DESC:TECHNICAL FIELD
[0001] The present disclosure relates to the field of draw out type circuit breakers. More particularly the present disclosures relates to a motorized rack kit that provides for distinct position locking of cradle of draw-out type circuit breakers.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Circuit breakers are incorporated in a power supply circuit for protection against potential damage that may be caused to electrical circuit and connected load by potentially damaging occurrences such as but not limited to overvoltage, short-circuit etc. Circuit breakers are designed to detect such potentially dangerous conditions and operate to disconnect the load automatically. After a fault has been diagnosed and rectified, circuit breaker can be either manually or remotely reset and power supply circuit can resume its normal operations/ functioning. They can also be used to isolate the connected load from power supply that may become necessary for various reasons such as maintenance.
[0004] Circuit breakers are designed according to their operating environment and intended purpose. They come in many different sizes and shapes. Circuit breakers are also of many different types. The present disclosure pertains to Air Circuit Breakers (ACB) of which there are two types namely, fixed type and extractable or withdrawal type. Fixed types of Air Circuit Breakers are standalone and need no external enclosure for their operations. In extractable or withdrawal type of Air Circuit Breakers, which the present disclosure relates to, the circuit breaker is housed inside an external frame or enclosure that encases the circuit breaker within in such a way that the circuit breaker can be switched off and extracted from within the enclosure for maintenance without removing the termination of bus bars. In extractable/ withdrawal type of circuit breakers, electrical connection between the circuit breaker and external enclosure is maintained with the help of array of movable and flexible contacts. Array of flexible contacts are fixed to the enclosure and remain energized even when the breaker is disconnected and is in withdrawn position. Thus, flexible contacts carry the system potential.
[0005] Most existing draw-out type circuit breaker manufacturers provide a racking arrangement without means to lock it in distinct positions of and means to acknowledge the position of the circuit breaker. Also, most such manufacturers provide a manual racking feature with the help of a racking handle and no provision of motorized racking is provided.
[0006] There is therefore a need in the art to provide a motorized racking arrangement for draw-out type circuit breaker that also incorporates means to achieve locking of the circuit breaker cradle in various cradle positions such as test, service, and isolated positions and further provides an acknowledgement of the locked position. .
[0007] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0008] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0009] 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.
[0010] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0011] 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 markush groups used in the appended claims.

OBJECTS OF THE INVENTION
[0012] It is the object of the present disclosure to provide a motorized racking arrangement for draw out type circuit breakers.
[0013] Another object of the present disclosure is to provide a racking arrangement that provides locking of the circuit breaker in distinct positions.
[0014] Yet another object of the present disclosure is to provide a motorized racking arrangement with means for locking in distinct positions that provides acknowledgement of the locked position.
[0015] Still another object of the present disclosure is to provide a motorized racking arrangement with means for locking and acknowledgement that can be retro-fitted on existing circuit breakers without any major changes.

SUMMARY
[0016] Aspects of the present disclosure relate to draw out type circuit breakers. In particular they pertain to racking arrangement for the circuit breaker. In an aspect, the disclosure provides a retro-fixable kit for motorized “racking in” and “raking out” of circuit breakers and incorporates provision of locking/moving the cradle in/to distinct positions followed by status/position acknowledgement to the user.
[0017] In an aspect, the kit can be mounted on an existing circuit breaker without any modifications to the circuit breaker, using two holes. In another aspect, the kit gets operatively coupled to racking screw of the breaker thus providing the racking effort instead of requirement of manual racking in and racking out.
[0018] In an aspect, the kit can comprise a motor unit configured to provide racking effort for racking of the cradle; an extension shaft operatively coupled to the motor unit and configured to couple with the racking screw of the breaker that drives the breaker inward or outward in cradle; thus transmitting the racking effort from the motor unit to the racking mechanism.
[0019] In an embodiment, the motor unit can be an AC synchronous motor whose direction of rotation can be reversed by reversing direction of electric supply thus enabling racking in and racking out.
[0020] In an aspect, the kit can further comprise means to lock/limit the movement of the cradle up to distinct positions. These positions, for example, can be connected position, disconnected position, test position or isolation position to name a few. These means can comprise a gear member fixedly attached to the extension shaft; a rack plate operatively coupled to the gear member and configured to travel laterally in proportion to the rotation of the extension shaft. The means to limit the movement to distinct positions can further comprise plurality of micro switches configured to engage with the rack plate and generate electric signals corresponding to the distinct positions of the breaker.
[0021] The kit can further comprise a control circuit configured to receive the electric signals from the plurality of micro switches and control operation of the motor unit to carry out racking in or racking out of the breaker to distinct positions based on selection made by a user through an interface means.
[0022] In an embodiment, all the constituents of the kit can be mounted on a bracket to make a compact unit and the bracket can incorporate holes such as two holes mentioned earlier, for mounting the kit on an existing circuit breaker.

BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 illustrates an exemplary schematic overview of the proposed racking kit in accordance with embodiments of the present disclosure.
[0024] FIG. 2 illustrates an exemplary top view of the racking kit in racked-in position in accordance with embodiments of the present disclosure.
[0025] FIG. 3 illustrates an exemplary top view of the racking kit in racked-out position in accordance with embodiments of the present disclosure.
[0026] FIG. 4 illustrates an exemplary control circuit of the proposed racking kit in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION
[0027] 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.
[0028] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0029] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure).
[0030] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0031] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0032] The term ‘Circuit Breaker’ as used herein refers to a mechanical switching device, capable of making, carrying and interrupting currents under normal circuit conditions, and also making and carrying for specified time and interrupting current under abnormal circuit conditions such as those occurring during short circuits. The term ‘Circuit Breaker’ herein refers to draw out type circuit breakers.
[0033] The term ‘Cradle’ as used herein refers to an assembly which provides all the necessary mechanical and electrical interlocks, circuit breaker supports, shutter mechanism, racking mechanism etc. for a draw-out type circuit breaker, which is intended in turn to be installed inside of a switchgear cell. The cradle is moved by means of a racking mechanism so as to connect or disconnect the circuit breaker.
[0034] The term ‘Racking’ as used herein refers to a process of moving the cradle of a draw-out type circuit breaker from the disconnected position to the test position and into the connected position, or vice-versa. Racking is done by a racking mechanism provided on the cradle. The racking mechanism converts the rotary force provided to a racking screw into a horizontal movement, thereby moving the cradle on which the moveable parts of the draw-out type circuit breaker are mounted.
[0035] The term ‘Test Position’ as used herein refers to a position in which the primary disconnecting devices of the removable element of a circuit breaker are separated by a safe distance from the stationary contact elements, and some or all of the secondary circuits are in operating contact.
[0036] The term ‘Service Position’ as used herein refers to a normal operational position of the circuit breaker in which primary disconnecting devices of the removable element of a circuit breaker are fully connected to the stationary contact elements and all the secondary circuits are fully operational. In case of a draw-out type circuit breaker, this can also be called its “racked in” position or the “on” position.
[0037] The term ‘Isolated Position’ as used herein refers to a position of a Circuit Breaker in which the primary disconnecting devices of the removable element of a circuit breaker are fully separated from the stationary contact and all the secondary circuits are inoperative. In case of a draw-out type circuit breaker, this can also be called its “racked out” position or the “off’ position.
[0038] Embodiments of the present disclosure relate to draw out type circuit breakers. In particular disclosure provides a retro-fittable motorized rack kit for draw-out type circuit breakers for motorized “racking in” and “raking out” of the circuit breaker and incorporates provision of locking/moving the cradle in/to distinct positions followed by status/position acknowledgement to the user.
[0039] In an aspect, the kit can be mounted on an existing circuit breaker without any modifications to the circuit breaker, using two holes. In another aspect, the kit gets operatively coupled to racking screw of the breaker thus providing the racking effort instead of requirement of manual racking in and racking out.
[0040] In an aspect, the kit can comprise a motor unit configured to provide racking effort for racking of the cradle; an extension shaft operatively coupled to the motor unit and configured to couple with the racking screw of the breaker that drives the breaker inward or outward in cradle; thus transmitting the racking effort from the motor unit to the racking mechanism.
[0041] In an aspect, the kit can further comprise means to lock/limit the movement of the cradle up to distinct positions. These positions, for example, can be connected position, disconnected position, test position or isolation position to name a few. These means can comprise a gear member fixedly attached to the extension shaft; a rack plate operatively coupled to the gear member and configured to travel laterally in proportion to the rotation of the extension shaft. The means to limit the movement to distinct positions can further comprise plurality of micro switches configured to engage with the rack plate and generate electric signals corresponding to the distinct positions of the breaker.
