A molded case circuit breaker (MCCB)

Abstract

Described herein is a molded case circuit breaker (MCCB) [100], comprising: a plurality of pole assemblies [102], each comprising a casing unit [116] defining a guide-slot [116h]; an actuator assembly [112] installed atop one of the plurality of pole assemblies [102], such that the guide-slot [116h] of the other of the plurality of pole assemblies [102] adjacent thereto are positioned proximal to the actuator assembly [112]; and a primary tripping accessory [146] defining a first portion [150] and a second portion [148]. Notably, the first portion [150] is adapted to slidably engage with the guide-slot [116h], to be fittingly installed atop one of the plurality of pole assemblies [102], while the second portion [148] is adapted to engage with a pair of fastening members [152] extending through at least a portion of a mid-cover assembly [106] of the MCCB [100], to be fittingly installed relative thereto, thereby facilitating an overall rigid mounting of the primary tripping accessory [146] within the MCCB [100].

Description

[0001] A MOLDED CASE CIRCUIT BREAKER (MCCB)

[0002] TECHNICAL FIELD

[0003] The present invention relates to the field of circuit breakers, and more particularly, to a moulded case circuit breaker (MCCB) and an arrangement thereof.

[0004] BACKGROUND OF THE INVENTION

[0005] This section is intended to provide information relating to the field of the invention and thus, any approach or functionality described below should not be assumed to be qualified as prior art merely by its inclusion in this section.

[0006] Circuit Breakers are electro-mechanical switching devices capable of carrying and interrupting a flow of current and are also commonly known as over current protective devices. Under normal circuit conditions, a circuit breaker closes the electrical circuit, carries current for a specified time, and breaks the electrical circuit under specified abnormal circuit conditions. These over current protective devices are also employed for current interruption. Accordingly, it is said that circuit breaker is an equipment which can open or close the circuit, under all conditions viz. no load, full load, and fault conditions. Low voltage circuit breakers are commonly known to be deployed for low voltage applications, for example 1000 Volt or lower.

[0007] Various examples of low voltage circuit breakers are known, for example, a miniature circuit breaker (MCB), a moulded case circuit breaker (MCCB), a residual current circuit breaker (RCCB), an air circuit breaker (ACB), and the like. Notably, the MCB is used in applications of current rating under 125 Amperes and interrupting current rating of under 10KA, while MCCB is used in applications of current rating up to 1600 Amperes usually and interrupting current in a range of 10KA -150KA. Accordingly, it is submitted that MCCB is used for relatively high current rating applications.

[0008] Moulded case circuit breaker (MCCB) is commonly a multipolar circuit breaker, which protects the electrical network / circuit and equipment from overloading or short-circuiting. Specifically, the MCCB is capable of operating between an ON position, an OFF position, and a TRIP position. Conventionally, the MCCB includes at least a base assembly, a mid-cover assembly, a fascia plate assembly, at least one pole assembly, a TRIP assembly, and an actuator assembly. In one embodiment, the MCCB is a three-pole unit comprising of three (3) pole assemblies. In such embodiments, the base assembly, a mid-cover assembly, a fascia plate assembly, in combination with each other, forms a housing to house and support the three pole assemblies therein. Further, the actuator assembly is mounted on at least one of the three (3) pole assemblies, while the TRIP assembly is mounted on at least one of the three (3) pole assemblies, such that the three (3) pole assemblies are connected and operated together between the ON position, the OFF position, and the TRIP position. Particularly, the actuator assembly includes a lever switch that can be manually adjusted, to operate the three (3) pole assemblies together between the ON position, the OFF position, and the TRIP position.

[0009] In light of the aforementioned, it is understood that each pole assembly operates between the ON position, the OFF position, and the TRIP position. Conventionally, each of the three pole assemblies includes a casing assembly, a rotary contact unit, a stationary contact unit, and an arc chute unit. The casing assembly is a left-right type casing which includes defined sections for positioning of each of the rotary contact unit, the stationary contact unit, and the arc chute unit, such that the casing assembly houses and supports each of these components therein. The stationary contact unit is a conducting plate positioned within the casing assembly, and mostly electrically connected to a line side of the electric circuit. The rotary contact unit is a rotary assembly that is rotatably positioned within the casing assembly, and generally electrically connected to a load side of the electric circuit. The rotary contact unit can be rotated in one direction to allow the rotary contact unit to contact with the stationary contact unit, and thus resulting in the ON position of the pole assembly, further, the rotary contact unit can be rotated in opposite direction to allow the rotary contact unit to release contact from the stationary contact unit, and thus resulting in the OFF position of the pole assembly.

[0010] Moreover, the rotary contact unit is a combination of a rotary member, a rotating arm member, a metal conducting plate electrically connected to the rotating arm member, and a toggling mechanism. The rotating arm member is connected to the rotary member, by way of the toggling mechanism. Notably, the rotary member, the rotating arm member, and the toggling mechanism, are rotated together, to adjust the pole assembly between the ON position and the OFF position. The toggling mechanism toggles the rotating arm member, to rotate in one direction, with respect to the rotating member, to adjust the pole assembly between the ON position and. Therefore, the rotary contact unit plays a vital role in determining the accuracy, speed, and effectiveness of adjustment of the pole assembly, between the ON position, the OFF position, and the TRIP position.

[0011] Reference may be made to the following: Publication no. IN1095 / MUM / 2014discloses an improved circuit breaker comprises of a first assembly (15), a second assembly (18), a third assembly (22), a fourth assembly (32), a fifth assembly (44), a sixth assembly (47), and a seventh assembly (50). The said sixth assembly (47) is a complete breaker assembly combining said first assembly (15), said second assembly (18), said third assembly (22), said fourth assembly (32), and said fifth assembly (44). Further, said sixth assembly (47) is configured to provide a hardware free assembly and flips locking of at least one moving contact.

[0012] Publication no. US6317018 discloses mechanism for operating a plurality of circuit interruption mechanisms of a circuit breaker, the mechanism applies a uniform force to the circuit interruption mechanisms. The mechanism applying a force to an elongated member for manipulating the circuit interruption mechanisms. The mechanism applying the force to the elongated member at a first position and a second position, the first position and the second position being intermediate to a center of the elongated member and the plurality of circuit interruption mechanisms.

[0013] Publication no. CN201359982 discloses multi-pole low-voltage rotation double-break molded case circuit breaker belongs to the technical field of low-voltage apparatus. The circuit breaker comprises an operation mechanism, a plurality of single-pole units and a connecting mechanism, wherein, each single-pole unit comprises a housing, a pair of static contact modules and a pair of movable contact modules, the movable contact modules comprise contacts and rotors; the connecting mechanism comprises at least two connecting sheets and two supporting shafts, the two connecting sheets are placed between the adjacent single-pole units, first connection holes and second connection holes are respectively formed on both ends of the connecting sheets, and third connection holes are formed in the middle of the connecting sheets; first connecting shafts penetrate through the first connection holes of the connecting sheets, and are connected with the movable contact modules of the single-pole units; second connecting shafts penetrate through the connection holes of the connecting sheets, and are connected with movable contact modules of the single-pole units, and are connected with a lower connecting rod of the operation mechanism; the two supporting shafts penetrate through the third connection holes of the corresponding connecting sheets, and both ends of the supporting shafts are mounted on the housing near to the adjacent single-pole units. The circuit breaker with simple structure and convenient installation is favorable for enhancing the mechanical service life.

[0014] Publication no. IN482 / CHE / 2008 discloses a contact system for a molded case circuit breaker, which reduces the constriction force between the contacts and produces higher blow out force when an arc is produced while contacts are being separated is provided. The contact system for molded case circuit breaker comprises of a contact system having a stationary contact, a movable contact, a spring-biased mechanism for enabling the coupling of the stationary and movable contacts, and a plurality of rods provided on the movable contact, wherein the movement of the rods provided on the movable contacts enable the translatory movement of the contact system. The improved contact system for a molded case circuit breaker of the present invention further enables greater opening between the movable and stationary contacts and is able to control short circuit withstanding time or current.

[0015] Publication no. EP2148351 discloses a mold cased circuit breaker (1) (MCCB) comprising a plurality of single pole breaking units simultaneously opened or closed by a pair of common shaft pins (31). The MCCB effectively transmits a torque for opening or closing contacts between movable contactors (34) and fixed contactors for a plurality of poles, to adjacent shafts (32) with a minimized loss, and prevents the shaft pins from being bent. The MCCB comprises a crank (35) installed across the pair of shaft pins so as to connect the shaft pins to each other.

[0016] Publication no. CN204167232 discloses jump buckle assembly of a molded case circuit breaker comprising a first jump buckle, a second jump buckle, a riveting shaft which connects the first jump buckle and a second jump buckle, and an upper connecting rod which is positioned between the first jump buckle and the second jump buckle and is capable of free rotation. A first through hole and a second through hole are formed in the upper connecting rod. The first through hole and a first jump buckle hole, the second through hole and the second jump buckle hole are connected through the same rivet structures. Each rivet structure includes a rivet cap which axially positions the upper connecting shaft, and a rivet body, wherein the rivet body includes a first shaft segment and a second shaft segment.

[0017] Publication no. CN216288224 discloses a molded case power distribution protection circuit breaker, which comprises a device body, an insulating plate and an electrical fire monitoring detector, two groups of second fixing pins are arranged on two sides of the outer part of the insulating plate, and the device body is arranged on the front surface of the insulating plate through the matching of the second fixing pins and the first fixing pins. A high-temperature- resistant panel is installed on the front face of the device body, an operation handle is installed in the center of the front face of the high-temperature-resistant panel, an electric appliance fire monitoring detector is installed on one side of the front face of the high-temperature-resistant panel, and a communicator is installed above the front face of the electric appliance fire monitoring detector. Publication no. CN209786778 relates to an intelligent molded case circuit breaker. Three-phase power of a main loop respectively passes through three mutual inductors. Electric energy signals detected by the three mutual inductors are partially supplied to the rectifying and filtering module, and a part of fdtered energy is supplied to the working power supply module to form a power supply of the controller so as to respectively supply power supply voltage to the microprocessor, the sampling circuit, the signal filtering circuit, the multi-way switching circuit, the window comparator, the amplifying circuit, the rectifying circuit and the driving circuit; the other part of the sampling signals of the three mutual inductors are connected with the sampling circuit and then connected with the fdter circuit; after processing, one part is connected with the window comparator circuit, the other part is connected with the multi-way switch circuit, the multi-way switch circuit is connected with the amplifying circuit, then connected with the signal rectifying circuit and then connected with the microprocessor, an output signal of the microprocessor is connected with the driving circuit and then connected with a lock catch rod of the circuit breaker, and the lock catch rod is connected with a tripping mechanism of the molded case circuit breaker.

