DE10307353A1 - Current feed unit has longitudinal bus bars almost completely embedded in insulating profile accessible in touch-proof manner via hole-shaped contacting openings made in insulation along long side - Google Patents

Abstract

The current feed unit (20) has several longitudinal bus bars (21) almost completely embedded in an insulating profile (22) and accessible in a touch-proof manner via hole-shaped contacting openings (23) made in the insulation along the long side. The current feed unit is of sandwich construction with several layers and the insulating profile can be of rectangular or U-shaped cross-section.

Description

The invention relates to a power supply unit with several in embedded in an insulating profile, running in its longitudinal direction, along a busbar accessible on the long side.

Such a power supply unit is known from DE 30 22 183 A1 and is used in particular for the adjustable connection of lights. In one U-shaped metal supports to be attached to a ceiling or wall insulating profiles on the side legs with protruding webs inserted busbars. Usable adapters are available for contacting intended. A similar power supply unit is also in DE 28 10 681 C2 shown. The adapters are fixed under rotary motion.

The object of the invention is to prepare a power supply unit steep, simple and safe with little installation effort Offers connection options.

This object is achieved with the features of claim 1. After that is provided that the busbars are almost completely in the insulating profile embedded and inserted in the insulation on the long side Hole-shaped contact openings are accessible so that they are safe to touch.

The power supply unit enables clear and simple secure connection options for the power supply or data signals and can easily and clearly, for example on a frame Control cabinet, a rack or an information technology Workplace arrangement with table to be attached. The inserted in the insulating profile hole-shaped, touch-proof contact openings result in a Protection against accidental contact similar to sockets, so that the busbars are not can be accidentally touched with your fingers. The contact openings are in particular in a along the length of the power supply unit continuous grid arrangement.

An advantageous one for compact manufacture and functional reliability Execution is that the insulating profile with the busbars in one Sandwich construction is built.

An advantageous structure and a favorable handling result from that the insulating profile has a rectangular or U-shaped cross section.

A simple way of attaching the insulating profile, for example, to one Frame profile or in a separate profile is achieved in that the insulating profile on lateral outer boundary surfaces with a Locking structure is provided for z. B. with a facing Inner surfaces of a receiving chamber of the frame profile or separate profile arranged further locking counter structure for fixing in the inserted state of the insulating profile interacts.

Simple connection options are offered by the fact that U-shaped cross section of the insulating profile on lateral inner boundary surfaces of An inner latching structure is arranged on the side legs, and that inserts are provided for contacting the busbars that on their side surfaces directed in the longitudinal direction of the busbars with the inner locking structure or with in a receiving chamber Frame profile or separate profile provided locking structure interacting locking Show counter structure. The inserts can be removable or not detachable or only detachably fixed with a tool.

Advantageous configurations for the construction and assembly, as well as security of the insulating profile consist in the fact that the insulating profile consists of a shell Busbars in longitudinally insulated chambers receiving insulating profile lower part and a covering the busbars and with the insulating openings provided top section is constructed, and in that the insulating profile lower part and the upper insulating profile part by means of each other facing longitudinal snap edges with complementary Snap elements or latching elements are connected to one another, and furthermore, that on the insulating profile lower side wall sections of the Isolierprofiloberteil are formed on both sides of longitudinal locking springs that are directed away from the lower insulating profile, a distance from the Have side walls of the upper insulating profile and with their free edge outward standing locking hooks are provided, which in on the side Engage the retaining grooves formed on the inner surfaces of the receiving chamber.

Advantageous connection options are obtained in that the inserts on its front base when inserted with protruding ones Contacting elements are provided, the location and essentially the Dimensions of the contact openings are adjusted.

Secure contacting results from the fact that the contacting elements are spring-mounted to generate a contact pressure or that on the Busbars U-shaped contact springs are attached to their web into which the Contacting elements intervene to make contact, taking it for safety It is advantageous that a contacting element forming a protective contact stands out from the others.