[0042] The kit can further comprise a control circuit configured to receive the electric signals from the plurality of micro switches and control operation of the motor unit to carry out racking in or racking out of the breaker to distinct positions based on selection made by a user through an interface means.
[0043] In an embodiment, all the constituents of the kit can be mounted on a bracket to make a compact unit and the bracket can incorporate holes such as two holes mentioned earlier, for mounting the kit on an existing circuit breaker.
[0044] Referring to FIG. 1 where an exemplary schematic diagram of the rack kit 100 is disclosed. The kit 100 can comprise a motor unit 102 which can be coupled to one end of an extension shaft 104. The other end of the extension shaft 104 can be configured to engage/couple with racking screw (not shown here) of the breaker that drives the breaker inward or outward in cradle; thus transmitting the racking effort from the motor unit to the racking mechanism.
[0045] In an embodiment, the motor unit 102 can be an AC synchronous motor whose direction of rotation can be reversed by reversing direction of electric supply thus enabling both racking in and racking out depending on requirement.
[0046] In an embodiment, the kit 100 can further comprise means to lock/limit the movement of the cradle up to distinct positions. These positions, for example, can be connected position, disconnected position, test position or isolation position to name a few. These means can comprise a gear member 106 fixedly attached to the extension shaft 104; a rack plate 108 operatively coupled to the gear member 106 and configured to travel laterally in proportion to the rotation of the extension shaft 104. In an embodiment, the coupling of the extension shaft 104 to the racking screw of the racking mechanism can be of quick engagement/disengagement type so as to be easily removable in order to allow for manual racking, if required. In the preferred embodiment it is of socket and plug type construction.
[0047] The means to limit the movement to distinct positions can further comprise plurality of micro switches such as 110-1, 110-2 and 110-3 configured to engage with the moving rack plate 108 at designated places during the travel of the rack plate 108 and generate electric signals corresponding to the designated distinct positions of the breaker.
[0048] In an embodiment, all the above constituents of the kit 100 can be mounted on a bracket 112 to make a compact unit and the bracket 112 can incorporate holes such as two holes 114-1 and 114-2, for mounting the kit 100 on a circuit breaker cradle with extension shaft 104 in engagement with the racking screw of the circuit breaker. After the kit 100 has been mounted on the circuit breaker cradle, the circuit breaker can either be racked-in or out depending on the rotation of the extension shaft 104 as can be provided by the motor unit 102.
[0049] FIG. 2 and FIG. 3 illustrate exemplary top views 200 and 300 of the racking kit 100 in racked-in and racked-out positions respectively in accordance with embodiments of the present disclosure. As shown, the laterally moving rack plate 108 can have a plurality of protrusions 116 which can operatively couple with the micro switches 110 (mounted on the bracket 112) as the rack plate 108 moves laterally to the gear member 106. The protrusions 116 and the micro switches 110 can be configured so that in certain designated/distinct position of the breaker during its lateral travel, the micro switches 110 send out electric signals. In an embodiment, the micro switches 110 can be proximity switches or contact type push switches.
[0050] FIG. 4 illustrates an exemplary control circuit 400 of the proposed racking kit 100 in accordance with embodiments of the present disclosure. The control circuit 400 can be configured to receive the electric signals from the plurality of micro switches 110 and control operation of the motor unit 102 to carry out racking in or racking out of the breaker to distinct positions based on selection made by a user through an interface means.
[0051] In an embodiment, the user interface for distinct positions selection can be but not limited to suitable switches such as a Double Pole Single Throw Switch SW1, a Double Pole Double Throw Switch SW2 and a Push Button Switch SW3. These switches SW1, SW2 and SW3 can be installed at any suitable and convenient position for operation by a user. In the preferred embodiment the switches SW1, SW2 and SW3 can be installed on bracket 112. Alternately it is possible to mount the switches SW1, SW2 and SW3 at a remote location from the Circuit Breaker.
[0052] In an embodiment, control signals for the control circuit derived from the micro switches 110can indicate how much has the cradle travelled in any direction whether in or out. In an embodiment, these control signals can be used to move and stop/lock the cradle to/in different positions. In an embodiment these control signals can also be used to provide audio or visual indications of the cradle’s position at Control Panels remote from the circuit breaker.
