Draw out unit

Abstract

A draw out unit mounts switching devices within a switchgear unit and electrically connects the switching devices to electrical bus bars. A cutout portion in draw out unit receives an insulative housing for a lug adapter assembly. Lug adapter assembly includes a plurality of clip assemblies positioned within receptacles formed on insulative housing. Each clip assembly slidably accepts one bus bar, thereby providing an electrical connection to bus bars. Lug adapter assembly also includes lugs, which are electrically connected to clip assemblies via a conductive bar. Lugs accept wires, which extend from lugs in switching device. Lugs are arranged to minimize bending of wires.

1 . A draw out unit arranged for mounting a switching device within a switchgear unit and electrically connecting the switching device to an electrical bus bar, the draw out unit comprising: 
 a frame arranged for supporting the switching device within the switchgear unit;    an insulative housing secured to said frame;    a clip assembly arranged within said insulative housing, said clip assembly for slidably receiving an edge of the bus bar;    a conducting plate electrically connected to said clip; and    a conductive lug electrically connected to said conducting plate, said lug being formed from a block of electrically conductive material, said conductive lug including    a first side having a first hole disposed therein for accepting a first electrical wire, said first electrical wire extending from an associated lug on the switching device, said first hole having an axis aligned with the associated lug, and    a second side having a second hole disposed therein for accepting a first set screw, said first set screw for securing said first wire within said first hole.    
     
     
         2 . The draw out unit of    claim 1    wherein said first side of said conductive lug includes: 
 a third hole disposed therein for accepting a second electrical wire, and said second side of said conductive lug includes a fourth hole for accepting a second set screw, said second set screw for securing said second wire within said third hole.  
 
     
     
         3 . The draw out unit of    claim 1    wherein said conductive lug further includes: 
 a third side, said third side having a shoulder formed thereon for contacting an edge of said conducting plate and aligning said conductive lug with said conducting plate.  
 
     
     
         4 . The draw out unit of    claim 1   , wherein said clip assembly includes: 
 a first clip arranged for slidably receiving said edge of the bus bar; said first clip including    a first contact arm arranged for contacting a first side of the bus bar, and    a second contact arm arranged for contacting a second side of the bus bar opposite said first side, said first and second contact arms extending a first distance from said edge; and    a second clip arranged for slidably receiving said edge of the bus bar, said second clip including    a third contact arm arranged for contacting said first side of the bus bar, and    a fourth contact arm arranged for contacting said second side of the bus bar opposite said first side, said third and fourth contact arms extending a second distance from said edge, said second distance being less than said first distance.    
     
     
         5 . The draw out unit of    claim 4   , wherein said first and third contact arms are formed from a first piece of electrically conductive material, and said second and fourth contact arms are formed from a second piece of electrically conductive material.  
     
     
         6 . The draw out unit of    claim 5   , wherein said clip assembly further includes: 
 a first common root portion formed from said first piece of electrically conductive material, said first and third contact arms extending from said first common root portion;    a first base portion formed from said first piece of electrically conductive material, said first base portion extending from said common root portion and contacting said conducting plate;    a second common root portion formed from said second piece of electrically conductive material, said second and fourth contact arms extending from said second common root portion; and    a second base portion formed from said second piece of electrically conductive material, said second base portion extending from said common root portion and contacting said conducting plate, said first root portion being attached to said second root portion.    
     
     
         7 . The draw out unit of    claim 5   , further including: 
 a common root portion formed from said first piece of electrically conductive material, said first and second contact arms extending from said common root portion, and wherein said first and second contact arms each have a first width where said first and second contact arms join said root portion, and said first and second contact arms each have a second width at a free end of said first and second contact arms, said first    width being greater than said second width.    
     
     
         8 . A draw out unit arranged for mounting a switching device within a switchgear unit and electrically connecting the switching device to an electrical bus bar, the draw out unit comprising: 
 a conductive lug including a first side having a first hole disposed therein for accepting a first electrical wire, said first electrical wire extending from an associated lug on the switching device, said first hole having an axis aligned with the associated lug, and a second side having a second hole disposed therein for accepting a first set screw, said first set screw for securing said first wire within said first hole, the axis of the first hole being perpendicular to an axis of the second hole.    
     
