Patent Publication Number: US-9406465-B1

Title: Polarity insensitive arc quench

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the protection of electrical devices, and more specifically, to arc extinguishing structures that are configured to rapidly extinguish an electrical arc regardless of the polarity of current through a circuit interrupter. 
     BACKGROUND OF THE INVENTION 
     Circuit interrupters are electrical components that are used to open an electrical circuit, interrupting the flow of current. A basic example of a circuit interrupter is a switch, which generally consists of two electrical contacts in one of two states; either closed, meaning that the contacts are in electrical contact with each other allowing electricity to flow between them, or open, meaning that the contacts are not in electrical contact with each other preventing the flow of electricity. A switch may be directly manipulated to provide a control signal to a system, such as a computer keyboard button, or to control power flow in a circuit, such as a light switch. 
     Another example of a circuit interrupter is a circuit breaker. A circuit breaker may be used, for example, in an electrical panel to limit the amount of current flowing through the electrical wiring. A circuit breaker is designed to protect an electrical circuit from damage caused by, for example, an overload, a ground fault or a short circuit. If a fault condition, such as, a power surge occurs in the electrical wiring, the breaker will trip. This will cause a breaker that was in an “on” position to flip to an “off” position and interrupt the flow of electrical power through the breaker. Circuit breakers are generally provided to protect the electrical wiring by limiting the amount of current transmitted through the wires to a level that will not damage them. Circuit breakers can also prevent destruction of the devices that may draw too much current. 
     A standard circuit breaker has a terminal connected to a source of electrical power, such as, a power line electrically connected to the secondary of a power company transformer, and second terminal electrically connected to the wires that the breaker is intended to protect. Conventionally, these terminals are referred to as the “line” and “load” respectively. The line is sometimes referred to as the input of the circuit breaker. The load, is sometimes referred to as the output of the circuit breaker, which connects to the electrical circuit and components receiving the electrical power. 
     A circuit breaker may be used to protect the electrical wiring that feeds an individual device, or a number of various devices. For example, an individual protected device, such as a single air conditioner, may be directly connected to a circuit breaker. Alternatively, circuit breaker may also be used to protect the wiring feeding multiple devices that may be connected to the circuit via various electrical outlets (e.g., various devices in a room each plugged into an outlet all on the same circuit). 
     A circuit breaker can be used as a replacement for a fuse. Unlike a fuse however, which typically operates to open in an over current situation once and then must be replaced; a circuit breaker can be “reset” (either manually or automatically) to resume operation. Fuses perform a similar role to circuit breakers, however, circuit breakers are easier to use and typically safer to service and operate. 
     In a situation where a fuse blows (open) thereby interrupting power to a circuit, it may not be apparent which of the multiple fuses in the panel, feeds the interrupted circuit. Typically, all of the fuses in the electrical panel would need to be inspected to determine which fuse is burned or spent. This fuse would then need to be removed and a new fuse installed. 
     Alternatively, in the situation where a circuit breaker trips, it is apparent which circuit breaker feeds the interrupted circuit by simply looking at the electrical panel and noting the breaker has tripped to the “off” position. This breaker can then be simply flipped to the “on” position and power will resume. 
     In general, a single pole circuit interrupter has two contacts positioned inside of a housing. The first contact is stationary and may be connected to either the line or the load. The second contact is movable with respect to the first contact, such that when the circuit breaker is in the “off” or tripped position, a gap exists between the first and second contact. 
     A problem with the above-described circuit interrupters arises when energized contacts are opened while under load. As the contacts separate transitioning from a closed to an open position, or when the opposition occurs, when the close transitioning from an open to a closed position, an electric arc may be formed in the gap. Arcs are caused when the breakdown voltage between the contacts is positively related to distance under pressure and voltage conditions in typical applications. 
     The creation of an arc during switching or tripping the circuit interrupter can result in undesirable effects that negatively affect the operation of the circuit interrupter, even potentially creating a safety hazard. 
     These negative effects can have adverse consequences on the operation of the circuit interrupter. 
     One possible consequence is that the arc may short to other objects in the circuit interrupter and/or to surrounding objects, causing damage and presenting a potential fire or safety hazard. 
