HK1062362B - Device for earthing a switching device arranged in a module frame in a displaceable manner - Google Patents

Description

Earthing device for a switching device which is movably arranged in a plug-in frame

Technical Field

The invention relates to a grounding device for a switching device, which is mounted in a switching device plug-in frame in a manner that the grounding device can move between a disconnecting position and a working position in the field of electric switching devices. Such an earthing device enables an earthing of a switching device inserted into or pulled out of the plug-in frame to be achieved throughout the entire movement from the disengaged position into the operating position, in which case an electric current of the order of 50KA can be reliably conducted away via the connected earthing piece within 1 second.

Background

In the known grounding device used for this purpose, a first contact designed as a contact blade is fixedly mounted on the switching device, and a second stationary contact provided with a contact key is fixedly mounted on the plug-in frame. The contact surfaces of the two contacts extend in the direction of movement of the switching device in such a way that they abut against one another when the switching device is moved from the disengaged position into the operating position. In order to conduct away very large currents in an orderly manner, it is important that the contact surfaces of the second contact bear against both sides of the first contact with the same contact force. To ensure this, the known device additionally has a contact-force spring which acts on the second contact. In this known device, in order to fix a grounding element, such as a cable, a terminal is actually formed on a rigid, cantilevered end of the contact support which is screwed to a second contact on the rear wall of the plug frame. The screw connection is designed in such a way that the second contact rests firmly against the outside of the rear wall of the plug frame via a first bearing surface and the stationary contact, which is assigned to the screw, rests firmly against the inside of the rear wall via a second bearing surface (ABB SACE technical catalog a.s505-D-01, 4 months 1997).

Disclosure of Invention

The object of the invention is to provide a grounding device for the known grounding purposes, in which the contact support is free from electrodynamic forces and which allows an easy assembly.

According to the invention, a grounding device for a switching device arranged in a plug-in frame in such a way that it can be moved between a disengaged position and an operating position is provided, the grounding device comprises a first contact arranged on the switch device, a second contact arranged on the plug frame and a contact support matched with the second contact, wherein the two contacts extend in the direction of movement of the switching device, so that the two contacts elastically abut against each other when the switching device is moved from the disengaged position to the operating position, wherein the contact carrier has a first section for connecting to a ground and a second section which can be connected to the second contact and a connecting section which connects the two sections, the first section can be fixedly connected to the plug frame, and the second section can be fixed to the rear wall of the plug frame with a movement play perpendicular to the direction of movement of the switching device.

In order to solve the technical problem, the known grounding device is improved: the contact carrier has a first section for connecting to a ground and a second section which can be connected to a second contact, and a connecting section connecting the two sections; the first section can be fixedly connected to the plug-in frame, and the second section is fixed to the rear wall of the plug-in frame with a movement play perpendicular to the direction of movement of the switching device.

In such a configuration, the two sections are not rigidly connected, but are mechanically decoupled from each other by a flexible conductive segment. The first section for connecting the ground is fixed to the plug-in frame after the ground is connected, so that the plug-in frame receives the electrical force. Due to the play (Spiel) of the second section of the contact support, which supports the second contact, the second contact is automatically optimally aligned with the first contact when the switching device is inserted into the plug frame. The clearance space is preferably realized by designing the second section of the contact support as a docking plate (lasch) which is movably arranged in a fixing groove on the plug frame. In this case, a guide element can be provided on this second section, which guide element engages in a guide opening located on the rear wall of the plug-in frame. With this configuration, on the one hand, the clearance of the second section can be limited to a predetermined preferred direction, in particular perpendicular to the contact surface of the contact, and on the other hand, the size of the clearance can be predetermined.

In addition, the contact support second section preferably rests against the inner side of the rear wall of the plug frame, and the plug frame has a passage for the connection section. The shape of the outside of the plug frame is thereby maintained, so that components (e.g. insulation walls) associated with the switchgear can likewise be maintained.

In this new grounding device, it is possible to design the first contact as a contact blade and the second contact as a stationary contact with a contact key and to arrange them appropriately in such a way that the contact faces of the two contacts extend parallel to the side walls of the plug frame. This ensures that the connecting section for connecting the two partitions has the shortest possible length.