[0018] Publication no. US2005046528 discloses multipole cassette assembly having a center pole cassette assembly includes a first side and a second side, a first outer pole cassette assembly having a first side and a second side, a first spacer interlocking receptacle positioned on one of the first side of the center pole cassette assembly and the second side of the first outer pole cassette assembly, and a first interlocking spacer positioned on one of the first side of the center pole cassette assembly and the second side of the first outer pole cassette assembly, wherein the first interlocking spacer is engaged with the first spacer interlocking receptacle. A method for maintaining spacing between poles of the multipole cassette assembly includes providing an interlocking spacer on the first cassette assembly, providing an interlocking receptacle on a second cassette assembly, and engaging the interlocking spacer with the interlocking receptacle.

[0019] Publication no. JPH0512976 relates to easily carring out an independent emulsifying mixing by spouting liquids to be mixed through each independent nozzle member with high pressure and fixing four sheets of linear members in a mixing camber connected with the opening ends of nozzle member. The pressurized liquids sent from nozzle members 2, 3 are injected to a 1st liner member 15 through through-holes 5, 6 provided to a block 8 forming a mixing chamber. The injected liquids move to the center direction of the liner member 15, reach the inner ends of guiding long apertures 19, 20, pass through guiding apertures 21, 22 of a 2nd liner member 16, and then, reach the outer ends of longitudinal part of a mixing aperture 24 of a 3rd liner member 17, from which the liquids flow to the center, and collide each other to be mixed and emulsified. The 3rd liner member 17 is made to be thinner than a 4th liner member 18 so that both liquids radically collide each other to be mixed.

[0020] Publication no. US5298874 discloses modular low voltage multipole circuit breaker, including a plurality of identical single-pole breaking units each including a parall elipipedic insulating box having two opposite parallel large side faces and two opposite parallel small side faces, two terminals located at respective opposite parallel small side faces, a stationary contact electrically connected to one of the terminals, a movable contact cooperable between a first position contacting the stationary contact and a second position separated from the stationary contact and a molded case for housing the single-pole breaking units. The molded case has two opposite parallel side walls having the same thickness, the single-pole breaking units being sequentially arranged and parallel to each other and parallel to the side walls such that adjacent single-pole breaking units are spaced apart a distance equal to twice the thickness of the side walls, the single-pole breaking units being spaced apart at a constant pitch. An operating mechanism is provided to be common to all single-pole breaking units for simultaneously operating all singlepole breaking units.

[0021] Publication no. US3991391 discloses circuit interrupter characterized by a movable contact arm disposed between two spaced stationary contacts which arm is movable to the open position by electromagnetic forces generated by an overload current condition.

[0022] Publication no. US2016104591 discloses single-pole breaking unit which includes a rotary contact bridge, a stationary contact operating with the contact bridge and connected to a current input, a rotary bar having radially extending axial end surfaces, and radial side surfaces with a transverse hole for the contact bridge which is salient through opposite radial side surfaces of the bar, an arc extinguishing chamber opening onto an opening volume for the contact bridge, two parallel side panels parallel to the axial end surfaces of the bar, with the rotary bar located between two sealing flanges between the axial end surfaces of the rotary bar and the side panels and movable axially toward the side panels to ensure tightness between the inside and the outside of the breaking unit, the sealing flanges each comprising a radially extending portion, and a cylindrical portion, both co-axial with the rotary bar, which cylindrical portion has an inside radius slightly less than the radial extent of the rotary bar, providing a space between the inside surface of the cylindrical portion and the rotary bar, the space permitting quenching gases to flow directly to push a sealing flange axially against a side panel to achieve tightness. Publication no. FR2891660 discloses circuit breaker (100) having actuator shafts (152) connected to a support shaft of each of a set of single-pole circuit breakers (HOa-l lOd) to simultaneously transmit a rotary force generated by a switchgear (150). Each single-pole circuit breaker has a mobile contactor selectively contacting a pair of fixed contactors, and the switchgear is arranged on the circuit breaker (110b) to selectively break a circuit. An actuator shaft's deformation preventing unit (170) is arranged between the circuit breaker (HOd) remotely spaced from the switchgear and the adjacent circuit breaker (110c).

[0023] Publication no. CN211376531 discloses a contact expansion device of an electronic thermal relay. The circuit comprises a relay KI, a live wire L and a null line N. A pin 10 of the relay KI is electrically connected with a rectifier bridge circuit, the rectifier bridge circuit is electrically connected with an external contact circuit, a pin 11 of the relay KI is electrically connected with the live wire L,and a power input end of the rectifier bridge circuit is electrically connected with the null line N. According to the utility model, the problem that the traditional relay in the prior art only has one group of contact signals, so that the traditional relay cannot provide alarm output signals for reflecting overload tripping protection is solved. The utility model has the advantages of simple structure, clear function, simple assembly, low cost and the like

[0024] Publication no. CN209488540 discloses a thermal memory circuit. Wherein the current sampling circuit and the capacitor charging and discharging circuit are respectively connected with the microprocessor, the current sampling circuit is used for providing a sampling signal of loop current for the microprocessor, and the capacitor charging and discharging circuit is used for charging and discharging an energy storage capacitor contained in the capacitor charging and discharging circuit under the control of the microprocessor; the capacitor charging and discharging circuit is composed of a resistor Rl, a resistor R2, an energy storage capacitor Cl and a diode D 1. One end of the resistor Rl is connected with one I / O port of the microprocessor, the other end of the resistor Rl is connected with the positive electrode of the diode DI, the negative electrode of the diode D 1 is connected with the positive electrode of the energy storage capacitor Cl and one end of the resistor R2, and the negative electrode of the energy storage capacitor Cl and the other end of the resistor R2 are both grounded. And the positive electrode of the diode DI is also connected with one AD port of the microprocessor. The utility model also discloses an electronic release and a circuit breaker.

[0025] Publication no. CN109905108 discloses a thermal memory circuit, wherein the current sampling circuit and the capacitor charging and discharging circuit are connected with the microprocessor, the current sampling circuit is used for providing sampling signals of loop current for the microprocessor, and the capacitor charging and discharging circuit is used for charging and discharging an energy storage capacitor contained in the capacitor charging and discharging circuit under the control of the microprocessor; The capacitor charging and discharging circuit consists of a resistor Rl; Resistor R2, wherein one end of the resistor R1 is connected with one I / O port of the microprocessor, the other end of the resistor Rl is connected with the positive electrode of the diode DI, the negative electrode of the diode DI is connected with the positive electrode of the energy storage capacitor C 1 and one end of the resistor R2, and the negative electrode of the energy storage capacitor C 1 and the other end of the resistor R2 are grounded; And the positive electrode of the diode D 1 is also connected with one AD port of the microprocessor.

[0026] Publication no. CN207234189 provides a low voltage fixed -type switchgear assembly for solve the poor problem of thermal diffusivity, it includes the cabinet body and cabinet door, and the louvre has been seted up to cabinet student end, and internal of cabinet is equipped with the dead lever, the horizontal baffle of fixed connection a plurality of on the dead lever, the internal portion right side of cabinet is equipped with the cable chamber, and cable chamber internal connection has the hold assembly, the double -colored LED status display lamp of fixed connection on the hold assembly, the back wall mounting on cabinet body upper portion has the semiconductor refrigeration piece, and the radiator is connected to the semiconductor refrigeration piece, and the bottom of radiator links to each other with the fan, it all connects the filter screen all to be equipped with blow vent and each blow vent on each horizontal baffle, each blow vent is not on a straight line, top cap one side of the cabinet body is provided with rings through hinge and cabinet body coupling on the top cap, cabinet body bottom is equipped with the supporting leg. The utility model discloses cabinet student portion is equipped with the louvre, all is equipped with the blow vent on the baffle, is equipped with semiconductor refrigeration piece, radiator and fan on the wall of cabinet body back to make heat dispersion promote greatly.

[0027] Publication no. CN206076750 relate to a novel low pressure panel mount switchgear. This novel low pressure panel mount switchgear includes: flexible lightning rod, electronic lock, heat dissipation fan, dustcoat, cabinet door, thermal dissipation baffle, universal wheel, support, electrical locking device, panel board, the cabinet body and high temperature alarm, both ends are respectively through hinge hinge connection about the cabinet body the cabinet door, the cabinet is equipped with on the side outdoors electronic lock, electrical locking device, cabinet body top is equipped with one the panel board, the outer cover of heat dissipation fan has the one deck the dustcoat, cabinet body lower extreme is equipped with one the support, the utility model discloses simple structure reasonable in design, cabinet body top is equipped with high temperature alarm, avoids equipment to be in work high temperature under, user of service does not know to result in electronic component to bum out, or equipment for some reason the barrier can result in equipment high temperature affect using by the conflagration, just adopt thermal dissipation baffle good heat dissipation, it is effectual to lower the temperature.

[0028] Publication no. US6313425 discloses cassette assembly for rotary contact circuit breakers utilizing a first electrically insulative cassette half piece and a second electrically insulative cassette half piece which are arranged to mate with each other to form an enclosure. The electrically insulative cassette half pieces include improper installation rejection features for both the rotor and arc chute assemblies. The inner surface of a electrically insulative cassette half piece including a groove and recesses formed therein. A rotor is properly positioned within the electrically insulative cassette half piece by inserting a pin on the face of the rotor into the groove. An arc chute assembly is properly positioned within the electrically insulative cassette half piece by inserting a tab located on a side member of the arc chute assembly into a corresponding recess located in the electrically insulative cassette half piece.

[0029] Publication no. US6750743 discloses a circuit breaker for a multi-pole electrical distribution circuit includes a cassette associated with each pole in the multi-pole electrical distribution circuit. Each cassette includes a housing, a pair of electrical contacts disposed in the housing, and a thermal and magnetic trip unit supported by the housing. The housing includes a first compartment having the electrical contacts disposed therein and a second compartment having at least a portion of the thermal and magnetic trip unit disposed therein. A wall separates the first and second compartments for isolating the second compartment from gasses generated by separation of the first and second contacts. A duct adjacent to the second compartment allows the gasses to pass to an exterior portion of the housing. The housing includes a pair of opposing slots formed therein for receiving edges of a load terminal. A lever has a first end disposed proximate an end of a bimetallic element and a second end disposed proximate an armature in the magnetic assembly of the trip unit. The lever is rotated by at least one of the bimetallic element and the armature to unlatch an operating mechanism.

