WO2000036623A1

WO2000036623A1 - Circuit breaker with multiple test switch assembly

Info

Publication number: WO2000036623A1
Application number: PCT/US1999/029282
Authority: WO
Inventors: Kevin J. Fuhr; Raymond Kelsey Seymour; Murali K. Magham
Original assignee: General Electric Company
Priority date: 1998-12-14
Filing date: 1999-12-10
Publication date: 2000-06-22
Also published as: WO2000036623A9; CA2320057A1; EP1055244A1

Abstract

A circuit breaker including a switch assembly for initiating one of at least two test conditions. The switch assembly is coupled ot a circuit board, an integrated circuit mounted thereon, and a solenoid, such that upon the initiation of either of the two conditions, the solenoid engages the armature latch in a circuit trip assembly within the breaker so as to cause the armature latch to initiate its movement from a first position to a second position. In this way, the circuit breaker can simulate a plurality of test conditions, such as fault conditions.

Description

CIRCUIT BREAKER WITH MULTIPLE TEST SWITCH ASSEMBLY

BACKGROUND OF THE INVENTION

The present invention relates generally to circuit breakers, and in particular, to an improved circuit breaker arrangement that can simulate at least two different test conditions to ensure that the circuit breaker is operating properly.

Circuit breakers that include a single push button to provide a user with the ability to simulate only one fault condition are known. That is, there is no ability to simulate a second and different fault condition in the known breaker. However, it is desirous to be able to test whether the circuit breaker will trip upon the detection of a plurality of fault conditions if the breaker is constructed to trip upon the detection of at least two different fault conditions. The known circuit breaker includes a button and leaf contact to permit the testing of only one fault condition, which by way of example, is a ground fault condition.

The present state of the art, therefore, is deficient in that there is no circuit breaker arrangements that permit the simulation of more than one fault condition, such as a ground fault condition and a line to line arc fault. The ability to simulate more than one fault condition is advantageous and desirable to ensure that the circuit breaker which may sense more than one fault condition (such as arcing to ground (i.e. ground fault) and arcing line to line or neutral) is operating properly.

It is therefore desirable to provide a circuit breaker which overcomes the aforementioned deficiency. The circuit breaker disclosed herein achieves the aforementioned and below mentioned objectives.

SUMMARY OF THE INVENTION

Generally speaking, in accordance with the invention, a circuit breaker for simulating plurality of fault or test conditions is provided. In the preferred embodiment, the circuit breaker detects at least two fault conditions. The circuit breaker includes a circuit trip assembly having an armature latch moving between a first position when the circuit breaker is in an operating condition and at least a second position when the circuit breaker is in a first or second tripped condition. The armature latch moves from its first position to its second position in response to both the first and second fault conditions. To this end, the circuit breaker can simulate at least two fault or test conditions by incorporating a switch assembly, supported by the housing, for initiating the first and second fault conditions. Hereinafter, reference to the simulation of a fault condition should also be understood to mean the simulation of a test condition, as the present invention is applicable to simulating a plurality of conditions, such as fault conditions. Therefore, the reference to simulating other test conditions is equally applicable. Additionally, the circuit breaker includes an electronic circuit board, an integrated circuit and a solenoid preferably mounted thereon, where upon the initiation of the first fault/test condition or the second fault/test condition, the integrated circuit sends respective signals to the solenoid which interfaces with the armature latch causing the armature latch to move from its first position to its second position.

Accordingly, it is an object of the present invention to provide a circuit breaker with a multiple test arrangement for testing the proper working order thereof .

Another object of the present invention is to provide a circuit breaker that can simulate more than one fault or test condition.

Another object of the . present invention is to provide a user friendly method of testing a circuit breaker for the proper detectability of a ground fault or arc fault condition.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying figures, in which:

Fig. 1 is a perspective view of a switch assembly constructed in accordance with the present invention;

Fig. 2 is a front elevational view of the switch assembly constructed in accordance with the present invention;

Fig. 3 is a front elevational view of a circuit breaker in the operating condition and the switch assembly in the neutral position, all constructed in accordance with the present invention;

Fig. 4 is another elevational view of the circuit breaker along a different cross-section thereof, more particularly illustrating the circuit board, a solenoid mounted thereon and the switch assembly, all constructed in accordance with the present invention;

Fig. 5 is a simplified elevational view of the present invention, with certain components removed for ease of illustration, and particularly illustrating the alignment of the solenoid with respect to the armature latch; and Fig. 6 is a detailed elevational view illustrating the circuit breaker, constructed in accordance with the present invention, in the tripped condition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is first made to FIGS. 1 and 2 wherein a switch assembly, generally indicated at 100, is constructed in accordance with the present invention. Switch assembly 100 preferably includes a rockable switch 102, a first contact 145, a second contact 150 and a third contact 155. In the preferred embodiment, contacts 145, 150 and 155 are metal leaf contacts. It will be understood by one of skill in the art that the reference to rockable will also include a switch that is slidable, pivotable or the like. Switch 102, preferably of a unitary plastic construction, includes integrally extending teeth 110 and 111 in facing alignment with each other. Teeth 110 and 111 together engage one end of contact 150.

