Abstract:
An improved circuit breaker for electric panelboards is configured to facilitate replacement of an existing circuit breaker when its buss bar mount is damaged due to circuit overload or other fault conditions. The improved circuit breaker has an extension section that extends the breaker housing to a buss bar connector on a distally positioned buss bar and an electrical connector in the extension section that engages the distal bar connector thereon. The improved circuit breaker is provided with a cavity on the bottom side thereof that is sized and configured to substantially straddle the damaged buss bar connector on the proximally positioned buss bar, to which the replaced circuit breaker was originally connected. In an alternative embodiment, preferably configured for twin or quad circuit breakers, a second electrical connector is provided in the cavity to engage a non-damaged proximal bar connector to better divide the electrical draw between buss bars.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    None. 
       BACKGROUND OF THE INVENTION 
       [0002]    A. Field of the Invention 
         [0003]    The field of the present invention relates generally to electric power distribution systems utilizing a panelboard having two or more power supply buss bars to deliver electrical power to one or more electrical circuits. More particularly, the present invention relates to circuit breakers utilized in such panelboards. Even more particularly the present invention relates to circuit breakers configured to either utilize more than one buss bar or straddle a damaged portion of one of the buss bars. 
         [0004]    B. Background 
         [0005]    Electrical power delivered to residential, commercial and industrial buildings from a source of electrical power, such as an electrical generating station via transmission lines, generally passes through the building&#39;s electrical power distribution system to distribute electricity to a plurality of individual branch circuits in the building so as to provide power for lights, machines and other electrical uses. The typical electrical power distribution system has a panelboard that interconnects input wires from the transmission system to the building&#39;s branch circuits. Disposed between the input wires and the branch circuits are circuit interrupters that are configured to protect the building&#39;s branch circuits and the items connected thereto from power overloads and fault conditions. The most commonly utilized circuit interrupters are circuit breakers that comprise contacts which electrically connect to the panelboard, contacts that attach to the electrical circuit and an operating mechanism disposed therebetween that automatically electrically disconnects the two contacts upon determination of an electric overload or fault condition. The standard circuit breakers also include an external switching mechanism that allows the user to selectively disconnect electrical power delivery to the attached branch circuit. A number of different circuit breaker configurations are commonly available and the internal operation and use thereof are well known to those skilled in the art of such devices. For instance, in one configuration, commonly referred to as a twin breaker or dual breaker, the circuit breaker is effectively two breakers joined together to share a single electrical connector. In another configuration, a quad breaker has four breakers joined together to share two electrical connections. 
         [0006]    The typical panelboard has a plurality of main power supply buss bars that connect to the branch circuits and a main service disconnect circuit breaker that allows the user to interrupt the delivery of electrical power from the transmission lines to the buss bars and, therefore, all of the building&#39;s branch circuits. The buss bar is configured as a conductor, typically made out of copper or aluminum, that serves as the common connection for two or more branch circuits. The electrical contact portion of the circuit breakers are adapted to electrically connect to the buss bars. As well known in the art, there are a variety of different types of panelboards and circuit breakers that utilize different configurations for the electrical and physical connection between the circuit breakers and the buss bars. In one common configuration, which is primarily utilized for a residential meter/breaker combination panel, the buss bars are provided with a plurality of outwardly projecting buss bar connectors or posts that the electrical connector portion of a circuit breaker engages to obtain the necessary electrical contact and to secure the circuit breaker in the panelboard. In this configuration, the circuit breaker is provided with a plug-on jaw at one end and a rail connector at the opposite end, typically referred to as the wire terminal end, where the branch circuit connects. The plug-on jaw is configured to engage the buss bar connector. The rail connector is configured to engage a mounting rail running parallel to the buss bar. Typically, the rail connector of the circuit breaker engages the mounting rail in a manner that allows the user to pivot the circuit breaker down toward the buss bar so that the plug-on jaw securely engages the buss bar connector. 
