Improved Installation System for Busbars of Electrical Switchgear

Abstract

Disclosed is an installation system (1) for a busbar (L1…L3, L1', N) of an electrical switchgear (12), which comprises: a plurality of retaining rails (2a, 2b); connecting profiles (3a, 3b) which interconnect the retaining rails (2a, 2b) and create a distance between the retaining rails (2a, 2b), and the installation system (1) comprises a plurality of busbar retainers (4a, 4b) which are arranged to receive the busbar (L1…L3, L1', N) and are arranged in the retaining rails (2a, 2b). Furthermore, disclosed is an arrangement (6) and an electrical switchgear (12) having a plurality of busbars (L1…L3, L1', N) and an installation system (1) for the busbar (L1…L3, L1', N). Generally speaking, in the installation system (1), the retaining rails (2a, 2b) are made of plastic and the busbar retainers (4a, 4b) are made of metal.

Description

Field of the Invention

[0001] The present invention relates to an installation system for a busbar of an electrical switchgear, which includes a plurality of holder rails; a connecting profile that interconnects the holder rails and creates a distance between the holder rails, and the installation system includes a plurality of busbar holders that are arranged to receive the busbars and are disposed in the holder rails. Furthermore, the present invention relates to an arrangement device for busbars, which has a plurality of busbars and the installation system for the busbars, and the busbars are fixed by the installation system. Finally, the present invention relates to an electrical switchgear, which includes several busbars, at least one switching device electrically connected to the busbars, and the installation system for the busbars, and the busbars are held in place within the electrical switchgear by the installation system. Background Art

[0002] Installation systems for busbars are generally known in the prior art. Usually, the holder rails are made of metal and the busbar holders are made of plastic in order to provide electrical insulation between the busbar holders and thus between the busbars held by the busbar holders. However, this solution has many drawbacks. Firstly, the busbar holders are relatively soft and generally cannot absorb the forces caused by the busbars, especially in the case of a short circuit, in which case the busbars are heavily pressed against the busbar holders. Secondly, although there is insulation between the busbars and the busbar holders, due to the electromagnetic field around the busbars, current can flow in the metal busbar holders, usually caused by alternating current flowing through the busbar holders. These induced currents in the busbar holders can have undesirable effects within the switchgear. Summary of the Invention

[0003] Therefore, the object of the present invention is to provide an improved installation system, an improved arrangement device having such an installation system, and an improved switchgear. Specifically, a solution should be proposed that can better absorb the forces caused by the busbars and avoid induced currents or eddy currents in the installation system.

[0004] The object of the present invention is solved by an installation system as disclosed in the opening paragraph, wherein the holder rails are made of plastic and the busbar holders are made of metal.

[0005] Furthermore, the object of the present invention is solved by an arrangement device for busbars, which has a plurality of busbars and the installation system for the busbars, and the busbars are fixed by the installation system.

[0006] Finally, the object of the present invention is solved by an electrical switchgear, which includes several busbars, at least one switching device electrically connected to the busbars, and the installation system for the busbars, and the busbars are held in place within the electrical switchgear by the installation system.

[0007] This is another way commonly carried out in the prior art, where the retainer guide rail is made of metal and the busbar retainer is made of plastic. However, the advantage of selecting materials in the proposed way is that the busbar retainer is relatively firm and can easily withstand the (electromagnetic) forces generated in the switchgear. Since the contact surface between the busbar retainer and the retainer guide rail is relatively large, although the retainer guide rail is made of plastic, these relatively large forces can be easily transferred from the busbar retainer to the retainer guide rail. In addition, the retainer guide rail provides electrical insulation, and thus also avoids the induced eddy currents caused by the current passing through the busbar. The closed iron-containing material loop around the busbar is naturally avoided by the non-ferrous material of the proposed retainer guide rail. This is not the case for the prior art retainer guide rails made of metal, where special measures must be taken to avoid such an iron-containing material loop and avoid or at least limit the induced current or eddy current.

[0008] Therefore, the present invention can also be seen in the insight that replacing the materials of the retainer guide rail and the busbar retainer with respect to the prior art solution results in an installation system that has advantages in many aspects.

[0009] Specifically, the retainer guide rail can be made of fiber-reinforced resin and is especially made by using pultrusion. The advantage of pultrusion is that regions with different fiber densities can be defined within the retainer guide rail. Therefore, the retainer guide rail can be made more firm where needed. A further advantage of pultrusion is that the retainer guide rail can be produced in standard lengths (several meters) and can then be cut as needed to fit any application. Therefore, the installation system can be easily adapted to different numbers of busbars.

[0010] The connecting profile can be produced in standard lengths (several meters) by using pultrusion and can also be cut as needed to fit any application. Therefore, the installation system can be easily adapted to different heights of the busbars. The connecting profile can be made of plastic or metal.

[0011] Therefore, a further advantage of the proposed solution is that a wide range of busbar sizes and / or busbar configurations can be covered by the installation system, although the components used are thus substantially the same for all these busbar sizes and / or busbar configurations. Therefore, the flexibility of the installation system is improved at a reduced cost compared to the prior art systems.

