Bottom venting circuit breaker

Abstract

A circuit interrupter having a first plate on which a stationary contact is positioned where the flow of electrical current through the first contact and first plate cause a magnetic field to form around the stationary contact such that an arc that may form in the vicinity of the stationary contact is urged toward arc extinguishing plate and vented out the bottom of the housing of the circuit interrupter. In one configuration the venting is formed as a split vent path to direct the venting of gas and debris in a controlled manner.

Claims

1. A circuit interrupter having a housing within which the components of the circuit interrupter are contained, the circuit interrupter comprising: a line terminal connectable to a source of electrical power; a load terminal connectable to a load; a stationary contact positioned on a first plate; a second plate connected at a first end to and extending substantially perpendicular from said first plate; a moveable contact arm having a moveable contact positioned thereon, said moveable contact configured to be moveable into and out of physical contact with said stationary contact by movement of said moveable contact arm, wherein said line terminal and said load terminal are in electrical communication via said stationary contact and said moveable contact when said stationary contact and said moveable contact are in physical contact; a current measurement device connected in series with said line terminal and said load terminal; a handle disposed on a first surface of said housing and coupled to a linkage, said linkage coupled to said moveable contact arm, wherein movement of said handle causes said linkage to move said moveable contact arm to open and close the moveable contact with respect to said stationary contact; wherein electrical current flowing through the first contact causes a first magnetic field to be formed in a clockwise direction relative to said first contact such that an arc that forms in the vicinity of said first contact is urged to travel an arc path in a direction away from said second plate, and wherein an opening is positioned in a second surface of said housing, said second surface being disposed on an opposite side of said housing as is said first surface, and wherein said opening provides a vent path for the venting of gas caused by the arc, said vent path being split so as to define two separate vent paths.

2. The circuit interrupter of claim 1, wherein said first plate further comprises a first side that includes a protrusion and said second plate is connected to said protrusion.

3. The circuit interrupter of claim 2, wherein said second plate is formed in the shape of a dog-leg.

4. The circuit interrupter of claim 2, wherein when said first and second contacts are in a closed position, electrical current flows through said first contact through said first plate and into said second plate.

5. The circuit interrupter of claim 4, wherein the electrical current flowing through said second plate forms a second magnetic field that rotates counter clockwise with respect to said first magnetic field.

6. The circuit interrupter of claim 2, wherein an arc plate is positioned in the arc path such that the arc is urged from the contacts toward the arc plate.

7. The circuit interrupter of claim 6, wherein the arc plate comprises a plurality of arc plates.

8. The circuit interrupter of claim 7, wherein said moveable contact arm moves said moveable contact along a radial path and the plurality of arc plates are positioned along the radial path.

9. The circuit interrupter of claim 1, wherein said opening provides a vent path for the venting of gas caused by the arc, the gas traveling along the vent path and exiting said housing in a substantially straight path.

10. The circuit interrupter of claim 1, further comprising a neutral terminal positioned on the side of said housing on which said opening is positioned.

11. The circuit interrupter of claim 10, wherein said two separate vent paths are configured such that gas is not vented directly onto said neutral terminal.

12. A circuit interrupter having a housing within which the components of the circuit interrupter are contained, the circuit interrupter comprising: a line terminal; a load terminal; a stationary contact mounted on a first plate; a moveable contact arm having a moveable contact positioned thereon, said moveable contact configured to be moveable into and out of contact with said stationary contact by movement of said moveable contact arm, wherein said line terminal and said load terminal are in electrical communication via said stationary contact and said moveable contact when said stationary contact and said moveable contact are in contact; a second plate a extending substantially perpendicular from a side of said first plate; wherein electrical current flowing through the first contact causes a first magnetic field to be formed in a clockwise direction relative to said first contact such that an arc that forms in the vicinity of said first contact is drawn toward an arc path that extends in a direction away from said second plate; and an opening in the housing providing a vent path for venting of the arc said vent path being split so as to define two separate vent paths.

13. The circuit interrupter of claim 12, wherein said first plate further comprises a first side that includes a protrusion and said second plate is connected to said protrusion.