     Another consequence of arcing is that the arc energy damages the contacts, causing some material to escape into the air as fine particulate matter. The debris which has been melted off of the contacts can migrate or be flung into the mechanism of the circuit interrupter, destroying the mechanism or reducing its operational lifespan. 
     Another effect of arcing stems from the extremely high temperature of the arc (tens of thousands of degrees Celsius), which can impact the surrounding gas molecules creating ozone, carbon monoxide, and other dangerous compounds. The arc can also ionize surrounding gasses, potentially creating alternate conduction paths. 
     Because of these detrimental effects it is very important to quickly cool and quench the arc to prevent damage to the circuit interrupter and the above-described dangerous situations. 
     Various techniques for improved arc quenching are known. For example, U.S. Published Patent Applications No. 2012/0037598 and 2012/0261382, assigned to Carling Technologies, Inc., variously relate to the use of an electromagnetic field to guide an arc toward an arc splitter. 
     However, generating an electromagnetic field to move an arc requires the use of power, and generates heat in the device. In order to avoid these negative issues, it has been conceived to incorporate a permanent magnet into the circuit interrupter, which produces a magnetic field without requiring a supply of electricity. However, permanent magnets produce a magnetic field having a fixed direction with respect to the magnet. Thus, known solutions for guiding an arc into an arc path using a permanent magnet are circuit polarity dependent. This is due to the fact that an magnetic field produced by a fixed permanent magnet has a fixed direction. As such, the mechanism for magnetically guiding the arc into the path depends upon the direction the current is flowing through the circuit interrupter. 
     This is a significant limitation, as it prevents such devices from being installed in a circuit where the electrical polarity of the circuit reverses, such as in a typical AC circuit. Hazardous conditions may also arise in a situation where such a device is accidentally installed backwards in that the magnetic field intended to be used to enhance arc quenching will, in fact, operate to drive the arc away from the arc path. 
     It is therefore desired to provide arc quenching usable with a circuit interrupter that overcomes the above-described limitations. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a circuit interrupter having an arc extinguisher that functions to arrest an arc between the circuit interrupter contacts regardless of the polarity of the circuit. 
     It is a further object of the present invention to provide a circuit interrupter having permanent magnets configured to drive an arc into an arc extinguisher regardless of the direction that current is flowing through the circuit interrupter. 
     These and other objectives are achieved by providing a circuit interrupter that includes a first contact and a second contact movable into and out of electrical contact with each other; an arc extinguisher; a permanent magnet disposed to guide an arc that develops between the contacts into the arc extinguisher regardless of a polarity of the contacts. 
     In some implementations, the arc extinguisher comprises a first arc path and a second arc path. The first arc path may extend in a direction substantially parallel to the second arc path, or substantially perpendicular to the second arc path. The permanent magnet may be disposed to drive the arc into the first arc path when a polarity of the first contact is positive, and is disposed to drive the arc into the second arc path when the polarity of the first contact is negative. 
     In some implementations, the permanent magnet comprises a first permanent magnet and the circuit interrupter further includes a second permanent magnet that is positioned such that the magnetic field produced by the second permanent magnet permeates the area in which the arc may form. The second permanent magnet may be positioned substantially opposite from the first permanent magnet such that the magnetic fields of the two permanent magnets interact to influence any arc that may develop in the vicinity of the contacts. 
     In some implementations, the permanent magnet is positioned such that the first contact is between the permanent magnet and the second contact. 
     In some implementations, the permanent magnet is a torridly shaped magnet. An axis of revolution of the torridly shaped magnet may intersect the first contact, and the torridly shaped magnet may surround a conductor that is in electrical contact with the first contact. The torrid may be a hollow cylinder or any other suitable torrid shape. In some implementations, the permanent magnet may be a hollow square or other suitable shape. 
     The circuit interrupter may include at least one pole piece disposed to direct a magnetic field of the permanent magnet. The at least one pole piece may be disposed to concentrate the magnetic field in an area where the arc is generated. 
