Description:DESCRIPTION

A TEST MECHANISM ARRANGEMENT FOR A CIRCUIT BREAKER

FIELD OF INVENTION:

[0001] The present disclosure relates to a test mechanism arrangement for a circuit breaker. Particularly, the present disclosure relates to a test mechanism arrangement with at least two fault detection device. More particularly, the present disclosure relates to a test mechanism arrangement with at least two fault detection device with dual test buttons.

BACKGROUND OF INVENTION:
[0002] In recommendation for the use of AFDDs in BS7671:2018 – the 18th Edition – has certainly created a lot of debate in the industry about their use, but one thing is for sure, their purpose and function is one that is unparalleled when it comes to detecting potentially deadly arc faults in electrical installations. The effectiveness of the any safety device must be verified by a test simulating an appropriate fault condition by a test button incorporated in the device.
[0003] Conventional residential and light industrial and commercial circuit breakers typically have a thermal trip mechanism which responds to persistent overcurrent of moderate magnitude to provide a delayed trip in the breaker. Also included in the circuit breaker is a magnetic trip mechanism which responds instantaneously to overcurrent conditions of greater magnitudes. It is becoming more common for these circuit breakers to further include a RCD Detection mechanism. The RCD fault trip mechanism includes a trip unit which detects faults between the line conductor and the neutral conductor. When a RCD fault exists, it creates a sizeable imbalance between the two currents in the two conductors which can be detected to further trip the tripping mechanism.
[0004] In addition, this circuit breaker includes mechanism designed to protect against arc faults. For example, an arc fault may occur in the device when bare or stripped conductors come into contact with one another. The arc that is caused by these faults can damage the conductors by melting the copper therein and this is especially true for stranded wire conductors such as extension cords, which can ignite surrounding materials. This protection works before the arc production by detecting the wave form signature and thus prevents the hazardous arc creation.
[0005] Typically, the circuit breaker includes contacts that open upon sensing arcing from line to neutral (Parallel Arc) & from Line to line or Neutral to Neutral (Series Arc) Arc fault circuit breakers typically use a sensor module in detecting rapid changes in the load current.
[0006] Unfortunately, many conventional circuit breakers, including residential circuit breakers, do not permit the user to test both the RCD and AFDD circuits in the device. Furthermore, the ability to test both of these circuits is very important for customer safety and because a vast amount of individuals do not understand the implications of a circuit failure, it is important to best educate these individuals about these implications and what systems are available to minimize the likelihood that such a circuit failure occurs.
[0007] CA2307812C discloses a circuit breaker with a dual test mechanism. It discloses a test mechanism for a circuit breaker comprising: a circuit board; a test button assembly including a test button, the test button including a top portion having first and second cantilevered surfaces, and a bottom portion having a clamp member, the clamp member having a pair of biasing arms pinching a first end of a pivotable conductor to the test button, the pivotable conductor comprising a leaf spring wherein depressing the first cantilevered surface places the test button in a first position and moves the second end of the pivotable conductor into contact with the second flat conductor to direct a first test signal to the circuit board, and depressing the second cantilevered surface places the test button in a second position and moves the second end of the pivotable conductor into contact with the first flat conductor to direct a second test signal to the circuit board; and a trip mechanism including a pair of separable contacts, the trip mechanism being electrically connected to the circuit board so that in response to receiving one of the first and second test signals, the circuit board generates a trip signal causing the trip mechanism to separate the pair of separable contacts.
[0008] EP0649207A1 discloses a self-testing circuit breaker ground fault and sputtering arc trip unit. In this patent, ground fault trip units for circuit breakers are tested by a passive test circuit which includes a test conductor passing through the current transformer sensing coil(s), and a test switch which selectively connects the test conductor in a loop which simulates a neutral-to-ground fault. In a dormant oscillator ground fault test circuit, the test conductor loop passes through both sensing coils. When the neutral-to-ground detector is combined with a sputtering arc fault detector sharing a common sensing coil, testing of all the components is accomplished by adding an additional test circuit which injects pulses derived from the line conductor into the sensing coil secondary, or which alternatively, connects a capacitor charged from a DC supply across the sensing coil secondary. Either of these alternative test circuits generates the successive events needed to produce a sputtering arc trip.
[0009] EP0954003A2 discloses a circuit breaker with common test button for ground fault and arc fault circuit. It discloses a miniature circuit breaker incorporating ground fault protection and arc fault protection has a common rocker button for selectively actuating a ground fault test switch and an arc fault test switch. A leaf spring seated in a groove in the rocker button has converging legs which bias the common rocker button from the ground fault test position, and in the opposite direction from the arc fault test position, respectively, toward a central, neutral position.
[0010] US6710687 discloses a test button assembly for circuit breaker. It discloses an improved test button assembly for use in a circuit breaker includes a frame and a button member, with the button member being pivotably mounted on the frame. A pair of microswitches are mounted on a printed circuit board that is disposed on the frame. The button member is alternately engageable with the two microswitches, with one of the microswitches being connectable with a ground fault protection circuit, and the other microswitch being connectable with an arc fault protection circuit. In an alternate embodiment, a common electrical contact is mounted on the button member, and a pair of contacts are mounted on the frame, with the common contact being alternately engageable with each of the contacts mounted on the frame. The contacts mounted on the frame are connected with the ground fault and arc fault protection circuits.
[0011] In all the above mentioned prior arts, single pole double way switch is used no separate switch is provided for separate test. The size of the switch is big, compatible for 2 module width modular device. One cannot accommodate the same switch for single module width sized modular device. Also a leaf spring is used as pivotable member which also required space for its configuration. Thus, there is a need to develop a compact modular circuit breaker which has two separate switch for separate tests and still able to be configured in a small space.