[0030] Publication no. KR100742166 discloses improving an actuator structure of an auxiliary switch so as to prevent reaction from an auxiliary switch from dropping the contact pressure of the main contact with a circuit breaker kept on. Constitution: A sub-switch (auxiliary switch) 11 mounted to a circuit breaker is composed of a micro switch 15, a main lever 18 with a tip facing a moving contact 5 of the circuit breaker as an actuator lever, and an auxiliary lever 19 interlaid between the main lever and an actuator 15a of the micro switch by changing its supporting position from that of the main lever. The point of action between the main lever and the auxiliary lever and the gearing angle thereof are so set as to make them different before and after the switch changeover operation of the auxiliary switch. A force vector applied to the main lever from the micro switch through the auxiliary lever in turning on the breaker is changed from a direction P to a direction Q after the switch changeover operation. Thereby, reaction from the auxiliary switch acting in a direction dropping the contact pressure of the main contact of the breaker body is reduced.

[0031] Publication no. US5341191 discloses molded case circuit breaker having current limiting capabilities optimized for relatively smaller frame sizes. More specifically, one aspect of the invention relates to a two-piece carrier assembly for carrying the main and arcing contact arms which allows the main and arcing contacts to be blown open during short circuit conditions. The two-piece carrier assembly includes an inner carrier and an outer carrier pivotally connected together. The contact arms are carried by the inner carrier. When sufficient magnetic repulsion forces are exerted on the contacts due to a short circuit condition, the inner carrier pivots relative to the outer carrier to allow the contact arms to blow open.

[0032] Publication no. IN201721011296 discloses a circuit breaker with robust rotor (1) construction with metallic spring holders (3, 3A) providing single break, ensuring contact pressure under normal and abnormal working conditions and enhancing current breaking in the circuit breaker is disclosed. It also provides a high-speed contact opening of a circuit breaker with negligible chances of reclosing, having improved reliability and longer operational life. The rotor (1) comprises a moving contact (7) connected to a compression spring (5) that provides the requisite contact pressure to the moving contact in ON condition. The spring (5) is supported by metal holders (3, 3A) and is compressed between a stopper pin (13) and metal holders (3, 15 3A).

[0033] Publication no. IN1963 / CHE / 2008 discloses a single break contact system for a circuit breaker comprising a fixed contact (4), a moving contact (6) comprising a contact head (15) configured to establish contact with the fixed contact (4), a hinge region (9), an intermediate region (13) configured to hold a first spring pin (16), and a braid region (11); a shaft (10) for mounting the moving contact (6) and configured to hold a second spring pin (8); and at least one compression spring (7) configured on the single break rotary type contact assembly to effectively provide the locking mechanism on the moving contact (6). The locking provided by the compression spring (7) advantageously increases the duration of the opening of the moving contact (6), thereby enabling quenching of the arc. Publication no. EP2107588 provides a circuit breaker including housing, a frame that is fixed to the housing, and a make and break mechanism. The housing is configured to comprise a doublebreak unit case having two pairs of the moving contact point and the stationary contact point or a member that is different from the double -break unit case. The frame has a first fixing portion for fixing the make and break mechanism to the double-break unit case and a second fixing portion for fixing the make and break mechanism to the housing in which the member is provided.

[0034] Publication no. US2022367136 relates to a molded case circuit breaker configured to protect its ports and cables is provided. The molded case circuit breaker comprises an electronic trip unit (ETU) including communication ports or a thermomagnetic trip unit (TMTU). The molded case circuit breaker further comprises a terminal cover configured to pass cables that connect to the communication ports of the ETU and pass the cables over lugs without touching the lugs. The molded case circuit breaker further comprises a cable box cover that protects the cables of the ETU from external harm.

[0035] Publication no. US2018061601 provides a multi-pole molded case circuit breaker (MCCB) with an insulation barrier for a rotary pin, in which an insulation barrier is provided in a rotary pin for inter-phase power transmission to prevent dielectric breakdown. The multi-pole MCCB includes a shaft assembly having a movable contactor and having a plurality of rotary pin holes formed in a penetrating manner, a base assembly to which the shaft assembly is rotatably accommodated to be coupled, a switching mechanism coupled to an upper portion of the base assembly and rotating the shaft assembly, a plurality of rotary pins coupled to the plurality of rotary pin holes in a penetrating manner, and an insulation barrier formed of an insulating material and covering the plurality of rotary pins.

[0036] Publication no. US2012061215 discloses a multi-pole circuit breaker with auxiliary supports, which comprises a base, a plurality of single-pole circuit breaking units, an operating mechanism and a rotation axis assembly, wherein the rotation axis assembly consists of a plurality of supporting assemblies and a plurality of support shaft parts in series; each of the support shaft parts is provided with a movable contact bridge; each of the supporting assembly consists of a rotation axis, an auxiliary support, an auxiliary support bearing and at least one supporting rod; the rotation axis maintains synchronous revolution with the support shaft parts; the outside of the bearing is tightly assembled with a bearing hole of the auxiliary support, while the inside is tightly assembled with the rotation axis; the supporting rod is tightly assembled with a supporting rod installing hole on the auxiliary support; the operating mechanism is fixedly connected with the supporting rod; and the supporting rod is fixedly installed on a housing of the single-pole circuit breaking unit and provides stable supporting force for the rotation axis through the auxiliary supports.

[0037] Publication no. CN103490309 relates to an environment-friendly constant-temperature low- voltage switchgear cabinet which comprises a cabinet body, solar battery pieces, an energy storage device, a thermal energy converter, a temperature control sensor and a control circuit board. The end face of the top end of the cabinet body and the side faces of the two sides of the cabinet body are respectively covered with one layer of the solar battery pieces, and the energy storage device is arranged at the bottom of an inner cavity of the cabinet body; the thermal energy converter, the temperature control sensor and the control circuit board are fixed to the inner wall of the cabinet body; the solar battery pieces, the energy storage device, the thermal energy converter and the temperature control sensor are all connected with the control circuit board; the thermal energy converter is connected with the energy storage device.

[0038] At least from the above listed prior arts, it is evident that in compact circuit breakers, providing a feature for mounting / holding / supporting of various internal accessories in a less space is a challenging task. In particular, the construction of the pole assemblies is non-uniform, and as such limits the space required for mounting various internal accessories such as, but not limited to, an auxiliary contact, a trip alarm contact, a shunt and under voltage (UV) release, a trip release, and the like, within the MCCB. Furthermore, an additional tedious task associated with the positioning of the aforementioned internal accessories within the MCCB is that such positioning should facilitate interaction between the said internal accessories and the actuator assembly, during the normal operation of the MCCB. In addition to the above, in the event of a fault condition arising within the MCCB, ionized gases and carbon soot are generated within one or more of the pole assemblies, which may lead to malfunction of one or more electronic components of the MCCB.

[0039] Accordingly, in view of the aforementioned limitations and other inherent drawbacks in the existing art, there exists a well felt need to provide a compact, reliable, and novel moulded case circuit breaker (MCCB), capable of efficiently housing various internal accessories therein, without compromising the overall integrity and functionality thereof, while providing ingress protection (IP) to various electronic components of the MCCB against the ionized gases and carbon soot generated due to a fault condition, which the present disclosure aims to address.

[0040] SUMMARY OF THE INVENTION

[0041] This section is intended to introduce certain aspects of the disclosed system in a simplified form and is not intended to identify the key advantages or features of the present disclosure. However, it may be understood that the below mentioned objects of the disclosed system are merely exemplary and not exhaustive.

[0042] The present disclosure relates to a molded case circuit breaker (MCCB), comprising a plurality of pole assemblies, an actuator assembly, and a primary tripping accessory. Each of the plurality of pole assemblies comprises a casing unit defining a guide-slot. The actuator assembly is installed atop one of the plurality of pole assemblies, such that the guide-slot of the other of the plurality of pole assemblies adjacent thereto are positioned proximal to the actuator assembly. Further, the primary tripping accessory defines a first portion and a second portion. Notably the first portion of the primary tripping accessory is adapted to slidably engage with a guide-slot defined in a casing unit of at least one of the plurality of pole assemblies, to be fittingly installed atop the said one of the plurality of pole assemblies. Furthermore, the second portion is adapted to engage with a pair of fastening members extending through at least a portion of a mid-cover assembly of the MCCB, to be fittingly installed relative to the mid-cover assembly, thereby facilitating an overall rigid mounting of the primary tripping accessory within the MCCB.

[0043] According to an aspect of the present disclosure, the primary tripping accessory is a flux shifter device.

[0044] According to another aspect of the present disclosure, the first portion of the primary tripping accessory defines a pair of male extension sections, such that the pair of male extension sections are adapted to slidably engage with the guide-slot, to fittingly install the primary tripping accessory relative to one of the plurality of pole assemblies.

[0045] According to yet another aspect of the present disclosure, the second portion of the primary tripping accessory defines a pair of threaded cavities adapted to lockingly receive the pair of fastening members extending from the mid-cover assembly, to fittingly install the primary tripping accessory relative to the mid-cover assembly, thus facilitating the rigid mounting of the primary tripping accessory within the MCCB.

[0046] According to yet another aspect of the present disclosure, the MCCB comprises a substantially U-shaped mounting bracket adapted to slidably engage with the guide-slot defined in the other of the plurality of pole assemblies, to be fittingly installed atop the said other of the plurality of pole assemblies. Notably, the mounting bracket is adapted to receive and support a trip actuation lever thereon, the trip actuation lever being adapted to translate a TRIP command from one of a shunt type tripping accessory and / or an undervoltage (UV) type tripping accessory, to the actuator assembly of the MCCB, to thereby cause tripping of the MCCB.

[0047] According to yet another aspect of the present disclosure, the MCCB comprises a secondary tripping accessory mounting arrangement, comprising at least one mounting bracket adapted to be sandwiched between each adjacent pair of the plurality of pole assemblies, the at least one mounting bracket adapted to receive and support thereon a secondary tripping accessory.