     Still further, a first magnetic field produced by the permanent magnet interacts with a second magnetic field produced by the arc such that the arc is directed toward the arc extinguisher regardless of whether the arc is emitted from the first contact or the second contact. 
     In some implementations, the arc extinguisher comprises at least one plate for splitting the arc into a first arc path and a second arc path. The first arc path may comprise a first plate and the second arc path may comprise a second arc plate that is different from the first arc plate. The first arc path and the second arc path may comprise a common arc runner. The circuit interrupter may include a lower arc runner in electrical contact with the first contact and having a first tab extending beneath the first arc path and a second tab extending beneath the second arc path. 
     Objects of the invention may be achieved by provision of a circuit interrupter providing for arc suppression. The circuit interrupter may comprise a first contact electrically connectable to a power source and a second contact electrically connectable to a load. The circuit interrupter is provided such that the first and second contacts are movable between a closed and open position relative to each other. The circuit interrupter further comprises an arc extinguisher for extinguishing an arc that develops in the vicinity of the first and second contacts and a permanent magnet disposed adjacent to at least one of the contacts and generating a magnetic field that permeates an area where the arc develops. The circuit interrupter is provided such that the magnetic field directs the arc toward the arc extinguisher regardless of a polarity of the contacts 
     Other objects of the invention may be achieved by provision of a circuit interrupter providing for arc suppression. The circuit interrupter may comprise a first contact electrically connectable to a power source and a second contact electrically connectable to a load. The circuit interrupter is provided such that the first and second contacts are movable between a closed and open position relative to each other. The circuit interrupter further comprises an arc extinguisher for extinguishing an arc that develops in the vicinity of said first and second contacts, the arc extinguisher having a first arc path and a second arc path. The circuit interrupter still further comprises a first permanent magnet generating a first magnetic field and positioned on a side of the first contact opposite from the second contact, and a second permanent magnet generating a second magnetic field and positioned on a side of the second contact opposite from the first contact. The circuit interrupter is further provided such that the first and second magnetic fields interact with the arc so as to direct the arc to the arc extinguisher regardless of an instantaneous polarity of the contacts. 
     Other objects of the invention and its particular features and advantages will become more apparent from consideration of the following drawings and accompanying detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates components of an example circuit interrupter according to aspects of the invention. 
         FIG. 2  is an overhead view of a portion of the circuit interrupter shown in  FIG. 1 . 
         FIG. 3  is a perspective view of some of the components shown in  FIGS. 1 and 2 . 
         FIG. 4  is a side view of portions of the circuit interrupter  100  illustrated in  FIGS. 1, 2, and 3 . 
         FIGS. 5A and 5B  are overhead views of permanent magnets shown from the same perspective shown in  FIG. 2 . 
         FIG. 6  is an orthographic view which further illustrates portions of the example circuit interrupter described with respect to  FIGS. 1-5 . 
         FIG. 7  illustrates components of the example circuit interrupter described with respect to  FIGS. 1-6 , showing an alternative arrangement of certain parts of the polarity-independent magnetic arc extinguishment features according to aspects of the invention. 
         FIG. 8  illustrates an overhead view of components of example circuit interrupter as shown in  FIG. 7 . 
         FIGS. 9A and 9B  are overhead views of a permanent magnet shown from the same perspective shown in  FIG. 7 . 
         FIGS. 10A and 10B  are side views of the permanent magnet as shown in  FIGS. 9A and 9B . 
         FIG. 11  is a side view of portions of the implementation of circuit interrupter illustrated in  FIGS. 6, 7, 8A, 8B, 9A, and 9B . 
         FIG. 12  is an orthographic view which further illustrates portions of the example circuit interrupter as described with respect to  FIGS. 7-11 . 
         FIG. 13  illustrates components of the example circuit interrupter as described with respect to  FIGS. 7-12 , showing additional features. 
         FIG. 14  illustrates another example circuit interrupter  1200  according to aspects of the invention. 
         FIG. 15  shows portions of the example circuit interrupter shown in  FIG. 14 , further illustrating a portion of a magnetic field. 
         FIG. 16  is an orthographic view which further illustrates portions of the example circuit interrupter described with respect to  FIGS. 13-15 . 