Advantageous configurations of the inserts for the construction, assembly and Security results from the fact that the contact elements in cross section rectangular and with their long sides in the longitudinal direction of the busbars and the slots of the contact springs attached to it are aligned, and in that at least one insert is designed like a socket and from an insert base receiving the contacting elements and a die Contacting elements that protect against contact, with plug-in openings provided insert top is assembled, and further in that the insert base on opposite sides with on locking fingers arranged locking lugs is provided, which in the inserted state with against Steep locking flanks assigned to steep locking flanks from in the direction of insertion lateral inner surfaces of the receiving chamber or the inner Reach behind the boundary surfaces of the insulating profile arranged locking grooves, being cheap it is provided that the locking finger sections of in an axis of rotation stored levers are and by exerting one towards the outside a spring force acting on a with respect to the axis of rotation Locking finger opposite lever section to release the locking connection are pivotable inwards. For the. Disassembly is still advantageous provided that a U-shaped or C-shaped removal bracket is provided the free ends of which can be pivoted inwards against its elasticity and insertable into the insert and simultaneously with the two Lever sections can be brought into operative connection, the elastic forces Spring forces exceed, and that the use while getting caught with the removal bracket is removable.

An advantageous training of the inserts is still that on the compartments facing away from the busbars for receiving contact inserts for plug pins, an earthing spring, Plug-in shoes and / or a resettable one, which can be inserted into the plug-in shoes Automatic circuit breaker is / are provided, the automatic circuit breaker by a bridge can be replaced.

The measures for connecting the inserts are also advantageous in that a busbar forming a protective conductor with respect to the width of the Insulating profile is arranged in the middle, as well as that at least five Busbars are provided. With z. B. five tracks for example a DC voltage supply and an AC voltage supply be provided or a power supply and a two-wire Bus arrangement for data signals. For extended uses are z. B. also seven tracks possible.

It is provided that at least two busbars each are arranged mirror-symmetrically to the center, so the same inserts can be used Contact can be used with different power rails, the inserts as Schuko or cold device connection units or data plug also in different country versions can be trained, in particular if it is envisaged that at least part of the use as a pantograph are formed for alternative contacting on the mirror-symmetrical Busbars can optionally be installed rotated by 180 °, whereby the Arrangement of the contact openings assigned to the busbars to the Arrangement of the contact elements in the two rotational positions is adapted.

A clear, stable arrangement is supported by the fact that the use hat-shaped in cross-section with an essentially cuboid Base body and an outer portion protruding over this on both sides is.

Easy handling is favored by the fact that the two Rotational positions of the insert with one on it, especially outside on the Marking attached to the outer section are marked.

Further favorable application possibilities result from the fact that at least one insert is provided with a current and / or voltage meter and / or that a total current and / or Total voltage meter is / are provided, as well as that at least an insert is designed as a display module of parameters.

A safe function is favored by the fact that a Microfuse and / or a monitoring contact and / or a switching means for local or remote controlled switching on and off is / are arranged, as well further in that one or more power supply lines is a central one Surge protection is connected upstream.

The invention is described below using exemplary embodiments Reference to the drawings explained in more detail. Show it:

Fig. 1 shows a portion of a power supply unit with insulating profile and inserts in a perspective disassembled view,

Fig. 2 shows the section 1 of the current supply unit of FIG. In assembled view in conjunction with a frame profile,

Fig. 3 shows the portion of FIG. 2 with inserted insulating profile and remote operations from a rear view,

Fig. 4A shows a further embodiment of a frame profile with current supply and an insert in disassembled perspective view;

FIG. 4B the cutout of the frame profile of Figure 4A with the power supply and operating in the assembled state.,

Fig. 5 shows a cross section of the frame profile according to FIGS. 4A and 4B,

Fig. 6A-6C different representations of the insulating profile used in the embodiment according to FIGS. 4A and 4B,

Fig. 7 is a Isolierprofilunterteil of the insulating profile according to FIGS. 6A to 6C with inserted current rails in perspective view,

Fig. 8 busbars according to Fig. 7 with mounted contact springs in a perspective view;

Fig. 9 is a compilation of the insulating bus-bar and an insert in perspective view;

FIG. 10A and 10B, two embodiments of an insert in a perspective, disassembled view

FIG. 11A and 11B, the composite insert according to Fig. 10A from the top and from the bottom in a perspective view and

FIG. 12A to 13D show various views of an insert.