[0048] According to yet another aspect of the present disclosure, the casing unit of each adjacent pair of the plurality of pole assemblies, defines a cylindrical depressed portion and a tapered protrusion, while the at least one mounting bracket defines a pair of cylindrical extension sections extending sidewards therefrom, such that one of the pair of cylindrical extension section of the at least one mounting bracket is received within the cylindrical depressed portion of one of each adjacent pair of plurality of pole assemblies, while the other of the pair of cylindrical extension section is received within the cylindrical depressed portion of the other of each adjacent pair of plurality of pole assemblies, to facilitate mounting the secondary tripping accessory mounting arrangement between each adjacent pair of the plurality of pole assemblies.

[0049] According to yet another aspect of the present disclosure, the at least one mounting bracket defines a pair of cut-out sections on either sides of a bottom edge thereof, such that one of the pair of cut-out sections rests on the tapered protrusion of one of each adjacent pair of plurality of pole assemblies, while the other of the pair of cut-out sections rests on the tapered protrusion of the other of each adjacent pair of plurality of pole assemblies.

[0050] According to yet another aspect of the present disclosure, the secondary tripping accessory is an ultra-fast tripping accessory.

[0051] According to yet another aspect of the present disclosure, each of the plurality of pole assemblies comprises a casing unit, a stationary contact unit, a rotary contact unit, an arc chute unit, and at least one hollow rivet member, wherein each of the stationary contact unit, the rotary contact unit, and the arc chute unit are sealingly enclosed within the casing unit, via the at least one hollow rivet member, and wherein the at least one hollow rivet member is adapted to facilitate connection of at least one of the plurality of pole assemblies with the other of the plurality of pole assemblies and / or an actuator assembly. According to yet another aspect of the present disclosure, the casing unit defines a pair of beanshaped slots, which allow mounting of an isolation disc member between two adjacent pole assemblies of the plurality of pole assemblies.

[0052] According to yet another aspect of the present disclosure, the isolation disc member defines a pin-shaped extruded portion and a through-hole, such that the pin-shaped extruded portion is adapted to at least partially extend within the hollow extension section of the rotary contact unit, while the through-hole allows a drive shaft to pass therethrough.

[0053] According to yet another aspect of the present disclosure, the casing unit defines a substantially rectangular cut-out section proximal to a bottom side thereof, to at least partially receive a polemounting nut therein, such that when the plurality of pole assemblies are fastened together, the pole-mounting nut is deployed between every adjacent pair of pole assemblies of the plurality of pole assemblies.

[0054] BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to explain the technical solution in the embodiments of the present application more clearly, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only some embodiments of the application. For those skilled in the art, without any creative work, other drawings can be obtained based on these drawings.

[0056] Figure 1 illustrates a perspective view of a moulded case circuit breaker (MCCB), in accordance with the concepts of the present disclosure.

[0057] Figure 2 illustrates a first partially exploded view of the MCCB of Figure 1, indicating the mounting of a hinge cover assembly thereon, in accordance with the concepts of the present disclosure.

[0058] Figure 3 illustrates a second partially exploded view of the MCCB of Figure 1, indicating the mounting of a fascia plate assembly thereon, in accordance with the concepts of the present disclosure.

[0059] Figure 4 illustrates a third partially exploded view of the MCCB of Figure 1, indicating the mounting of one or more tripping accessory devices, in accordance with one or more embodiments of the present disclosure. Figure 5 illustrates a fourth partially exploded view of the MCCB of Figure 1, indicating the mounting of a trip assembly cover member, in accordance with the first embodiment of the present disclosure.

[0060] Figure 6 illustrates a fifth partially exploded view of the MCCB of Figure 1, indicating the mounting of the trip assembly cover member, in accordance with a second embodiment of the present disclosure.

[0061] Figure 7 illustrates a rear exploded view of an arrangement of a mid-cover assembly, a TRIP assembly, an actuator assembly, a base assembly, and three (3) pole assemblies of the MCCB of Figure 1, in accordance with the concepts of the present disclosure.

[0062] Figure 8 illustrates a front exploded view of the arrangement of the mid-cover assembly, the TRIP assembly, the actuator assembly, the base assembly, and the three (3) pole assemblies of the MCCB of Figure 1, in accordance with the concepts of the present disclosure.

[0063] Figure 9 illustrates an exploded view of an arrangement of the three (3) pole assemblies, the actuator assembly, the TRIP assembly, and the base assembly, in accordance with the first embodiment of the present disclosure.

[0064] Figure 10 illustrates an exploded rear view of the arrangement of the three (3) pole assemblies, the actuator assembly, the TRIP assembly, and the base assembly, in accordance with the second embodiment of the present disclosure.

[0065] Figure 11 illustrates an exploded view of the base assembly, indicating the mounting of a nutretention unit comprised therein, in accordance with the concepts of the present disclosure.

[0066] Figure 12 illustrates an exploded view of the nut-retention unit, in accordance with the concepts of the present disclosure.

[0067] Figure 13a illustrates a perspective view of an arrangement of the actuator assembly and the three (3) pole assemblies, and the TRIP assembly, in accordance with the first embodiment of the present disclosure.

[0068] Figure 13b illustrates a partially exploded view of Figure 13a, indicating the connection between the arrangement of the actuator assembly and the three (3) pole assemblies, and the TRIP assembly, in accordance with the first embodiment of the present disclosure.

[0069] Figure 14 illustrates a perspective view of the arrangement of the actuator assembly and the three (3) pole assemblies, and the TRIP assembly, in accordance with the second embodiment of the present disclosure.

[0070] Figure 15a illustrates a perspective view of an arrangement of the actuator assembly and the three (3) pole assemblies, in accordance with the concepts of the present disclosure.

[0071] Figure 15b illustrates a sectional front view of the arrangement of Figure 15a, in accordance with the concepts of the present disclosure.

[0072] Figure 16 illustrates a first partially exploded view of Figure 15a, indicating a nut mounting arrangement, at least one mounting bracket, and a pole -positioning spacer unit, in accordance with the concepts of the present disclosure.

[0073] Figure 17 illustrates a second partially exploded view of Figure 15a, indicating the connection between the three (3) pole assemblies of the MCCB of Figure 1, in accordance with the concepts of the present disclosure.

[0074] Figure 18 illustrates a partially exploded view of an arrangement of the actuator assembly and two (2) pole assemblies, indicating an isolation disc member, in accordance with the concepts of the present disclosure.

[0075] Figure 19-21 illustrates steps of dismantling an arrangement of the actuator assembly and one of the three (3) pole assemblies, in accordance with the concepts of the present disclosure.

[0076] Figure 22 illustrates an exploded view of an arrangement of one of the three (3) pole assemblies and the tripping accessory device, in accordance with the concepts of the present disclosure.

[0077] Figure 23 illustrates a sectional view of one of the three (3) pole assemblies, indicating a hollow rivet member comprised therein, in accordance with the concepts of the present disclosure.

[0078] Figure 24 illustrates a partially exploded view of one of the three (3) pole assemblies of Figure 23, indicating the hollow rivet member comprised therein, in accordance with the concepts of the present disclosure.

[0079] Figure 25 illustrates a perspective view of a first arrangement of the actuator assembly, the three (3) pole assemblies, and a primary tripping accessory and a mounting-bracket, in accordance with the concepts of the present disclosure.

[0080] Figure 26 illustrates a perspective view of a second arrangement of the actuator assembly, the three (3) pole assemblies, and the primary tripping accessory and the mounting-bracket, in accordance with the concepts of the present disclosure.

[0081] Figure 27 illustrates a perspective view of an arrangement of the actuator assembly, the three (3) pole assemblies, the primary tripping accessory, a mounting-bracket and the base assembly, in accordance with the concepts of the present disclosure.

[0082] Figure 28 illustrates another perspective view of the MCCB, in accordance with the concepts of the present disclosure.

[0083] Figure 29 illustrates a front view of Figure 28, in accordance with the concepts of the present disclosure.

[0084] Figure 30 illustrates a sectional perspective view of the MCCB, in accordance with the concepts of the present disclosure.

[0085] Figure 30a illustrates a zoomed in perspective view of section A of Figure 30, in accordance with the concepts of the present disclosure.

[0086] DETAILED DESCRIPTION

[0087] In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent, however, that embodiments of the present invention may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address any of the problems discussed above or might address only one of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein. Exemplified embodiments of the present invention are described below, as illustrated in various drawings in which like reference numerals refer to the same parts throughout the different drawings.

[0088] Figure 1 illustrates a perspective view of a moulded case circuit breaker (MCCB)

[0100] , in accordance with the concepts of the present disclosure. Figure 2 illustrates a first partially exploded view of the MCCB

[0100] of Figure 1, indicating the mounting of a hinge cover assembly

[0138] thereon, in accordance with the concepts of the present disclosure. Figure 3 illustrates a second partially exploded view of the MCCB

[0100] of Figure 1, indicating the mounting of a fascia plate assembly

[0108] thereon, in accordance with the concepts of the present disclosure. Figure 4 illustrates a third partially exploded view of the MCCB

[0100] of Figure 1, indicating the mounting of one or more tripping accessory devices, in accordance with one or more embodiments of the present disclosure. Figure 5 illustrates a fourth partially exploded view of the MCCB

[0100] of Figure 1, indicating the mounting of a trip assembly cover member

[0144] , in accordance with the first embodiment of the present disclosure. Figure 6 illustrates a fifth partially exploded view of the MCCB

[0100] of Figure 1, indicating the mounting of the trip assembly cover member

[0144] , in accordance with a second embodiment of the present disclosure. Figures 1-6 are to be viewed in conjunction with each other, in order to better understand the concepts of the present disclosure. The structure and arrangement of the MCCB

[0100] will be described hereinafter in detail, while drawing references from the aforementioned accompanying drawings, wherever required.

[0089] The moulded case circuit breaker (MCCB)

[0100] is a low-voltage and high-current circuit breaker, employed to protect electrical networks / circuits from over-load or short-circuit conditions. The MCCB

[0100] is positioned between at least one load phase on a load side and at least one line phase on a line side, for providing protection during over-load or short-circuit conditions. The MCCB

[0100] operates between each of an ON position, an OFF position, and a TRIP position, wherein the MCCB

[0100] is manually adjusted between the ON position and the OFF position, whereas MCCB

[0100] is automatically adjusted to the BLOW OPEN position followed by TRIP position due to short-circuit fault at the line side or the load side of the MCCB

[0100] , In the ‘ON’ position, the MCCB

[0100] allows a flow of current therethrough, while in each of the ‘OFF’ position, the ‘BLOW OPEN’ position, and the ‘TRIP’ position, the MCCB

[0100] restricts the flow of current therethrough.

