Embodiments of the invention in general relates to the field of circuit breaker and accessories, and more particularly to a short-rated shunt so as to introduce a safety feature in which the micro switch will not allow current to pass through the accessory until it is assembled inside the breaker.
BACKGROUND OF THE INVENTION
A Molded Case Circuit Breaker widely known as MCCB, is one which is amass in closed housing of insulating material for making, carrying and breaking currents under normal and abnormal condition. It should be working acceptably under overload and short circuit conditions as per design. MCCBs are mostly designed to deliver protection to low voltage distribution systems.
The MCCB is being increasingly accepted in Indian industries as a circuit protection device with several advantages over old age practice of using switch and fuse units. There has been a nonstop surge in the manufacture of MCCBs because of a number of factors, such as compactness and market stresses, consistent performance, use of advanced rating insulating material and introduction of new technologies such as solid state and microprocessor based trip and control systems. These improvements have significantly enlarged the system flexibility of MCCB and it is now possible to adapt a MCCB to an extensive variety of applications.
The primary function of MCCBs is to keep protected core circuit elements in the event of an unnecessary fault. A MCCB mechanically separates the electrical circuit under continued overloads or short circuit.
A short rated shunt device trips the circuit breaker on receiving impulsive supply from the control room. This alleviates remote tripping feature.
Embodiments of the present invention relates to features of accessories and to assemble them with ease and serve the purpose of tripping effectively. The major

disadvantage of current products is the use of extra components to adapt the same feature. It increases the assembly time and cost as well.
In view of the prior art, there is a dire need of an arrangement, where all the requisite functions can be achieved in a more simplistic way and by using fewer components in comparison to other inventions, thereby ensuring robust and reliable way of achieving the requisite functions.
SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.
According to one aspect of the present invention, moulded case circuit breaker, MCCB, comprising: a front cover pivotably coupled to a main cover of the MCCB, said main cover comprises at least one cavity integrating at least one internal accessory into the cavity, wherein the internal accessory is operably coupled to a tripping mechanism for mechanical tripping in case of any abnormal conditions.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:
Fig. 1 illustrates a 3-Dimentsional view of a MCCB with shunt assembly inside cover cavity, according to an embodiment of the present invention.

Fig. 2 illustrates a front view of MCCB with section to be taken to understand details in fig 7-12, according to an embodiment of the present invention.
Fig. 3 illustrates a 3-Dimentsional view of stand alone shunt release, according to an embodiment of the present invention.
Fig. 4 illustrates a spring arrangement with a flapper, according to an embodiment of the present invention.
Fig. 5 illustrates a lever arrangement in shunt release, according to an embodiment of the present invention.
Fig. 6 illustrates a lever arrangement with shunt micro switch, according to an embodiment of the present invention.
Fig. 7 illustrates the flapper cam arrangement with cover during assembly, according to an embodiment of the present invention.
Fig. 8 illustrates the flapper final arrangement post final assembly in cover, according to an embodiment of the present invention.
Fig. 9 illustrates the lever arrangement with MCCB drive shaft, according to an embodiment of the present invention.
Fig. 10 illustrates an enlarged view of lever arrangement, Flapper and Drivershaft when MCCB is in ON condition, according to an embodiment of the present invention.
Fig. 11 illustrates the micro switch NC state when MCCB is in ON condition, according to an embodiment of the present invention.
Fig. 12 illustrates the micro switch NO state when MCCN is in OFF condition, according to an embodiment of the present invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary

embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
The present disclosure will now be described more fully with reference to the accompanying drawings, in which various embodiments of the present disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the various embodiments set forth herein, rather, these various embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the present disclosure. Furthermore, a detailed description of other parts will not be provided not to make the present disclosure unclear. Like reference numerals in the drawings refer to like elements throughout.
The subject invention lies in providing safety to end customer from hazardous burning of accessory. If the short rated shunt is energized in stand-alone state, there will be no mechanism to cut-off the supply after actuation. Thus, continuous flow of current through short rated shunt coil might lead to burning of coil or permanent damage. The flapper arrangement keeps the shunt circuit in open condition until it is assembled in the breaker, thereby ensuring no current flow in the coil in stand-

alone condition. Even if the customer supplies current outside MCCB, SHR will remain safe by not allowing current to flow from circuit.
The basic circuit breaker 1, as shown in Figure 1, includes a front cover 4 properly pivoted with a main cover 3. The front cover 4 is demonstrated open and an internal accessory 2 housed into a cavity 3a of the main cover 3. The internal accessory 2 is integrated with the main cover 3.
Normally SHR outside MCCB, a shunt lever (2d) pushes the micro switch (2e) with the help of a torsion spring (2f) estabhshingNC configuration. This ensures current flow through shunt release even if the shunt is not assembled into MCCB which causes burning of coil when current is allowed to flow for a longer duration at rated voltage. The introduction of a flapper (2g) gives the safety feature where shunt micro switch outside MCCB will be in NO condition where no supply can pass through shunt and after assembly into MCCB cover it will come to NC when MCCB is in ON condition and allow current to pass when instantaneous current given.
Here the ends of torsion spring (2f) are fixed on two different rotating parts, one at the flapper hole 2g (ii) and other at the lever (2d), as shown in Figure 4 and Figure 5. The micro switch force rotates shunt lever (2d) in a clockwise direction and free angle of spring rotates the flapper component in a clockwise direction. In this way, assembly outside MCCB ensures NO state of switch by keeping it in open condition. In this state shunt cannot pass any supply so cannot burn outside MCCB.
The cross-section of circuit breaker 1 is shown in Figure 3, with section line shown in Figure 2, is prior to insertion of the accessory 2 inside the main cover 3. The line of section is also drawn in Figure 2 for reference of figures ahead.
During the assembly of shunt release the flapper cam surface 2g (i) interacts with main cover 3 wall. This cam rotates once we push shunt assembly inside cover cavity. Total rotation of flapper component is 20 degree higher than shunt lever; this achieves 20 degree spring assembly angle and apply required force on micro