         FIGS. 17A and 17B  show an example arrangement of certain components of the example circuit interrupters described regarding  FIGS. 1-16 . 
         FIGS. 18A and 18B  show another example arrangement of certain components of the example circuit interrupters described regarding  FIGS. 1-16 . 
         FIG. 19  shows an overhead view of certain components of example circuit interrupters described regarding  FIGS. 1-18 , illustrating an alternative venting arrangement according to aspects of the invention. 
         FIG. 20  shows an overhead view of certain components of example circuit interrupters described regarding  FIGS. 1-18 , illustrating another alternative venting arrangement according to aspects of the invention. 
         FIG. 21  shows an overhead view of certain components of example circuit interrupters described regarding  FIGS. 1-18 , illustrating a further alternative venting arrangement according to aspects of the invention. 
         FIG. 22  is an orthographic view of certain components of example circuit interrupters described regarding  FIGS. 1-18 , illustrating still another alternative venting arrangement according to aspects of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates components of an example circuit interrupter  100  having polarity independent magnetic arc extinguishment features according to aspects of the invention. 
     Circuit interrupter  100  may be any device which can be used to make and break an electrical circuit. For example, it will be clear to those of skill in the art that circuit interrupter  100  may comprise a switch, or may be implemented as a circuit breaker. 
     Circuit interrupter  100  includes stationary contact  110 , which is electrically connected to line terminal  120  via conductor  195 . The line terminal receives electrical power from a power source (not shown), which in some applications is supplied by a power company. It will, however, be understood by those of skill in the art that the power may be provided and conditioned by any commercial means including, but not limited to, a commercial electrical power grid, a generator(s), solar panels, fuel cells, and so on. In the present example, stationary contact  110  is connected to a lower arc runner  190 , as discussed in more detail below. Those of skill in the art will understand that lower arc runner  190  may be connected in a number of different configurations as desired without departing from aspects of the invention. 
     A movable contact  130  is disposed on a movable contact arm  140 , which is movable between a closed and an open position relative to the stationary contact  110 . In  FIG. 1 , contact arm  140  is shown in a closed position, with movable contact  130  physically contacting stationary contact  110 . 
     Movable contact  130  is connected to load terminal  150  through a conductor  160 . When contact arm  140  is in the closed position as shown, movable contact  130  is electrically connected to stationary contact  110  such that electrical current is allowed to flow between line terminal  120  and load terminal  150 . 
     Permanent magnets  170  and  170 ′ are disposed on opposite sides of the contacts  110 ,  130  and oriented to produce magnetic fields  180  through the region where an arc may form between contacts  110 ,  130 . 
     Contact arm  140  may be actuated via a switch, trip mechanism, and/or any other known mechanism (not shown) depending on the desired implementation of circuit interrupter  100 . 
     Permanent magnets  170 ,  170 ′ are shown arranged in the same plane of travel of contact arm  140 , but in a position where magnets  170 ,  170 ′ will not obstruct the travel of contact arm  140 , and at different heights with respect to the fixed contact  130 . This arrangement provides the advantage of creating magnetic fields  180  which maintain a desired field strength and direction over the expected travel path of an arc generated between contacts  110 ,  130 . While it has been found that the configuration illustrated in  FIG. 1  provides exemplary results, it will be understood that other arrangements of permanent magnets may be evident to those of skill in the art. In the example depicted in  FIG. 1 , magnets  170  and  170 ′ are oriented such that the individual magnetic fields produced by each magnet are additive such that a single, relatively strong magnetic field flows from one magnet to the other, although this may not be the case in other implementations. 
       FIG. 2  is an overhead view of a portion of the circuit interrupter  100  shown in  FIG. 1 , including additional components. 
     Lower arc runner  190  is shown extending perpendicularly to the contact arm  140 , and having tabs extending away from contact arm  140  in a curve converging on a parallel with contact arm  140 . Arc splitter plate  200  is shown arranged above lower arc runner  190  to one side of contact arm  140 . The shapes of lower arc runner  190  and arc splitter plate  200  are contemplated to electromagnetically draw an arc into the arc splitter plate  200 . These components are at least partially enclosed by housing  210 . 