[0090] Commonly, the MCCB

[0100] is a multipolar circuit breaker. Although, in the present disclosure the MCCB

[0100] is described as a three-pole circuit breaker, it may be obvious to a person skilled in the art that the MCCB

[0100] may also be a single-pole circuit breaker, a four-pole circuit breaker, or a circuit breaker with any number of poles. As seen from the accompanying figures, the MCCB

[0100] includes three (3) pole assemblies

[0102] , a base assembly

[0104] , a midcover assembly

[0106] , a fascia plate assembly

[0108] , a hinge cover assembly

[0138] , an actuator assembly

[0112] , and a TRIP assembly

[0114] ,

[0091] Figure 11 illustrates an exploded view of the base assembly, indicating the mounting of a nutretention unit comprised therein, in accordance with the concepts of the present disclosure. Figure 12 illustrates an exploded view of the nut-retention unit, in accordance with the concepts of the present disclosure. Figures 11 and 12 are to be viewed in conjunction with each other, in order to better understand the structure and arrangement of the base assembly

[0104] of the MCCB

[0100] described hereinafter. As seen from figures 11 and 12, the base assembly

[0104] of the MCCB

[0100] is a lower structure that provides a mounting base and support structure for holding and supporting each of the three pole assemblies

[0102] therein. In particular, the base assembly

[0104] defines dedicated pole holding cavities (not shown) to mount and support each of the three pole assemblies

[0102] therein. Notably, the three pole assemblies

[0102] are fixedly attached within the pole holding cavities defined by the base assembly

[0104] by fastening means. More particularly, the base assembly

[0104] defines at least one nut-retention unit holding portion [104a] on the load side and the line side thereof, as seen from figure 11, adapted to slidably receive at least one nut-retention unit

[0132] therein, for mounting the three pole assemblies

[0102] on to the base assembly

[0104] , while ensuring efficient alignment thereof.

[0092] In the preferred embodiment, each of the at least one nut-retention unit

[0132] defines a pair of longitudinal grooves [132a] on either sides thereof, while each of the at least one nut-retention unit holding portion [104a] defines a pair of guide rails [104b]. Notably, the pair of longitudinal grooves [132a] of each of the at least one nut-retention unit

[0132] is adapted to slidably engage with the pair of guide rails [104b] defined in the at least one nut-retention unit holding portion [104a], to facilitate slidable mounting of the at least one nut-retention unit

[0132] within the base assembly

[0104] ,

[0093] Figure 7 illustrates a rear exploded view of an arrangement of a mid-cover assembly

[0106] , the TRIP assembly

[0114] , the actuator assembly

[0112] , the base assembly

[0104] , and the three (3) pole assemblies

[0102] of the MCCB of Figure 1, in accordance with the concepts of the present disclosure. Figure 8 illustrates a front exploded view of the arrangement of the mid-cover assembly

[0106] , the TRIP assembly

[0114] , the actuator assembly

[0112] , the base assembly

[0104] , and the three (3) pole assemblies

[0102] of the MCCB

[0100] of Figure 1, in accordance with the concepts of the present disclosure. Figures 7 and 8 are to be viewed in conjunction with each other, in order to better understand the concepts of the present disclosure.

[0094] As seen from figures 7 and 8, the mid-cover assembly

[0106] is an upper structure that is engaged with the base assembly

[0104] , to at least partially cover the three pole assemblies

[0102] and protect the same from external environment. Usually, the mid-cover assembly

[0106] is fittingly engaged with the base assembly

[0104] , to at least partially cover the three pole assemblies

[0102] and protect the same from external environment. Notably, the mid-cover assembly

[0106] defines a mid-cover cavity [106a] to allow at least a portion of the actuator assembly

[0112] to extend therethrough. As seen from figure 4, the mid-cover assembly

[0106] further defines one or more depressed portions [106b] adapted to house and support one or more tripping accessory devices therein. ‘Tripping accessory devices’ can be one of a shunt or under voltage (UV) type tripping accessory

[0158] , a flux shifter device (FSD), an electronic trip unit (ETU), and the like. For ease of understanding, there is shown the shunt or UV type tripping accessory

[0158] being deployed within the one or more depressed portions [106b] of the mid-cover assembly

[0106] , Particularly, the shunt or UV type tripping accessory

[0158] is adapted to provide a TRIP command to the actuator assembly

[0112] of the MCCB

[0100] , to facilitate tripping of the MCCB

[0100] , Those skilled in the art may appreciate that other widely known tripping accessory devices not mentioned herein may also be mounted within the one or more depressed portions [106b] defined in the mid-cover assembly

[0106] , and the same lies well within the scope of the present disclosure.

[0095] Additionally, the mid-cover assembly

[0106] further defines a provision for holding and supporting a push-to-trip (PTT) arrangement (not shown) therein, wherein the PTT arrangement is adapted to allow a user to manually trip the MCCB

[0100] as per the user’s requirement.

[0096] Referring to figures 2 and 3 accompanying the present disclosure, the fascia plate assembly

[0108] is fittingly mounted on the mid-cover assembly

[0106] of the MCCB

[0100] , to cover the midcover assembly

[0106] , The fascia plate assembly

[0108] defines a fascia plate cavity [108a], such that when fittingly mounted on the mid-cover assembly

[0106] , the fascia plate cavity [108a] and the mid-cover cavity [106a] are coaxially aligned with each other, to allow at least a portion of the actuator assembly

[0112] to extend therethrough, such that the said portion of the actuator assembly

[0112] is accessible to the user, for manually adjusting the actuator assembly

[0112] between the ‘ON’ position and the ‘OFF’ position. Further, the fascia plate assembly

[0108] defines a pair of rotatable indicators [108b] on either sides of the fascia plate cavity [108a], wherein the pair of rotatable indicators [108b] define various electrical parameters related to MCCB

[0100] thereon. ‘Electrical parameters’ refers to basic technical data of the MCCB

[0100] such as, but not limited to, rated current, rated service, rated ultimate short-circuit breaking capacity, rated frequency, rated impulse withstand voltage, and the like. Additionally, the fascia plate assembly

[0108] defines at least two pairs of mounting grooves [108c] on either sides thereof, to facilitate the mounting of the hinge cover assembly

[0138] as seen from figure 2. Preferably, one of the at least two pair of mounting grooves [108c] is defined proximal to a top edge of the fascia plate assembly

[0108] , while the other of the at least two pair of mounting grooves [108c] is defined proximal to a bottom edge thereof. Referring to figure 2, the hinge cover assembly

[0138] comprises a first hinge cover plate

[0140] and a second hinge cover plate

[0142] adapted to be mounted on the top edge and the bottom edge of the fascia plate assembly

[0108] , respectively. In particular, the first hinge cover plate

[0140] defines a first pair of snap attachment sections adapted to engage with one of the at least two pair of grooves [108c] defined proximal to the top edge of the fascia plate assembly

[0108] , While, the second hinge cover plate

[0140] defines a second pair of snap attachment sections adapted to engage with the other of the at least two pair of grooves [108c] defined proximal to the bottom edge of the fascia plate assembly

[0108] , Further, each of the first and second hinge cover plates

[0140] defines a male attachment portion which is adapted to engage with the mid-cover assembly

[0106] , to lock thereto by means of a snap-fit attachment.

[0097] Figure 15a and 15b illustrate a perspective view and a sectional front view of an arrangement of the actuator assembly

[0112] and the three (3) pole assemblies

[0102] , respectively, in accordance with the concepts of the present disclosure. Figure 16 illustrates a first partially exploded view of Figure 15a, indicating a pole-mounting nut

[0126] , a at least one mounting bracket

[0122] , and a pole-positioning spacer

[0124] , in accordance with the concepts of the present disclosure. Figure 17 illustrates a second partially exploded view of Figure 15a, indicating the connection between the three (3) pole assemblies

[0102] of the MCCB

[0100] of Figure 1, in accordance with the concepts of the present disclosure. Figure 18 illustrates a partially exploded view of an arrangement of the actuator assembly

[0112] and two (2) pole assemblies

[0102] , indicating an isolation disc member

[0134] , in accordance with the concepts of the present disclosure. Figure 22 illustrates an exploded view of an arrangement of one of the three (3) pole assemblies

[0102] and the mounting-bracket

[0130] , in accordance with the concepts of the present disclosure. Figures 23 and 24 illustrate a sectional view and a partially exploded view, respectively, of one of the three (3) pole assemblies

[0102] , indicating a hollow rivet member

[0128] comprised therein, in accordance with the concepts of the present disclosure. Figures 15a- 18 and 22-24 are to be viewed in conjunction with one another to clearly understand the concepts of the present disclosure.

[0098] Each of the three pole assemblies

[0102] of the MCCB

[0100] are independent units capable of protecting the electrical networks / circuits from over-load or short-circuit conditions. In particular, each of the three pole assemblies

[0102] transmits electric current from the at least one line phase to the at least one load phase, while ensuring protection from overcurrent or short- circuit along the at least one load phase. Each of the three pole assemblies

[0102] operate in each of the ‘ON’ position, the ‘OFF’ position, and the ‘TRIP’ position. Notably, the three pole assemblies

[0102] are connected together with one or more components of the actuator assembly

[0112] , to adjust each of the three pole assemblies

[0102] together among the ‘ON’ position, the ‘OFF’ position, and the ‘TRIP’ position, resulting in manipulation of the MCCB

[0100] amongst the ‘ON’ position, the ‘OFF’ position, and the ‘TRIP’ position. The ‘ON’, ‘OFF’, and ‘TRIP’ positions of the three pole assemblies

[0102] are commonly known to those skilled in the art, and therefore, are not illustrated in the accompanying figures.

[0099] In light of the figures 15 a- 18 and 22-24, the structure and arrangement of one of the three pole assemblies

[0102] will be described hereinafter, and a similar structure and arrangement of the remaining of the three pole assemblies

[0102] may be envisioned in light of the same. Those skilled in the art may appreciate that the concepts of the present disclosure, although described herein to be applicable to the pole assembly

[0102] of a single break contact type assembly, may also extend to the pole assembly employed in a multiple break contact type assembly.

