Reset device for a protective switching device

Abstract

Reset device for resetting a trigger plunger (2) of a release (1) in a protective switching device, in particular a residual current circuit breaker or FI / LS combination device, with the aid of a reset joint (9) which is designed to reset the trigger plunger (2) into its rest position.

Description

TECHNICAL FIELD

[0001] The invention relates to a reset device of a protective switching device, in particular a multi-pole protective switching device, for example a combined line and residual current circuit breaker (residual current breaker with overcurrent protection, abbreviated to RCBO), as well as a protective switching device which contains such a reset device. STATE OF THE ART

[0002] Protective switching devices are used to protect against overcurrent (circuit breakers) and fault currents (residual current circuit breakers) in low-voltage networks. As is well known, these devices have at least one pair of contacts, with each pair comprising at least one moving and one fixed contact. If a fault occurs in the low-voltage network, the devices separate the two contacts. To restore power, the contacts must then be closed once the fault has been rectified. During the closing process, mechanical energy is stored in the device, for example in a spring, which is used to separate the contacts the next time the device is triggered. As a result, reconnecting the device requires a correspondingly high level of force.

[0003] Therefore, devices designed to reduce this force are known in the prior art. DE102023104113 and CN116344279 each describe reset devices that use the force of the trigger to reset the trigger.

[0004] Both devices are characterized by a large number of moving parts, some of which have complex geometries. This takes up unnecessary space. In the closed, non-triggered state, an unnecessarily large number of parts are under mechanical stress. In the long run, this reduces their service life.

[0005] Multi-pole circuit breakers are also known. Multi-pole circuit breakers can also be designed as residual current devices (RCDs). These devices offer protection against residual currents and overcurrents. With these devices, it is advantageous if it can be indicated which of the various tripping mechanisms of the circuit breaker has triggered, i.e., whether an overcurrent or a residual current has occurred. For this purpose, EP4064314, for example, shows an indicator element that displays a different display depending on which mechanism has triggered. This indicator element has lateral springs that carry a locking lug that engages in the housing. When the indicator element moves, a resistance must be overcome, which reduces the service life of the locking lugs and the associated springs.

[0006] Multi-pole circuit breakers are also characterized by the fact that they contain two or more electrically opening and closing contact pairs. These poles are often separated from each other by housing elements. Above certain current levels, arcs occur at the electrically opening and closing contacts, which must be controlled to prevent damage to the electrical contacts or other surrounding components and to enable safe separation of the electrical contacts. Conventionally, either a splitter stack is used for each contact pair to control the spread of the arcs, or a coupled mechanism with a transmission mechanism so that one of the contacts always opens or closes first. If only one contact opens initially, a splitter stack is necessary at that location, for the reasons stated above.By eliminating the need for an arc splitter package, not only are resources conserved, but space is also saved, allowing switchgear to be made smaller or to accommodate other useful components.

[0007] In DE102023104113, a common switch mechanism is used to switch two contact pairs. DE102023104113 uses a complex arrangement of several moving parts, making it unnecessarily complicated and space-consuming.

[0008] The present invention is therefore based on the object of providing a reset device that is as simple and space-saving as possible.

[0009] This object is achieved according to the invention by a reset device according to claim 1. Preferred embodiments are described in the dependent claims.

[0010] The invention will be better understood with the help of the following description which refers to several preferred embodiments given as non-limiting examples and explained with reference to the attached schematic drawings. Fig. 1: Perspective view of a two-pole FI / LS combination device in a preferred embodiment of the invention Fig. 2 shows a detailed view of the release lever and the reset lever in the latched position as a perspective view (a) and as a top view (b) Fig. Figure 3 shows a section through a residual current device incorporating a reset device according to the invention. The residual current device is switched on. Fig. 4A and Fig. 4B shows a section through a residual current circuit breaker, which includes a reset device according to the invention. Fig. 4A the residual current device is triggered, but the tripping movement is not yet complete. Fig. 4B the release movement is completed. Fig. 5 shows a detailed view of the return joint as a perspective view (a) and as a top view (b) Fig. 6 shows a section through the miniature circuit breaker LS. Fig. 7 shows a perspective view of the coupling element. Fig. Figure 8 shows a section through the coupling element at a time when the release of the residual current circuit breaker has tripped and the contacts of the LS pole are just being opened. Fig. 9A shows the display element in top view. Fig. 9B shows the display element in side view. Fig. 10A shows a detailed view of the display element in the FI pole. Fig. 10B shows the same view as Fig. 10A, with the display element removed