[0012] Other advantageous embodiments are disclosed in the claims, the description, and the drawings.

[0013] Advantageously, the holder guide is a strut profile with an H-shaped cross-section. In this way, on the one hand, the busbar holder can be received in one opening of the "H", and the components for mounting the busbar holder (such as busbar holder screws or rivets) can be received in the opposite opening of the "H". Thus, in particular, the heads of the mounting components (such as the heads of busbar holder screws or rivets) are positioned in the recesses, preventing unintentional contact by personnel. It should be noted in this context that if the mounting components are made of metal, they may be live if no other measures are taken to avoid this. Additionally, the H-shaped cross-section advantageously provides good anti-deflection stiffness. It should be noted that while using an H-profile is beneficial, other shapes can also be used for the holder guide. For example, the holder guide can have a U-shaped cross-section or a square tube cross-section.

[0014] In a further advantageous embodiment of the mounting system, the H-shaped cross-section of the holder guide includes recesses on both sides in the bottom region facing the busbar holder. Specifically, protrusions that can be fixed to the busbar holder or other devices on the holder guide can extend into the recesses. Thus, the busbar holder or other devices can be snapped into the holder guide, such that the busbar holder or other devices do not unintentionally disengage from the holder guide before the busbar holder or other devices are finally fixed to the holder guide by mounting components (such as by busbar holder screws or rivets). This is particularly useful if the busbar holder or other devices are mounted upside down on the holder guide.

[0015] Furthermore, it is advantageous if the busbar holder is a strut profile with a square tube cross-section and a cutout for the busbar. Thus, the busbar holder can be easily cut from standard profiles and manufactured at low cost. The cutout forms a recess for receiving the busbar. Advantageously, the cutout is made by laser, but other production techniques can also be applied. A further advantage of the square tube cross-section is that it makes the busbar holder relatively stable. Additionally, different busbar arrangements with different numbers of busbars per busbar holder can be easily achieved. The only difference in that regard is the number of cutouts and / or the length of the busbar holder for each busbar holder. Thus, the busbar holder can have one cutout for one busbar, two cutouts for two busbars, and so on.

[0016] Specifically (meaning despite the special shape), the busbar retainer can be coated / sprayed to reduce the friction between the busbar retainer and the busbar, to provide electrical isolation and / or to mark each electrical phase with a separate color. For example, one busbar can be blue, one busbar can be brown, etc. To provide better coating adhesion, the base material of the busbar retainer can have a rough surface. This rough surface can be made, for example, by sandblasting, but can also be made by a laser that burns small pits on the surface of the base material of the busbar retainer. Specifically, the same laser can be used for this purpose, which is also used to cut the incision. It is also possible that only the surface of the busbar retainer is provided with these pits that may come into contact with other components. Thus, in particular, the edges of the incision can be provided with pits to locally increase the adhesion there.

[0017] In a very advantageous embodiment, the top region of the incision has protruding or curved portions on both sides. These protruding or curved portions provide a number of advantages. First, it becomes easier to insert the busbar into the incision because the risk of wedging is reduced, even if only a small gap is provided between the busbar and the busbar retainer. Second, when the busbar moves in the longitudinal direction, especially during the assembly of the mounting system, the surface of the busbar is not scratched. This is particularly useful if the busbar is coated because the coating is also not scratched. The protruding or curved portions can also additionally have chamfers or radii to further improve the above effects. Third, the busbar can be bent without exerting too much pressure on the vertical edges of the incision. For example, this bending can occur when a large electromagnetic force acts on the busbar. Fourth, even excessive pressure on the protruding or curved portions does not cause the busbar retainer to collapse because the material selection does avoid this situation. Specifically, metals and especially steel have a large range of plastic deformation in addition to elastic deformation. Thus, if the busbar is heavily pressed against the protruding or curved portions, the material of the busbar retainer can be locally plasticized, but it does not collapse as a whole. For example, this pressure occurs in the case of excessive current in the busbar and the electromagnetic force generated thereby during a short circuit. However, plasticization is usually not a major problem because plasticization is allowed based on standard IEC 61439-1 / 2 as long as there are no visible cracks on the component. In addition, this local plasticization has two further effects that have a positive impact on the stability of the busbar retainer. First, the material strength of the busbar retainer is locally increased. This is an effect known from cold working and used, for example, for cold-rolled steel. Second, the protruding or curved portions are slightly flattened, so that the area effective for surface pressure increases. Consequently, if the level of the force remains constant, the surface pressure is reduced. Thus, these effects lead to a reduced risk of further plasticization of the protruding or curved portions. In other words, an equilibrium is reached when the busbar retainer can withstand the forces within the mounting system without further deformation. Basically, this adaptation is "automatically" or strictly speaking through the special shape on the side of the incision.