     Arc splitter plate  200  forms a part of an arc path through the intended region  250  into which an arc (not shown) that may develop between contacts  110 ,  130  would be directed by magnets  170 ,  170 ′. The corresponding region  250 ′ would also contain an arc splitter plate (e.g.,  200 ′); however, this plate is omitted for clarity to clearly illustrate the configuration of lower arc runner  190 . 
     It will be evident to those of skill in the art that arc suppression is enhanced by the positioning and configuration of the arc splitter plates regardless of the polarity of the contacts. This arraignment further utilizes permanent magnets such that no electromagnetic energy is consumed and no additional heat is generated. 
     Housing  210  may include vents  220 ,  220 ′ to allow gasses and debris that may be produced by any arcing that occurs to escape housing  210 . 
       FIG. 3  is a perspective view of some components illustrated in  FIGS. 1 and 2 . Arc splitter plate  200  is shown positioned at an acute angle  300  relative to the lower arc runner  190 . One advantage of providing the arc splitter plate  200  at an angle is that it allows for provision of a larger surface area for arc splitter plate  200  (increasing the total size of the plate) while at the same time allowing for the plate to be positioned in the housing  210  that continues to be relatively small in size. The increased surface area of arc splitter plate  200  functions to increase the efficiency of the arc splitter plate. 
       FIG. 4  is a side view of portions of the circuit interrupter  100  illustrated in  FIGS. 1, 2, and 3 , illustrating still other components. 
     For example, arc splitter plate  200  is illustrated to be positioned at an acute angle  300  relative to lower arc runner  190 . Additional arc splitter plates  200 ′ and an upper arc runner  400  are shown stacked above arc splitter plate  200  to form an arc path in region  250 . 
     A corresponding set of arc splitter plates  200 ″ are illustrated positioned between lower arc runner  190  and upper arc runner  400  to form another arc path in region  250 ′. 
     It should be noted that while the arrangements of splitter plates in regions  250  and  250 ′ are described as two arc paths, one of skill in the art could describe the system as a single arc extinguisher. In practice, an arc that develops between stationary contact  110  and movable contact  130  will, at any particular moment in time, be drawn into one of the arc paths. The region into which the arc is drawn depends upon the polarity of the contacts  110 ,  130  at the given time. In other words, the region into which the arc is drawn depends upon the instantaneous direction of current flow between contacts  110 ,  130 . 
       FIGS. 5A and 5B  are top views of permanent magnets  170 ,  170 ′ and illustrate the effect of magnetic field  180  upon an arc developing between contacts  110 ,  130 . 
     For example, in  FIG. 5A , an arc  500 A is illustrated developing between stationary contact  110  and movable contact  130  (shown in  FIGS. 1-4 ) when contact  110  is in a first state of charge and contact  130  is in a second state of charge opposite to the first state of charge. This state gives rise to an electromagnetic field  510 A surrounding arc  500 A in a counter-clockwise direction indicated. Electromagnetic field  510 A interacts with magnetic field  180  to move arc  500 A in the direction illustrated by arrow  520 A (i.e., to the right in  FIG. 5A ). Referring to the corresponding structures in  FIG. 2 , this movement will drive the arc  500 A into the arc splitter plates  200 ″ of region  250 ′ ( FIG. 6 ) to be extinguished. 
     In  FIG. 5B , an arc  500 B is illustrated developing between stationary contact  110  from and movable contact  130  (shown in  FIGS. 1-4 ) when contact  110  is in a second state of charge and contact  130  is in a first state of charge opposite to the second state of charge. This state gives rise to an electromagnetic field  510 B surrounding arc  500 B in a clockwise direction indicated. Electromagnetic field  510 B interacts with magnetic field  180  to move arc  500 B in the direction illustrated by arrow  520 B (i.e., to the left in  FIG. 5B ). Referring to the corresponding structures in  FIG. 2 , this movement will drive the arc  500 B into the arc splitter plates  200 ,  200 ′ of region  250  ( FIG. 6 ) to be extinguished. 