Drawings

Embodiments of the grounding device of the present invention will be further described with reference to the accompanying drawings (fig. 1 to 5):

fig. 1 is a low-voltage circuit breaker insertable into a plug-in frame;

fig. 2 is a part of an internal view of a plugging frame into which the low-voltage circuit breaker of fig. 1 is inserted;

fig. 3 shows in an exploded view the components of the grounding device according to the invention assigned to a plug-in frame;

FIG. 4 is a portion of an exterior view of the jack frame;

fig. 5 is a cross-sectional view of the grounding device part arranged on the plugging frame in fig. 4 along the line a-a.

Detailed Description

In electrical switching devices, the plug-in frame for receiving the electrical switch has a terminal for connecting to a grounding element (for example a cable connected to a grounding point) for personal safety reasons. In order to meet the general safety requirements, it is sufficient if, when the switching device is inserted into such a plug-in frame to be earthed, the metal region of the outer wall of the switching device is brought into contact with the plug-in frame and is then earthed via the earthing terminal of the plug-in frame. In this connection, suitable known switching devices are in contact with the plug frame, for example via their guide rails or via contact springs which are located on their side walls and slide on the side walls of the plug frame. However, such devices do not meet the more stringent safety requirements of local applications where, for example, currents of up to 60KA are required to be reliably output from the switch. The embodiments of the grounding device according to the invention described below relate to a retrofittable additional grounding device with which the switching device can be retrofitted when it meets such stricter safety requirements.

According to fig. 1, such a retrofittable grounding device has two first contacts 1 designed as contact blades, which are electrically conductively connected to one another via a support 2 and are arranged in the base region of a switching device 3 designed as a low-voltage circuit breaker. The contact blade extends with its contact surface 4 parallel to the switching device side wall 9 in the direction of the plug-in frame (direction of movement 5 of the switching device) (in front of the primary contact 39 and the secondary contact 40). The support 2 has at its two ends angled faces 6 which extend parallel to the contact blade 1. The contact blades are each fastened to an electrically conductive side plate 8 of a side wall 9 of the switching device 3 by means of two screw connections 7 via electrically conductive spacers which are not visible in the drawing. In order to mount the low-voltage circuit breaker in a plug-in frame 10 (see fig. 2), the low-voltage circuit breaker is placed with the feet 11 formed on the side plates 8 on rails 12 (see fig. 2) which can be partially led out of the plug-in frame. The plug frame can be arranged in a chamber of a switchboard of a switchgear. The switching device can be moved along the guide rail 12 from the disengaged position into the operating position by means of a displacement mechanism, which is not further shown. The transfer mechanism here may be designed similarly to the transfer mechanism disclosed in european patent specification EP0228987B 1.

According to fig. 2, the attachment also has two second contacts 13 associated with the plug frame 10. These contacts are designed as stationary contacts with a plurality of contact keys 14 (see also fig. 3). The two second contacts 13 are fixed on the inner side 15 of the upwardly bent part 16 of the base plate 17 (which becomes part of the rear wall 18 of the plug frame), the first of which is near the left side wall and the second near the right side wall. The two second contacts 13 likewise extend in the direction of movement 5 of the switching device with their contact surfaces 19 (see also fig. 3) which are designed to contact the key 14. For this purpose, the second contacts 13 are each designed in a U shape, on the legs of which a plurality of contact keys 14 are formed. When the switching device 3 is inserted into the plug-in frame 10, the contact keys 14 bear resiliently against both sides of the contact blade from the disengaged position of the switching device in the plug-in frame to the operating position thereof. The second contact 13 is fixedly connected to the contact support 20 by screws.

According to fig. 3, each contact carrier 20 has a first section 23 which is assigned to the ground piece 21 (see fig. 4 and 5) and for this purpose has a first connection opening 22, a second section 24 which is assigned to the second contact 13, and a connecting section 25 which connects the two sections 23, 24. The connecting section 25, which is a flexible copper strip, forms an electrically conductive connection between the two sections 23, 24, but the two sections are mechanically decoupled. Two screws 27 with cylindrical screw heads 26 (operated by their internal hexagonal edges) are used to fix the second contact 13 to the second section 24 of the contact carrier 20, which is designed as a butt plate. These screws 27 pass through the docking plate 24 in the region of two holes 29 and are fixedly connected to the second contact 13.

