Patent Publication Number: US-7586058-B2

Title: Electrical switching apparatus, and ARC hood assembly and chimney therefor

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates generally to electrical switching apparatus and, more particularly, to arc hood assemblies for electrical switching apparatus, such as circuit breakers. The invention also relates to chimneys for circuit breaker arc hood assemblies. 
   2. Background Information 
   Electrical switching apparatus, such as circuit breakers, provide protection for electrical systems from electrical fault conditions such as, for example, current overloads, short circuits, abnormal voltage and other fault conditions. Typically, circuit breakers include housing, and an operating mechanism which opens separable electrical contacts to interrupt the flow of current through the conductors of an electrical system in response to such fault conditions as detected, for example, by a trip unit. 
   Some low-voltage circuit breakers, for example, have arc chute vents on a portion (e.g., without limitation, the top) of the housing. When the separable electrical contacts rapidly open, for example, in response to an overload or short circuit condition, an arc is created which generates gases that are expelled from the vents. The gases can be extremely hot, are at least partly ionized, and may carry debris, such as molten metal particles. Furthermore, the gases and debris can be electrically conductive and, therefore, can cause additional undesirable arcing between the circuit breaker and grounded electrically conductive features proximate the circuit breaker, including but not limited to, the metallic enclosure in which such circuit breakers are typically installed. The gases may also be expelled with explosive force and may, therefore, damage components of the enclosure. 
   Accordingly, switchgear enclosures are typically designed to include one or more channels in which arc gases can be directed for dissipation thereof. Some switchgear cabinets also include an insulated barrier, commonly referred to as an arc hood, which is mounted above the arc chute vents of the circuit breaker through which the arc gases are exhausted. The arc hood functions to manage the effects of the arc gases and, in particular, to cool and dissipate the arc gases within the arc hood. However, there is room for improvement in arc hoods and, in particular, with respect to the interface (e.g., seal) between the arc hood, and the circuit breaker housing and the arc chute vents of the circuit breaker. Specifically, proper sealing is required in order to resist the escape of arc gases through gaps or openings between the circuit breaker and the arc hood, and to thereby avoid undesirable consequences associated therewith such as, for example, arcing across the poles of the circuit breaker and/or damage to components of the circuit breaker. 
   There is, therefore, room for improvement in arc hood assemblies for electrical switching apparatus, such as circuit breakers. 
   SUMMARY OF THE INVENTION 
   These needs and others are met by embodiments of the invention, which are directed to an arc hood assembly and chimney therefor for electrical switching apparatus, such as circuit breakers, wherein such chimney is biased toward the circuit breaker housing in order to establish and maintain an effective seal between the arc hood assembly and the circuit breaker. 
   As one aspect of the invention, a chimney is provided for an arc hood assembly of an electrical switching apparatus including a housing and a number of arc chute vents structured to exhaust arc gases from the housing. The arc hood assembly includes a body having a first side facing the housing, and a second side disposed opposite the first side. The first side includes a number of apertures. The chimney comprises: a base structured to be disposed at or about a corresponding one of the number of arc chute vents; a duct structured to extend outwardly from the base and through a corresponding one of the number of apertures; and a plurality of resilient protrusions structured to movably couple the chimney to the first side of the body at or about the corresponding one of the number of apertures. When the arc gases are exhausted from the corresponding one of the number of arc chute vents, the duct is structured to receive the arc gases and direct them into the body of the arc hood assembly. The resilient protrusions are structured to bias the base toward engagement with the housing at or about the corresponding one of the number of arc chute vents, in order to resist the arc gases being undesirably discharged between the base and the housing. 