In Figs. 1 to 13D a power supply unit 20 with an insulating element 22 embedded therein and accessible along a longitudinal side bus bars 21 is shown. Inserts 30, for example in the form of Schuko or cold device inserts or sockets, are inserted or can be used in the power supply unit 20 or the insulating profile 22 , which is essentially rectangular or U-shaped in cross section. Referring to FIGS. 2 through 4B, the insulating element of a frame profile 10 may, of the rack 22 in a receptacle chamber 11. B. a control cabinet, racks or workstation system with table for industrial or information technology applications. The receiving chamber 11 is a one-piece, integral part of the frame profile 10 . Alternatively, a separate profile with the receiving chamber 11 can be provided, which with the frame profile 10 z. B. can be connected by means of screws, clamps, clips, rivets, gluing, welding or the like.

The receiving chamber 11 accessible from the inward opening side has an approximately rectangular or square basic shape. The side walls directed towards the opening side, which are parallel to one another, have latching counter-structures on their mutually facing inner surfaces. B. in the form of longitudinal, projecting into the receiving chamber 11 locking webs that have an insertion slope to the opening side and on the side facing away from the opening side a locking shoulder, or in the form of holding grooves 11.5 and / or locking grooves 11.6 . A base wall opposite the opening side of the receiving chamber 11, which is essentially U-shaped in cross section, serves to abut the insulating profile 22 which is adapted to the receiving chamber 11 . The base wall 11.3 can be flush on its outside with the adjacent sealing edge 12 (FIGS . 2 and 3), set back relative to it or protrude relative to it by means of a wall projection 11.4 of the side walls 11.1 ( FIGS. 4A to 5).

In the embodiment according to FIGS. 1 to 3, the insulating profile 22 has a plate-like base web 22.1 with the busbars 21 embedded therein and side legs 22.2 on the side, on the outside of which an outer latching structure 22.3 is formed, which with the latching counter-structure on the inner surfaces the receiving chamber 11 cooperates, and on the inside of which an inner latching structure 22.4 is formed, which is likewise designed as a longitudinal latching web with an insertion bevel directed towards the opening side and a latching shoulder facing away from the opening side, and for latching receiving the inserts 30 , between the side legs 22.2 and the base web 22.1 a receiving space 20.1 for the inserts 30 is formed. The busbars 21 are insulated and embedded in a contact-safe manner in the base web , only one hole pattern of contact openings 23 leading to the receiving space 20.1 being formed, through which the inserts 30 come into contact with the respective busbars 21 .

The inserts 30 , for example in the form of a plug connection, are hat-shaped in cross-section with a cuboid section which engages in the receiving space 20.1 and essentially fills it, and an integrally or separably adjoining flat section projecting laterally beyond the opening side, the z. B. flat, rear edges 34 of this section, for example, in laterally adjacent to the opening side of the receiving chamber 11 and the receiving space 20.1 adjacent recesses of the frame profile 10 and are provided on their front with a side marking 35 . Instruct the side leg 22.2 of the insulating profile 22 adjacent side surfaces 32 with the inner latching structure 22.4 of the insulating profile 22 cooperating and adapted thereto detent recesses 33, whereby the locking connection may be configured such that the inserts can be but unlatched 30 either by hand or with a tool , The support edges 34 of the outer section of the inserts 30 contribute to its clear, stable fit.

On the base web 22.1 of the insulating profile 22 facing the base 31 of the inserts 30 project a plurality of peg-like resilient contacting elements 36 , which are adapted in cross section and in their arrangement to the contacting openings 23 of the insulating profile 22 , for example only one of the number lying on the opening side Connection elements 37 of the inserts 30 corresponding number of contacting elements 36 are provided. For example, the inserts 30 designed for a voltage supply are provided with three contacting elements 36 , which are assigned to the two poles of the voltage supply and a protective conductor connection, the middle busbar 21.3 serving as a protective conductor. The two other contacting elements and the contacting openings 22 assigned to them are arranged in such a way that the insert 30 can be inserted rotated by 180 °, these contacting elements 36 interacting with different pairs of the busbars in the two rotated positions. This arrangement of the contacting elements 36 and contacting openings 23 has the advantage that the same inserts 30 can be used for different contactings, for example for alternating current or direct current or two different phases of alternating current, the same protective contact always being effective and overloading being avoided. Furthermore, it is advantageously provided that the contacting element 36 assigned to the protective conductor 21.3 is designed to be somewhat longer than the other contacting elements 36 , so that contact is first made with the protective conductor when it is inserted. A marking on the inserts 30 indicates which voltage supply or alternatively data lines are / are currently being used.