       FIG. 6  is a perspective view further illustrating portions, structure and positioning of components of the circuit interrupter  100  described in connection with  FIGS. 1-5 . 
       FIG. 7  illustrates components of circuit interrupter  100  showing an alternative arrangement of certain parts according to aspects of the invention. 
     Stationary contact  110 , line terminal  120 , movable contact  130 , and contact arm  140  are arranged in substantially the same configuration shown with respect to  FIGS. 1-5 . However, in the implementation of  FIG. 6 , permanent magnet  770  is located beneath stationary contact  110  as illustrated, and the permanent magnets  170 ,  170 ′ of  FIGS. 1-5  are not present. Permanent magnet  770  generates a magnetic field  780 , which permeates a region where an arc between contacts  110 ,  130  may form. 
       FIG. 8  illustrates a top view of components of circuit interrupter  100  in the configuration of  FIG. 7 . The view shown in  FIG. 8  illustrates the alternative placement of permanent magnet  770  with respect to contacts  110 ,  130 , lower arc runner  190 , and contact arm  180 . 
     Although permanent magnet  770  is shown having a particular polarity, those having skill in the art will appreciate that the magnetic polarity may be reversed without departing from the invention. 
       FIGS. 9A and 9B  are overhead views of permanent magnet  770  from the same perspective shown in  FIG. 7 , and illustrate the effect of magnetic field  780  upon an arc developed between the contacts  110 ,  130 . 
     In  FIG. 9A , an arc  900 A is shown developing between the stationary contact  110  and the movable contact  130  (contacts  110 ,  130  not shown for clarity). The electric charge of the arc gives rise to an electromagnetic field  910 A surrounding arc  900 A as illustrated. Electromagnetic field  910 A interacts with magnetic field  780  to direct arc  900 A as shown by arrow  920 A. 
     Referring to the corresponding structures in  FIG. 8 , this movement will direct the arc  900 A into region  250 ′. 
     In  FIG. 9B , an arc  900 B is shown developing between the stationary contact  110  and the movable contact  130  (contacts  110 ,  130  not shown for clarity) albeit where the charges on the contacts  110 ,  130  are reversed with respect to  FIG. 9A . This electric charge of the arc gives rise to an electromagnetic field  910 B surrounding arc  900 B as illustrated. Electromagnetic field  910 B interacts with magnetic field  780  to direct arc  900 B as shown by arrow  920 B. 
     Referring to the corresponding structures in  FIG. 8 , this movement will direct the arc  900 B into region  250 . 
       FIGS. 10A and 10B  are side views of permanent magnet  770  and arcs  900 A and  900 B, further illustrating the relative orientations of magnetic field  780  and electromagnetic fields  910 A and  910 B. 
       FIG. 11  is a side view of portions of the implementation of circuit interrupter  100  illustrated in  FIGS. 6, 7, 8A, 8B, 9A, and 9B . The view of  FIG. 11  corresponds to the view shown in  FIG. 4 , and shows contact arm  140  in an open position. Magnetic field  780  (omitted for clarity) permeates the region between contacts  110 ,  130  where an arc may arise. Depending upon the polarity of contacts  110 ,  130 , magnetic field  780  will direct such an arc toward the arc path in either region  250  or  250 ′. In addition, lower arc runner  190  is shown at an optional angle  1100  from arc splitter  200 . This may have the advantage of facilitating an arc runner having a greater surface area in a housing  210  having a relatively small dimension. 
       FIG. 12  is a perspective view that further illustrates portions of the circuit interrupter  100  as described with respect to  FIGS. 7-11 . 
       FIG. 13  illustrates components of the implementation of circuit interrupter  100  shown in  FIGS. 7-12 . Contact arm  140 , movable contact  130 , stationary contact  110 , and permanent magnet  770  are all arranged substantially as shown in  FIG. 7 , however, in  FIG. 13  pole pieces  1300  and  1310  have been added adjacent to magnet  770 . Pole pieces  1300  and  1310  are arranged to produce a shaped magnetic field  1380  through the region where an arc (not shown) may form between contacts  110 ,  130 . 