   The base may comprise a planar portion and an upturned collar extending outwardly from the planar portion. The resilient protrusions may be a first tab and a second tab. The first side of the body of the arc hood assembly may further include a first slot disposed proximate the corresponding one of the number of apertures, and a second slot disposed proximate the corresponding one of the number of apertures opposite the first slot. Each of the first tab and the second tab may extend outwardly from the planar portion of the base and through a corresponding one of the first slot and the second slot, and may include a barb structured to secure the chimney to the first side of the body of the arc hood assembly, without a number of separate fasteners. Each of the first slot and the second slot may have an edge, and each of the first tab and the second tab may further include a taper extending from at or about the planar portion of the base toward the barb. When the base engages the housing, the taper may engage a corresponding one of the edge of the first slot and the edge of the second slot, to bias the base toward the housing in order to resist the base becoming disengaged from the housing. 
   The base may further comprise a plurality of posts and a plurality of resilient elements, wherein the posts are structured to extend outwardly from the planar portion and toward the first side of the body of the arc hood assembly, and each of the resilient elements may be structured to be disposed on a corresponding one of the posts between the planar portion of the base and the first side of the body of the arc hood assembly. The bias elements may be structured to bias the chimney toward the housing. The chimney may be a single-piece molded member wherein the base, the duct, and the resilient protrusions comprise different segments of the single-piece molded member. 
   As another aspect of the invention, an arc hood assembly is provided for an electrical switching apparatus including a housing and a number of arc chute vents structured to exhaust arc gases from the housing. The arc hood assembly comprises: a body including a first side structured to face the housing and including a number of apertures, and a second side disposed opposite the first side; and a number of chimneys, each of the chimneys comprising: a base structured to be disposed at or about a corresponding one of the number of arc chute vents, a duct extending outwardly from the base and through a corresponding one of the number of apertures, and a plurality of resilient protrusions movably coupling such each of the chimneys to the first side of the body at or about the corresponding one of the number of apertures. When the arc gases are exhausted from the corresponding one of the number of arc chute vents, the duct is structured to receive the arc gases and direct them into the body of the arc hood assembly. The resilient protrusions are structured to bias the base toward engagement with the housing at or about the corresponding one of the number of arc chute vents, in order to resist the arc gases being undesirably discharged between the base and the housing. 
   As another aspect of the invention, an electrical switching apparatus comprises: a housing; separable contacts enclosed by the housing; an operating mechanism structured to open and close the separable contacts, which are structured to create an arc that generates arc gases when the separable contacts open; a number of arc chute vents disposed on the housing and being structured to exhaust the arc gases from the housing; and an arc hood assembly comprising: a body including a first side facing the housing, and a second side disposed opposite the first side, and a number of chimneys, the first side including a number of apertures, each of the chimneys comprising: a base structured to be disposed at or about a corresponding one of the number of arc chute vents, a duct extending outwardly from the base and through a corresponding one of the number of apertures, and a plurality of resilient protrusions movably coupling such each of the chimneys to the first side of the body at or about the corresponding one of the number of apertures. The arc gases are exhausted from the corresponding one of the arc chute vents, through the duct, and into the body of the arc hood assembly. The resilient protrusions bias the base toward engagement with the housing at or about the corresponding one of the number of arc chute vents, in order to resist the arc gases being undesirably discharged between the base and the housing. 