Inserts of different designs can be provided, for example with non-replaceable integrated fine fuse, with fine fuse and monitoring contact, with microfuse and a switching option for local or remote controlled switching on and off, with power and / or Voltage measurement or as a display module. Switching can be done automatically, depending on various parameters such as temperature, humidity, external digital Switching signals, electrical load, Ethernet network load or the like. moreover or alternatively, a central surge protection can be provided in front of the Power supply and / or a total current or Total voltage measurement done.

The power supply unit 20 is advantageously constructed in a sandwich construction with different layers, which results in a compact, reliable construction. The power supply unit 20 designed in this way can be delivered unequipped or partially or fully equipped and / or can also be delivered integrated in a frame profile 10 .

The locking structures shown and interacting with them Locking counter structures can also be designed differently, for example their arrangement be mixed up on the respective components. Additionally or alternatively you can to connect these components clamp, screw, adhesive connections or similar be used.

Another embodiment of the insulating profile 22 with the busbars 21 arranged therein is shown in FIGS. 4A to 9. In this case, there is a rectangular in cross-section substantially insulating profile 22 consists of two partial profiles, namely a Isolierprofilunterteil 22.5 with longitudinally extending, toward the opening side of the receiving chamber 11 open chambers 22:52, in which the bus bars are received 21, and a Isolierprofiloberteil 22.6, with the bus bars 21 protected against accidental contact are and that only the z. B. has rectangular contact openings 23 . As can be clearly seen in particular in FIGS. 6A to 6C, the lower insulating profile part 22.5 and the upper insulating profile part 22.6 are locked together, for which purpose two webs delimiting the outer chambers and projecting vertically from a base wall are bulged at their free edges on the outside to form snap edges 22.51 and project from downwards Counter ridges with adapted recesses of the upper insulating profile 22.6 are gripped. Laterally from the mating ridges of the receiving chamber 11 directed strip-like locking springs 22.61 are formed on these both sides in the direction towards the opening side, which, at their approximately level with the top wall of the Isolierprofiloberteils 22.6 lying free upper edges of outwardly pointing locking hooks 22.62. With the locking hooks 22.62 , which run approximately parallel to the cover side on their side facing the opening side of the receiving chamber 11 , the insulating profiles are not snapped removably into the holding grooves 11.5 without destruction, for which purpose the holding grooves 11.5 also have correspondingly steep holding flanks against the direction of insertion of the insulating profile 22 . In the inserted state, the lower insulating profile part 22.5 and the upper insulating profile part 22.6 can no longer be separated from one another by these measures. In contrast, the latching hooks 22.62 have insertion bevels in the direction of insertion.

As the exemplary embodiment according to FIGS . 4A to 13D shows, the inserts 30 can also be inserted directly into the receiving chamber 1 l of the frame profile 10 , lateral latching fingers 30.21 with a latching nose (cf. e.g. FIG. 12B) of an insert lower part 30.2 in 11.6 engage the locking grooves mentioned on the inside of the side walls 11.1 and 30 used extraction strap 38 can be unlocked by means of an in a plug opening or the like. an insert upper part 30.1 of Fig. 9 for the removal of the insert. For this purpose, the removal bracket 38 interacts with an actuating section 30.22 on the latching finger 30.21 . The receiving chamber 11 enlarged by means of the wall projection 11.4 compared to the exemplary embodiment according to FIGS. 1 to 3 makes it possible to design the inserts 30 and the power supply 20 with the insulating profile 22 and the busbars 21 also for carrying higher currents.

The busbars 21 embedded in the longitudinally extending chambers of the insulating profile lower part 22.5 formed with insulating parallel longitudinal webs are provided on their flat side facing away from the base wall with cross-sectionally U-shaped contact springs 24 which are arranged corresponding to the contact openings 23 in the upper insulating profile part 22.6 and for contacting which in this case receive flat contacting elements 36 (cf. also FIGS. 12A to 13D) of inserts 30 . The contact springs 24 have in the region of the U-web an elongated base plate 24.1 in the longitudinal direction of the busbars 21 , with which they can be attached to the busbars, for. B. are attached by laser welding, and lugs 24.2 , with which they can rest stabilizing on the free edges of the longitudinal webs forming the chambers. The free edges of the contact springs 24 are bent inwards and form convex contact surfaces directed against one another for reliable contacting and good guidance.