OBJECTS OF THE DISCLOSURE:
[0012] It is an object of the present disclosure to provide a test mechanism arrangement which is capable to test dual faults on a single module AFDD (Art fault detection device) RCBO (residual current operated circuit breaker) device.
[0013] It is another object of the present disclosure to provide test mechanism arrangement having two separate buttons to separately test arc fault and residual current.
[0014] Further object of the present disclosure is to provide a test mechanism arrangement with indicator in a compact sized module AFDD RCBO circuit breaker.

SUMMARY OF INVENTION:
[0015] This summary is provided to introduce concepts related to the test mechanism arrangement with multiple test buttons to test multiple circuit breaker circuits. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0016] In an aspect, the present disclosure provides a test mechanism arrangement for a circuit breaker having at least two fault detection device, the test mechanism arrangement comprising: a printed circuit board. It includes at least a first test button, and at least a second test button provided on the circuit breaker, the test button including a top portion configured to actuate the button upon pressing, a bottom portion and a peripheral portion between the top portion and bottom portion and a pivotable spring is provided on the printed circuit board having a first end connected with the bottom portion of first test button and a second end connected to of the bottom portion the second test button. It also comprises a first conductor and a second conductor electrically connected to the circuit board, wherein pressing the top portion of first test button moves the first end of the pivotable spring into contact with the first conductor to direct a first test signal to the printed circuit board, and pressing the top portion of the second test button moves the second end of the pivotable spring into contact with the second conductor to direct a second test signal to the circuit board; and a trip mechanism being electrically connected to the circuit board so that in response to receiving one of the first and second test signals generates a trip signal causing the trip, wherein the peripheral portions of the test button have a plurality of protruded parts, the test buttons are mounted in the circuit breaker in such a manner that the protruded part of first test button guides the positioning of the second test bottom and the pivotable spring is a double torsional spring.
[0017] In an embodiment, the present disclosure provides that for actuating the test button, the top portion of the test button is pressed and moved from a first position to a second position, the pivotable spring is configured to bring the test button back to the first position after actuation.
[0018] In yet another embodiment, the present disclosure provides that the double torsional spring comprises first torsional spring wound in clockwise direction and a second torsional spring wound in anticlockwise direction and connected with each other at their one ends and other open ends forming the first end and second end of the pivotable spring.
[0019] In still another embodiment, the present disclosure provides that the one end of the first and second torsional spring are extended and connected with each other by forming a bridge.
[0020] In further embodiment, the present disclosure provides that first and second conductors are cylindrical metallic pins soldered on the printed circuit board.
[0021] In preferred embodiment, the present disclosure provides that the circuit breaker having at least two fault detection device comprises an arc fault detection device (AFDD) and a Residual current operated Circuit Breaker with overcurrent protection device and where the first test button is configured to test the arc fault detection device, the second test button is configured to test the Residual current operated Circuit Breaker with overcurrent protection device.
[0022] In another embodiment, the present disclosure provides that the first test button is formed of a transparent plastic material to facilitate the light diffusion and the Printed Circuit board consist of a plurality of LED at its bottom to provide the light to the first test button for indicating the type of arc fault.
[0023] In yet another embodiment, the present disclosure provides that the trip mechanism comprises a current sensing module connected with a microcontroller 2, an arc sensing module connected with microcontroller 1, a common SCR connected with microcontroller 1 and microcontroller 2.
[0024] In still another embodiment, the present disclosure provides that t upon pressing the top portion of first test button, the first test button creates an artificial arc wave form as first test signal which is further detected by the arc sensing module, the arc sensing module transmit the first test signal to the microcontroller 1 and the microcontroller 1 trigger the common SCR to perform the tripping operation.
[0025] In another embodiment, the present disclosure provides that upon pressing the top portion of second test button, the second test button creates a leakage current b/w 15mA to 30 mA as second test signal which is further detected by the current sensing module, the current sensing module transmit the test signal to the microcontroller 2 and the microcontroller 2 trigger the common SCR to perform the tripping operation.