[0011] Fig. 1 shows a preferred embodiment of the invention, an FI / LS combination device, wherein a miniature circuit breaker module LS is located on the left in the image, and a residual current device module FI is located on the right. It is of course also possible to arrange the miniature circuit breaker module to the right of the residual current device module. In the embodiment shown, only the miniature circuit breaker has a knob 11, which is used to switch both modules of the combination device on and off. Alternatively, it is of course possible for both the miniature circuit breaker module LS and the residual current device module FI, and thus both modules, to have a knob each. It is also possible to provide a common knob that extends across the full width of the FI / LS combination device. In the event of a trip, the position of the knob 11 indicates that the trip has occurred.The residual current device module (FI) has a button for initiating a test 21. Also shown are two display windows 38 in the housing 31. A display element 15 is visible through each of these windows when triggered. The display element in the FI module's window is only visible when triggered by the FI module (i.e., due to a residual current). The display element in the LS module is visible when triggered by the LS module (i.e., due to an overcurrent) and when triggered by the FI module (i.e., due to a residual current). Neither of the two display elements is visible when the contacts are manually switched off or opened by turning the knob.

[0012] The functional sequence of the reset device according to the invention is described below with reference to Fig. 3 and Fig. 4. The reset device according to the invention fits into a standard housing of a residual current circuit breaker, thus being between half and slightly less than a full pitch width.

[0013] As in Fig. As shown in Figure 3, a residual current device (RCD) has a release 1 and at least one contact pair consisting of a fixed contact 5 and a moving contact 4. Furthermore, a reset device is generally provided which resets the release after it has been triggered for the next use.

[0014] The reset device according to the invention consists of release lever 3, reset lever 6, toggle 11, a release with a pawl 17, reset joint 9, as well as the Fig. 3 coupling element 20 not shown.

[0015] In the illustrated case, the release 1 is a residual current release or differential release. However, the reset device according to the invention can also be used in conjunction with other releases, for example, an electromagnetic coil release, as long as they have a tripping plunger. Likewise, the reset device can also be used in other protective switching devices and is not limited to use in a residual current device.

[0016] In the event of a fault, the trigger 1 is triggered. This causes the trigger plunger 2 to extend. As shown in Fig. 4A, the release plunger 2 contacts the release lever 3, which rotates clockwise around the axis 13, which is a common axis of rotation of the release lever 3, the locking lever 29 and the movable contact 4, whereby the locking lug 19 moves out of the position shown in Fig. 2 is released with the reset lever 6.

[0017] The reset lever 6 subsequently rotates counterclockwise around its axis of rotation 14 under the action of the return spring 8 until it comes into contact with the movable contact 4. In this case, an indicator element lever 33 arranged on the reset lever 6 presses against the indicator element 15 from below. The further functioning of the indicator element 15 will be described later. In addition, a driver 18 attached to the reset lever 6 acts on a coupling element 20. The coupling element 20 directly or indirectly transmits the movement of the reset lever via the web 22 of the locking lever 29 of the movable contact 4 to the locking pawl 17, whereby the movable contact 4, driven by the switching spring 7, rotates clockwise around the axis of rotation 13 and separates from the fixed contact 5. The movable contact 4 comes into contact with one end of the return joint 9 and carries it along in the movement.The return joint 9 is rotated clockwise around its rotational axis 10. After just a short rotation, the other end of the return joint comes into contact with the release lever 3 and pushes it back counterclockwise until the rest position is slightly exceeded. The release lever 3 then acts on the release plunger 2, which is pushed back to its rest position.

[0018] The reset lever 6 is rotated clockwise about its rotational axis 14 by the movable contact 4, with the end position being beyond the rest position. This enables easy re-engagement. Furthermore, energy is stored in the reset spring 8. Preferably, the forces acting in this process lead to an elastic deformation of the reset joint 9 and place the release lever 3 under tension. The reset joint 9 thus also serves as an energy storage device for the energy released during release. This situation is Fig. 4A.

[0019] Preferably, the knob 11 is rotated in a known manner by the free release about its rotation axis 12 from the “on” position to the “released” position, as shown in Fig. 4B. ).