The inserts shown in more detail in FIGS. 10A to 13D have in their lower part on the upper side remote from the contacting elements 36 several chambers for different elements, for example a circuit breaker 40 with a reset pin 40.1 or alternatively a bridge 41 , the circuit breaker 40 or the bridge 41 can be inserted into corresponding plug-in shoes 43 . In addition, an earthing spring 42 is provided and contact inserts 44 are arranged at suitable points. To actuate the reset pin 40.1 , a trigger opening 45 is made in the insert upper part 30.1 . The upper insert 30.1 and the lower insert 30.2 can be screwed or locked together.

In this exemplary embodiment, too, there are the alternative design options mentioned above in connection with the exemplary embodiment according to FIGS. 1 to 3.

The described power supply unit 20 can easily z. B. be attached to another, in particular flat contact surface of a frame profile or the like.

The electrical devices installed in a frame at any point, such as. B. Control units or servers can be easily connected by means of an insert 30 inserted into the power supply unit 20 or the insulating profiles 22 with the embedded busbars 21 according to FIGS. 1 to 4B and 9 to 13D.

The power supply unit 20 can be connected to a voltage supply by means of a suitable adapter or from the lower or also the upper end face or via a special additional insert 30 . For a series of frame frames, adapters to be inserted into the frame profiles 10 lying next to one another can be connected to one another, so that only a connection to a voltage supply is required.

Under the terms named frame, rack, control cabinet, Workstation system, table arrangement are in particular also such arrangements or to understand combinations of these for information technology (IT) z. B. also rack structures or shelves for monitors or server cabinets or like.

Claims (28)