BRIEF DESCRIPTION OF DRAWINGS:
[0026] The illustrated embodiments of the subject matter will be best understood by reference to the drawings. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:
[0027] FIG. 1A illustrates a perspective view of the circuit breaker with test mechanism arrangement in accordance with an embodiment of the present disclosure;
[0028] FIG. 1B illustrates a perspective view of the circuit breaker with test mechanism arrangement in accordance with an embodiment of the present disclosure;
[0029] FIG. 2 illustrates the sub components of test mechanism arrangement in accordance with an embodiment of the present disclosure;
[0030] FIG. 3 illustrates the perspective view of double torsional spring of test mechanism arrangement in accordance with an embodiment of the present disclosure;
[0031] FIG. 4A illustrates the actuation of first test button of test mechanism arrangement in accordance with an embodiment of the present disclosure.
[0032] FIG. 4B illustrates the actuation of first test button of test mechanism arrangement in accordance with an embodiment of the present disclosure.
[0033] FIG. 5 illustrates the block diagram of working of test mechanism arrangement in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION WITH REFERENCE TO ACCOMPANYING DRAWINGS:
[0034] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0035] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0036] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
[0037] Definitions of one or more terms that will be used in this disclosure are described below without limitations. For a person skilled in the art, it is understood that the definitions are provided just for the sake of clarity, and are intended to include more examples than just provided below.
[0038] Various embodiments are further described herein with reference to the accompanying figures. It should be noted that the description and figures relate to exemplary embodiments, and should not be construed as a limitation to the subject matter of the present disclosure. It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the subject matter of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the subject matter of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof. Yet further, for the sake of brevity, operation or working principles pertaining to the technical material that is known in the technical field of the present disclosure have not been described in detail so as not to unnecessarily obscure the present disclosure.
[0039] FIG. 1A shows a perspective & FIG. 1B shows a front view of a combined Arc Fault Detection Device & RCBO in one module with dual test button for use in a dual test mechanism arrangement in accordance with the present invention.
[0040] The present invention relates generally to a circuit breaker. More specifically the present invention relates to a dual test button with Indicator and test mechanism to check both an arc fault detection device (AFDD) and a Residual current operated Circuit Breaker with overcurrent protection (RCBO) in a single module (approx. 18mm) circuit breaker. the first test button is configured to test the arc fault detection device, the second test button is configured to test the Residual current operated Circuit Breaker with overcurrent protection device.
[0041] Referring to FIG. 2, shows an exemplary embodiment of test mechanism arrangement 100 and its subcomponents. It has dual test button – a first test button 130 and a second test button. The first test button is configured to test the arc fault detection device, the second test button is configured to test the Residual current operated Circuit Breaker with overcurrent protection device. Test button 130 to check AFDD function also includes the indicator to identify the type of arc fault (series or parallel). The first test button 130 is formed of a transparent plastic material to facilitate the light diffusion and the Printed Circuit board consist of a plurality of LEDs 190 at its bottom to provide the light to the first test button 130 for indicating the type of arc fault. The test button 130 or 140 including a top portion configured to actuate the button upon pressing, a bottom portion 132 and 142 and a peripheral portion between the top portion and bottom portion.
[0042] A test mechanism arrangement 100 for a circuit breaker as shown in FIG 2 also having a printed circuit board 150, a pivotable spring 160 is provided on the printed circuit board 150 having a first end connected with the bottom portion of first test button 132 and a second end connected to of the bottom portion the second test button 140. It also has a first conductor 170 and a second conductor 180 electrically connected to the circuit board, wherein pressing the top portion of first test button 130 moves the first end of the pivotable spring 160 into contact with the first conductor 170 to direct a first test signal to the printed circuit board, and pressing the top portion of the second test button 140 moves the second end of the pivotable spring 160 into contact with the second conductor 180 to direct a second test signal to the circuit board; and a trip mechanism being electrically connected to the circuit board so that in response to receiving one of the first and second test signals generates a trip signal causing the trip.
[0043] The test buttons 130, 140 having the peripheral portions have a plurality of protruded parts 131, 141. The test buttons are mounted in the circuit breaker in such a manner that the protruded part of first test button 131 abut against the protruded part of second test button 141 in such a manner so that the first test button 130 guides the positioning of the second test bottom 140 and the pivotable spring is a double torsional spring. This leads to space saving and to achieve the concept in single module size (18mm)
[0044] This mechanism is designed as surfaces for the user to depress depending upon which circuit is to be tested in circuit breaker. More specifically, first test button 130 is depressed if testing of the AFDD circuit is desired and second test button 140 is depressed if testing of the RCD circuit is desired. First and second test button surfaces 130, 140 are used to operate the common double torsional spring 160 integral with the printed circuit board (PCB) 150 to get a common neutral through a connected neutral wire 110. Two conductors in the form of cylindrical pins 170, 180 are soldered to the printed circuit board (PCB) 150 to provide the phase for RCD and AFDD function respectively.
[0045] For actuating the test button, the top portion of the test button is pressed and moved from a first position to a second position, the double torsional spring 160 is configured to bring the test button back to the first position after actuation.
[0046] FIG. 3 shows the double torsional spring. As their name suggests, double torsion springs are nothing but two torsion springs combined together to form one single spring. The most characteristic feature of double torsion springs is that they have two coils. One coil is wound in a clockwise direction, whereas the other is wound in an anti-clockwise direction. Both these coils are bridged in the middle of the spring. More specifically, the double torsional spring comprises first torsional spring 161 wound in clockwise direction and a second torsional spring 162 wound in anticlockwise direction. The one end of the first and second torsional spring are extended and connected with each other by forming a bridge 163 and other open ends forming the first end and second end of the pivotable spring. This double torsion spring is used to operate both the test buttons. Double torsion spring is strong, and have the capability to exert greater force. This spring is capable of generating a total force, which is same as the forces created by two individual springs together.
[0047] The actuation of first and second test buttons are represented in figures 4A and 4B. For testing the AFDD circuit, first test button 130 is depressed. The test mechanism arrangement with pressed first test button 130 is shown in figure 4A. Upon pressing the first test button 130, the first test button 130 moves the first end of the pivotable spring connected to the bottom potion of first test button 132 into contact with the first conductor 170 to direct a first test signal to the printed circuit board, and a trip mechanism being electrically connected to the circuit board so that in response to receiving the first test signals generates a trip signal causing the trip.
[0048] For testing the RCD circuit, second test button 140 is depressed. The test mechanism arrangement with pressed second test button 140 is shown in figure 4A. Upon pressing the second test button 140, the second test button 140 moves the second end of the pivotable spring connected to the bottom potion of second test button 142 into contact with the second conductor 180 to direct a second test signal to the circuit board; and a trip mechanism being electrically connected to the circuit board so that in response to receiving the second test signal generates a trip signal causing the trip. Upon releasing the test buttons, the double torsional spring 160 brings the test button back to the first position after actuation.
[0049] As, shown in the Block Diagram FIG. 5 two Micro Controller are integrated on the Printed Circuit board (PCB) 150 to sense the RCD & AFDD fault.
[0050] The pressing operation of AFDD Test button 130 creates an artificial arc wave form which will be further detected by the Arc sensing module (as shown Fig. 3). The Arc sensing module will send the output to the Micro-controller 1 (as shown Fig. 4) and Micro Controller 1 will trigger the common SCR (as shown Fig. 4) to perform the tripping operation.
[0051] The pressing operation of RCD Test button 140 creates a leakage current b/w 15mA to 30 mA which will be further detected by the current sensing module. The current sensing module (i.e Current Transformer) will send the output to the Micro-controller 2 (as shown Fig. 4) and Micro Controller 2 will trigger the common SCR (as shown Fig. 3) to perform the tripping operation.
[0052] The foregoing description of the preferred embodiment of the invention has been presented for the purpose of illustration and description. It is not intended to be exhaustive, nor is it intended to limit the invention to the precise form disclosed. It will be apparent to those skilled in the art that the disclosed embodiment may be modified in light of the above teachings.
, Claims:We Claim:

1. A test mechanism arrangement 100 for a circuit breaker having at least two fault detection device, the test mechanism arrangement 100 comprising:
a printed circuit board 150;
at least a first test button 130, and at least a second test button 140 provided on the circuit breaker, the test button 130, 140 including a top portion configured to actuate the button upon pressing, a bottom portion 132, 142 and a peripheral portion between the top portion and bottom portion;
a pivotable spring 160 is provided on the printed circuit board 150 having a first end connected with the bottom portion of first test button 131 and a second end connected to of the bottom portion the second test button 141,
a first conductor 170 and a second conductor 180 electrically connected to the circuit board, wherein pressing the top portion of first test button 130 moves the first end of the pivotable spring into contact with the first conductor 170 to direct a first test signal to the printed circuit board 150, and pressing the top portion of the second test button 140 moves the second end of the pivotable spring into contact with the second conductor 180 to direct a second test signal to the circuit board; and
a trip mechanism being electrically connected to the circuit board 150 so that in response to receiving one of the first and second test signals generates a trip signal causing the trip,
wherein the peripheral portions of the test button have a plurality of protruded parts 131, 141, the test buttons 130, 140 are mounted in the circuit breaker in such a manner that the protruded part of first test button 131 guides the positioning of the second test button and the pivotable spring 160 is a double torsional spring.