switch through 2d-ii to 2e-i. Hence, after full assembly inside MCCB shunt will be in NC State, as shown in Figures 7-10.
The cross-section of circuit breaker 1 is shown in Figures 9-10 with section line shown in Figure 2, wherein the accessory unit 2 is located at final intended position. The flapper 2g is at its final fixed position rotating the lever through spring force ensures micro switch in NC condition. Here if we supply the current it will trip the MCCB. After tripping mechanism drive shaft will come up and actuate lever through 2d-iii profile and 2d-ii profile of lever will push 2e-ii profile of micro switch and keep shunt in NO condition, as shown in Figures 7-8 and Figures 11-12.
Thus, the present invention ensures no burning of shunt outside of MCCB assembly. Shunt will only wok inside cover after full assembly inside MCCB cover.
Some of the non-limiting advantages of the rotating flapper arrangement in short rated shunt for no continuity in shunt in standalone state are:
1. When shunt is outside MCCB cover- Micro switch will remain in NO condition and not allow current to flow inside circuit. This is achieved by no force on micro switch through lever during this state.
2. When Shunt is outside MCCB cover- Short rated shunt circuit will remain in NO condition and not allow current to pass.
3. Short rated shunt cannot burn outside MCCB cover as it will remain in NO condition outside cover cavity.
4. No current supply outside MCCB provides safety feature for human use.
5. Torsion spring will remain in free condition when shunt is not assembled into cover cavity, and the torsion spring will remain always in loaded condition only when shunt is fully assembled in cover cavity.
6. When shunt is inside cover cavity and breaker is in ON condition - Cam between flapper (2g-i and 2g-ii) and cover ensures micro switch will remain into NC condition through spring and profile 2d-ii of lever. This will allow current to flow when remote tripping supply given to Shunt.

Although rotating flapper arrangement in short rated shunt for no continuity in shunt in standalone state has been described in language specific to structural features, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific methods or devices described herein. Rather, the specific features are disclosed as examples of implementations of rotating flapper arrangement in short rated shunt for no continuity in shunt in standalone state.

WE CLAIM:

1. A moulded case circuit breaker, MCCB (1), comprising:
a front cover (4) pivotably coupled to a main cover (3) of the MCCB, said main cover (3) comprises at least one cavity (3a) integrating at least one internal accessory (2) into the cavity (3 a), wherein the internal accessory (2) is operably coupled to a tripping mechanism (5) for mechanical tripping in case of any abnormal conditions.
2. The moulded case circuit breaker, MCCB, as claimed in claim 1, wherein the internal accessory (2) is a Short rated shunt release, said shunt release comprises a shunt lever (2d) operably coupled to a micro switch (2e) via a torsion spring (2f) and a flapper (2g), said torsion spring (2f) ends are operably coupled between two different rotating parts, one at the flapper hole 2g (ii) and other at the shunt lever (2d), where the micro switch (2e) outside MCCB will be in Normally Open, NO, condition where no supply can pass through shunt and after assembly into MCCB cover it will come to Normally Closed, NC, when MCCB is in ON condition and allow current to pass when instantaneous current is given.
3. The moulded case circuit breaker, MCCB, as claimed in claim 1, wherein the shunt lever (2d) is adapted to push the micro switch (2e) with the help of a torsion spring (2f) establishing NC configuration, to ensure current flow through the shunt release (2) even if the shunt is not assembled into MCCB which causes burning of coil when current is allowed to flow for a longer duration at rated voltage.
4. The moulded case circuit breaker, MCCB, as claimed in claim 1, wherein the micro switch (2e) force is adapted to rotate the shunt lever (2d) in a clockwise direction and free angle of torsion spring (2f) is adapted to rotate the flapper (2g) component in a clockwise direction, such that assembly outside MCCB ensures NO state of switch by keeping it in open condition, and shunt cannot pass any supply so cannot burn outside MCCB.

5. The moulded case circuit breaker, MCCB, as claimed in claim 1, wherein a flapper cam surface 2g (i) interacts with the wall of the main cover (3) during assembly of the shunt release, and the cam is adapted to rotate on pushing the shunt release inside the cavity (3a).
6. The moulded case circuit breaker, MCCB, as claimed in claim 1, wherein the total rotation of the flapper (2g) component is 20 degree higher than the shunt lever (2d), to achieve a 20 degree spring assembly angle and apply required force on the micro switch (2e) through surfaces 2d-ii to 2e-i.
7. The moulded case circuit breaker, MCCB, as claimed in claim 1, wherein the flapper (2g) at its final fixed position is adapted to rotate the lever through spring force to ensure that the micro switch is in NC condition, and supplying current will trip the MCCB.
8. The moulded case circuit breaker, MCCB, as claimed in claim 7, wherein after tripping mechanism drive shaft will come up and actuate lever through 2d-iii profile and 2d-ii profile of lever will push 2e-ii profile of micro switch and keep shunt in NO condition.
9. The moulded case circuit breaker, MCCB, as claimed in claim 1, wherein the torsion spring (2f) will remain in free condition when shunt release is not assembled into the cover cavity (3 a), and the torsion spring (2f) will remain always in loaded condition only when shunt release is fully assembled into the cover cavity (3a).