1. Power supply unit ( 20 ) with several embedded in an insulating profile ( 22 ), in the longitudinal direction thereof, accessible along a long side accessible busbars ( 21 ), characterized in that the busbars ( 21 ) almost completely embedded in the insulating profile ( 22 ) and over hole-shaped contact openings 123 ) made in the insulation on the long side are accessible in a touch-safe manner. 2. Power supply unit according to claim 1, characterized, that they are built in a sandwich construction with multiple layers is. 3. Power supply unit according to claim 1 or 2, characterized in that the insulating profile ( 22 ) has a rectangular or U-shaped cross section. 4. Power supply unit according to one of the preceding claims, characterized in that the insulating profile ( 22 ) is provided on lateral outer boundary surfaces with a latching structure ( 22.3 ). 5. Power supply unit according to claim 3 or 4, characterized in that in the case of a U-shaped cross section of the insulating profile ( 22 ) an inner latching structure ( 22.4 ) is arranged on lateral inner boundary surfaces of side legs ( 22.2 ). 6. Power supply unit according to one of the preceding claims, characterized in that inserts ( 30 ) for contacting the busbars ( 21 ) are provided, which on their in the longitudinal direction of the busbars ( 21 ) directed side surfaces ( 32 ) with the inner locking structure ( 22.4 ) or have locking counter-structure ( 33 ) cooperating with locking structure ( 11.6 ) provided in a receiving chamber ( 11 ) of a frame profile ( 10 ) or a separate profile. 7. Power supply unit according to one of the preceding claims, characterized in that the insulating profile ( 22 ) in a shell-like manner from an insulating profile lower part ( 22.5 ) which accommodates the busbars ( 21 ) in longitudinal chambers that are insulated from one another and a busbar ( 21 ) covering the busbars ( 21 ) and with the contact openings ( 23 ) provided insulating profile upper part ( 22.6 ) is constructed. 8. Power supply unit according to claim 7, characterized in that the lower insulating profile part ( 22.5 ) and the upper insulating profile part ( 22.6 ) are connected to one another by means of mutually facing longitudinal snap edges ( 22.51 ) with complementary snap elements or latching elements. 9. Power supply unit according to claim 7 or 8, characterized in that on the insulating profile lower part ( 22.5 ) facing side wall sections of the upper insulating profile part ( 2.6 ) are formed on both sides longitudinal locking springs ( 22.61 ) which are directed away from the lower insulating profile part ( 22.5 ), a distance from the side walls of the insulating profile upper part ( 22.6 ) and are provided on their free edge with outwardly projecting locking hooks ( 22.62 ) which engage in locking grooves ( 11.5 ) formed on the lateral inner surfaces of the receiving chamber ( 11 ). 10. Power supply unit according to one of claims 6 to 9, characterized in that the inserts ( 30 ) on their front base when inserted ( 31 ) are provided with projecting contact elements ( 36 ) which are adapted to the position of the contact openings ( 23 ). 11. Power supply unit according to claim 10, characterized in that the contacting elements ( 36 ) for generating a contact pressure are resiliently mounted or that on the busbars ( 21 ) U-shaped contact springs ( 24 ) are fastened with their web into which the contacting elements ( 36 ) intervene to make contact. 12. Power supply unit according to claim 11, characterized in that the contacting elements ( 36 ) are rectangular in cross section and are aligned with their long sides in the longitudinal direction of the busbars ( 21 ) and the slots of the contact springs ( 24 ) mounted thereon. 13. Power supply unit according to one of claims 6 to 12, characterized in that at least one insert (30) is configured socket-like and covering provided from a the contacting (36) having insert lower part (30.2) and the contacting (36) contact-protected, with plug pin openings Insert upper part ( 30.1 ) is assembled. 14. Power supply unit according to one of claims 6 to 13, characterized in that the insert lower part ( 30.2 ) is provided on opposite sides with latching lugs arranged on latching fingers ( 30.21 ), which in the inserted state have steep latching flanks associated with steep latching heels opposite to the direction of insertion engage behind the side inner surfaces of the receiving chamber ( 11 ) or the inner boundary surfaces of the insulating profile ( 22 ) arranged locking grooves ( 11.6 ). 15. Power supply unit according to claim 14, characterized in that the latching fingers ( 30.21 ) are sections of levers mounted in an axis of rotation and by exerting an outward force acting against a spring force on a lever section opposite the latching finger ( 30.21 ) with respect to the axis of rotation ( 30.22 ) can be pivoted inwards to release the latching connection. 16. Power supply unit according to claim 15, characterized in that a U-shaped or C-shaped removal bracket ( 38 ) is provided, the free ends of which can be pivoted inward against its elastic force and inserted into the insert and with the two lever sections ( 30.22 ) in operative connection can be brought, the elastic forces exceeding the spring forces, and that the insert can be removed while at the same time getting caught with the removal bracket ( 38 ). 17. Power supply unit according to one of claims 13 to 16, characterized in that on the top of the insert lower part ( 30.2 ) facing away from the busbars ( 21 ) compartments for receiving contact inserts ( 44 ) for plug pins, an earthing spring ( 42 ), plug shoes ( 43 ) and / or a resettable, can be inserted into the plug-in shoes (43), circuit breakers (40) are provided, wherein the circuit breaker (40) is replaceable by a bridge (41). 18. Power supply unit according to one of claims 10 to 17, characterized in that a contacting element ( 36 ) forming a protective contact protrudes further from the others. 19. Power supply unit according to one of the preceding claims, characterized in that a busbar ( 21 ) forming a protective conductor is arranged in the center with respect to the width of the insulating profile ( 22 ). 20. Power supply unit according to one of the preceding claims, characterized in that at least five busbars ( 21 ) are provided. 21. Power supply unit according to claim 20, characterized in that in each case at least two busbars ( 21 ) are arranged mirror-symmetrically to the center. 22. Power supply unit according to claim 21, characterized in that at least some of the inserts ( 30 ) are designed as current collectors, which can optionally be installed rotated by 180 ° for alternative contacting on the mirror-symmetrical busbars ( 21 ), the arrangement of the busbars ( 21 ) assigned contact openings ( 23 ) is adapted to the arrangement of the contact elements ( 36 ) in the two rotational positions. 23. Power supply unit according to one of claims 6 to 22, characterized in that the insert ( 30 ) is hat-shaped in cross section with an essentially cuboid base body and a protruding outer portion. 24. Power supply unit according to claim 22 or 23, characterized in that the two rotational positions of the insert ( 30 ) are identified by a mark attached to it. 25. Power supply unit according to one of the preceding claims, characterized in that at least one insert ( 30 ) is provided with a current and / or voltage meter and / or that a total current and / or total voltage meter is / are provided for each power supply unit ( 20 ). 26. Power supply unit according to one of the preceding claims, characterized in that at least one insert ( 30 ) is designed as a display module of parameters. 27. Power supply unit according to one of the preceding claims, characterized in that a microfuse and / or a monitoring contact and / or a switching means for local or remote-controlled switching on and off is / are arranged in the insert ( 30 ). 28. Power supply unit according to one of the preceding claims, characterized in that a power supply unit ( 20 ) is preceded by a central overvoltage protection.