Abstract:
According to the invention, the busbar system comprises at least one first ( 2 ) and one second busbar block ( 3 ) with busbars ( 6 ), whereby the busbars ( 6 ) of the first busbar block ( 2 ) are electrically connected to a number of supply terminals ( 5 ) mounted in a fixed manner thereon and to the busbars ( 6 ) of the second busbar block ( 3 ) by means of a multiphase connecting plug ( 4 ).

Description:
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/DE02/04151 which has an International filing date of Nov. 8, 2002, which designated the United States of America and which claims priority on German Patent Application number DE 101 56 214.4 filed Nov. 15, 2001, the entire contents of which is hereby incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The invention generally relates to a polyphase or multiphase busbar system for supplying power to two or more switching devices. 
   BACKGROUND OF THE INVENTION 
   Until now, a terminal strip has been used as a separate supply terminal for supplying power via a busbar system in the case of power breakers having cage clamp spring terminal connections. The power is supplied by lines from the terminal strip to a busbar system to which the individual power breakers or switching devices are connected by way of flexible lines. If, for example, four outgoing branches are supplied with power by a busbar system such as this, and four further outgoing branches are to be added in parallel with the same power supply, this is only possible by the power in the busbar being fed via the terminals of the fourth power breaker. 
   SUMMARY OF THE INVENTION 
   It is therefore the object of an embodiment of the invention to improve a polyphase or multiphase busbar system such that it can be extended in a simple manner for the purpose of connecting further switching devices. 
   An object may be achieved by a busbar system having at least one first and one second busbar block, the busbars of the first busbar block being electrically connected to two or more permanently attached supply terminals and, by way of a multipole connecting plug, to the busbars of the second busbar block. 
   Thus, two or more outgoing branches or switching devices can be supplied with power by only one supply point, the restriction being the total power of the supply terminals at the supply point. 
   One advantageous development of an embodiment of the invention is provided if a further busbar block is connected to at least one of the free ends of the busbar blocks by way of a further connecting plug. 
   One further advantageous embodiment is provided if the connecting plug is in the form of a dual lyre-shaped connecting plug having four lyre-shaped contacts per phase, of which two make contact with one of the busbars of the first busbar block and the other two make contact with the opposing busbar of the second busbar block. In this manner, a reliable supply of power is possible with low contact resistance. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages, features and details of the invention will become evident from the description of illustrated exemplary embodiments given hereinbelow and the accompanying drawings, which are given by way of illustration only and thus are not limitative of the present invention, wherein: 
       FIG. 1  shows a front view of a polyphase busbar system according to an embodiment of the invention for supplying power to two or more switching devices, 
       FIG. 2  shows a sectional illustration through the busbar system shown in  FIG. 1  in the region of the supply point, and 
       FIG. 3  shows a sectional illustration of the busbar system shown in  FIG. 1  in the region of the connection of two busbar blocks. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows a polyphase busbar system according to an embodiment of the invention for supplying power to switching devices  1 . The busbar system has a first polyphase busbar block  2  and a second polyphase busbar block  3 , which are each arranged above the switching devices  1  and are electrically connected to one another by a multipole connecting plug  4 . A supply point having two or more supply terminals  5  is permanently attached to the busbar block  2 , i.e. there is only a low non-reactive resistance between each busbar  6  of the busbar block  2  and the associated supply terminal  5 . As a result, there are only small contact current losses during operation. 
   The multipole connecting plug  4  is in the form of a dual lyre-shaped connecting plug having four lyre-shaped contacts  15  per phase which are electrically connected to one another. Two of the lyre-shaped contacts  15  make contact with one of the busbars  6  of the first busbar block  2 , the other two make contact with the opposing busbar of the second busbar block  3 . Further busbar blocks  7 ,  8  can be connected to the free ends of the two busbar blocks  2 ,  3 , as shown in  FIG. 1 , using multipole connecting plugs  4 . The number of possible switching devices  1  is in this case restricted by the total permissible power for which the supply point of the busbar system is dimensioned. 
     FIG. 2  shows, in cross section, the busbar block  2  and a switching device  1  in the region of the supply terminals  5 . The busbar block  2  having the three busbars  6  and the permanently attached supply terminals  5  are retained by a fixing block  9 . In accordance with  FIG. 1 , three switching devices  1  are snapped onto the fixing block  9  associated with the busbar block  2  using top-hat rails as the fixing device, only one of these three switching devices  1  being visible in  FIG. 2  owing to the sectional illustration. 
   There is in each case one continuous, electrically conductive connection  10  from the busbars  6  to the respective supply terminals  5 , on the one hand. Further, on the other hand, there are connections from the busbars  6  to connections  11  within the busbar block  2 , which serve the purpose of making the electrical connection with the connections  12  of the switching device  1 . The supply terminals  5  and the connections  11 ,  12  are all in the form of cage clamp spring terminals. 
   However, it is also possible to use screw connections for the switching devices  1 . In this case, the three-pole electrical connection to the switching device usually makes use of individual conductors. When dismantling a switching device having screw connections under stress, for reasons of safety the line to the busbar must first be detached using an insulated screwdriver. 
   The electrical connection between the connections  11  and  12  is made by way of a further connecting plug  13  using a simple plug connection. The cage clamp spring terminals  5  are used to supply power from the outside via the branch lines  14 . 
     FIG. 3  shows the busbar system shown in  FIG. 1  in the region of the connection of the two busbar blocks  2  and  3 . In  FIG. 3 , the components already known from  FIG. 2  have the reference numerals used in  FIG. 2 . In order to avoid repetition, only the differences from the illustration shown in  FIG. 2  are described below. Accordingly, the connecting plug  4  having the lyre-shaped contacts  15  is provided for each of the busbars  6 , as described above, for the electrical connection of the two busbar blocks  2 ,  3 . 
   When providing busbar blocks with and without supply terminals it is possible to connect up any desired number of outgoing branches or switching devices  1 . 
   Simple Example
         4 outgoing branches having a power of 4 kW; required is:
           1× a block of 4 busbars with a supply terminal   
               

   Extreme Example
         18 outgoing branches having a power of 1.5 kw; required are:
           1× a block of 4 busbars with a supply terminal   2× a block of 4 busbars without a supply terminal   2× a block of 3 busbars without a supply terminal   4× connecting plugs with dual lyre-shaped contacts.   
               

   Exemplary embodiments being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.