Referring briefly to FIG. 3 for a moment, it is clear that a circuit breaker 10, constructed in accordance with the invention by its inclusion of switch assembly 100, includes a housing 12, a line terminal 14, a load terminal 16, and a circuit trip assembly, generally indicated at 20, connected between line terminal 14 and load terminal 16. Circuit trip assembly 20 is similar to circuit trip assembly 120 disclosed in pending application Serial No. 09/196,647, filed on November 19, 1998, which is assigned to the present assignee and incorporated by reference as if fully set forth herein.

For example, and discussed in greater detail in application Serial No. 09/196,647, when armature latch 28 moves in the "xl" direction, a cradle 22 disengages from armature latch 28 and rotates in a direction indicated by arrow "yl." An arm 44 likewise rotates in the direction of arrow "zl." Upon the rotation of cradle 22, a knee portion 150 thereof will engage a trip support 130 so as to cause trip cam 130 to rotate about pin 132. As an advantageous feature, circuit breaker 10 may include a trip indicator 140 rotatable about a pin 142 on housing 12 from a first position where it is not visible through a window 72 in housing 12 to a second position where trip indicator 140 is visible through window 72. An aperture 145 in the body of trip indicator 140 receives a guide pin 144 of trip cam 130. Guide pin 144 is provided to transfer the movement of trip cam 130 to trip indicator 140 to rotate trip indicator 140 about pin 142. In this way, upon a simulated or real fault or test condition, a portion of trip indicator 140 is visible through window 72. This tripped condition is illustrated in FIG. 6, for example, and also illustrates components, such as trip indicator 140, trip cam 130, cradle 22 and arm 44 in their rotated positions so as to cause line terminal 14 to electrically disconnect from load terminal 16.

Referring to FIGS. 4 and 5, also included within housing 12 is a circuit board 140 that, in combination with components- such as an integrated circuit (as discussed below) provides the electrical circuitry necessary for the proper operation of a solenoid 160 and the circuit breaker disclosed herein. The manner in which circuit board 140 and solenoid 160 is incorporated into housing 12 would be well understood by one of skill in the art.

Reference is again made to FIGS. 1 and 2 wherein housing 12 is depicted with a plurality of integrally molded posts 120, 125, 130 and 135. Positioned between posts 120 and 125 is contact 145. Likewise positioned between posts 125 and 130 is contact 150. Similarly, positioned between posts 130 and 135 is contact 155. As depicted in FIG. 2, contact 145 is preferably bent over an inwardly angled top surface 126 of post 125, while contact 155 is preferably bent over an inwardly angled top surface 131 of post 130. Contact 150 extends above the top of posts 125 and 130 so as to be engaged by teeth 110 and 111 of switch 102. It should now be understood that as switch 102 is "rocked" or pivoted (as explained below)- in either a clockwise (or "a" direction (FIG. 2) ) or counterclockwise (or "b" direction (FIG. 2) ) direction, the first (or extended) end of contact 150 will respectively electrically contact either the first end of contact 155 or the first end of contact 145. The second ends of contacts 145, 150 and 155 each have an "L" shaped leg so as to be inserted into respective apertures 146, 151 or 156 and connected to circuit board 140. It should also be understood that posts 120, 125, 130 and 135 may be mounted on the face of board 140 as depicted in FIG. 4, molded into housing 12 as shown in FIG. 1, or may be eliminated altogether. The connection to circuit board 140 also permits the electrical connection to an integrated circuit thereon. Specifically, circuit board 140 has mounted thereon an integrated circuit 142 which is preferably an ASIC. Connections between contacts 145, 150 and 155 are made to circuit 142 such that the electrical connection between contact 145 and 150 causes a first output signal to be generated by circuit 142 and the electrical connection between contact 150 and 155 causes a second output signal to be generated by circuit 142.

As stated above, electrical contact between contact 150 and the respective contacts 145 and 155 is achieved by the rocking or pivoting nature of switch 102. To achieve this rocking action, housing 12 preferably includes a recess 115 within the inner housing wall thereof. Recess 115 may be formed by two smaller arcing recesses 116, 117 and a notch portion 118 therebetween. Notch portion 118 will engage a complimentary shaped tab 106 integrally molded on switch 102. Switch 102 also includes an integrally formed rail 105 extending along the front and back surfaces of switch 102. In this manner both sides of housing 12 can support switch 102 in the manner herein described. The combination of tab 106 and rail 105 permits the pivoting within recess 115 so as to achieve the limiting rocking movement of switch 102. As stated above, it would be within the scope of the artisan to construct the present invention using a pivotable or somewhat slidable switch configuration while remaining within the scope of the invention. Moreover, the shape of switch 102 is by way of example and not limitation, as it could also be made with a concave top surface for example, as opposed to the disclosed rounded top surface. The multiple test switch assembly constructed in accordance with the present invention is mountable within the circuit breaker housing. Switch 102, however, may extend outside the housing so as to be accessible to a user. The remaining and preferred construction of the circuit breaker is more particularly disclosed in the aforementioned U.S. application Serial No. 09/196,647, but it should be understood that such disclosure is only by way of example, as it will become evident that the present invention is adaptable and utilizable in any number of circuit breaker configurations that are constructed to detect at least two fault or test conditions .