   The electrical switching apparatus may be a circuit breaker, wherein the housing of the circuit breaker further includes a cassette having a bottom, and first and second sides extending perpendicularly outwardly from the bottom. Each of the first and second sides of the cassette may include an end, and the circuit breaker may be disposed between the first and second sides of the cassette. The body of the arc hood assembly may be coupled to the first and second sides of the cassette at or about the end thereof. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
       FIG. 1  is an isometric view of a circuit breaker and an arc hood assembly therefor, in accordance with an embodiment of the invention, showing the circuit breaker operating mechanism, a pair of separable contacts, and an arc in block form; 
       FIG. 2  is a partially exploded isometric view of the circuit breaker and arc hood assembly therefor of  FIG. 1 ; 
       FIG. 3  is a partially exploded isometric view of the arc hood assembly of  FIG. 2 , also showing chimneys therefor, in accordance with an embodiment of the invention; 
       FIG. 4  is an isometric view of the underside of the arc hood assembly of  FIG. 2 , showing three chimneys therefor; 
       FIG. 5  is a sectional view taken along line  5 - 5  of  FIG. 4 , also showing a portion of one arc chute vent of the circuit breaker housing in simplified form in phantom line drawing; 
       FIG. 6  is an isometric view of one of the chimneys of  FIG. 5 ; 
       FIG. 7  is a close-up view of a portion of one of the chimneys, a portion of the arc hood assembly, and a portion of the arc chute vent of  FIG. 5 ; 
       FIG. 8  is an isometric, partially exploded view of a chimney in accordance with another embodiment of the invention; 
       FIG. 9  is a close-up sectional view of a portion of the chimney of  FIG. 8 , also showing a portion of the arc hood assembly; and 
       FIG. 10  is an isometric, partially exploded view of a chimney in accordance with another embodiment of the invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   For purposes of illustration, embodiments of the invention will be described as applied to low-voltage circuit breakers, although it will become apparent that they could also be applied to a wide variety of electrical switching apparatus (e.g., without limitation, circuit switching devices and other circuit interrupters, such as contactors, motor starters, motor controllers and other load controllers) other than low-voltage circuit breakers and other than low-voltage electrical switching apparatus. 
   Directional phrases used herein, such as, for example, left, right, top, bottom, upper, lower, front, back and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein. 
   As employed herein, the term “DIN rail” refers to any known or suitable connecting structure for mounting and/or electrically connecting a number of components (e.g., without limitation, electrical terminals) to an electrical switching apparatus, wherein the structure is designed to satisfy standards established by Deutsches Insitut für Normung eV (DIN), which is a standard-setting organization for Germany. 
   As employed herein, the term “fastener” shall mean a separate element or elements which is/are employed to connect or tighten two or more components together, and expressly includes, without limitation, rivets, pins, screws, bolts and the combinations of bolts and nuts (e.g., without limitation, lock nuts) and bolts, washers and nuts. 
   As employed herein, the statement that two or more parts are “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. 
   As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality). 
     FIGS. 1 and 2  show an electrical switching apparatus such as, for example, a low-voltage circuit breaker  2 , and an arc hood assembly  100  therefor. The circuit breaker  2  includes a housing  4 , separable contacts  6  (shown in simplified form in hidden line drawing in  FIG. 1 ) enclosed by the housing  4 , an operating mechanism  10  (shown in simplified form in hidden line drawing in  FIG. 1 ), which is structured to open and close the separable contacts  6  ( FIG. 1 ), and a number of arc chute vents  20  ( FIG. 2 ; also partially shown in simplified form in phantom line drawing in  FIGS. 5 and 7 ) disposed on the housing  4  and being structured to exhaust arc gases  14  ( FIGS. 2 and 5 ) from the housing  4 . The arc gases  14  are generated from an arc  12  that is created when the separable contacts  6  open, as shown in simplified form in  FIG. 1 . 
   The housing  4  of the example circuit breaker  2  includes a first end  22 , a second end  24 , a first side  26 , a second side  28 , a front  30 , and a back  32 , and includes three arc chute vents  20  disposed at or about the first end  22 , as shown in  FIG. 2 . The example circuit breaker  2  is disposable within a cassette  170 , which in the example shown and described herein includes a bottom  172  and first and second sides  174 , 176  extending perpendicularly outwardly from the bottom  172 . When the circuit breaker  2  is disposed within the cassette  170 , as shown in  FIGS. 1 and 2 , the first side  26  of the circuit breaker  4  is disposed adjacent the first side  174  of the cassette  170 , and the second side  28  of the circuit breaker housing  4  is disposed adjacent the second side  176  of the cassette  170 . Thus, the second end  24  of the circuit breaker housing  4  is disposed adjacent the bottom  172  of the cassette  170 , and the first end  22  of the circuit breaker housing  4  is disposed at or about the ends  178 , 180  of the first and second sides  174 , 176  of the cassette  170 , as shown. As will be discussed, the ends  178 , 180  of the example cassette sides  174 , 176 , respectively include access holes  182 , 184  (both shown in  FIG. 2 ) to receive corresponding recesses  186 , 188  of the arc hood assembly  100 , when the arc hood assembly  100  is installed at or about the first end  22  of the circuit breaker housing  4 , as shown in  FIG. 1 . 