14. The circuit interrupter of claim 13, wherein said protrusion second plate is formed in the shape of a dog-leg.

15. The circuit interrupter of claim 13, wherein the electrical current flowing through said second plate forms a second magnetic field that rotates counter clockwise relative to said first contact.

16. The circuit interrupter of claim 12, further comprising a current measurement device connected in series with said line terminal and said load terminal.

17. The circuit interrupter of claim 12, further comprising a handle coupled to a linkage, said linkage coupled to said moveable contact arm, wherein movement of said handle causes said linkage to move said moveable contact arm to open and close the moveable contact with respect to said stationary contact.

18. The circuit interrupter of claim 12, wherein an arc plate is positioned in the arc path such that the arc is urged from the contacts toward the arc plate.

19. The circuit interrupter of claim 18, wherein the arc plate comprises a plurality of arc plates.

20. The circuit interrupter of claim 19, wherein said moveable contact arm moves said moveable contact along a radial path and the plurality of arc plates are positioned along the radial path.

21. The circuit interrupter of claim 18, wherein the opening is positioned on a side of said housing opposite to a side of said housing that holds said handle.

22. The circuit interrupter of claim 21, wherein said opening provides a vent path for the venting of gas caused by the arc, the gas traveling along the vent path and exiting said housing in a substantially straight path.

23. The circuit interrupter of claim 21, further comprising a neutral terminal positioned on the side of said housing on which said opening is positioned.

24. The circuit interrupter of claim 23 wherein said two separate vent paths are configured such that gas is not vented directly onto said neutral terminal.

25. A circuit interrupter having a housing within which the components of the circuit interrupter are contained, the circuit interrupter comprising: a line terminal operable to be connected to a source of electrical power; a load terminal operable to be connected to an attached load; a stationary contact mounted on a first plate; a moveable contact arm having a moveable contact positioned thereon, said moveable contact configured to be moveable into and out of contact with said stationary contact by movement of said moveable contact arm, wherein said line terminal and said load terminal are in electrical communication via said stationary contact and said moveable contact when said stationary contact and said moveable contact are in physical contact; a current measurement device connected in series between said line terminal and said load terminal; a handle disposed on a first surface of said housing and coupled to a linkage, said linkage coupled to said moveable contact arm, wherein movement of said handle causes said linkage to move said moveable contact arm to open and close the moveable contact with respect to said stationary contact; an arc extinguisher for extinguishing an arc that develops in the vicinity of said first and second contacts, said arc extinguisher including an arc runner and a plurality of arc plates positioned in the vicinity of said contacts; and an opening in the housing for venting of gas caused by an arc, said opening positioned in a second surface of said housing, said second surface being disposed on an opposite side of said housing as is said first surface; wherein said plurality of arc plates are positioned in the vicinity of said opening and wherein said opening provides a vent path for the venting of gas caused by the arc, said vent path being split so as to define two separate vent paths.

26. The circuit interrupter of claim 25, wherein said contact arm rotates about a pivot and moves said moveable contact along a radial path, wherein said arc plates are positioned along the radial path.

27. The circuit interrupter of claim 26, wherein the arc is drawn toward one end of at least one of the plurality of arc plates and the gas is drawn along the path of the arc toward said at least one of the plurality of arc plates, the gas passing between the plurality of arc plates an out through said opening along an essentially straight path.

28. The circuit interrupter of claim 27, wherein said arc runner includes a tab that extends at an acute angle relative to said arc runner, said tab extending substantially perpendicular to at least one of said plurality of arc plates.

29. The circuit interrupter of claim 25, further comprising a neutral terminal positioned on the side of said housing on which said opening is positioned.

30. The circuit interrupter of claim 29, wherein said two separate vent paths are configured such that gas is not vented directly onto said neutral terminal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an illustration of one aspect of the circuit interrupter according to the invention.

(2) FIG. 2 is partial view of a portion of the circuit interrupter according to FIG. 1.

(3) FIG. 3 is a view along Section A-A according to FIG. 2.

(4) FIG. 4 is a view of a portion of the circuit interrupter according to FIG. 3.