[0100] The pole assembly

[0102] includes a casing unit

[0116] , a stationary contact unit (not shown), a rotary contact unit

[0120] , and an arc chute unit (not shown). The stationary contact unit is an electric contact plate structure that may be positioned within a defined portion in the casing unit

[0116] , In particular, in complete assembly of the MCCB

[0100] , the electrical wires from the line side are usually connected to the stationary contact unit. Notably, the casing unit

[0116] of each of a plurality of pole assemblies

[0102] comprised in the MCCB

[0100] is such that the plurality of pole assemblies

[0102] are arranged with each other, in a modular manner. More particularly, a number of the plurality of pole assemblies

[0102] , in combination, define a number of electrical connection poles of the MCCB

[0100] , such that one or more of the plurality of pole assemblies

[0102] can be removed and / or deployed, in order to vary the number of electrical connection poles of the MCCB

[0100] , Accordingly, the terms ‘the plurality of pole assemblies

[0102] ’ and ‘the three (3) pole assemblies

[0102] ’ shall be interchangeably referred hereinafter.

[0101] The rotary contact unit

[0120] is a moving structure that engages / disengages with the stationary contact unit

[0120] , to allow / restrict the flow of electric current therethrough. The rotary contact unit

[0120] is rotatably positioned within a defined portion in the casing unit

[0116] , and is provided to connect to electrical wires from the load side. Further, the rotary contact unit

[0120] is rotatably adjusted while being positioned within the casing unit

[0116] , to make / release a contact relative to the stationary contact unit, in order to allow / restrict the flow of electric current therebetween. Notably, the rotary contact unit

[0120] makes a contact relative to the stationary contact unit to allow the flow of electric current (the ‘ON’ position), and the rotary contact unit

[0120] releases a contact relative to the stationary contact unit, to restrict the flow of electric current (the ‘OFF’ position). Additionally, the rotary contact unit

[0120] is adjusted without rotation, to release a contact relative to the stationary contact unit, to restrict the flow of electric current (the ‘BLOW OPEN’ position). Essentially, rotary contact unit

[0120] defines a hollow extension portion, as seen from figure 16, which at least partially extends out of the casing unit

[0116] of the pole assembly

[0102] ,

[0102] The arc chute unit is positioned within a defined portion in the casing unit and comprises of a two-wall shaped arc chute holder member and an arc chute member. The arc chute holder member and an arc chute member, are arranged together, to vent out gases generated by an arc caused due to engagement / disengagement of the rotary contact unit relative to the stationary contact unit through a vent channel.

[0103] The casing unit

[0116] houses and supports each of the stationary contact unit, the rotary contact unit

[0120] , and the arc chute unit of the pole assembly

[0102] therein. In particular, the casing unit

[0116] defines various dedicated sections for housing and supporting the stationary contact unit, the rotary contact unit

[0120] , and the arc chute unit of the pole assembly

[0102] , Preferably, the casing unit

[0116] has a substantially reduced height at a load terminal side, to facilitate interchangeability of TRIP assembly

[0114] , which can be one of a thermal and magnetic trip unit (TMTU) and an electronic trip unit (ETU).

[0104] The casing unit

[0116] is a two-part unit comprising a first casing member [116a] and a second casing member [116b], wherein each of the first and second casing members [116a] define an inner surface and an outer surface. Either or both of the first casing member [116a] and a second casing member [116b] at least partially or completely house the stationary contact unit, the rotary contact unit

[0120] , and the arc chute unit therein, and are suitably fastened together, to form the pole assembly

[0102] , The structure and arrangement of the internal surface of the first and second casing members [116a, 116b] are commonly known to a person skilled in the art, and therefore, are not reiterated herein for the sake of brevity. A structure and arrangement of the outer surface of the first and second casing members [116a, 116b] will be described hereinafter in detail.

[0105] Each of the first and second members [116a, 116b] define a plurality of fastening cavities [116c], such that the first and second casing members [116a, 116b] are fastened together, with various components of the pole assembly

[0102] housed therein, by means of a hollow rivet member

[0128] , The hollow rivet member

[0128] facilitates a quick and easy assembly and dismantling of each of the three pole assemblies

[0102] relative to the other. More particularly, the three pole assemblies

[0102] are assembled together, using a unary fastening means adapted to pass through the hollow rivet

[0128] comprised in each of the three pole assemblies

[0102] , With such a provision for hollow rivet member

[0128] and the unary fastening means passing therethrough, the actuator assembly

[0112] can be conveniently mounted on one of the three pole assemblies

[0102] , thereby eliminating the requirement of separate mounting provisions therefor. Moreover, such an arrangement facilitates ease in stacking or removal of one or more of the pole assemblies

[0102] , In other words, the aforementioned arrangement promotes ease of adaptability in switching between the three-pole configuration of the pole assemblies

[0102] described herein to a four-pole configuration of the pole assemblies

[0102] , Additionally, the provision of hollow rivet member

[0128] in the pole assembly

[0102] also ensures an improved sealing of the casing unit

[0116] , to prevent escape of ionized gases generated in the event of a fault condition in the MCCB

[0100] , and thus, prevent damage and / or malfunction of the TRIP assembly

[0114] , connected to the pole assembly

[0102] , and components thereof.

[0106] Referring to figure 22, each of the first and second casing members [116a, 116b] defines a guideslot [116h] extending along the length thereof, proximal to the front side.

[0107] Furthermore, each of the first casing member [116a] and the second casing member [116b] also define a substantially rectangular cut-out section [116e] proximal to a bottom side thereof, to at least partially receive a pole-mounting nut

[0126] therein. In particular, when the pole assemblies

[0102] are fastened together, the pole-mounting nut

[0126] is deployed between every adjacent pair of pole assemblies

[0102] , Notably, such a positioning of the pole-mounting nut

[0126] on the outer surface of the pole assembly

[0102] ensures proper electrical isolation thereof from current flowing through the pole assemblies

[0102] internally, thereby eliminating the probability of pole- to-pole electrical tracking, in the event of a short-circuit fault condition in the MCCB

[0100] ,

[0108] Additionally, each of the first and second casing members [116a, 116b] define a cylindrical depressed portion [I I6f] and a tapered protrusion [116g], proximal to the front side thereof. Referring to figures 25 to 30, there is shown a primary tripping accessory

[0146] being deployed within the MCCB

[0100] , Preferably, the primary tripping accessory

[0146] is the flux shifter device (FSD). The primary tripping accessory

[0146] defines a first portion

[0150] and a second portion

[0148] ,

[0109] Notably, the first portion

[0150] of the primary tripping accessory

[0146] is adapted to slidably engage with the guide-slot [ 116h] defined in the casing unit

[0116] of at least one of the plurality of pole assemblies

[0102] , to be fittingly installed atop the said one of the plurality of pole assemblies

[0102] , More particularly, the first portion

[0150] of the primary tripping accessory

[0146] defines a pair of male extension sections [150a], such that the pair of male extension [150a] sections are adapted to slidably engage with the guide slot [116h] of at least one of the plurality of pole assemblies

[0102] , to fittingly install the primary tripping accessory

[0146] atop at least one of the plurality of pole assemblies

[0102] ,

[0110] On the other hand, the second portion

[0148] is adapted to engage with a pair of fastening members

[0152] extending through at least a portion of a mid-cover assembly

[0106] of the MCCB

[0100] , to be fittingly installed relative to the mid-cover assembly

[0106] , thereby facilitating an overall rigid mounting of the primary tripping accessory

[0146] within the MCCB

[0100] , More particularly, the second portion

[0148] of the primary tripping accessory

[0146] defines a pair of threaded cavities [148a] adapted to lockingly receive the pair of fastening members

[0152] extending from the mid-cover assembly

[0106] , to fittingly install the primary tripping accessory

[0146] relative to the mid-cover assembly

[0106] , thus facilitating the rigid mounting of the primary tripping accessory

[0146] within the MCCB

[0100] ,

[0111] In particular, the aforementioned mounting of the primary tripping accessory

[0146] proximal to the actuator assembly

[0112] facilitates efficient and rapid tripping of the MCCB

[0100] , and consequently, the overall reliability of the MCCB

[0100] is substantially improved. Additionally, such a snugged mounting of the primary tripping accessory

[0146] between one of the plurality of pole assemblies

[0102] and the mid-cover assembly

[0106] also aids in minimizing the overall size of the MCCB

[0100] , thereby making the same compact in size.

[0112] Additionally, the MCCB

[0100] also comprises a substantially U-shaped mounting bracket

[0130] adapted to slidably engage with the guide-slot [ 116h] defined in the other of the plurality of pole assemblies

[0102] , to be fittingly installed atop the said other of the plurality of pole assemblies

[0102] , Notably, the mounting bracket

[0130] is adapted to receive and support a trip actuation lever

[0156] thereon, the trip actuation lever

[0156] being adapted to translate a TRIP command from one of the shunt type tripping accessory

[0158] and / or the undervoltage (UV) type tripping accessory

[0158] , to the actuator assembly

[0112] of the MCCB

[0100] , to thereby cause tripping of the MCCB

[0100] ,

[0113] Referring to figures 16 to 17, the MCCB

[0100] comprises a secondary tripping accessory mounting arrangement. The secondary tripping accessory mounting arrangement comprises at least one mounting bracket

[0122] adapted to be sandwiched between each adjacent pair of the plurality of pole assemblies

[0102] , Notably, the at least one mounting bracket

[0122] is adapted to receive and support thereon a secondary tripping accessory

[0154] , Preferably, the secondary tripping accessory

[0154] is an ultra-fast tripping accessory.

[0114] The casing unit

[0116] of each adjacent pair of the plurality of pole assemblies

[0102] , defines a cylindrical depressed portion [116f] and a tapered protrusion [116g], while the at least one mounting bracket

[0122] defines a pair of cylindrical extension sections [122a] extending sidewards therefrom, such that one of the pair of cylindrical extension section [122a] of the at least one mounting bracket

[0122] is received within the cylindrical depressed portion [116f] of one of each adjacent pair of plurality of pole assemblies

[0102] , while the other of the pair of cylindrical extension section [122a] is received within the cylindrical depressed portion [ 116f] of the other of each adjacent pair of plurality of pole assemblies

[0102] , to facilitate mounting the secondary tripping accessory mounting arrangement between each adjacent pair of the plurality of pole assemblies

[0102] ,

[0115] The at least one mounting bracket

[0122] defines a pair of cut-out sections [122b] on either sides of a bottom edge [122c] thereof, such that one of the pair of cut-out sections [122b] rests on the tapered protrusion [116g] of one of each adjacent pair of plurality of pole assemblies

[0102] , while the other of the pair of cut-out sections [122b] rests on the tapered protrusion [116g] of the other of each adjacent pair of plurality of pole assemblies

[0102] .