   When the circuit breaker  2  is fully installed within the cassette  170  beneath (with respect to  FIGS. 1 and 2 ) the arc hood assembly  100 , the arc hood assembly  100  is structured to engage and align with the first end  22  of the circuit breaker housing  4  and, in particular, the arc chute vents  20  ( FIG. 2 ) thereof. More specifically, as shown in  FIGS. 3-5 , the example arc hood assembly  100  includes a body  102  having a first side  104  structured to face the circuit breaker housing  4  (best shown in  FIG. 2 ) and including a number of apertures  106  ( FIGS. 3 ,  5  and  7 ), and a second side  108  disposed opposite the first side  104 . A chimney  200  is disposed in each of the apertures  106 , as best shown in the cross-sectional view of  FIG. 5 . The example arc hood assembly  100  includes three apertures  106  and three chimneys  200  therefor. One of the chimneys  200  will now be described in greater detail. It will, however, be appreciated that the other two chimneys  200  are substantially identical in the example shown and described herein. Also, it will be appreciated that any known or suitable number and/or configuration of chimneys (e.g., without limitation, chimney  200  of  FIGS. 3-7 ; see also chimneys  300  and  400  of  FIGS. 8-9  and  10 , respectively) could be employed, without departing from the scope of the invention. 
   As shown in  FIGS. 5-7 , each of the example chimneys  200  includes a base  202 , which is structured to be disposed at or about a corresponding one of the aforementioned arc chute vents  20  of the circuit breaker  2 , as partially shown in simplified form in phantom line drawing in  FIG. 5 . A duct  204  extends outwardly from the base  202  and through a corresponding one of the apertures  106 . A plurality of resilient protrusions, which in the example shown and described herein are first and second tabs  206 , 208  (both shown in  FIG. 6 ), movably couple each of the chimneys  200  to the first side  104  of the body  102  of the arc hood assembly  100  at or about the corresponding aperture  106  thereof, as shown in  FIG. 5 . Thus, when the arc gasses  14  (indicated by arrows  14  in  FIGS. 1 ,  2  and  5 ) are exhausted from the corresponding arc chute vent  20  ( FIG. 2 ), the duct  204  of the chimney  200  receives the arc gasses  14  and directs them into the body  102  of the arc hood assembly  100  to be cooled and dissipated therein. As will be discussed in greater detail hereinbelow, the first and second tabs  206 , 208  are structured to bias the base  202  toward engagement with the circuit breaker housing  4  (partially shown in simplified form in phantom line drawing in  FIG. 5 ) at or about the corresponding arc chute vent  20  (one arc chute vent  20  is shown in simplified form in phantom line drawing in  FIG. 5 ), in order to resist the arc gasses  14  being undesirably discharged between the base  202  and the housing  4 . Accordingly, it will be appreciated that the arc chute vent  20  is only shown in exaggerated form, slightly spaced apart from the base  202  of the chimney  200  in  FIG. 5 , for simplicity of illustration. 