[0020] As a result of the movement sequence, at the end of the release the release plunger 2 is back in the rest position, the release lever 3 is still in contact with the release plunger 2 at this point in time.

[0021] Preferably, a display element 15 is moved during the movement sequence in such a way that it indicates that the triggering has taken place.

[0022] To complete the reset, the pawl 17 of the release mechanism must finally be returned to the engaged position using the toggle 11 in the known manner. In this case, the movable contact 4 is also closed again using the toggle in the known manner. The force applied to the toggle is at least partially stored in the switching spring 7. At the same time, the rotation of the toggle causes the detent 19 of the release lever 3 to re-engage with the reset lever 6. As a result, part of the energy released by the release is stored in the return spring 8 by the detent 19 being positioned between the release lever 3 and the reset lever 6. The energy stored in the reset joint 9 supports the reset, so that less force needs to be applied to the toggle 11.

[0023] At the end of the reset process, the reset joint is separated from the release lever by an air gap, which is also separated from the release plunger by an air gap. In this state, the reset joint 9 is free of mechanical stress. This corresponds to the Fig. 3 shown switched on state.

[0024] Fig. Figure 5 shows a representation of the preferred embodiment of the return joint 9. The return joint 9 is S-shaped in plan view. The widened ends ensure sufficient force transmission from the movable contact 4 or to the release lever 3. At the same time, the thinned center section enables the return joint 9 to mesh with the movable contact 4. The elastic deformation of the return joint that occurs during the release process also compensates for dimensional deviations of the components involved.

[0025] The return joint 9 can be made of any material that has the necessary elasticity and strength. In particular, the return joint 9 can be made of plastic. In particular, a plastic is used that does not flow or only slightly flows under sustained load. The return joint 9 can be manufactured using suitable processes, in particular injection molding or additive manufacturing.

[0026] The reset lever 3 and the release lever 6 are also made of plastic, preferably of high-strength plastic, in particular of a plastic with a modulus of elasticity greater than 3000 MPa and a tensile strength of > 100 MPa, more particularly with a modulus of elasticity of 3500 MPa and a tensile strength of 129 MPa. The reset lever 3 and the release lever 6 can be manufactured using suitable processes, in particular injection molding or additive manufacturing. Particularly preferably, the coupling element additionally effects coordinated release of a combined residual current device (RCD / LSD).

[0027] Residual current breakers (RCBOs) are designed to protect one or more electrical devices from overcurrent and also to shut off the power in the event of a fault current. A residual current breaker (RCB) or combined residual current breaker (RCCB) is a combined device consisting of a miniature circuit breaker (MCB) and a residual current device (RCCB).

[0028] In the FI / LS combination device, one module (LS module) contains a miniature circuit breaker, while the second module (FI module) contains a residual current device. The miniature circuit breaker, which is located in Fig. 6, typically includes a toggle switch 11, a release mechanism with a locking pawl 17, a thermal release 24, an electromagnetic short-circuit current release 25, and a spark-extinguishing chamber 23. The residual current device includes a summation current transformer 16, a residual current release 1, and the reset device described above. Both switches are connected to each other via the coupling element 20 mentioned above, which ensures coordinated tripping of both poles.

[0029] When a fault current occurs, a summation current transformer 16 of the residual current device measures a signal and triggers the release 1 by means of a control signal. This extends the release plunger 2. The release plunger 2 contacts the release lever 3, which rotates clockwise around the axis 13, which is a common axis of rotation of the release lever 3, the locking lever 29 and the movable contact 4, whereby the locking lug 19 moves out of the Fig. 4 is released with the reset lever 6. The reset lever 6 subsequently rotates counterclockwise around its rotational axis 14 under the action of the return spring 8 until it comes into contact with the movable contact 4. In this case, an indicator element lever 33 arranged on the reset lever 6 presses against the indicator element 15 from below. The further functioning of the indicator element 15 will be described later. In addition, a driver 18 attached to the reset lever 6 acts on the coupling element 20, as shown in Fig. 8. The coupling element 20 transmits the movement of the reset lever 6 to the web 32 of the locking lever 30 of the movable contact 34 of the LS module, causing the movable contact 34 in the LS module to open. The web 32 of the locking lever 30 of the movable contact is located in a recess 27 of the coupling element 20. As soon as the inner wall of the recess 27 touches the web 32 of the locking lever 30, the movement is transmitted to the web 32. The coupling element 20 then stops. The movable contact 34 of the LS module opens. Once this movement is initiated, the movable contact 34 moves further in the direction of the arrow ( Fig. 8) until the web 32 reaches the opposite wall of the recess 27, causing the coupling element 20 to be pushed again, again in the direction of the arrow. Subsequently, the inner wall of the recess 26 of the residual current device module also touches the web 22 of the locking lever 29 of the associated contact 4, and the movable contact 4 is also opened.