[0018] In yet another highly advantageous embodiment, the bottom region of the incision has a flat or convex elevation with rounded corners on both sides of the elevation. Additionally, in the installed state of the mounting system, it is advantageous if the retainer guide reaches above the elevation of the busbar retainer. On the one hand, due to the advantageous coefficient of friction between the metal and the plastic, the busbar can slide easily on the retainer guide. On the other hand, if the retainer guide collapses locally due to material fatigue, the elevation in the busbar retainer forms a hard stop for the busbar. Thus, serious damage to the mounting system can be avoided. Furthermore, if the busbar retainer itself deforms due to excessive force acting on the busbar through the busbar retainer, the elevation in the busbar retainer also indeed forms a hard stop. Such excessive force can cause deformation in such a way that the longitudinal axis of the busbar retainer becomes arcuate. For example, this can occur if more than one busbar with the same voltage level is arranged in the busbar retainer. During a short circuit, the busbars of the busbar retainer are exposed to different forces, which results in an asymmetric load on the busbar retainer. Consequently, a torque is induced in the busbar retainer. If this torque is very high, there is a risk that the busbar retainer fails to be fixed in the retainer guide (or there is a lack of fixation due to, for example, the dropping of the busbar retainer screws or rivets in the mounting system during operation), which in turn causes the aforementioned bending of the busbar retainer. Thus, the elevation or ridge moves towards the busbar. Once the elevation touches the busbar, further deformation of the busbar retainer is avoided or at least prevented. Therefore, the elevation itself also indeed acts as a hard stop for the busbar retainer. Advantageously, the rounded corners avoid the formation of cracks in the corners of the incision, and this is especially true in this case. Thus, the mounting system is highly fault-tolerant and does not cause the entire mounting system to collapse even if the busbar retainer fails to be fixed or there is a lack of fixation.

[0019] Additionally, it is particularly advantageous if the busbar retainer is fixed to the retainer guide by a mounting member implemented as a self-cutting busbar retainer screw. Using self-cutting busbar retainer screws offers many advantages. First, it is not necessary to cut a separate thread into the busbar retainer because the self-cutting busbar retainer screw itself cuts the thread. Second, even if the mounting system is exposed to vibrations such as those occurring within switchgear, the self-cutting busbar retainer screws are not likely to unscrew on their own. Thus, additional screw locking can be omitted. Third, the self-cutting busbar retainer screws can be manufactured shorter than screws fixed with nuts. Therefore, even if the busbar retainer screws fall out of the mounting system, the likelihood of arc flash or short circuit caused by the busbar retainer screws is relatively low. This is based on a simple reason that the self-cutting busbar retainer screws are shorter than screws fixed with nuts and cannot bridge large gaps between conductors under voltage.

[0020] In yet another advantageous embodiment, one of the self-cutting busbar retainer screws has a threaded portion and a non-threaded portion, wherein the outer diameter of the threaded portion is smaller than the diameter of the non-threaded portion, and wherein the threaded portion is screwed into one of the busbar retainers in the busbar retainer, and the non-threaded portion is positioned within one of the retainer guide rails in the retainer guide. Specifically, the threaded portion is screwed into a busbar retainer hole in the busbar retainer, and the non-threaded portion is positioned within a retainer guide hole in the retainer guide. Because the diameter of the non-threaded portion is relatively large, the surface pressure on the retainer guide and the shear stress in the retainer guide are relatively low, enabling a larger force to be transmitted between the busbar retainer screw and the retainer guide. This is the case even if the retainer guide is made of plastic. The busbar retainer screw as defined above can also be regarded as a shoulder screw.

[0021] In an alternative advantageous embodiment, the busbar retainer is fixed to the retainer guide by means of a mounting member, which is embodied as a rivet, in particular as a snap-in in the rivet. In this way, even if the busbar retainer is oriented in an upright position, the assembly of the mounting member can always be carried out from above. In this case, the rivet is inserted through a cutout D in the busbar retainer, and the head of the rivet is positioned within the busbar retainer in the mounted state. If the busbar retainer is oriented upside down, the rivet is inserted through a mounting hole in the retainer guide. In both cases, the rivet is not easily accidentally detached.

[0022] Furthermore, it is advantageous if the mounting members for one of the busbar retainers in the busbar retainer are positioned at different distances from the longitudinal axis of the retainer guide and / or on different sides of the longitudinal axis, and the busbar retainer is fixed to the retainer guide. In this way, the risk of cracks forming in the retainer guide can be reduced.

[0023] Finally, it is beneficial if the width of the busbar retainer is slightly lower than the internal dimension of the H-shaped cross-section of the retainer guide. Thus, the busbar retainer can be easily mounted to the retainer guide. However, it may also be useful if the width of the busbar retainer is slightly higher than the internal dimension of the H-shaped cross-section of the retainer guide. The busbar retainer is then held in the retainer guide by friction. Thus, the busbar retainer will not accidentally disengage from the retainer guide before it is finally fixed to the retainer guide by means of mounting members (e.g. by busbar retainer screws or rivets). This is particularly useful if the busbar retainer or other devices are mounted upside down to the retainer guide. In any case where the width of the busbar retainer matches the internal dimension of the H-shaped cross-section, rotation of the busbar retainer is avoided even if only a single busbar retainer screw is used to fix the busbar retainer or even if the mounting members for the busbar retainer of the mounting system (e.g. by busbar retainer screws or rivets) accidentally fall off during operation. Thus, the mounting system is highly fault-tolerant and the retainer guide acts as a kind of component jig during assembly, thus simplifying the manufacture of the mounting system. Description of the Drawings

[0024] The present invention will now be described in more detail with reference to specific embodiments, however the invention is not limited to these specific embodiments.