[0053] In an aspect, the present disclosure fulfils the need for achieving position locking of the cradle of the draw-out type circuit breaker along with automatic racking of the cradle without manual intervention. In another aspect, the motorized rack kit 100 can be externally fitted to the existing draw-out type circuit breaker arrangement, which ensures position locking of the cradle of the circuit breaker without doing any changes in the cradle arrangement.
[0054] To understand the operation of the invention in accordance with embodiments of the present disclosure, reference can be made to FIG.2, FIG. 3 and the circuit diagram illustrated in FIG. 4.SW1is a Double Pole Single Throw (DPST), Normally Open (NO) switch, which is the main supply control switch for the entire motorized rack kit100. When a user switches on SW1, its normally open (NO) contacts (1-3 & 2-4) close, and the circuit is powered up. Depending on the position of the rack plate (108), the micro switches 110-2, 110-3, and 110-1 are actuated. 110-2, 110-3, and 110-1 are Single Pole Double Throw (SPDT) switches. Assuming that the breaker is in racked-out position as shown in FIG. 3, protrusion 116-1 of the rack plate 108 would keep the micro switch 110-2 pressed, resulting in opening of normally closed (NC) contact (1-2) of 110-2. This will not allow the rack-in operation of the motorized rack kit 100 to start immediately as the supply to the motor unit 102 would be cut-off. In order to start the rack-in operation, the push button switch SW3needs to be pressed till the motor unit 102 continues to move. Pressing the switch SW3 bypasses the opened NC contacts (1-2) of the micro switch 110-2 and the motor unit 102 on getting power supply starts and continues to move. As the circuit breaker moves towards racked-in position, the gear member 106 drives the rack plate 108 laterally and when the breaker is racked in fully, the rack plate 108’sprotrusion116-2 presses/engages with the micro switch 110-2, causing the NC contacts (1-2) of 110-2 to open, thereby cutting off the supply to the motor unit 102. The motor unit 102 and consequently the cradle’s further movement is stopped. This position indicates the test position of the circuit breaker.
[0055] When it is desirable to rack-in the circuit breaker further, the push-button switch SW3 can be pressed again till the motor unit 102 continues to move. Pressing the switch SW3 bypasses the opened NC contacts (1-2) of micro switch110-2 and as the motor unit 102 keeps gets power supply ,it starts moving and the circuit breaker continues to get racked in and gear member 106 continues to drive the rack plate 108 laterally. When the breaker reaches the service position, micro switch 110-2 is now pressed by protrusion 116-3 of the rack plate 108. At this moment, protrusion 116-5 of the rack plate 108 also actuates micro switch 110-1, causing the NC contacts (1-2) of the micro switch 110-1to open, thereby causing the motor supply to be cut-off. At this position, the circuit breaker has moved in completely and is in its “racked-in” position.
[0056] To rack-out the breaker, the Double Pole Double Throw Switch (DPDT) SW2 can be toggled to the other position, which reverses the winding terminals of the AC synchronous motor and also shorts terminals (1-2) of micro switch110-1. Again, the push button switch SW3 can be pressed for the motor unit 102 to start moving in opposite direction, in turn driving the circuit breaker cradle as well as the rack plate 108 in their respective opposite directions. The same cycle is repeated till the breaker reaches full racked-out condition. At this point, protrusion 116-1 actuates the micro switch 110-2 and the NC contacts (1-2) of 110-2 open and the circuit breaker stops moving further. Also, at the same time, micro switch 110-3 is actuated by protrusion 116- of the rack plate 108. The circuit breaker cradle cannot move further till the direction of rotation of motor unit 102 is reversed, that is, switch SW2is toggled. Again, to rack-in the breaker, the switch SW2 is toggled to the other position, which now reverses the motor unit102direction and also connects the NC terminals (1-2) of the micro switch 110-3 externally. Now, to rack-in the breaker again, the push-button switch SW3 is pressed momentarily and the entire cycle starts again.
[0057] It can be appreciated that the motor unit 102 continues driving the extension shaft 104 until the micro switch 110-2 is pressed by rack plate protrusions (116-1, 116-2, or 116-3) as shown in FIGs. 2 and 3. Further, in racked in position, micro switch 110-1 is pressed by protrusion 116-5 while in racked-out position micro switch 110-3 is pressed by protrusion 116-4 respectively. This in turn interrupts the electric supply to the motor unit 102. Consequently, the motor unit 102 stops rotating and so the extension shaft 104 as well as the rack plate 108 stop. As the extension shaft 104 in turn drives the racking mechanism of the cradle of the circuit breaker, the cradle also stops moving.