         [0007]    Panelboards are provided with either a single column or row of circuit breaker locations or provided with multiple columns or rows of such locations. The typical panelboard has two parallel, spaced apart power supply buss bars, a parallel mounting rail and one or more neutral or ground buss bars per column or row of circuit breaker locations. The power supply buss bars, neutral buss bars and mounting rails are fixed to the inside bottom of an open front panel box, which is enclosed by a cover plate, occasionally referred to as a dead front cover. The cover plate has a plurality of knock-out panels through which, when the panels are knocked out, the front of the circuit breaker extends to allow the user access to the manual disconnect switch thereon. In circumstances where not all of the circuit breaker locations in a column or row are being utilized, the user simply leaves the knock-out panels in place, thereby covering up this section of the buss bar. In single column or row configurations, the circuit breaker extends from the single mounting rail to engage the plug-on jaw with the first or proximal buss bar connector, that being the one positioned nearest the mounting rail. The distal buss bar and its connectors, not being utilized for circuit breakers, are covered up by a portion of the cover plate. In most meter/breaker combination panels, the manufacturer utilizes a standardized buss bar, which is the same buss bar used in sub-panels wherein both sides are being utilized. Generally, the manufacturer also produces a twin or duplex circuit breaker that is configured to mount on a single buss bar that was originally designed for one full sized breaker. This results in two circuits being fed from a location (i.e., having the same surface area for the connection) that was originally only configured for one circuit. 
         [0008]    Unfortunately, an overload or fault situation or corrosion can result in one or more buss bar connectors being burned or otherwise damaged, resulting in the inability to transfer electrical current through to the circuit breaker and the branch circuit in the building. If there is an empty portion of the buss bar available, the user would connect the affected branch circuit to a new circuit breaker and then place the new circuit breaker in the position of one of the unused buss bar connectors. Alternatively, the user could install a twin breaker or a quad breaker to double up on an available bussing. If, as is frequently the situation, there are no unused buss bar connector locations in the panelboard to connect the affected branch circuit, then the user must replace or have replaced the entire panelboard or add an additional sub-panel in order to re-feed the circuits. Replacing an entire panelboard and/or adding a sub-panel is labor intensive and requires purchase of a new panelboard, making it quite costly. An alternative approach, heretofore unavailable, would be to utilize the buss bar connectors on the adjacent buss bar. 
         [0009]    What is needed, therefore, is an improved circuit breaker that is configured to fit in place of the existing circuit breaker but utilize the buss bar connector on the distal buss bar instead of the connector on the damaged proximal buss bar. The preferred circuit breaker should be configured to straddle or otherwise bypass the damaged buss bar connector on the proximal buss bar and connect instead to the buss bar connector on the distal buss bar. The preferred circuit breaker should be sized and configured to be positioned under the breaker cover without replacement thereof. Also, for a dual/duplex breaker or quad breaker configuration, the preferred circuit breaker can be configured to connect to the buss bar connectors on both the proximal and distal buss bars, assuming the buss bar connector on the proximal bar is not damaged, thereby assuring contact with the same amount of surface area as a full sized breaker. 
       SUMMARY OF THE INVENTION 
       [0010]    The replacement circuit breaker for electrical panelboards of the present invention solves the problems and provides the benefits identified above. That is to say, the present invention discloses a new and improved circuit breaker that provides a preferred alternative to adding a sub-panel or replacing a panelboard when all of the buss bar connectors are being utilized and one of the connectors is damaged or otherwise becomes unuseable. The improved circuit breaker of the present invention is sized and configured to extend from the mounting rail to the distal buss bar to connect the electrical connector to the buss bar connector thereon in a manner that straddles and bypasses the damaged buss bar connector on the proximal buss bar. The improved circuit breaker substantially reduces the costs of repairing a damaged panelboard. The improved circuit breaker can also be configured to provide an improved twin breaker by allowing each of the joined circuit breakers to directly connect to a buss bar connector instead of having to share a single buss bar connector, thereby greatly decreasing the likelihood of damage even occurring. 