   As best shown in  FIG. 6 , the base  202  of the example chimney  200  includes a planar portion  220  and an upturned collar  222 , which extends outwardly from the planar portion  220  toward the first side  104  of the body  102  of the arc hood assembly  100 , as shown in  FIGS. 3-5  and  7 . The chimney duct  204  extends outwardly from the planar portion  220 . The first and second tabs  206 , 208  of the example chimney  200  also extend outwardly from the planar portion  220  at or about the upturned collar  222  and generally parallel with respect to the duct  204 . The base  202  has a first end  224 , a second end  226  disposed opposite and distal from the first end  224 , a first edge  228 , and a second edge  230  disposed opposite and distal from the first edge  228 . Accordingly, it will be appreciated that the base  202  of the example chimney  200  is generally rectangular in shape, with the first tab  206  being disposed at or about the first edge  228  of the base  202 , and the second tab  208  being disposed at or about the second edge  230  of the base  202  opposite the first tab  206 , as shown. 
   Referring again to  FIG. 5 , and also to the close-up view of  FIG. 7 , it will be appreciated that the first side  104  of the body  102  of the arc hood assembly  100  further includes a first slot  110  disposed proximate the corresponding aperture  106 , and a second slot  112  ( FIG. 5 ) disposed proximate such aperture  106  opposite the first slot  110 . The first and second tabs  206 , 208  extend outwardly from the planar portion  220  of the base  202  and through the first and second slots  110 , 112 , respectively, as shown in  FIG. 5 . The first and second tabs  206 , 208  also include at least one barb  232 , 234  (first and second barbs  232 , 234  are shown for each chimney  200  in the sectional view of  FIG. 5 ; see also barbs  232 , 232 ′ and  234 , 234 ′ of  FIG. 6 ) for securing the chimney  200  to the first side  104  of the body  102  of the arc hood assembly  100 , without requiring a number of separate fasteners. 
   As shown in  FIG. 6 , the first and second tabs  206 , 208  of the example chimney  200  are each segmented to include two barbs  232 , 232 ′ and  234 , 234 ′, respectively. However, it will be appreciated that any known or suitable number and configuration of tabs (e.g., without limitation,  206 , 208 ) and barbs (e.g., without limitation,  232 , 232 ′, 234 , 234 ′) could be employed without departing from the scope of the invention, as will be described, for example, with respect to  FIGS. 8-10 , discussed hereinbelow. 
   Referring back to  FIG. 5 , and also to  FIG. 7 , the first slot  110  includes first and second edges  114 , 116 . Likewise, the second slot  112  ( FIG. 5 ) includes first and second edges  118 , 120  ( FIG. 5 ). The first and second tabs  206 , 208  (both shown in  FIG. 5 ) each include a taper  122 , 124 , respectively, extending from at or about the planar portion  220  of the base  202  toward the barb  232 , 234 . As best shown in  FIG. 7 , when the tab  206  is inserted through the corresponding first slot  110  in the body  102  of the arc hood assembly  100 , and the base  202  engages the circuit breaker housing  4  (partially shown in simplified form in phantom line drawing), and the taper  122  engages the corresponding one of the first and second edges  114 , 116  (taper  122  is engaging first edge  114  of the first slot  110  in  FIG. 7 ) of the slot  110 , the taper  122  biases the base toward the housing  4  in the direction generally indicated by arrow  240 . In this manner, the disclosed chimney  200  is resilient (e.g., spring-loaded), in order to establish and maintain an effective seal between the base  202  of the chimney  200  and the circuit breaker housing  4  and thereby resist the base  202  from becoming disengaged from the housing  4 , and undesirably allowing arc gasses  14  ( FIGS. 2 and 5 ) to escape therebetween. 