Accordingly, it will now be appreciated how the present invention simulates the above two mentioned arc fault or ground fault/test conditions. In particular, the rotation of switch 102 in a first direction, for example, so as to achieve electrical contact between contacts 150 and 145, will simulate the first fault/test condition which may be the arc fault condition so as to insure the circuit breaker is operating properly. In particular, the contact of contacts 145 and 150 causes integrated circuit 142 to send a first signal to solenoid 160. Solenoid 160 then engages armature latch 28 (FIGS. 3 and 5) causing armature latch 28 to move in the "xl" direction, thereby achieving a fault condition and moving the armature latch to its second position. Specifically, FIG. 5 illustrates the positioning of solenoid 160 with respect to armature latch 28 although it should be understood that FIG. 5 is a simplified illustration since solenoid 160 is preferably not on the same side of board 140 as circuit trip assembly 20. However, FIGS. 4 and 5 in combination adequately discloses how a portion of board 140 may be removed to permit solenoid 160 to engage latch 28. Similarly, the rotation of switch 102 in the second direction to achieve electrical contact between contacts 150 and 155 likewise causes integrated circuit 142 to output a second signal to solenoid 160 causing solenoid 160 to engage armature latch 28 in a similar manner causing armature latch 28 to move from its operating position to its second position thereby simulating the second fault or test condition.

It will thus be seen that the present invention makes it possible for an end user to verify that the circuit breaker including all mechanical and electrical components are functioning properly. For an AFCI/GFCI combined circuit breaker, the switch assembly constructed in accordance with the present invention allows the user to test the AFCI mode of operation by rocking or rotating the switch in one direction and to test the GFCI mode by rocking or rotating the switch in the other direction. Moreover, it should be understood that the switch assembly disclosed herein is not and should not be limited to incorporation with an AFCI and/or GFCI circuit breaker. That is, if a breaker is required to trip upon the detection of any other fault or test conditions, the present invention is equally utilizable therewith, merely with the programming of the integrated circuit to simulate the desired testing or faulting conditions.

Claims

CLAIMSWhat we claim is:

1. A circuit breaker, the circuit breaker comprising:

a housing;

a circuit trip assembly including an armature latch movable between a first position when the circuit breaker is in an operating condition and at least a second position when the circuit breaker is tripped, wherein the armature latch moves from its first position to its second position in response to both a first condition and at least a second condition;

simulation means for simulating the first condition and for simulating the second condition; and

a switch assembly, supported by the housing and coupled to the simulation means, for initiating the first condition and for initiating the second condition.

2. The circuit breaker as claimed in claim 1, wherein the simulation means includes a circuit board, an integrated circuit mounted thereon, and a solenoid; wherein upon the initiation of the first condition or the second condition, the integrated circuit sends a signal to the solenoid causing the solenoid to contact the armature latch causing the armature latch to move from its first position to its second position.

3. The circuit breaker as claimed in claim 1, wherein the switch assembly initiates the first condition when the switch assembly is in a first position and for initiating the second condition when the switch assembly is in a second position.

4. The circuit breaker as claimed in claim 3, wherein the switch assembly includes a first contact, a second contact and a third contact, and wherein the. electrical contact between the first contact and the second contact causes the simulation means to simulate the first condition and the contact between the first contact and the third contact causes the simulation means to simulate the second condition.

5. The circuit breaker as claimed in claim 3, wherein the switch assembly includes a switch, the switch being rockable between at least the first position and the second position.

6. The circuit breaker as claimed in claim 5, wherein the switch assembly further includes a first contact, a second contact and a third contact, and wherein when the switch is in the first position, the first contact contacts the second contact and when the switch is in the second position the first contact contacts the third contact.

7. The circuit breaker as claimed in claim 4 , wherein the first, second and third contacts are metal leaf contacts .

8. The circuit breaker as claimed in claim 2, and including a housing, a line terminal and a load terminal, wherein the line terminal is electrically connected to the load terminal when the circuit breaker is in its operating condition and electrically disconnected from the load terminal when the circuit breaker is tripped, wherein the circuit trip assembly is within the circuit breaker housing and comprises a cradle rotatable between at least a first position and a second position, and the armature latch is engagable with the cradle;

wherein upon the initiation of the first condition or the second condition, the solenoid contacts the armature latch causing the armature latch to move from its first to its second position, thereby causing the rotation of the cradle from its first position to its second position causing the line terminal to electrically disconnect from the load terminal .

9. The circuit breaker as claimed in claim 1, wherein the first condition is a ground fault condition and the second condition is an arc fault condition.