         [0011]    In one general aspect of the present invention, the improved circuit breaker has a breaker housing with a terminal end that connects to a branch circuit to deliver electricity to the structure and a connector end that connects to a power buss bar mounted on the bottom wall of the panelboard&#39;s box section. The terminal end is adapted to connect, preferably in a pivotal manner, to a mounting rail. The standard panelboard has a pair of parallel buss bars positioned parallel to the mounting rail, one located proximally thereto and one located distally thereto. The prior art circuit breaker engages a proximal bar connector on the proximal buss bar. The improved circuit breaker of the present invention has an extension section that extends the breaker housing to the distal buss bar. A distal electrical connector located in the extension section near the connector end of the circuit breaker engages a distal bar connector on the distal buss bar. A cavity is provided on the bottom side of the breaker housing to allow the circuit breaker to substantially straddle the damaged proximal bar connector on the proximal buss bar. Other than the addition of the extension section and the cavity, the circuit breaker can be made of the same materials and components as existing or prior art circuit breakers and be configured to engage a variety of different types of buss bar connectors. Use of the improved circuit breaker allows the user to effectively bypass the damaged proximal bar connector on the proximal buss bar, thereby eliminating the need to replace an entire panelboard when other circuit breaker positions are not available. In an alternative embodiment, a second electrical connector is provided in the cavity to connect to a non-damaged proximal bar connector to provide additional surface area contact for the electrical connection. The alternative embodiment is particularly useful for twin and quad type circuit breakers that would normally have to share a single buss bar connector and for larger amperage circuit breakers (which tend to be more susceptible to overload damage). 
         [0012]    In accordance with one aspect, the present invention provides a replacement circuit breaker for electric panelboards that provides the advantages discussed above and overcomes the disadvantages and limitations associated with presently available circuit breakers. 
         [0013]    In accordance with another aspect, the present invention provides an improved circuit breaker that facilitates replacement of a circuit breaker in an electric panelboard that has a buss bar connector damaged due to circuit overload or other fault condition when no other circuit breaker positions are available. 
         [0014]    In accordance with another aspect, the present invention provides an improved circuit breaker that has a breaker housing with an extension section that extends the electrical connector at the connector end of the housing to connect to a distal bar connector on an unused distal buss bar, identified relative to the parallel mounting rail, and a cavity that substantially straddles the previously utilized, and now damaged, proximal bar connector on a proximally located buss bar. 
         [0015]    The present invention provides an improved circuit breaker that has an extension section to extend the breaker housing to a distally located buss bar, a distal electrical connector to engage a bar connector on the distal buss bar, a cavity to substantially straddle the proximally positioned buss bar and a proximal electrical connector to engage a bar connector on the proximal buss bar. 
         [0016]    The above and other aspects of the present invention will be explained in greater detail by reference to the attached figures and the description of the preferred embodiment which follows. As set forth herein, the present invention resides in the novel features of form, construction, mode of operation and combination of processes presently described and understood by the claims. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    In the drawings which illustrate the preferred embodiments and the best modes presently contemplated for carrying out the present invention: 
           [0018]      FIG. 1  is side view of a circuit breaker configured according to a preferred embodiment of the present invention particularly showing the location of the distal electrical connector relative to the cavity on the bottom side of the breaker housing; 
           [0019]      FIG. 2  is a bottom plan view of the circuit breaker of  FIG. 1 ; 
           [0020]      FIG. 3  is a top perspective view of a circuit breaker configured according to the present invention shown positioned in a typical electric panelboard; 
           [0021]      FIG. 4  is a bottom plan view of an alternative embodiment of the circuit board of the present invention showing a cavity disposed in the middle of the bottom side of the housing; and 
           [0022]      FIG. 5  is a bottom plan view of an alternative embodiment of the circuit breaker of the present invention showing an electrical connector disposed in the cavity. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    With reference to the figures where like elements have been given like numerical designations to facilitate the reader&#39;s understanding of the present invention, the preferred embodiments of the present invention are set forth below. The enclosed figures and drawings are merely illustrative of a preferred embodiment and represent one of several different ways of configuring the present invention. Although specific components, materials, configurations and uses are illustrated, it should be understood that a number of variations to the components and to the configuration of those components described herein and in the accompanying figures can be made without changing the scope and function of the invention set forth herein. For instance, although the figures and description provided herein are primarily directed to a single pole circuit breaker, those skilled in the art will readily understand that this is merely for purposes of simplifying the present disclosure and that the present invention is not so limited, as the present invention is equally applicable for multiple pole circuit breakers, such as twin/duplex or quad circuit breakers. 
