which leads to an extension of the air and leakage paths between two adjacent screws of two screw connections. Moreover, when the cover 47 is in its closed position, the risk of dirt or moisture entering the individual screw wells 46 is reduced.Finally, it can also be seen from FIG. 7 that a telecommunication plug 48 can be connected to the rear side 25 of the socket housing 20. In the socket housing 20, a corresponding telecommunication contact is then arranged corresponding to the telecommunication plug 48, via which contact in particular the state of the individual overvoltage protection elements 6 can be output. If the device socket 2 does not have a telecommunication contact or if no telecommunication plug 48 is connected to the device socket 2, the corresponding openings are closed by blind plugs 49, so that no dirt or residues of stripped conductors can enter through the corresponding openings. The blind plugs 49 are preferably designed in such a way that they latch on the base housing 20 in the mounted state, so that they cannot fall out unintentionally.Reference numerals denote reference numerals1 Overvoltage protection device 2 device base 3 plug part 4 plug contacts 5 conductor connection terminals 6 overvoltage protection element 7 mating plug contact 8 connection elements 9 busbar arrangement 20 base housing 21 recess 22 top side 23 opening 24 front side 25 rear side 26 conductor insertion openings 27 collar 28 opening (connection elements) 29 ribs 30 plug housing 40 frame part 41 wall elements 42 wall element 43 sections 44 holding element 45 holding element 46 screw shaft 47 cover 48 remote indicator plug 49 blind plug E plug-in direction L longitudinal direction

Claims

Overvoltage protection device (1), having a device base (2) and at least one plug part (3) which can be plugged onto the device base (2), wherein the device base (2) has a base housing (20) with a recess (21) for receiving the plug part (3), plug contacts (4) and conductor connection terminals (5) connected to the plug contacts (4), wherein the at least one plug part (3) has a plug housing (30), an overvoltage protection element (6) arranged in the plug housing (30) and mating plug contacts (7) which correspond to the plug contacts (4) and are electrically conductively connected to the overvoltage protection element (6), wherein the plug contacts (4) and the conductor connection terminals (5) are arranged in the base housing (20), wherein openings (23) are formed in the upper side (22) of the base housing (20) facing the recess (21), through the mating plug contacts (7) can be inserted into the corresponding plug contacts (4), and wherein conductor insertion openings (26) are arranged in the front side (24) and the rear side (25) of the base housing (20), via which openings the conductor connection terminals (5) are accessible, characterized in that an air and creepage distance extension is formed in each case in the region of the openings (23) and / or in the region of the conductor insertion openings (26).Overvoltage protection device (1) according to claim 1, characterised in that the air and creepage distance extensions formed in the region of the openings (23) are each formed as encircling collars (27), which each project into the recess (21).Overvoltage protection device (1) according to claim 1 or 2, characterized in that the air and creepage distance extensions formed in the region of the conductor insertion openings (26) are realized in that the conductor connection terminals (5) are arranged in the base housing (20) set back to the corresponding front side (24) or rear side (25) of the base housing (20).Overvoltage protection device (1) according to one of claims 1 to 3, having at least two plug parts (3) which can be plugged onto the device base (2), characterized in that additional connection elements (8) are arranged in the base housing (20), which are each assigned to a conductor connection terminal (5) and are electrically conductively connected thereto, in that the connection elements (8) are each accessible via an opening (28) which are arranged in the front side (24) or rear side (25) of the base housing (20), and in that ribs (29) are formed on the front side (24) and / or the rear side (25) of the base housing (20), which ribs are each arranged laterally next to an opening (28) for a connection element (8) and run parallel to the insertion direction (E) of the plug part (3) into the recess (21) in the base housing (20).Overvoltage protection device (1) according to one of claims 1 to 4, characterised in that at least one frame part (40) is provided which can be fastened to the front side (24) and / or to the rear side (25) of the base housing (20), and in that the frame part (40) has wall elements (41) which surround at least the individual conductor insertion openings (26).Overvoltage protection device (1) according to claim 5, characterised in that the at least one frame part (40) has sections (42) which project at least partially into the individual conductor insertion openings (26).Overvoltage protection device (1) according to claim 5 or 6, characterized in that the at least one frame part (40) can be fastened to the front side (24) and / or to the rear side (25) of the base housing (20), for which purpose at least one holding element (44) is formed on the frame part (40) and at least one holding element (45) corresponding thereto is formed on the front side (24) and / or on the rear side (25) of the base housing (20).Overvoltage protection device (1) according to one of claims 1 to 7, wherein the individual conductor connection terminals (5) are designed as screw connections and wherein a screw shaft (46) is respectively formed in the base housing (20) with respect to the individual screw connections, characterized in that at least one cover (47) is arranged on the base housing (20), which can be brought, in particular pivoted, from a first position, in which the screw shafts (46) are accessible, into a second position, in which the screw shafts (46) are not accessible.Overvoltage protection device (1) according to one of claims 1 to 8, characterised in that a connection contact for a telecommunication is arranged in the device base (2) and that the base housing (20) has an opening into which a telecommunication plug (48) can be inserted.Overvoltage protection device (1) according to claim 9, characterized in that the opening for the telecommunication plug (48) is closed with a blind plug (49) when no telecommunication plug (48) is inserted in the opening.

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