[0025] Figure 1 The mounting system for the busbar in the mounted state of the busbar is shown in perspective view;

[0026] Figure 2 shown in exploded view Figure 1 of the mounting system;

[0027] Figure 3 A detailed perspective view of the busbar retainer is shown;

[0028] Figure 4 Shown Figure 3 a top view of the busbar retainer of;

[0029] Figure 5 A front view of the busbar retainer and the busbar mounted to the retainer guide is shown;

[0030] Figure 6 Shown in cross-sectional view Figure 5 of the arrangement device;

[0031] Figure 7 A top view of the retainer guide is shown;

[0032] Figure 8 A cross-sectional view of the busbar retainer screwed to the retainer guide is shown as well as

[0033] Figure 9 A partial side view of the switchgear is shown.

[0034] List of reference numerals

[0035] 1 Mounting system

[0036] 2a, 2b Retainer guide rails

[0037] 3a, 3b Connecting profiles

[0038] 4a, 4b Busbar retainers

[0039] 5a, 5b Frame connectors

[0040] 6 Arrangement device

[0041] 7a, 7b Busbar retainer screws

[0042] 8a, 8b Connecting profile screws

[0043] 9a, 9b Frame connector screws

[0044] 10a, 10b Busbar retainer holes

[0045] 11a, 11b Retainer guide rail holes

[0046] 12 Switchgear

[0047] 13 Switchgear frame

[0048] 14 Switching device

[0049] B Cutout

[0050] C Protrusion / bending part

[0051] D Bulge

[0052] E Fillet

[0053] F Groove in the retainer guide rail

[0054] G Threaded part

[0055] J Unthreaded part

[0056] K Retainer guide rail axis

[0057] L1…L3, L1', N Busbars

[0058] b Distance between the busbar retainer screw and the retainer guide rail axis

[0059] d1 Outer diameter of the threaded part

[0060] d2 Diameter of the unthreaded part

[0061] h Height difference Detailed implementation method

[0062] Generally, the same or similar components are denoted by the same / similar reference numerals and names. The features disclosed in the description apply to the components with the same / similar reference numerals. The indication of orientation and relative position relates to the associated drawings, and the indication of orientation and / or relative position must therefore be modified accordingly in different drawings depending on the circumstances.

[0063] Figure 1 and Figure 2 The mounting system 1 for the busbars L1…L3, L1', N of an electrical switchgear is shown in perspective. Figure 1 The mounting system 1 is shown in a mounted view, and Figure 2 in an exploded view.

[0064] The mounting system 1 comprises two holding rails 2a, 2b; connecting profiles 3a, 3b which interconnect the holding rails 2a, 2b and create a distance between the holding rails 2a, 2b, and the mounting system comprises a plurality of busbar holders 4a, 4b which are arranged to receive the busbars L1…L3, L1', N and are arranged in the holding rails 2a, 2b. Generally, the holding rails 2a, 2b are made of plastic and the busbar holders 4a, 4b are made of metal. In this example, there is a lower holding rail 2a and an upper holding rail 2b as well as a left connecting profile 3a and a right connecting profile 3b. However, there may also be more holding rails 2a, 2b and / or more connecting profiles 3a, 3b. In addition, the mounting system 1 comprises frame connectors 5a, 5b by means of which the holding rail 2a and thus the entire mounting system 1 can be fixed to the frame of the switchgear. The mounting system 1 together with the busbars L1…L3, L1', N forms an arrangement device 6. In this example, the busbars L1…L3, L1', N form the three phases and the neutral line of an AC system. However, other configurations are equally possible.

[0065] Figure 2 Shows how the components of the mounting system 1 can be interconnected. Specifically, the busbar holders 4a, 4b are mounted to the holding rails 2a, 2b by means of busbar holder screws 7a, 7b, the connecting profiles 3a, 3b are mounted to the holding rails 2a, 2b by means of connecting profile screws 8a, 8b, and the frame connectors 5a, 5b can be mounted to the holding rail 2a and the switchgear frame by means of frame connector screws 9a, 9b.

[0066] Specifically, the retainer guide rails 2a, 2b can be made of fiber-reinforced resin and are particularly made by using pultrusion. The advantage of pultrusion is that regions of different fiber densities can be defined within the retainer guide rails 2a, 2b. Thus, the retainer guide rails 2a, 2b can be made more rigid where required. A further advantage of pultrusion is that the retainer guide rails 2a, 2b can be produced in standard lengths and can subsequently be cut as required to fit any application. Thus, the mounting system 1 can be easily adapted to different numbers of busbars L1…L3, L1', N.