[0116] In particular, the cylindrical depressed portion [116f] and the tapered protrusion [116g] assists in mounting and supporting the at least one mounting bracket

[0122] between every adjacent pair of the pole assemblies

[0102] ,

[0117] More particularly, referring to figures 16 and 17, the at least one mounting bracket

[0122] defining the pair of cylindrical extension sections [122a] extending sidewards therefrom such that one of the pair of cylindrical extension section [122a] of the at least one mounting bracket

[0122] is received within the cylindrical depressed portion [116f] of the first casing member [116a] of one pole assembly

[0102] of the plurality of pole assemblies

[0102] , while the other of the pair of cylindrical extension section [122a] is received within the cylindrical depressed portion [116f] of the second casing member [116b] of the adjacent pole assembly

[0102] ,

[0118] Furthermore, the at least one mounting bracket

[0122] defining the pair of cut-out sections [122b] on either sides of the bottom edge [122b] thereof, such that one of the pair of cut-out sections [122b] rests on the tapered protrusion [116g] of the first casing member [116a] of one pole assembly

[0102] of the plurality of pole assemblies

[0102] , while the other of the pair of cut-out sections [122b] rests on the tapered protrusion [116g] of the second casing member [116b] of the adjacent pole assembly

[0102] , With such a positioning of the at least one mounting bracket

[0122] between every adjacent pair of pole assemblies

[0102] , the ultra-fast tripping accessory can be mounted thereon, capable of actuating the actuator assembly

[0112] , in the event of any fault condition in the MCCB

[0100] , In addition to the above, at least one mounting bracket

[0122] further comprises a nut member (not shown) for assisting in mounting of the pole assemblies

[0102] fastened together, on to the base assembly

[0104] ,

[0119] In addition to the aforementioned, each of the first and second casing members [116a, 116b] further defines a pair of bean-shaped slots [116i, I I6j], as seen from figure 16, such that the pair of bean-shaped slots [I I6i, 116j] allow the drive shaft and the extension section [120a] of the rotary contact unit

[0120] to extend therethrough, respectively. Notably, such a provision in the casing unit

[0116] allows mounting of an isolation disc member

[0134] between the two adjacent pole assemblies

[0102] , In particular, the isolation disc member

[0134] defines a pin-shaped extruded portion [134a] and a through-hole [134b], such that the pin-shaped extruded portion [134a] is adapted to at least partially extend within the hollow extension section [120a] of the rotary contact unit

[0120] , while the through-hole allows the drive shaft to pass therethrough.

[0120] With such an arrangement of the pole assemblies

[0102] employing each of the pole-positioning spacer

[0124] , the pole-mounting nut

[0126] , the at least one mounting bracket

[0122] , and the isolation disc member

[0134] therebetween, a proper alignment of one pole assembly

[0102] relative to the adjacent pole assembly

[0102] as well as the three pole assemblies

[0102] relative to the base assembly

[0104] is achieved, which further ensures proper connection of each of the pole assemblies

[0102] with the respective line side conductor and load side conductor.

[0121] Figures 19-21 illustrate steps of dismantling of the arrangement of the actuator assembly

[0112] and the pole assembly

[0102] , in accordance with the concepts of the present disclosure. Figures 19-21 should be viewed in conjunction with each other, in order to better understand the concepts of the present disclosure. In light of the aforementioned accompanying drawings, the structure and arrangement of the actuator assembly

[0112] will be described hereinafter in detail.

[0122] The actuator assembly

[0112] is a multi-part assembly mounted on one of the pole assemblies

[0102] , and connected to the rotary contact unit

[0120] of one of the pole assemblies

[0102] , by coupling means, such that the rotary contact unit

[0120] of each of the three pole assemblies

[0102] are adjusted together, among the ‘ON’ position, the ‘OFF’ position, and the ‘TRIP’ position corresponding to command transmitted manually or by the TRIP assembly

[0114] , The actuator assembly

[0112] includes a fork lever [112a] adapted to be manually adjusted to adjust the three pole assemblies

[0102] together between the ‘ON’ position and the ‘OFF’ position. In particular, the fork lever [112a] of the actuator assembly

[0112] may be manipulated, to adjust the three pole assemblies

[0102] together from the ‘ON’ position to the ‘OFF’ position and vice versa. Moreover, one or more of the three pole assemblies

[0102] may be adjusted to the ‘BLOW OPEN’ position, during short-circuit fault condition in the MCCB

[0100] , Notably, the fork lever [112a] defines a substantially rectangular-shaped protruded section adapted to receive a knob unit

[0136] thereon, as seen from figure 19. Although, in figure 19, the knob unit

[0136] is illustrated as a two-part assembly, comprising a knob support member [136a] and a knob cover member [136b], those skilled in the art may appreciate that the knob support member [136a] and the knob cover member [136b] can be a single integrated component, and the same is within the scope of the present disclosure. Further, the fork lever [112a] of the actuator assembly

[0112] may be manipulated to reset the three pole assemblies

[0102] together from the ‘TRIP’ position to the ‘OFF’ position.

[0123] The actuator assembly

[0112] comprises an operating mechanism, a latching mechanism, a pair of side cover plates, a trip arm, a trip bar, and a rivet arrangement, wherein the rivet arrangement facilitates the mounting and pivotally supports each of the operating mechanism, the latching mechanism, and the trip bar between the pair of side cover plates. The operating mechanism, comprising of the fork lever [112a], is adapted to manipulate the rotary contact unit

[0120] amongst the ‘ON’, ‘OFF’, and ‘TRIP’ positions thereof. The latching mechanism is commonly known to latch the trip arm thereto, during normal operating conditions of the MCCB

[0100] i.e., the ‘ON’ position or the ‘OFF’ position thereof, and release the trip arm therefrom, in the event of any fault condition, thereby tripping the MCCB

[0100] to the ‘TRIP’ position thereof. The details pertaining to the relative arrangement of the aforementioned components of the actuator assembly

[0112] are commonly known to those skilled in the art, and therefore, omitted herein for the sake of brevity.

[0124] Figure 5 illustrates a fourth partially exploded view of the MCCB

[0100] of Figure 1, indicating the mounting of atrip assembly cover member

[0144] , in accordance with the first embodiment of the present disclosure. Figure 6 illustrates a fifth partially exploded view of the MCCB

[0100] of Figure 1, indicating the mounting of the trip assembly cover member

[0144] , in accordance with a second embodiment of the present disclosure. Figures 13a and 13b illustrate a perspective view and exploded view, respectively, of an arrangement of the actuator assembly

[0112] and the three (3) pole assemblies

[0102] , and the TRIP assembly

[0114] , in accordance with the first embodiment of the present disclosure. Figure 14 illustrates a perspective view of the arrangement of the actuator assembly

[0112] and the three (3) pole assemblies

[0102] , and the TRIP assembly

[0114] , in accordance with the second embodiment of the present disclosure. Figures 5, 6, 13a, 13b, and 14 are to be viewed in conjunction with each other to better understand the first and second embodiments of the present disclosure. As seen from figures 13a, 13b, and 14, the TRIP assembly

[0114] is mounted and supported on one or each of the three pole assemblies

[0102] , such that the TRIP assembly

[0114] triggers the actuator assembly

[0112] to adjust the three pole assemblies

[0102] together, from the ‘BLOW OPEN’ position to the ‘TRIP’ position.

[0125] In the first embodiment of the present invention, as represented by figures 5, 13a, and 13b, the TRIP assembly

[0114] comprises a trip adjustment module [114a] and a trip unit [114b], wherein the trip unit [114b] triggers the actuator assembly

[0112] to adjust the three pole assemblies

[0102] together, while the trip adjustment module [114a] includes a trip unit adjustment knob adapted to adjust one or more threshold values required for actuation of trip unit [114b]. In the first embodiment, the trip unit [114b] is a thermal and magnetic trip unit (TMTU). In assembly of the first embodiment, the trip unit [114b] is initially mounted and supported on each of the three pole assemblies

[0102] , by means of conventionally known fastening means. Thereafter, the trip adjustment module [114a] is mounted thereon, and finally the TRIP assembly

[0114] is covered by mounting the trip assembly cover member

[0144] thereon. Notably, in the first embodiment, the trip assembly cover member

[0144] covers and protects each of the trip adjustment module [114a] and the thermal and tripping unit of the TRIP assembly

[0114] , while being mounted on to the base assembly

[0104] ,

[0126] In the second embodiment of the present invention, as seen from figures 6 and 14, the TRIP assembly

[0114] comprises a trip unit [114b], wherein the trip unit [114b] is an electronic trip unit (ETU) comprising one or more current transformers (CT), a flux shifter, and a printed circuit board (PCB). In assembly of the second embodiment, the trip unit [114b] is initially mounted and supported on each of the three pole assemblies

[0102] , by means of conventionally known fastening means. Notably, in the second embodiment, the trip assembly cover member

[0144] covers and protects the electronic trip unit and components comprised therein, while being mounted on to the base assembly

[0104] , Furthermore, the trip assembly cover member

[0144] indicates technical data pertaining to knob settings for different types of tripping operation of the MCCB

[0100] ,

[0127] In assembly, the actuator assembly

[0112] is mounted on one of the three pole assemblies

[0102] , and thereafter, the other of the three pole assemblies

[0102] are connected to the aforementioned arrangement, by means of a fastening means passing through the hollow rivet member

[0128] of each of the three pole assemblies

[0102] , thereby assembling an arrangement of the actuator assembly

[0112] and the three pole assemblies

[0102] , In the said arrangement, each of the polemounting nut

[0126] , the pole-positioning spacer

[0124] , the isolation disc member

[0134] , and the at least one mounting bracket

[0122] are suitably mounted in their dedicated sections between the two adjacent pole assemblies

[0102] ,

[0128] Thereafter, the TRIP assembly

[0114] is mounted on to each of the three pole assemblies

[0102] , by means of conventionally known fastening means. The arrangement so formed, is positioned within the base assembly

[0104] , such that the line side terminal and the load side terminal engage with the at least one retention unit

[0132] employed in the base assembly

[0104] ,

[0129] The mid-cover assembly

[0106] is thereafter fittingly mounted on the base assembly

[0104] to cover the three pole assemblies

[0102] and the actuator assembly

[0112] mounted thereon, by conventionally known fastening means. Next, the trip assembly cover member

[0144] is fittingly mounted on the base assembly

[0104] to cover the TRIP assembly

[0114] , by conventionally known fastening means.