     Using pole pieces to direct and/or concentrate a magnetic field in this manner allows for more precise control in directing and extinguishing an arc that forms between the contacts. 
     Pole pieces  1300  and  1310  may be made of any suitable material including, for example, but not limited to an iron material. Those of skill in the art will appreciate that one or more pole pieces comprising any desired shape may be used in conjunction with any of the magnet arrangements described herein or otherwise consistent with the invention to shape a desired magnetic field. 
       FIG. 14  illustrates certain components of another circuit interrupter  1200  according to aspects of the invention. Circuit interrupter  1400  includes stationary contact  1410  which is electrically connected to line terminal  1420 . Stationary contact  1410  is connected to a lower arc runner  1490 , although those of skill in the art will appreciate that lower arc runner  1490  may be connected in different configurations without departing from the invention. 
     A movable contact  1430  is disposed on a movable contact arm  1440 , which can be moved between a closed position and an open position. In  FIG. 14 , contact arm  1440  is shown in a closed position, with movable contact  1430  contacting stationary contact  1410 . 
     Movable contact  1430  is connected to load terminal  1450  through a conductor  1460 . When contact arm  1440  is in the closed position, movable contact  1430  physically contacts stationary contact  1410  such that electrical current can flow between line terminal  1420  and load terminal  1450 . 
     A permanent magnet  1470  is located beneath stationary contact  1410  as shown, and oriented to produce a magnetic field  1480  (omitted for clarity) through the region where contacts  1410 ,  1430  touch when the contact arm  1440  is in the closed position and where an arc may form between contacts  1410 ,  1430  when the contacts open or close. Permanent magnet  1470  is shown comprising a hollow cylindrical shape arranged to surround line terminal  1420 , however it will be appreciated by those of skill in the art that other shapes, and/or other arrangements may be utilized. 
     Circuit interrupter  1400  may be any device that can be used to open or close an electrical circuit. For example, circuit interrupter  1400  may be implemented as a switch, or may be implemented as a circuit breaker. 
     Contact arm  1440  may be actuated via a switch, trip mechanism, and/or any other known mechanism (not shown) according to the desired implementation of circuit interrupter  1400 . 
     Lower arc runner  1490  is shown in electrical contact with stationary contact  1410 . Arc splitter plates  14200  and  14200 ′ are illustrated arranged in arc path  14250 ; and arc splitter plates  14200 ″ is illustrated arranged in arc path  14250 ′. Depending upon the polarity of contacts  1410 ,  1430 , an arc developing between the contacts will be directed toward either arc path  14250  or  14250 ′ by the interaction of an electromagnetic field surrounding the arc (not shown) with magnetic field  1480  (omitted from  FIG. 14  for clarity, shown in  FIG. 15 ). 
     It will be evident to those of skill in the art that this arrangement provides for assisted arc suppression using arc splitter plates regardless of the polarity of the contacts, and using permanent magnets without requiring the consumption of power. 
     It is also clear that by arranging the arc paths  14250 ,  14250 ′ and the magnetic field  1480  as shown in  FIG. 14 , the profile of circuit interrupter  1400  is made thinner than the profile of circuit interrupter  100 , for the reason that the arc paths  14250 ,  14250 ′ are not in a side-by-side configuration, and thus do not require the housing to be wider than a single arc path. 
       FIG. 15  illustrates portions of the circuit interrupter  1400  as shown in  FIG. 14 , further illustrating a portion of magnetic field  1480  which permeates the area where an arc may form between contacts  1410 ,  1430 . The magnetic field functions to direct such arcs toward either region  14250  or  14250 ′ depending upon the polarity of the contacts. 
       FIG. 16  is a perspective view, which further illustrates portions of the circuit interrupter  1400  described with respect to  FIGS. 13-15 ; while  FIGS. 17A-B  and  18 A-B show arrangements of certain components of circuit interrupters described herein. 
       FIG. 17A  illustrates the electromagnetic field generated by current flowing through contact arm  140  and conductor  195  according to aspects of the invention. 