         [0024]    A circuit breaker that is manufactured out of the components and configured pursuant to a preferred embodiment of the present invention is shown generally as  10  in the figures. The primary embodiment of the present invention is best shown in  FIGS. 1 and 2 , with circuit breaker  10  having a molded breaker housing  12  with a wire terminal end  14  and a connector end  16 . Typically, breaker housing  12  is made from plastic or like materials. As with standard prior art circuit breakers, circuit breaker  10  of the present invention is configured with circuit connector mechanism  18  at wire terminal end  14  to connect to a branch circuit, not shown, that distributes electricity throughout a house, commercial building or other structure from a source of electricity, also not shown, such as an electrical generating facility via transmission lines. Typically, but not exclusively, circuit connector mechanism  18  comprises a screw or bolt that threadably engages the operative circuit passing/breaking mechanism, shown generally as  19  in  FIGS. 1 and 2 , located in the interior of breaker housing  12 , as enclosed by top side  20 , bottom side  22  and first side wall  24  and opposing second side wall  26 . The configuration and operation of various circuit passing/breaking mechanisms  19  suitable for use with circuit breaker  10  of the present invention are well known to those skilled in the art and is not set forth herein. As readily understood by those skilled in the art, in normal operation the circuit passing/breaking mechanism allows electrical current to pass through circuit breaker  10  to a branch circuit unless there is a circuit overload or other fault, which automatically triggers the mechanism to electrically isolate the branch circuit from the source of electricity. As with standard circuit breakers, circuit breaker  10  includes a manual switch  28  on the top side  20  of breaker housing  12  that allows the user to manually engage the breaking mechanism to electrically isolate the branch circuit from the source of electricity. 
         [0025]    Circuit breaker  10  of the present invention is configured for use with an electrical panelboard, as exemplified by panelboard  30  shown in  FIG. 3 , generally comprising a box section  32  and cover plate  34 . Box section  32  has a bottom wall  36  and a plurality of upstanding side walls  38  at the periphery thereof. Received into box section  32  are conductor wires  40  that connect to the electrical transmission system to bring electricity to panelboard  30 . Once in box section  32 , conductor wires  40  typically connect to a master circuit breaker  42  that supplies power to a pair of main power supply buss bars, identified as proximal buss bar  44  and distal buss bar  46 , as identified by their positions relative to mounting rail  48 . Proximal buss bar  44  and distal buss bar  46  are in spaced apart relation, although located relatively close to each other, and are positioned on bottom wall  36  parallel to each other and to mounting rail  48 . Typically, the components are connected to and/or incorporated into a separate molded component that properly positions them relative to each other in box section  32 . Master circuit breaker  42  includes a manually operative master switch  50  that allows the user to disconnect all electrical power to proximal  44  and distal  46  buss bars and, therefore, all of the branch circuits connected thereto. Also mounted to the bottom wall  36  of box section  32  is a neutral buss bar  52  which connects the various circuits and components of panelboard  30  to ground. Proximal buss bar  44  has a plurality of proximal bar connectors  54  and distal buss bar  46  has a plurality of distal bar connectors  56  suitable for engagement by circuit breaker  10 , as set forth in more detail below. Cover plate  34  attaches to box section  32  to enclose the components therein. The master switch  50  of master circuit breaker  42  extends outwardly through master switch opening  58  in cover plate  34 . Cover plate  34  also includes a plurality of knock-out plates  60  that can be removed to provide one or more plate openings  62  (one shown open in  FIG. 3 ) for the reduced width section  64  of circuit breaker  10  to extend therethrough for easy access to manual switch  28 . 