[0058] The plurality of micro switches 110 and the Switches SW1, SW2 and SW3 can further be used to provide control signals to lock the cradle in different positions as well as provide acknowledgement to the user for further racking operations as will be readily understood by a person skilled in the art.
[0059] In an aspect of the present disclosure, the proposed motorized rack kit 100 can be mounted on the circuit breaker cradle by fastening on 2 mounting holes 114-1 and 114-2 as shown in FIG.1. The motorized rack kit 100 can ensure motorized input to drive the extension shaft 104 whose rotation allows motion of circuit breaker cradle from rack-in to rack-out position & vice versa. At distinct positions such as three positions corresponding to test, service, and isolate positions, the motorized rack kit 100 can stop further motion of the circuit breaker cradle and the motion can be re-started using the user interface.
[0060] In an aspect, the proposed construction enables automatic rack-in & rack- out operation of the circuit breaker cradle in draw-out type switchgear, and further enables position locking of the cradle of the circuit breaker with acknowledgement to the user. Furthermore, no modification or additional components are required in the rack or in the breaker assembly to achieve motorized racking and position locking, thereby enhancing the reliability of the operation. The proposed construction further includes an additional feature of viability to use the same unit for different frames and sizes of switchgear devices. Furthermore, use of short-circuit proof synchronous motor gives excellent on load performance and enhanced reliability.
[0061] As used herein, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously.
[0062] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C …. and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
[0063] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0064] The present disclosure provides a motorized racking arrangement for draw out type circuit breakers.
[0065] The present disclosure provides a racking arrangement that provides locking of the circuit breaker in distinct positions.
[0066] The present disclosure provides a motorized racking arrangement with means for locking in distinct positions that provides acknowledgement of the locked position.
[0067] The present disclosure provides a motorized racking arrangement with means for locking and acknowledgement that can be retro-fitted on existing circuit breakers without any major changes.
,CLAIMS:1. A rack kit for racking in or racking out cradle of a draw-out type circuit breaker; the kit comprising :
a motor unit;
an extension shaft operatively coupled to the motor unit and configured to couple with racking screw of the cradle;
a gear member fixedly attached to the extension shaft;
a rack plate operatively coupled to the gear member and configured to travel laterally in proportion to rotation of the extension shaft;
plurality of micro switches configured to engage with the rack plate and generate electric signals corresponding to one or more distinct positions of the breaker; and
a control circuit configured to receive the electric signals from the plurality of micro switches and control operation of the motor unit; wherein the control circuit operates the motor unit to carry out racking in or racking out of the circuit breaker to the one or more distinct positions based on selection made by a user through an interface means.

2. The kit of claim 1, wherein the motor unit comprises a synchronous motor.

3. The kit of claim 1, wherein the engagement between the plurality of micro switches and the rack plate is by means of plurality of protrusions on the rack plate and position of the plurality of protrusions on the rack plate correspond to the one or more distinct positions of the circuit breaker.

4. The kit of claim 1 wherein the one or more distinct positions of the circuit breaker correspond to one or a combination of positions selected from group consisting of testing position, service position, isolated position.

5. The kit of claim 1, wherein the kit further comprises a bracket and all parts of the kit are assembled on the bracket.

6. The kit of claim 5, wherein the kit is retro-fittable and retro-fitment is done through holes configured on the bracket.
7. The kit of claim 1, wherein the interface means for selecting one or more distinct positions are one or more switches.

8. The kit of claim 7, wherein the one or more switches are one or a combination of switches selected from group consisting of Double Pole Single Throw Switch, Double Pole Double Throw Switch and Push Button Switch.

9. The kit of claim 1, wherein the interface means are additionally configured to indicate status of the circuit breaker racking.

10. The kit of claim 9, wherein the interface means are remotely located.