According to fig. 4, the plug frame 10 has two ground contacts each with a second connection opening 30, which are designed as lug-like extensions 31 that project from the side walls to the rear of the rear wall 18 of the plug frame 10. Between the upwardly bent part 16 of the base plate 17 and the lug-like extension 31 there are two channels 32 for the connecting section 25. The connecting section 25 extends through the region of the passage 32 and the first partial section 23 of the contact carrier lies flat against one of the side wall lug-shaped extensions 31 in each case in such a way that the first connecting bore 22 formed in the first partial section 23 extends coaxially with the second connecting bore 30 of the plug frame. This ensures that the first partial regions 23 of the two contact supports are simultaneously fixed to the plug frame 10 when the ground piece 21 is fixedly connected.

In the region of the upwardly bent part 16 of the base plate, two guide holes 33 are provided, which are designed as elongated holes and through which screws with cylindrical heads 26, which serve as guides for the contact support, can be passed. The rear, upwardly bent part of the base plate has two edge parts 28 which are bent into the inner region of the plug-in frame and each have a recess. They are each penetrated by a first edge of the second section of the contact carrier, which is designed as a counter plate, so that they form holding grooves 34 of the second section 24.

According to fig. 5, further retaining grooves 37 are respectively formed in the base plate 17 and in the sections 36 of the side plates which extend parallel to the base plate. When the two contact supports are assembled, the further holding grooves 37 can be inserted by the second edge 38 of the abutment plate 24 to such an extent that the abutment plates lie flat against the upwardly bent floor part 16. The abutment plate can then be moved such that its first edge 35 is inserted into the first retaining groove 34 and the hole 29 of the abutment plate 24 extends coaxially with the elongated hole 33. After which a screw 27 with internal hexagonal ridges is inserted and tightened. The second section 24 of the respective contact support 20 is thereby fixed to the rear wall of the plug frame by means of a cylindrical screw head 26 which is movable along the elongated hole 33 with a movement clearance perpendicular to the contact surface 4 of the first contact 1 and the contact surface 19 of the second contact 13.

When the switching device is inserted into the plug frame, the second contacts 13 are automatically aligned with the first contacts 1 depending on the position of the switching device, so that the contact keys 14 of the respective second contacts 13 bear against both sides of the associated contact blade 1 with the same contact force.

Claims (6)

1. A grounding device for a switching device (3) which is arranged in a plug-in frame (10) in a manner such that it can be moved between a disengaged position and an operating position, comprising a first contact (1) which is arranged on the switching device (3), a second contact (13) which is arranged on the plug-in frame (10) and a contact support (20) which is assigned to the second contact (13),

wherein the two contacts (1, 13) extend in the direction of movement (5) of the switching device (3) such that they lie elastically against one another when the switching device is moved from the disengaged position into the operating position,

wherein the contact carrier (20) has a first section (23) for connecting to ground and a second section (24) which can be connected to the second contact, and a connecting section (25) connecting the two sections,

the first sub-area (23) can be fixedly connected to the plug-in frame (10),

the second sub-area (24) is fixed on the rear wall (18) of the plug-in frame in a manner of moving clearance perpendicular to the moving direction (5) of the switch device (3).

2. The apparatus of claim 1, wherein: the second sub-area (24) is designed as a docking plate which is movably arranged in a fixing groove (34, 37) formed on the plug-in frame.

3. The apparatus of claim 1 or 2, wherein: a guide (27) is provided on the second sub-area (24) and is inserted into a guide opening (33) in the rear wall of the plug-in frame.

4. The apparatus of claim 3, wherein: the contact carrier (20) is fixedly connected to the second contact (13) by means of the guide (27).

5. The apparatus of claim 1, wherein: the second sub-area (24) of the contact carrier (20) rests against the inner side (15) of the rear wall (18) of the plug frame, and the plug frame (10) has a passage (32) for the connection section (25).

6. The apparatus of claim 1, wherein: the first contact (1) is designed as a contact blade and the second contact (13) is designed as a stationary contact with contact keys (14), wherein the contact surfaces (4, 19) of the two contacts (1, 13) extend parallel to the side walls (9) of the plug frame (10).