(5) FIG. 5 is an illustration of another aspect of the circuit interrupter according to FIG. 1.

(6) FIG. 6 is an illustration of another aspect of the circuit interrupter according to FIGS. 1 and 5.

DETAILED DESCRIPTION OF THE INVENTION

(7) Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views.

(8) FIG. 1 illustrates components of an example circuit interrupter 100 having a stationary and a moveable contact in a bottom vent configuration according to aspects of the invention.

(9) Circuit interrupter 100 is provided with a housing 102 that contains the working elements of the device. The circuit interrupter is further provided with a set of contacts including a stationary contact 104 and movable contact 106. The moveable contact 106 is positioned on a moveable contact arm 108 that is designed to pivot about an axis 110.

(10) The moveable contact arm 108 is coupled to a handle 114 via a linkage assembly 112. The moveable contact arm 108 is configured to move between an open and closed position relative to the stationary contact 104 by manual actuation of the handle 114 as is known in the art.

(11) Also shown in FIG. 1 is a line terminal 120, which is designed to be connected to a source of electrical power, such as a bus bar in a panel board or load center. The line terminal 120 is provided with a connection 122 that electrically connects the line terminal 120 to a current measurement device 124. Current measurement device 124 is, in turn, connected to moveable contact arm 108 via connection 126.

(12) Stationary contact 104 is mounted onto a first plate 130, which in turn has a second plate 132 affixed thereto at one end and a connection 134 attached at a second end that couples stationary contact to load terminal 136.

(13) In operation, electrical power is input into circuit interrupter 100 via line terminal 120, which passes through current measurement device 124. If the electrical current exceeds a threshold level, current measurement device 124 will function to trip the circuit interrupter 100 by opening the circuit (opening the contacts relative to each other) such that the flow of electrical current through the contacts ceases. In the event that the electrical current does not exceed the threshold level set by current measurement device 124, the electrical power is coupled to load terminal 136, which in turn, provides electrical power to the connected circuit and/or equipment.

(14) Turning now to FIGS. 2-4, the contacts are shown in greater detail. FIGS. 2 and 3 show the configuration of the first plate 130 relative to the second plate 132. In the event that moveable contact arm 108 rotates moveable contact 106 away from stationary contact 104, if electrical current is flowing through the contacts, it is likely that an electrical arc 150 will develop across the gap between the contacts. As has been previously discussed, the electrical arc that develops may cause damage to the circuit interrupter 100 and in particular, to the contacts and surroundings mechanisms. Accordingly, it is highly desirable to move the arc off of the contacts as quickly and efficiently as possible.

(15) Referring to FIG. 3, the stationary contact 104 mounted on first plate 130 is illustrated. As can be seen FIG. 3 is a view along section line A-A of FIG. 2. For illustrative purposes, it is assumed that the contacts are in a closed position and electrical current is flowing through stationary contact 104. Stationary contact 104 is illustrated having two arrows in a circular clockwise pattern, which are provided to represent magnetic field 160. As electrical current (170) flows through stationary contact 104 and travels through first plate 130 and into second plate 132, it will be understood that the magnetic field 160 will form in the pattern indicated. Likewise, when electrical current flows through second plate 132, a magnetic field 162 will be formed that will rotate in a counterclockwise direction (relative to stationary contact 104) as indicated in FIG. 3.

(16) The generation of the magnetic field(s) will function to urge the arc 150 to travel along an arc extinguishing path 152 as indicated in FIG. 3. Referring now back to FIG. 1, arc plates (138, 138, 138, 138) are also illustrated in the vicinity of the contacts.

(17) Moveable contact arm 108 is designed to move moveable contact 106 in a radial path about pivot 110. Arc plates (138, 138, 138, 138) are positioned along the radial path of movement such that if an arc develops in the gap between the contacts (e.g., when the contacts are opening) the arc will be drawn toward one or more of the arc plates (138, 138, 138, 138). The positioning of the arc plates (138, 138, 138, 138) is contemplated to electromagnetically draw the arc into the arc plates (138, 138, 138, 138). These components are at least partially enclosed by housing 102.