[0030] When an overcurrent or short-circuit current occurs, the circuit breaker module trips. The trigger (thermal trigger 24 or electromagnetic short-circuit current release 25) acts directly or indirectly on the coupling element 20 via the web 32 of the locking lever 30 of the movable contact 34. As described above, the coupling element 20 transmits the movement of the respective trigger to the locking pawl 17 of the trip-free mechanism of the circuit breaker module, causing the movable contact 34 in the circuit breaker module to open. The locking pawl 17 rotates counterclockwise, with a bulge 36 pressing against the indicator element from below. The further functionality of the indicator element 15 will be described later. The coupling element 20 subsequently also touches the inner wall of the cavity 26 of the FI module, the web 22 of the locking lever 29 of the corresponding contact 4 of the FI module, and the movable contact 4 is also opened.

[0031] In any case, the electrical pole in the circuit breaker module opens first, eliminating the need for a spark-extinguishing chamber on the RCD module side. The delay between the opening of the electrical pole in the circuit breaker module and the opening of the electrical pole in the RCD module can be adjusted via the precise dimensions of the recesses in the coupling element 20 and the drivers 22 and 32. The delay is preferably between 1 and 5 ms, particularly preferably 2 ms.

[0032] The release in the residual current device (RCD) module is reset using the reset device described above. The electromagnetic short-circuit current release in the circuit breaker module is preferably reset in a known manner using a spring in the electromagnetic short-circuit current release.

[0033] The coupling element 20 is in Fig. 7. It is approximately trapezoidal in shape and has recesses 26, 27 on both sides into which the webs 22, 32 engage. For space-saving installation in the combination device, the coupling element 20 is thinned at both ends. The coupling element has a circular opening 28, which serves both to attach the coupling element 20 to the housing and also as a pivot bearing. The coupling element 20 rotates around the common rotation axis 13 of the movable contacts 4, 34 and the release lever 3.

[0034] The coupling element 20 is preferably a molded part. The coupling element 20 is preferably made of plastic, in particular of high-strength plastic.

[0035] Fig. 9A shows a top view of the display element 15. In Fig. Figure 9B shows a side view of the indicator element. On the top side of the indicator element is an indicator surface 41, which is visible through the window 38 in the housing 31 after triggering. Also visible is a spring 39 of the indicator element. The indicator element is installed in the housing in such a way that it is anchored by an anchor 45 on both sides in an anchor 44 on the housing. At its opposite end, the indicator element 15 rests with its toggle-side edge 37 on a two-stage step element 32 molded onto the housing. When the protective switching device is reset or switched on, a finger 40 attached to the underside of the indicator element 15 is displaced by the locking pawl 17 in such a way that the spring 39 is compressed. As a result, the indicator surface 41 moves away from the toggle and thus out of the area visible in the window 38.When the spring 39 is sufficiently compressed, the toggle-side edge 37 falls from the upper step 42 to the lower step 43 of the two-stage step element 32. The indicator element remains here until triggered. During the triggering process, depending on which pole is triggered first, the respective indicator element is subjected to a torque, whereby it is pushed upwards from the lower step 43 until the lower edge of the indicator element 15 reaches the height of the upper step 42. The spring 39 now relaxes and the toggle-side edge 37 moves towards the toggle. The indicator element 15 then rests firmly on the upper step 42, as shown in FIG. Fig. 10A and Fig.10B, until it is moved back to the lower level 43 by a further reset. In this position, the display surface 41 is visible through the window 38. In the RCD module, the torque is applied by the display element lever 33, which presses counterclockwise from below onto the display element 15. In the CB module, the bulge 36 of the locking pawl 17 also presses against the display element 15 from below during tripping, thus applying the torque. To prevent the locking pawl of the RCD module from displacing the display element of the RCD module when tripped by the CB module, the display element in the RCD module is arranged somewhat higher. This means that the bulge 36 cannot come into contact with the display element 15 when the locking pawl 17 in the RCD module rotates, and it can be reliably distinguished which of the two modules has tripped. When switched off manually by operating the knob 11, neither of the two display elements 15 is moved.