[0067] The connecting profiles 3a, 3b can be produced in standard lengths by using pultrusion and can also be cut as required to fit any application. Thus, the mounting system 1 can be easily adapted to different heights of the busbars L1…L3, L1', N. The connecting profiles 3a, 3b can be made of plastic or metal.

[0068] Thus, an advantage of the proposed solution is that a wide range of busbar sizes and / or busbar configurations can be covered by the mounting system 1, although the components used are thus substantially the same for all these busbar sizes and / or busbar configurations. Thus, the flexibility of the mounting system 1 is increased at reduced cost compared to prior art systems.

[0069] Figure 3 and Figure 4 shows the busbar retainer 4a in more detail. Figure 3 shows a perspective view of the busbar retainer 4a, and Figure 4 shows a top view of the busbar retainer 4a. Advantageously, the busbar retainer 4a is a strut profile with a square tube cross-section and has cutouts B for the busbars L1…L3, L1', N. Thus, the busbar retainer 4a can be easily cut from a standard profile and can be manufactured at low cost. The cutouts B form recesses for receiving the busbars L1…L3, L1', N. Advantageously, the cutouts B are made by laser, but other production techniques can also be applied. A further advantage of the square tube cross-section is that the busbar retainer 4a is relatively rigid.

[0070] The busbar retainer 4a has two cutouts B, but other numbers of cutouts B are also possible. Thus, different busbar arrangements with different numbers of busbars L1…L3, L1', N in each busbar retainer 4a can be easily achieved. The only difference in that regard is the number of cutouts B in each busbar retainer 4a and / or the length of the busbar retainer 4a.

[0071] It should be noted that although Figure 3 and Figure 4 only one busbar retainer 4a is depicted, the other busbar retainers 4a, 4b preferably look the same. Thus, the technical disclosure related to the busbar retainer 4a equally relates to the busbar retainer 4b.

[0072] Now, by additionally using Figure 5 and Figure 6 the function of the busbar retainer 4a will be explained in more detail. Figure 5 A front view showing a cutout of the mounting system 1 is presented. Specifically, the busbar retainer 4a is installed in the lower retainer guide 2a and the busbars L1, L1' are received.

[0073] Advantageously, the top region of the cutout B has protruding or curved portions C on both sides, which provides many advantages. First, since the risk of wedging is reduced, it becomes easier to insert the busbars L1, L1' into the cutout B, even if only a small gap is provided between the busbars L1, L1' and the busbar retainer 4a.

[0074] Second, when the busbars L1, L1' move in the longitudinal direction, especially during the assembly of the mounting system 1, the surfaces of the busbars L1, L1' will not be scratched. If the busbars L1, L1' are coated, this will be particularly useful because the coating will not be scratched either. The protruding or curved portions C may also have chamfers or radii at the top and bottom edges to further improve the above effects.

[0075] Third, the busbars L1, L1' can be bent without exerting excessive pressure on the vertical edges of the cutout B. For example, this bending occurs when a large electromagnetic force acts on the busbars L1, L1'.

[0076] Fourth, even excessive pressure on the protruding or curved portions C will not cause the busbar retainer 4a to collapse because the material selection does avoid this situation. Specifically, metals and especially steel have a wide range of plastic deformation in addition to elastic deformation. Therefore, if the busbars L1, L1' are heavily pressed on the protruding or curved portions C, the material of the busbar retainer 4a can be locally plasticized, but it will not collapse as a whole. For example, this pressure occurs in the case of excessive current in the busbars L1, L1' and the electromagnetic force generated during a short circuit. However, plasticization is usually not a major problem because as long as there are no visible cracks on the component, plasticization is allowed based on the standard POV IEC 61439-1 / 2. In addition, this local plasticization has two further effects, which have a positive impact on the stability of the busbar retainer 4a. First, the material strength of the busbar retainer 4a is locally increased. This is an effect known in cold working and is used, for example, for cold-rolled steel. Second, the protruding or curved portions C become slightly flatter, so that the area effective for surface pressure increases. Consequently, if the level of the force remains constant, the surface pressure will decrease. Therefore, these effects result in a reduced risk of further plasticization of the protruding or curved portions C. In other words, equilibrium is reached when the busbar retainer 4a can withstand the forces within the mounting system 1 without further deformation. Basically, this adaptation is "automatically" or strictly speaking, is carried out by the special shape on the side of the cutout B.

[0077] Advantageously, the cutout B has a flat or convex elevation D, in particular with rounded corners E on both sides of the elevation D. Furthermore, in the installed state of the mounting system 1, i.e. when the busbar retainer 4a is mounted to the retainer guide 2a, it is advantageous if the retainer guide 2a reaches above the elevation D of the busbar retainer 4a. Thus, there is a height difference h between the elevation D and the busbars L1, L1' as well as between the elevation D and the upper edge of the retainer guide 2a.