(18) Also illustrated in FIG. 1 is vent 142 positioned at a bottom portion of the circuit interrupter 100. Vent 142 is provided to allow gasses and debris that may form due to the generation of an arc 150, to escape from the interior of the housing 102 of circuit interrupter 100. The vent 142 is positioned at a bottom of the housing 102 so that none of the gas or debris is vented toward an adjacent circuit interrupter that may be positioned in the same enclosure as circuit interrupter 100. As stated previously, it would be disadvantageous to vent the gas or debris in a manner that could possibly damage or degrade adjacent devices and/or electrical contacts.

(19) Referring to the corresponding structures in FIGS. 2-4, the arc 150 is urged away from the stationary contact 104 to travel along an arc path 152 due in part to the magnetic field 160 and the positioning of the arc plates (138, 138, 138, 138). When the arc 150 is driven along the arc extinguishing path 152 into the arc plates (138, 138, 138, 138), this will function to quickly and efficiently extinguish the arc 150. The associated gas and debris will be vented out of vent 142.

(20) Turning now to FIG. 5, in some configurations, it is contemplated that a neutral connection may be provided on a bottom surface of circuit interrupter 100. For example, while it has been common practice to wire a neutral wire to a neutral bar in an electrical panel or load center, when a typical circuit breaker is removed only the line is disconnected going out to the equipment, whereas the neutral remains connected to the neutral bus. A relatively new type of configuration allows for the circuit interrupter 100 to include a connection to a neutral bus so that both the hot and the neutral wires feeding a circuit are connected to the circuit interrupter. So while the line terminal 120 is shown at a bottom end of the housing for connection to a source of electrical power (not shown), a neutral terminal (148) may be positioned on the underside (bottom) of the housing in the vicinity of the vent 142. However, this raises the issue of venting gas and debris toward the location where the neutral terminal of the circuit interrupter 100 contacts the neutral bar in the panelboard. To address this problem a new configuration is illustrated in FIG. 4 in which the gas and debris is split into two separate vent paths 144, 146 such that gas and debris are vented in the manner illustrated by the arrows shown in FIG. 4.

(21) Referring now to FIG. 6, circuit interrupter 100 is illustrated including many of the features described in connection with FIG. 1. Line terminal 120 is illustrated comprising a plate 130 on which stationary contact 104 is located. A moveable contact arm 108 is provided that has a moveable contact 106 located thereon that is moved into and out of contact with stationary contact 104 to open and close the circuit as discussed in connection with FIG. 1. A connection 122 extends from the moveable contact arm 108 to current measurement device 124, which is in turn, electrically connected to load terminal 136 via connection 126.

(22) Also illustrated in FIG. 6 is connection 1134, which connects load terminal 136 to arc runner 180. Those of skill in the art will understand that lower arc runner 180 may be connected in a number of different configurations as desired without departing from aspects of the invention.

(23) Arc plates (138, 138, 138, 138) are positioned in the vicinity of stationary contact 104 and moveable contact 106 and are provided to drawn an arc that may develop between the contacts toward the arc plates (138, 138, 138, 138) where any gas and debris can be vented out vent 142. These components are at least partially enclosed by housing 120.

(24) The vent 142 is positioned on a bottom of the housing 102, which is opposite to handle 114 positioned on housing 102. In this manner, gasses and debris that may be created due to arcing will be vented out of the bottom of the housing and not toward any adjacent circuit interrupters that may be positioned in, for example, a panelboard or other electrical enclosure. A major benefit of this configuration is that the arc is drawn directly toward the vent 142 such that the gas and debris our vented on a straight and direct path out of the housing 102 and substantially in line with the positioning of the arc plates (138, 138, 138, 138). This provides the least amount of resistance to the venting processes to efficiently and effectively remove any caustic gas (illustrated in FIG. 6 as arrows in vent 142 that show the flow of gas from the contacts, through the vent 142 and exiting from housing 102) that could damage the internal mechanisms of the circuit interrupter 100.

(25) 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 other modifications and variations will be ascertainable to those of skill in the art.