   It will be appreciated that the example chimney  200  is a single-piece molded member wherein the base  202 , duct  204 , and resilient protrusions (e.g., tabs  206 , 208 ) comprise different segments of the same piece of material that comprises the single-piece molded member  200 . However, as previously discussed, it will be appreciated that the chimney (e.g., without limitation,  200 ) could have any known or suitable alternative configuration in order to provide the desired seal between the chimney (e.g., without limitation,  200 ) and the circuit breaker housing  4 , as contemplated by the invention. For example and without limitation,  FIG. 8  shows an example chimney  300  in accordance with another embodiment of the invention wherein the chimney  300  includes a base  302  having a planar portion  320 , which is generally rectangular in shape, and includes first and second opposing ends  324 , 326  and first and second opposing sides  328 , 330 . Similar to chimney  200 , previously discussed hereinabove in connection with  FIGS. 3-7 , the chimney  300  further includes a duct  304 , first and second tabs  306 , 308 , and an upturned collar  322 , all of which extend outwardly from the planar portion  320  of the base  302  of the chimney  300 . 
   As shown in  FIG. 9 , the chimney  300  cooperates with the arc hood assembly  100 ′ and, in particular, aperture  106 ′ and slot  110 ′ on the first side  104 ′ of the body  102 ′ of the arc hood assembly  100 ′, in much the same manner as the tabs  206 , 208  of chimney  200 , previously discussed. However, rather than having a taper disposed on the external side of the tab (see, for example, taper  122  on the external side of the first tab  206  of  FIG. 7 ), tab  306  of chimney  300  includes a taper  122 ′ extending from at or about the planar portion  320  of the base  302  toward the barb  332 , on the interior side of the tab  306 . Accordingly, rather than engaging the first edge  114  of the first slot  110 , as shown in  FIG. 7 , taper  122 ′ of the first tab  306  of chimney  300  engages the second edge  116 ′ of the first slot  100 ′, as shown in  FIG. 9 , in order to bias the chimney  300  toward the circuit breaker housing  4  (not shown in  FIG. 9 ; see housing  4  shown in simplified form in phantom line drawing in  FIG. 7 ) in the direction generally indicated by arrow  340 . 
     FIG. 10  shows a chimney  400  in accordance with another embodiment of the invention. The chimney  400  includes a base  402  with a planar portion  420 , which is generally rectangular in shape and includes first and second opposing sides  424 , 426  and first and second opposing edges  428 , 430 , and a duct  404 , first and second tabs  406 , 408  and an upturned collar  422  all of which extend generally perpendicularly outwardly from the planar portion  420 , as shown. Each of the first and second tabs  406 , 408  comprises a portion of the duct  404 , and includes a corresponding barb  432 , 434 . In the example of  FIG. 10 , the chimney  400  also includes three posts  436 , which extend perpendicularly outwardly from the planar portion  420  of the base  402 , and receive resilient elements such as, for example and without limitation, the springs  438 , which are shown. More specifically, each spring  438  includes a plurality of coils  440 , and each post  436  is disposed through the coils  440  of a corresponding one of the springs  438 . Unlike chimneys  200  and  300  discussed hereinabove, it is the springs  438 , or other suitable resilient element (not shown), rather than the first and second tabs  406 , 408 , that function to bias the chimney  400  toward the circuit breaker housing  4  (not shown in  FIG. 10 ). Accordingly, chimney  400  provides an alternative mechanism to the aforementioned tapers  122 , 124  ( FIGS. 5 and 6 ),  122 ′, 124 ′ ( FIG. 8 ), to bias the chimney  400  and to maintain a seal between the chimney  400  and housing  4  (not shown in  FIG. 10 ), thereby resisting undesired escaping of arc gasses  14  ( FIGS. 2 and 5 ) therebetween. 
   The arc hood assembly  100  will now be discussed in greater detail with reference to  FIGS. 3-5 . Specifically, the example arc hood assembly  100  includes a top  130 , a bottom  132 , a fastening mechanism  136 , which in the example shown and described herein is a plurality of screws  136  (four are shown) securing the top  130  and bottom  132 , first and second opposing edges  138 , 140 , and first and second ends  142 , 144 . It will, however, be appreciated that any known or suitable alternative fastener (not shown), as defined herein, or fastening mechanism (not shown), could be employed in any known or suitable alternative number and/or configuration (not shown) without departing from the scope of the invention. 