[0078] On the one hand, due to the advantageous coefficient of friction between the metal and the plastic, the busbars L1, L1' can slide easily on the retainer guide 2a. On the other hand, if the retainer guide 2a collapses locally due to material fatigue, the elevation D in the busbar retainer 4a forms a hard stop for the busbars L1, L1'. Thus, serious damage to the mounting system 1 can be avoided. Furthermore, if the busbar retainer 4a itself is deformed due to excessive forces acting on the busbars L1, L1', the elevation D in the busbar retainer 4a also indeed forms a hard stop. Such excessive forces can cause deformation in such a way that the longitudinal axis of the busbar retainer 4a becomes arcuate. For example, this can occur if more than one busbar L1, L1' with the same voltage level is arranged in the busbar retainer 4a, as Figure 5 and Figure 6 shown in the example. During a short circuit, the busbars L1, L1' of the busbar retainer 4a are exposed to different forces, which results in an asymmetric load on the busbar retainer 4a. If the busbars L1, L1' are laterally stressed in different directions, a torque is induced in the busbar retainer 4a. If this torque is very high, there is a risk that the busbar retainer 4a is not fixed in the retainer guide 2a, which in turn causes the aforementioned bending of the busbar retainer 4a. Thus, the elevation or ridge D moves towards the busbars L1, L1'. Once the elevation D touches the busbars L1, L1', further deformation of the busbar retainer 4a is avoided or at least prevented. Thus, the elevation D itself also indeed acts as a hard stop for the busbar retainer 4a. Advantageously, the rounded corners E avoid the formation of cracks in the corners of the cutout B, and this is especially true in this case. Thus, the mounting system 1 is very fault-tolerant and does not cause the entire mounting system 1 to collapse even if the busbar retainer 4a is not fixed or is missing a fixation.

[0079] Specifically, the busbar retainer 4a can be coated / sprayed to reduce the friction between the busbar retainer 4a and the busbars L1…L3, L1', N, to provide electrical isolation and / or to color-code each electrical phase separately. For example, the busbar N can be blue, the busbar L1 can be brown, etc. To provide better coating adhesion, the base material of the busbar retainer 4a can have a rough surface. Such a rough surface can be made by, for example, sandblasting, but can also be made by laser ablation of small pits on the surface of the base material of the busbar retainer 4a. Specifically, the same laser used for cutting the notch B can be used. It is also possible that only the surface of the busbar retainer 4a is provided with these pits that may come into contact with other parts. Thus, in particular, the edges of the notch B can be provided with pits to locally improve the adhesion there.

[0080] Now, the installation of the busbar retainer 4a onto the retainer guide 2a will be explained in more detail by additionally using Figure 7 and Figure 8 Figure 193 and Figure 194. Figure 7 Shows a top view of an exemplary retainer guide 2a, and Figure 8 shows a cross-sectional view of the busbar retainer 4a installed onto the retainer guide 2a.

[0081] Advantageously, the retainer guide 2a can be a strut profile having an H-shaped cross-section, as is the case in the figures. In this way, on the one hand, the busbar retainer 4a can be received in one opening of the "H", and the components for mounting the busbar retainer 4a (such as the busbar retainer screws 7a, 7b or rivets) can be received in the opposite opening of the "H". Thus, in particular, the heads of the mounting components, such as the heads of the busbar retainer screws 7a, 7b or rivets, are located in the grooves, thereby preventing unintentional contact by personnel. It should be noted in this context that if the mounting components are made of metal, they may be energized if no other measures are taken to avoid this. Additionally, the H-shaped cross-section advantageously provides good anti-deflection stiffness. It should be noted that while the use of an H-profile is beneficial, other shapes can also be used for the retainer guide 2a. For example, the retainer guide 2a can have a U-shaped cross-section or a square tube cross-section.

[0082] If the H-shaped cross-section of the retainer guide 2a includes grooves F on both sides facing the busbar retainer 4a in the bottom region, as shown in Figure 6 and Figure 8 It should be noted that there seems to be an error in the original text where "Figure 193 and Figure 194" is expected in the translation of line . I have made the correction accordingly. If this is not what you intended, please let me know.It is also advantageous if, as shown. Specifically, an optional protrusion that can be fixed to the busbar retainer 4a of the retainer guide 2a or other devices can extend into the recess F. Thus, the busbar retainer 4a or other devices can be snapped into the retainer guide 2a so that the busbar retainer or other devices do not accidentally disengage from the retainer guide 2a before the busbar retainer 4a or other devices are finally fixed to the retainer guide 2a by mounting members (such as by busbar retainer screws 7a, 7b or rivets). If the busbar retainers 4a, 4b or other devices are installed upside down on the retainer guides 2a, 2b, as Figure 1 and Figure 2 in the case of the upper busbar retainer 4b. This can be particularly useful.

[0083] Advantageously, the mounting members for the busbar retainer 4a are located at different distances b from the longitudinal axis K of the retainer guide 2a and / or on different sides of the longitudinal axis K, and the busbar retainer 4a fixes the retainer guide, as in the example shown in the drawings. In this case, Figure 4 shifted busbar retainer holes 10a, 10b are shown, and Figure 7 shifted retainer guide holes 11a, 11b are shown. By using these measures, the risk of forming cracks in the retainer guide 2a can be reduced.