     When current flows through conductor  195  and contact arm  140  in the direction indicated by arrows  1750 A (i.e. line to load), it gives rise to electromagnetic fields  1700 A and  1720 A respectively. An arc developing between stationary contact  110  and movable contact  140  will generate an electromagnetic field  1710 A. The conductor  195  and contact arm  140  are oriented and disposed such that the effect of electromagnetic fields  1700 A and  1720 A on the arc does not substantially hinder the directing of the arc into an arc path as compared with other possible implementations. 
       FIG. 17B  illustrates the electromagnetic field generated by current flowing through contact arm  140  and conductor  195  according to aspects of the invention. 
     When current flows through conductor  195  and contact arm  140  in the direction indicated by arrows  1750 B (i.e. load to line), it gives rise to electromagnetic fields  1700 B and  1720 B respectively. An arc developing between stationary contact  110  and movable contact  140  will also generate an electromagnetic field  1710 B. The conductor  195  and contact arm  140  are oriented and disposed such that the effect of electromagnetic fields  1700 B and  1720 B on the arc does not substantially hinder the directing of the arc into an arc path as compared with other possible implementations. 
       FIGS. 18A and 18B  show another arrangement to manage the electromagnetic field generated by current flowing through contact arm  140 , and conductor  195  according to aspects of the invention. The arrangement shown in  FIGS. 18A and 18B  are similar to the arrangement shown in  FIGS. 17A and 17B , except in that the conductor  195  is arranged to accommodate a permanent magnet (not shown) positioned beneath stationary contact  110 . 
     When current flows through conductor  195  and contact arm  140  in the direction indicated by arrows  1850 A (i.e. line to load), it gives rise to electromagnetic fields  1800 A and  1820 A respectively. An arc developing between stationary contact  110  and movable contact  140  will also generate an electromagnetic field  1810 A. The conductor  195  and contact arm  140  are oriented such that the effect of electromagnetic fields  1800 A and  1820 A on the arc does not substantially hinder the directing of the arc into an arc path as compared with other possible implementations. 
       FIG. 18B  shows an arrangement to manage the electromagnetic field generated by current flowing through contact arm  140 , and conductor  195  according to aspects of the invention. 
     When current flows through conductor  195  and contact arm  140  in the direction indicated by arrows  1850 B (i.e. load to line), it gives rise to electromagnetic fields  1800 B and  1820 B respectively. An arc developing between stationary contact  110  and movable contact  140  will also generate an electromagnetic field  1810 B. The conductor  195  and contact arm  140  are oriented such that the effect of electromagnetic fields  1800 B and  1820 B on the arc does not substantially hinder the directing of the arc into an arc path as compared with other possible implementations. 
       FIG. 19  shows an overhead view of certain components of circuit interrupter  100 , illustrating an alternative venting arrangement according to aspects of the invention. 
     The components shown in  FIG. 19  are arranged substantially as shown in  FIG. 8 , with the addition of housing  1910 . Housing  1910  is substantially similar to housing  210  as illustrated in  FIG. 2 , except that vents  1900  are shown in an elongated configuration, which differs from the configuration of vents  220 ,  220 ′ shown in  FIG. 2 . 
       FIG. 20  illustrates a side view of housing  1910  and vents  1900 . Vents  1900  provide the advantage of allowing for increased flow of gasses generated by potential arcing within housing  1910 . 
       FIG. 21  illustrates another side view of housing  1910  showing another alternative venting arrangement. Vents  2100 ,  2100 ′,  2100 ″ are aligned in a manner substantially similar to vents  1900  as shown in  FIGS. 19 and 20 , except that vents do not extend in the portions of housing  1910  between vents  2100  and  2100 ′, and the portions between vents  2100 ′ and  2100 ″. This provides the advantage of encouraging a desirable flow of gasses generated by arcing within housing  1910 , while also providing shielding over regions of the interior of housing  1910  where the arc will be directed according to aspects of the invention. 
       FIG. 22  is an perspective view of the housing  1910  including vents  2200 ,  2200 ′,  2200 ″, showing a further alternative arrangement. 
     Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many modifications and variations will be ascertainable to those of skill in the art.