         [0026]    As with the typical configuration of prior art circuit breakers, wire terminal end  14  of circuit breaker  10  has a rail engagement mechanism, shown as  66  in  FIG. 1 , configured to removably engage mounting rail  48 . In a standard configuration, mounting rail  48  has a plurality of engagement tabs  68 , shown in  FIG. 3 , that extend outwardly from mounting rail  48  toward proximal buss bar  44  that are adapted to be engaged by rail engagement mechanism  66 . As shown in  FIG. 1 , rail engagement mechanism  66  can comprise a shaped and configured area of the wire terminal end  14  of breaker housing  12 . As with standard prior art circuit breakers, rail engagement mechanism  66  is configured to allow the user to engage tabs  68  and pivot circuit breaker  10  downward toward the appropriate proximal bar connector  54  on proximal buss bar  44 . Standard prior art circuit breakers are configured with an electrical connector that engages one of the proximal bar connectors  54  on proximal buss bar  44  in a manner that provides a electrical connection with the circuit breaker and which secures the circuit breaker inside box section  32  of panelboard  30 . The distal bar connectors  56  on distal buss bar  46  are not utilized by prior art circuit breakers. Instead, the distal bar connectors  56  and distal buss bar  46  are covered by cover plate  34 . 
         [0027]    In the standard prior art configuration, when the user wants or needs to replace a circuit breaker he or she merely pulls back on the circuit breaker to break the connection with proximal bar connector  54 , pivots the circuit breaker toward the mounting rail  48  and then removes the circuit breaker from the box section  32 . When a proximal bar connector  54  is damaged by overload or other fault condition, the user only has to attach the branch circuit to a new circuit breaker and move the circuit breaker to a new area of the box section  32  and connect the circuit breaker to an unused rail engagement mechanism  66  of mounting rail  48  and to proximal buss bar  44 . As described above, however, it is common for all of the circuit breaker locations to be in use, meaning there are no combination mounting rail  48  and proximal buss bar  44  areas open for a new circuit breaker. In this circumstance, the entire panelboard  30  must be replaced. As this requires a person of considerable skill in the area of electrical systems, replacing panelboard  30  can be somewhat costly. 
         [0028]    Circuit breaker  10  of the present invention eliminates the need to replace panelboard  30  under the above-identified circumstances. As set forth in more detail below, circuit breaker  10  allows the user to utilize the heretofore unused distal buss bar  46  to electrically connect the incoming electricity with the subject branch circuit. As shown in  FIG. 1 , circuit breaker  10  has an extended section  70 , shown with the bracket and the dash-dot line, in which is positioned distal electrical connector  72  configured to engage and electrically contact one of the distal bar connectors  56 .  FIG. 3  shows circuit breaker  10  mounted in box section  32  of panelboard  30 . Distal electrical connector  72  can be any of the types of electrical connectors commonly available that are utilized in prior art circuit breakers and be positioned at bottom side  22  at or near connector end  16  of circuit breaker  10  (i.e., disposed in a connector cavity at or near connector end  16 ). As known to those skilled in the art, distal electrical connector  72  must be cooperatively configured with distal bar connector  56  to both physically attach and provide the necessary electrical contact. Distal electrical connector  72  is the same type of electrical connector that connects to proximal bar connector  54  in the prior art circuit breaker. As further known to those skilled in the art, the replacement circuit breaker  10  of the present invention must be provided with the same type of electrical connector that is being replaced due to a damaged proximal bar connector  54  for the type and configuration of panelboard  30  being utilized to properly distribute the electricity from conductor wires  40  to the various branch circuits in the structure. 