[0084] Advantageously, the busbar retainer 4a can be fixed to the retainer guide 2a by mounting members implemented as Figure 8 the self-cutting busbar retainer screws 7a, 7b depicted in. Using the self-cutting busbar retainer screws 7a, 7b offers many advantages. First, it is not necessary to cut a separate thread into the busbar retainer 4a because the self-cutting busbar retainer screws 7a, 7b cut the thread themselves. Second, even if the installation system is exposed to vibrations such as those occurring within switchgear, the self-cutting busbar retainer screws 7a, 7b are not likely to unscrew themselves. Thus, additional screw locking can be omitted. Third, the self-cutting busbar retainer screws 7a, 7b can be made shorter than screws fixed with nuts. Therefore, even if the busbar retainer screws 7a, 7b fall out of the installation system 1, the possibility of arc flash or short circuit caused by the busbar retainer screws 7a, 7b is relatively low. This is for a simple reason that the self-cutting busbar retainer screws 7a, 7b are shorter than screws fixed with nuts and cannot bridge a large gap between conductors under voltage.

[0085] Advantageously, the self-cutting busbar retainer screws 7a, 7b have a threaded portion G and a non-threaded portion J, wherein the outer diameter d1 of the threaded portion is smaller than the diameter d2 of the non-threaded portion J, and wherein the threaded portion G is screwed into the busbar retainer 4a, and the non-threaded portion J is positioned within the retainer guide 2a. Specifically, the threaded portion G is screwed into one of the busbar retainer holes 10a, 10b in the busbar retainer 4a, and the non-threaded portion J is positioned within one of the retainer guide holes 11a, 11b in the retainer guide 2a. Since the diameter d2 of the non-threaded portion J is relatively large, the surface pressure on the retainer guide 2a and the shear stress in the retainer guide 2a are relatively low, enabling a greater force to be transmitted between the busbar retainer screws 7a, 7b and the retainer guide 2a. This is the case even if the retainer guide 2a is made of plastic. The busbar retainer screws 7a, 7b as defined above can also be regarded as a shoulder screw.

[0086] Alternatively, the busbar retainer 4a can be fixed to the retainer guide 2ab by means of a mounting member, which is embodied as a rivet, in particular as a snap-in in the rivet. In this way, even if the busbar retainers 4a, 4b are oriented in an upright position, the assembly of the mounting member can always be carried out from above, as in the case of the lower busbar retainer 4a. In this case, the rivet is inserted through the cutout D in the busbar retainer 4a, and the head of the rivet is positioned within the busbar retainer 4a in the mounted state. If the busbar retainers 4a, 4b are oriented upside down, as in the case of the upper busbar retainer 4b, the rivet is inserted through the mounting holes 11a, 11b in the upper retainer guide 2b. In both cases, the rivet is not likely to fall off accidentally.

[0087] Generally, it is advantageous if the width of the busbar retainer 4a is slightly lower than the internal dimensions of the H-shaped cross-section of the retainer guide 2a. Thus, the busbar retainer 4a can be easily mounted to the retainer guide 2a. However, it may also be useful if the width of the busbar retainer 4a is slightly higher than the internal dimensions of the H-shaped cross-section of the retainer guide 2a. The busbar retainer 4a is then held in the retainer guide 2a by friction. Thus, the busbar retainer 4a does not accidentally disengage from the retainer guide 2a until the busbar retainer 4a is finally fixed to the retainer guide 2a by means of mounting members (e.g., by busbar retainer screws 7a, 7b or rivets). This is particularly useful if the busbar retainer 4a or other devices are to be mounted upside down to the retainer guide 2a, as is the case with the busbar retainer 4b. In any case where the width of the busbar retainers 4a, 4b matches the internal dimensions of the H-shaped cross-section, rotation of the busbar retainer 4a is avoided even if only a single busbar retainer screw 7a, 7b is used to fix the busbar retainers 4a, 4b or even if the mounting members (e.g., by busbar retainer screws 7a, 7b or rivets) of the mounting system 1 for the busbar retainers 4a, 4b accidentally fall off during operation. Thus, the mounting system 1 is highly fault-tolerant and the retainer guide 2a acts as a kind of component jig during assembly, thus simplifying the manufacture of the mounting system 1.

[0088] It should be noted at this point that the upper retainer guide 2b looks the same as the lower retainer guide 2a. Thus, the technical disclosure presented in the case of the lower retainer guide 2a equally applies to the upper retainer guide 2b. The same techniques are also important for the lower and upper busbar retainers 4a, 4b.

[0089] Figure 9 Finally, a side view of a cutout showing the electrical switchgear 12 is presented, which includes several busbars L1…L3, L1', N, a frame 13 and switching devices 14 electrically connected to the busbars L1…L3, L1', N. By using the mounting system 1, the busbars L1…L3, L1', N are held in place within the electrical switchgear 12. Specifically, the mounting system 1 can be fixed to the frame 13 by means of frame connectors 5a, 5b and frame connector screws 9a, 9b.