2. The test mechanism arrangement 100 as claimed in claim 1, wherein for actuating the test button 130, 1401, the top portion of the test button is pressed and moved from a first position to a second position, the pivotable spring 160 is configured to bring the test button back to the first position after actuation.

3. The test mechanism arrangement 100 as claimed in claim 1, wherein the double torsional spring 160 comprises first torsional spring 161 wound in clockwise direction and a second torsional spring 162 wound in anticlockwise direction and connected with each other at their one ends and other open ends forming the first end and second end of the pivotable spring.

4. The test mechanism arrangement 100 as claimed in claim 1, wherein the one end of the first and second torsional spring are extended and connected with each other by forming a bridge 163.

5. The test mechanism arrangement 100 as claimed in claim 1, wherein the first and second conductors 170, 180 are cylindrical metallic pins soldered on the printed circuit board 150.

6. The test mechanism arrangement 100 as claimed in claim 1, wherein the circuit breaker having at least two fault detection device comprises an arc fault detection device (AFDD) and a Residual current operated Circuit Breaker with overcurrent protection device and where the first test button 130 is configured to test the arc fault detection device, the second test button 140 is configured to test the Residual current operated Circuit Breaker with overcurrent protection device.

7. The test mechanism arrangement 100 as claimed in claim 6, wherein the first test button 130 is formed of a transparent plastic material to facilitate the light diffusion and the Printed Circuit board 150 consist of a plurality of LED 190 at its bottom to provide the light to the first test button for indicating the type of arc fault.
8. The test mechanism arrangement 100 as claimed in claim 1, wherein the trip mechanism comprises a current sensing module connected with a microcontroller 2, an arc sensing module connected with microcontroller 1, a common SCR connected with microcontroller 1 and microcontroller 2.
9. The test mechanism arrangement 100 as claimed in claim 8, wherein upon pressing the top portion of first test button 130, the first test button 130 creates an artificial arc wave form as first test signal which is further detected by the arc sensing module, the arc sensing module transmit the first test signal to the microcontroller 1 and the microcontroller 1 trigger the common SCR to perform the tripping operation.
10. The test mechanism arrangement 100 as claimed in claim 8, wherein upon pressing the top portion of second test button 140, the second test button 140 creates a leakage current b/w 15mA to 30 mA as second test signal which is further detected by the current sensing module, the current sensing module transmit the test signal to the microcontroller 2 and the microcontroller 2 trigger the common SCR to perform the tripping operation.