[0036] The invention is, of course, not limited to the embodiments described and illustrated in the accompanying drawings. Modifications remain possible, particularly with regard to the nature of the various elements or by substitution of technical equivalents, without departing from the scope of the invention, which is defined by the claims. Reference symbol: 1 release / residual current release 2 trigger plungers 3 release levers 4, 34 movable contact 5, 35 fixed contact 6 reset levers 7 Switch spring 8 Return spring 9 Return joint 10 Rotation axis of the return joint 11 gags 12 Axis of rotation of the toggle 13 Rotation axis of the movable contact 14 Rotation axis of the return lever 15 Display element 16 summation current transformers 17 Release pawl 18 carriers 19 locking lug 20 coupling element 21 Button to trigger a test 22, 32 web of the locking lever 23 Spark extinguishing chamber 24 bimetal triggers 25 electromagnetic trigger 26, 27 Hollowing out the coupling element 28 Opening 29, 30 locking lever 31 housings 32 step element 33 Display element lever 36 bump 37 edge 38 display windows 39 Spring of the display element 40 fingers of the display element 41 display area 42 upper level 43 lower level 44 Housing-side anchoring 45 Anchoring of the display elements QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 102023104113 [0003, 0007] CN 116344279

[0003] EP 4064314

[0005]

Claims

[1] Reset device for resetting a trip plunger (2) of a trip release (1) in a protective switching device, wherein the release plunger (2) has a retracted rest position and an extended release position, a movable contact (4), a fixed contact (5), a reset lever (6) which has a released position and a rest position, a coupling element (20), a release lever (3) which has a released position and a rest position and a return joint (9) which has a released position and a rest position, wherein the release lever (3) has a locking lug (19) which is engaged with the return lever (6), and wherein the trigger (1) is configured to cause a separation of the movable contact (4) from the fixed contact (5) by the release plunger (2) acting on the release lever (3) and thereby releasing the latch, wherein the coupling element (20) is designed to move the movable contact (4) away from the fixed contact (5) by releasing the latch, wherein the movable contact (4) contacts the return joint (9) and carries it along in the movement, wherein the return joint (9) puts the release lever (3) under tension and thereby returns the release plunger (2) and the release lever to their rest position. [2] Reset device according to claim 1, characterized by , that the locking lug (19) is engaged by actuating a toggle (11) with the return lever (6). [3] Reset device according to any of the preceding claims, characterized by, that the release lever (3) in the rest position has no contact with the release plunger (2) and / or the return joint (9). [4] Reset device according to any of the preceding claims, characterized by , that the return joint (9) is S-shaped and / or the return joint (9) is elastically deformable, in particular when triggered by the movable contact (4), further in particular that the energy stored in the elastic deformation of the return joint (9) is used to close the movable contact (4). [5] Reset device according to any of the preceding claims, characterized by , that the return joint (9) is made of plastic, in particular a plastic which does not flow or flows only slightly under sustained stress, in particular by 3D printing or injection molding. [6] Reset device according to any of the preceding claims, characterized by, that an indicator element (15) is present which indicates that a trigger has been activated. [7] Resetting device according to one of the preceding claims, wherein the width of the resetting device is between half and slightly less than a whole division width. [8] Residual current protection device comprising a summation current transformer and a residual current release as well as a reset device according to claims 1-7, in particular wherein the residual current protection device is one module (18mm) wide. [9] Combined RCBO consisting of at least 2 modules, wherein an RCBO module includes a summation current transformer (16) and a residual current release (1) and a reset device according to claims 1-7, and wherein at least one MCB module includes a toggle switch (11), a free release (17), a thermal release (24), an electromagnetic short-circuit current release (25) and a spark extinguishing chamber (23). [10] Combined RCBO according to claim 9, wherein the coupling element (20) is configured to transmit the tripping movement of one module to another module, and wherein the coupling element (20) is configured to ensure that the pole of the MCB module opens first, in particular wherein the pole of the RCBO module opens between 1 and 5 ms after the pole of the MCB module, in particular wherein the pole of the RCBO module opens 2 ms after the pole of the MCB module.

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