[0090] Due to the material selection of the retainer guides 2a, 2b and the busbar retainers 4a, 4b, i.e., because the retainer guides 2a, 2b are made of plastic and the busbar retainers 4a, 4b are made of metal, the busbar retainers 4a, 4b are relatively sturdy and can easily withstand the forces generated in the switchgear 12. This is contrary to the prior art solutions where the retainer guides 2a, 2b are made of metal and the busbar retainers 4a, 4b are made of plastic.

[0091] Because the contact surfaces between the busbar retainers 4a, 4b and the retainer guides 2a, 2b are relatively large, these additional large forces can be easily transferred from the busbar retainers 4a, 4b to the retainer guides 2a, 2b, even though the retainer guides 2a, 2b are made of plastic. In addition, the retainer guides 2a, 2b provide electrical insulation and thus also avoid induction currents or eddy currents caused by the currents flowing through the busbars L1…L3, L1', N. The non-ferrous material of the proposed retainer guides 2a, 2b naturally avoids closed iron-containing material loops around the busbars L1…L3, L1', N. This is not the case for prior art retainer guides 2a, 2b made of metal, where special measures must be taken to avoid such iron-containing material loops and to avoid or at least limit the eddy currents.

[0092] It should be noted that the invention is not limited to the embodiments disclosed above, but combinations of different variants are possible. In fact, the mounting system 1 and the switching device 12 may have more or fewer components than those shown in the drawings. In addition, the present description may include the subject matter of additional independent inventions.

[0093] It should also be noted that the term "comprising" does not exclude other elements, and the use of the article "a" or "an" does not exclude a plurality. Elements described in connection with different embodiments may also be combined. It should also be noted that the reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. An installation system (1) for a busbar (L1…L3, L1', N) of an electrical switchgear (12), which comprises: - a plurality of holder rails (2a, 2b) made of plastic, - connecting profiles (3a, 3b) which interconnect the holder rails (2a, 2b) and create a distance between the holder rails (2a, 2b), and - a plurality of busbar holders (4a, 4b) made of metal, which are arranged to receive the busbar (L1…L3, L1', N) and are disposed in the holder rails (2a, 2b), characterized in that - the busbar holders (4a, 4b) are strut profiles having a square tube cross-section and having a cutout (B) for the busbar (L1…L3, L1', N).

2. The installation system (1) according to claim 1, characterized in that the holder rails (2a, 2b) are strut profiles having an H-shaped cross-section.

3. The installation system (1) according to claim 2, characterized in that the H-shaped cross-section of the holder rails (2a, 2b) comprises grooves (F) on both sides in the bottom region facing the busbar holders (4a, 4b).

4. The installation system (1) according to claim 1, characterized in that the top region of the cutout (B) has protruding or curved portions (C) on both sides.

5. The installation system (1) according to claim 1, characterized in that the bottom region of the cutout (B) has a flat or protruding bulge (D), and has rounded corners (E) on both sides of the bulge (D).

6. The installation system (1) according to claim 5, characterized in that in the installed state of the installation system (1), the holder rails (2a, 2b) reach above the bulge (D) of the busbar holders (4a, 4b).

7. The installation system (1) according to claim 1, characterized in that the busbar holders (4a, 4b) are fixed to the holder rails (2a, 2b) by mounting members which are implemented as self-cutting busbar holder screws (7a, 7b).

8. The installation system (1) according to claim 7, characterized in that one of the self-cutting busbar holder screws (7a, 7b) has a threaded portion (G) and a non-threaded portion (J), wherein the outer diameter (d1) of the threaded portion is smaller than the diameter (d2) of the non-threaded portion (J), and wherein the threaded portion (G) is screwed into one of the busbar holders (4a, 4b), and the non-threaded portion (J) is positioned within one of the holder rails (2a, 2b).

9. The installation system (1) according to claim 1, characterized in that the busbar holders (4a, 4b) are fixed to the holder rails (2a, 2b) by mounting members which are implemented as rivets.

10. The installation system (1) according to claim 1, characterized in that The mounting member for one of the busbar retainers (4a, 4b) is positioned at different distances (b) from the longitudinal axis (K) of the retainer guide (2a, 2b) and / or on different sides of the longitudinal axis (K), and the busbar retainer (4a, 4b) is fixed to the retainer guide (2a, 2b).

11. The mounting system (1) according to claim 2, wherein, the width of the busbar retainer (4a, 4b) is slightly lower than the internal dimension of the H-shaped cross-section of the retainer guide (2a, 2b).

12. An arrangement device (6) for busbars, wherein, the arrangement device (6) has a plurality of busbars (L1…L3, L1', N) and the mounting system (1) according to any one of claims 1 to 11, and the busbars (L1…L3, L1', N) are fixed by the mounting system (1).

13. An electrical switchgear (12), which comprises: - several busbars (L1…L3, L1', N), and - at least one switching device (14) which is electrically connected to the busbars (L1…L3, L1', N), wherein, - the mounting system (1) according to any one of claims 1 to 11, and the busbars (L1…L3, L1', N) are held in place within the electrical switchgear (12) by the mounting system (1).

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