         [0029]    In order to utilize the replacement circuit breaker  10  of the present invention, the user must be able to bypass or skip over the existing damaged proximal bar connector  54 . To accomplish this, circuit breaker  10  is provided with a cavity  74  disposed on the bottom side  22  of breaker housing  12 . Cavity  74  must be sized and configured to substantially straddle the subject proximal bar connector  54  so that distal electrical connector  72  at the connector end  16  of circuit breaker  10  can be pivoted down onto and connect with the appropriate distal bar connector  56  on distal buss bar  46 . The specific size of cavity  74  will be dependent on the maximum size of proximal bar connector  54  which must be accommodated by cavity  74  and yet not be so large as to interfere with circuit mechanism  19  of circuit breaker  10  or substantially (i.e., unsafely) weaken breaker housing  12 . In the embodiment shown in  FIGS. 1 and 2 , cavity  74  extends across bottom side  22  from first side wall  24  to second side wall  26 . In the alternative embodiment shown in  FIG. 4 , cavity  74  is placed in the interior of bottom side  22  and does not extend all the way across. In the configuration of  FIG. 4 , cavity  74  must be sufficiently wide and long to be fully placed over proximal bar connector  54 , preferably without contact therewith. In this manner, when the user engages rail engagement mechanism  66  in mounting rail  48  and pivots circuit breaker  10  downward to lock it into place, as shown in  FIG. 3 , cavity  74  will be placed over and substantially straddle the upstanding (as typically utilized) proximal bar connector  54  on proximal buss bar  44  to engage the distal electrical connector  72  with distal bar connector  56  on distal buss bar  46 . 
         [0030]    The configuration of  FIGS. 1 ,  2  and  4 , described above, is useful for replacing an existing circuit breaker when the proximal bar connector  54  is damaged due to overload or other fault. The circuit breaker  10  of the present invention can also be configured to provide improved contact when using twin or quad circuit breakers. As set forth above, the current configuration is for both or all of the breakers to share a single proximal bar connector  54  on proximal buss bar  44 . As shown in  FIG. 5 , the circuit breaker  10  can be provided with a proximal electrical connector  76  disposed in cavity  74  to engage an undamaged proximal bar connector  54 . In this manner, each component of a twin breaker or only a pair of components for a quad breaker will have its own bar connector, with the proximal electrical connector  76  engaging proximal bar connector  54 .and distal electrical connector  72  engaging distal bar connector  56 , thereby providing an improved electrical connection and reducing the electrical load on an individual bar connector. 
         [0031]    In use, once the user removes the existing circuit breaker from the damaged proximal bar connector  54  in panelboard  30 , the replacement circuit breaker  10  of the present invention can be utilized by first engaging rail engagement mechanism  66  with mounting rail  48  and then pivoting circuit breaker  10  downward to engage distal electrical connector  72 , located in the extended section  70 , with distal bar connector  56  on distal buss bar  46 . Cavity  74  will substantially straddle the existing, damaged proximal bar connector  54  on proximal buss bar  44 , effectively isolating it from the useful distal bar connector  56 . Once engaged, electrical current will flow from distal buss bar  46  through circuit breaker  10  to the branch circuit connected thereto, thereby avoiding the need to replace panelboard  30  when each circuit breaker area is being utilized and one of the proximal bar connectors  54  becomes damaged due to overload or other fault condition. If circuit breaker  10  is configured as a twin or quad circuit breaker, then it will be supplied with a proximal electrical connector  76  in cavity  74  to also engage a non-damaged or functional proximal bar connector  54  on proximal buss bar  44 , thereby reducing the load on a single bar connector that exists with the use of existing twin or quad circuit breakers. 
         [0032]    While there are shown and described herein specific forms of the invention, it will be readily apparent to those skilled in the art that the invention is not so limited, but is susceptible to various modifications and rearrangements in design and materials without departing from the spirit and scope of the invention. In particular, it should be noted that the present invention is subject to modification with regard to any dimensional relationships set forth herein and modifications in assembly, materials, size, shape and use. For instance, there are numerous components described herein that can be replaced with equivalent functioning components to accomplish the objectives of the present invention.