     
         9 . The draw out unit of    claim 8    wherein said first side of said conductive lug further comprises a third hole disposed therein for accepting a second electrical wire, and said second side of said conductive lug further comprises a fourth hole for accepting a second set screw, said second set screw for securing said second wire within said third hole.  
     
     
         10 . The draw out unit of    claim 9    further comprising a conducting plate, wherein said conductive lug further comprises a third side, said third side having a shoulder formed thereon for contacting an edge of said conducting plate and aligning said conductive lug with said conducting plate.  
     
     
         11 . The draw out unit of    claim 10    wherein the conductive lug further comprises a tab having a fifth hole, the fifth hole for receiving a retaining bolt securing the conducting plate to the conductive lug.  
     
     
         12 . The draw out unit of    claim 9    wherein the second hole and the fourth hole are threaded.  
     
     
         13 . The draw out unit of    claim 9    wherein the second side of the conductive lug is sloped and wherein the second hole and the fourth hole are offset from each other.  
     
     
         14 . The draw out unit of    claim 9    wherein the longitudinal axis of the second hole and a longitudinal axis of the fourth hole are parallel, and wherein the longitudinal axis of the first hole and a longitudinal axis of the third hole are parallel.  
     
     
         15 . The draw out unit of    claim 8    further comprising a switching device, the switching device having a switching device lug as the associated lug.  
     
     
         16 . The draw out unit of    claim 15    wherein the switching device is a circuit breaker.  
     
     
         17 . An electrical distribution system comprising a switchgear, the switchgear comprising a plurality of draw out units and a bus bar, each draw out unit comprising: 
 a switching device having a switching device lug;    a frame arranged for supporting the switching device within the switchgear;    an insulative housing secured to the frame;    a clip assembly arranged within the insulative housing, the clip assembly for slidably receiving an edge of the bus bar;    a conducting plate electrically connected to the clip;    a conductive lug electrically connected to the conducting plate; and,    a first electrical wire connecting the switching device lug to the conductive lug.    
     
     
         18 . The electrical distribution system of    claim 17    wherein the frame of each draw out unit includes a bottom side, the clip assembly extending from the bottom side, and further wherein the first electrical wire is securable within the conductive lug through a top side of the frame.  
     
     
         19 . The electrical distribution system of    claim 17    wherein the insulative housing of each draw out unit comprises a plurality of receptacles for receiving a plurality of clip assemblies.  
     
     
         20 . The electrical distribution system of    claim 17    wherein the insulative housing of each draw out unit includes a pair of spaced apart walls for receiving the conducting plate.  
     
     
         21 . A draw out unit arranged for mounting a switching device within a switchgear unit and electrically connecting each phase of the switching device to a separate electrical bus bar, the draw out unit comprising: 
 a frame arranged for supporting the switching device within the switchgear unit;    a plurality of clip assemblies, each clip assembly for slidably receiving an edge of a bus bar; and,    an insulative housing secured to the frame, the housing having a plurality of receptacles, each receptacle receiving a clip assembly.    
     
     
         22 . The draw out unit of    claim 21    wherein the insulative housing includes a plurality of dowels for placing within holes of the frame.  
     
     
         23 . The draw out unit of    claim 21    wherein the insulative housing includes a pair of mounting guides.  
     
     
         24 . The draw out unit of    claim 23    wherein each mounting guide includes a slot for slidably accepting a portion of the frame.  
     
     
         25 . The draw out unit of    claim 21    further comprising a conducting plate in electrical contact with the clip assemblies, the insulative housing comprising an opening for receiving the conducting plate.  
     
     
         26 . The draw out unit of    claim 21    wherein each receptacle is formed by an upper wall, a lower wall, and a pair of side walls.  
     
     
         27 . The draw out unit of    claim 26    wherein each upper and lower wall includes a V-shaped cutout.