   The example arc hood assembly  100  further includes a terminal mount  150  coupled to the first end  142  of the body  102 . The terminal mount  150  includes at least one protrusion  152 , 154  (two are shown), as shown in  FIGS. 3 and 4 . The protrusions  152 , 154  are structured to be coupled to the first end  22  of the circuit breaker housing  4  (see, for example, protrusion  152  partially shown engaging the first end  22  of circuit breaker housing  4  in  FIG. 1 ). Accordingly, when the arc hood assembly  100  is coupled to the circuit breaker  2 , as shown in  FIG. 1 , the first end  142  of the body  102  of the arc hood assembly  100  faces the front  30  of the circuit breaker housing  4 , and the second end  144  of the body  102  faces the back  32  of the circuit breaker housing  4 . The first edge  138  of the body  102  of the arc hood assembly  100  is generally aligned with the first side  32  of the circuit breaker housing  4 , and the second edge  140  is generally aligned with the second side  28  of the circuit breaker housing  4 . Also, when the first edge  138  of the body  102  of the arc hood assembly  100  is coupled to the end  178  of the first side  174  of the aforementioned circuit breaker cassette  170 , and the second edge  140  of the body  102  of the arc hood assembly  100  is coupled to the end  180  of the second side  176  of the cassette  170 , the first and second recesses  186  and  188 , are accessible through the aforementioned first and second recesses  182  and  184 , respectively, of the first and second cassette sides  174 , 176  (see, for example, recess  186  of arc hood assembly  100  accessible through access hole  182  of the cassette  170  in the example of  FIG. 1 ). In this manner, the recesses  186 , 188  may, for example, serve as handles for facilitating the manipulation (e.g., without limitation, transporting; lifting; inserting; withdrawing) of the circuit breaker  2 . 
   As shown in  FIG. 3 , the terminal mount  150  of the example arc hood assembly  100  further includes a DIN rail  156 , and a comb  158  that extends outwardly from the DIN rail  156  on the first end  142  of the body  102  of the arc hood assembly  100 . The comb  158  is structured to receive and secure a plurality of terminals such as, for example and without limitation, the user terminals  160  shown in the example of  FIGS. 1 and 2 . The DIN rail  156 , which is also partially shown in  FIGS. 1 and 2 , is preferably made of an electrically conductive material (e.g., without limitation, a suitable conductive metal) and, therefore, is structured to electrically connect such terminals  160  ( FIGS. 1 and 2 ) to the circuit breaker  2 . It will, however, be appreciate that the primary function of the disclosed arc hood assembly  100  (see also arc hood assembly  100 ′ partially shown in  FIG. 9 ) is to receive and dissipate arc gasses  14  ( FIGS. 1 ,  2  and  5 ) through the disclosed chimneys  200  ( FIGS. 3-7 ),  300  ( FIGS. 8 and 9 ),  400  ( FIG. 10 ), which are structured to resist the undesired escape of gasses between the arc hood assembly  100  ( FIGS. 1-5  and  7 ),  100 ′ ( FIG. 9 ) and circuit breaker housing  4  ( FIGS. 1 and 2 ; see also circuit breaker housing  4  partially shown in simplified form in phantom line drawing in  FIGS. 5 and 7 ). It will, therefore, be appreciated that any known or suitable alternative configuration of arc hood assembly (not shown) which employs such chimneys (e.g., without limitation,  200 , 300 , 400 ) in any known or suitable number and configuration, could be employed, without departing from the scope of the invention. It will, therefore, also be appreciated that certain components of the arc hood assembly  100  such as, for example and without limitation, the aforementioned terminal mount  150  and/or the protrusions  152 , 154 , the DIN rail  156 , the comb  158 , and the terminals  160  thereof, are not meant to be limiting aspects of the disclosed invention and, therefore, are not required. 
   While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.