[0130] Thereafter, the fascia plate assembly

[0108] is fittingly mounted onto the mid-cover assembly

[0106] , and the first and second hinge cover plates [140,142] of the hinge cover assembly

[0138] are pivotally mounted on the top and bottom edges of the fascia plate assembly

[0108] , respectively. Further, the first and second hinge cover plates [140,142] are locked onto the midcover assembly

[0106] , by means of snap-fit attachment, thus completing the assembly of the MCCB

[0100] ,

[0131] Advantageously, the dedicated sections in each of the three pole assemblies

[0102] for accommodating each of the pole-mounting nut

[0126] , the at least one mounting bracket

[0122] , the pole-positioning spacer

[0124] , and the isolation disc member

[0134] , eliminates the requirement of additional spacers between the pole assemblies

[0102] for vertical mounting thereof. Moreover, the aforementioned components ensure proper electrical isolation thereof from the internal components of the pole assembly

[0102] , Additionally, the aforementioned components facilitate efficient alignment of the three pole assemblies

[0102] , relative to each other as well as the base assembly

[0104] , thereby ensuring proper electrical connection of each of the three pole assemblies

[0102] on the load side as well as the line side.

[0132] Furthermore, the provision of hollow rivet member

[0128] in the pole assembly

[0102] also ensures an improved sealing of the casing unit

[0116] , to prevent escape of ionized gases generated in the event of a fault condition in the MCCB

[0100] , and thus, prevent damage and / or malfunction of the TRIP assembly

[0114] , connected to the pole assembly

[0102] , and components thereof. Moreover, by employing the hollow rivet member

[0128] , the actuator assembly

[0112] can be conveniently mounted on one of the three pole assemblies

[0102] with the same fastening means employed to mount the three pole assemblies

[0102] together, thereby eliminating the requirement of separate mounting provisions therefor. In addition to the above, the hollow rivet member

[0128] further promotes ease of adaptability in switching between the three-pole configuration of the pole assemblies

[0102] described herein to a four-pole configuration of the pole assemblies

[0102] ,

[0133] Additionally, the substantially reduced height of the casing unit

[0116] at a load terminal side, facilitates interchangeability of TRIP assembly

[0114] between a thermal and magnetic trip unit (TMTU) and an electronic trip unit (ETU). Thus, in essence, the MCCB

[0100] , as disclosed in the present invention, ensures efficient mounting of various internal accessories therein, without compromising the overall integrity or functioning thereof. The above listed advantages are merely illustrative and not exhaustive, and those skilled in the art may envision other advantages in light of the present disclosure.

[0134] While the preferred embodiments of the present invention have been described hereinabove, it should be understood that various changes, adaptations, and modifications may be made therein without departing from the spirit of the invention. It will be obvious to a person skilled in the art that the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.

[0135] LIST OF REFERENCE NUMERALS

[0136] 100 - Moulded case circuit breaker

[0137] 102 - Pole assembly

[0138] 104 - Base assembly

[0139] 104a - Nut-retention unit holding portion

[0140] 104b - Guide rails

[0141] 106 - Mid-cover assembly

[0142] 106a - Mid-cover cavity 106b - Depressed portions

[0143] 108 - Fascia plate assembly

[0144] 108a - Fascia plate cavity

[0145] 108b - Rotatable indicators

[0146] 108c - Mounting grooves

[0147] 112 - Actuator assembly

[0148] 112a - Fork lever

[0149] 114 - TRIP assembly

[0150] 114a - Trip adjustment module

[0151] 114b - Trip unit

[0152] 116 - Casing unit

[0153] 116a - First casing member

[0154] 116b - Second casing member

[0155] 116c - Fastening cavities

[0156] 116e - Cut-out section

[0157] 116f - Depressed portion

[0158] 116g - Tapered protrusion

[0159] 116h - Guide-slot

[0160] 116i, 116j - Bean-shaped slots

[0161] 120 - Rotary contact unit

[0162] 120a - Extension section

[0163] 122 - Mounting bracket a - Cylindrical extension sectionsb - Cut-out sections c - Bottom edge - Pole-positioning spacer - Pole -mounting nut - Hollow rivet member - Mounting-bracket - Nut-retention unit a - Longitudinal grooves - Isolation disc member a - Pin-shaped extruded portionb - Through-hole - Knob unit a - Knob support member b - Knob cover member - Hinge cover assembly - First hinge cover plate - Second hinge cover plate - Trip assembly cover member - Primary tripping accessory - Second portion a - Pair of threaded cavities 150 - First portion

[0164] 150a - Male extension

[0165] 152 - Fastening members

[0166] 154 - Secondary tripping accessory 156 - Trip actuation lever

[0167] 158 - Shunt / Under Voltage (UV) type tripping accessory

Claims

I / We Claim:

1. A molded case circuit breaker (MCCB) [100], comprising:- a plurality of pole assemblies [102], each comprising a casing unit [116] defining a guide-slot [116h];- an actuator assembly [112] installed atop one of the plurality of pole assemblies [102], such that the guide-slot [116h] of the other of the plurality of pole assemblies [102] adjacent thereto are positioned proximal to the actuator assembly [112]; and- a primary tripping accessory [146] defining a first portion [150] and a second portion [148], wherein the first portion [150] of the primary tripping accessory [146] is adapted to slidably engage with the guide-slot [116h] defined in at least one of the plurality of pole assemblies [102], to be fittingly installed atop the said one of the plurality of pole assemblies [102], while the second portion [148] is adapted to engage with a pair of fastening members [152] extending through at least a portion of a mid-cover assembly [106] of the MCCB [100], to be fittingly installed relative to the mid-cover assembly [106], thereby facilitating an overall rigid mounting of the primary tripping accessory [146] within the MCCB [100],2. The MCCB [100] as claimed in claim 1, wherein the primary tripping accessory [146] is a flux shifter device.

3. The MCCB [100] as claimed in claim 1, wherein the first portion [150] of the primary tripping accessory [146] defines a pair of male extension sections [150a], such that the pair of male extension [150a] sections are adapted to slidably engage with the guide slot [ 116h] of at least one of the plurality of pole assemblies [102], to fittingly install the primary tripping accessory [146] atop at least one of the plurality of pole assemblies [102],4. The MCCB [100] as claimed in any of the claims 1 or 3, wherein the second portion [148] of the primary tripping accessory [146] defines a pair of threaded cavities [148a] adapted to lockingly receive the pair of fastening members [152] extending from the mid-cover assembly [106], to fittingly install the primary tripping accessory [146] relative to the mid-cover assembly [106], thus facilitating the rigid mounting of the primary tripping accessory [146] within the MCCB [100],5. The MCCB [100] as claimed in claim 1, comprising:- a substantially U-shaped mounting bracket [130] adapted to slidably engage with the guide-slot [116h] defined in the other of the plurality of pole assemblies [102], to be fittingly installed atop the said other of the plurality of pole assemblies [102], wherein the mounting bracket [130] is adapted to receive and support a trip actuation lever [156] thereon, the trip actuation lever [156] being adapted to translate a TRIP command from one of a shunt type tripping accessory [158] and / or an undervoltage (UV) type tripping accessory [158], to the actuator assembly [112] of the MCCB [100], to thereby cause tripping of the MCCB [100],6. The MCCB [100] as claimed in claim 1, wherein the MCCB [100] comprises a secondary tripping accessory mounting arrangement, comprising:- at least one mounting bracket [122] adapted to be sandwiched between each adjacent pair of the plurality of pole assemblies [102], the at least one mounting bracket [122] adapted to receive and support thereon a secondary tripping accessory [154],7. The MCCB [100] as claimed in any of the claims 1 or 6, wherein the casing unit [116] of each adjacent pair of the plurality of pole assemblies [102], defines a cylindrical depressed portion [ 116f] and a tapered protrusion [116g], while the at least one mounting bracket [122] defines a pair of cylindrical extension sections [122a] extending sidewards therefrom, such that one of the pair of cylindrical extension section [122a] of the at least one mounting bracket [122] is received within the cylindrical depressed portion [116f] of one of each adjacent pair of plurality of pole assemblies [102], while the other of the pair of cylindrical extension section [122a] is received within the cylindrical depressed portion [116f] of the other of each adjacent pair of plurality of pole assemblies [102], to facilitate mounting the secondary tripping accessory mounting arrangement between each adjacent pair of the plurality of pole assemblies [102],8. The MCCB [100] as claimed in any of the claims 6 or 7, wherein the at least one mounting bracket [122] defines a pair of cut-out sections [122b] on either sides of a bottom edge [122c] thereof, such that one of the pair of cut-out sections [122b] rests on the tapered protrusion [116g] of one of each adjacent pair of plurality of pole assemblies [102], while theother of the pair of cut-out sections [122b] rests on the tapered protrusion [116g] of the other of each adjacent pair of plurality of pole assemblies [102].

9. The MCCB [100] as claimed in claim 6, wherein the secondary tripping accessory [154] is an ultra-fast tripping accessory.

10. The MCCB [100] as claimed in claim 1, wherein each of the plurality of pole assemblies [102] comprises:- a casing unit [116];- a stationary contact unit;- a rotary contact unit [120] ;- an arc chute unit; and- at least one hollow rivet member [128], wherein each of the stationary contact unit, the rotary contact unit [120], and the arc chute unit are sealingly enclosed within the casing unit [116], via the at least one hollow rivet member [128], and wherein the at least one hollow rivet member [128] is adapted to facilitate connection of at least one of the plurality of pole assemblies [102] with the other of the plurality of pole assemblies [102] and / or an actuator assembly [112],11. The MCCB [100] as claimed in claim 10, wherein the casing unit [116] defines a pair of bean-shaped slots [116i, 116j], which allow mounting of an isolation disc member [134] between two adjacent pole assemblies [102] of the plurality of pole assemblies [102],12. The MCCB [100] as claimed in claim 11, wherein the isolation disc member [134] defines a pin-shaped extruded portion [134a] and a through-hole [134b], such that the pin-shaped extruded portion [134a] is adapted to at least partially extend within the hollow extension section [120a] of the rotary contact unit [120], while the through-hole allows a drive shaft to pass therethrough.

13. The MCCB [100] as claimed in claim 10, wherein the casing unit [116] defines a substantially rectangular cut-out section [ 116e] proximal to a bottom side thereof, to at least partially receive a pole-mounting nut [126] therein, such that when the plurality of poleassemblies [102] are fastened together, the pole-mounting nut [126] is deployed between every adjacent pair of pole assemblies [102] of the plurality of pole assemblies [102],

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