WO2024151865A1

WO2024151865A1 - Drop-out current limiting fuse

Info

Publication number: WO2024151865A1
Application number: PCT/US2024/011263
Authority: WO
Inventors: Chandiran SUNDARRAJ; Siddharthkumar TILALA
Original assignee: Hubbwll Incorporated
Priority date: 2023-01-14
Filing date: 2024-01-11
Publication date: 2024-07-18

Abstract

An actuator assembly for mounting a current limiting fuse to a cutout, the current limiting fuse configured to eject a striker in response to an occurrence of an electrical fault. The actuator assembly includes a housing that couples the actuator assembly to the current limiting fuse, a hinge that connects the actuator assembly to a lower terminal of the cutout, and a dropout mechanism that operates to disconnect the current limiting fuse from an upper terminal of the cutout when the striker is ejected from the current limiting fuse.

Description

DROP-OUT CURRENT LIMITING FUSE

FIELD

[0001] The present application relates to circuit interrupting devices, such as current limiting fuses.

SUMMARY

[0002] A fuse is a circuit interrupting device that is employed in a power distribution system to protect equipment, such as transformers, capacitor banks, cables, and/or other equipment, from overload and fault currents by opening the circuit. Two types of fuses are commonly employed in power distribution systems, expulsion fuses and current limiting fuses. Expulsion fuses are non-current limiting and may include a fusible element and an internal arc quenching liner, which may be formed of bone fiber, melamine, aluminum trihydrate, and/or other materials. When the fusible element melts, for example in response to an overload and/or fault current, a resultant arc plasma consumes the liner material and produces deionizing gas(es). As a result, hot gases, along with flames and/or debris, are expelled violently into the atmosphere in conjunction with a loud noise. Furthermore, expulsion fuses are designed to mount in an industry standard distribution cutout and drop open to provide visible indication that a fault has been cleared.

[0003] In contrast, current limiting fuses do not expel hot gases into the environment after operation. For example, a current limiting fuse may consist of one or more wires and/or strip elements (e.g., formed of silver and/or copper) with a reduced cross-section area over its length and a fusible element that is surrounded by highly compacted quartz/sand. At higher currents faults, the fusible element melts first at the reduced cross-section area and then at the remaining length of the element. A resulting arc dissipates its heat energy into the surrounding sand, which forms a glass like structure such as fulgurite. The generated arc voltage, loss of heat energy, and the confinement of the arc by the glass fulgurite limits the fault current, thereby interrupting the circuit without expelling any by-product into the environment.

[0004] However, existing current limiting fuses are not designed to be directly mounted to industry standard cutouts. Rather, they are typically designed to accommodate a clip style mounting. As utility providers are increasingly concerned with the negative effects that expelled gases have on vegetation and wildlife, current limiting fuses, which do not expel hot gases into the environment after interrupting a circuit, are preferred over expulsion fuses. Thus, a mounting option that enables industry standard current limiting fuses to be mounted to industry standard cutouts is desired.

[0005] A first aspect of the present disclosure provides a circuit interrupter assembly including a current limiting fuse and an actuator assembly. The current limiting fuse includes a terminal that connects the current limiting fuse to a first terminal of a cutout and an striker that is ejected from the current limiting fuse in response to an occurrence of an electrical fault. The actuator assembly includes a housing that couples the actuator assembly to the current limiting fuse, a hinge that connects the actuator assembly to a second terminal of the cutout, and a dropout mechanism that operates to disconnect the current limiting fuse from the first terminal of the cutout when the striker is ejected from the current limiting fuse.

[0006] A second aspect of the present disclosure provides an actuator assembly for mounting a current limiting fuse to a cutout, the current limiting fuse configured to eject a striker in response to an occurrence of an electrical fault. The actuator assembly includes a housing that couples the actuator assembly to the current limiting fuse, a hinge that connects the actuator assembly to a lower terminal of the cutout, and a dropout mechanism that operates to disconnect the current limiting fuse from an upper terminal of the cutout when the striker is ejected from the current limiting fuse.

[0007] Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. l is a perspective view of an indsutry standard distribution cutout, according to one example.

[0009] FIG. 2 is a perspective view of a circuit interrupter assembly mounted to the standard distribution cutout of FIG. 1, according to example. [0010] FIG. 3A is a side view of a standard current limiting fuse included in the circuit interrupter assembly of FIG. 2, according to one example.

[0011] FIG. 3B is a perspective view of an offset cap included in the current limiting fuse of FIG. 3A, according to one example.

[0012] FIG. 3C is a cross-section view of the standard current limiting fuse of FIG. 3A, according to one example.

[0013] FIG. 4A is a perspective view of an actuator assembly included in the circuit interrupter assembly of FIG. 2, according to one example.

[0014] FIG. 4B is another perspective view of an actuator assembly included in the circuit interrupter assembly of FIG. 2, according to one example.

[0015] FIG. 5 A is a perspective view of a housing of the actuator assembly of FIGS. 4A and

4B, according to one example.

[0016] FIG. 5B is a perspective view of a current bridge assembly included in the housing of FIG. 5 A, according to one example.

[0017] FIG. 6 is a perspective view of a hinge included in the actuator assembly of FIGS. 4A and 4B, according to one example.

[0018] FIG. 7A is a perspective view of a dropout mechanism included in the actuator assembly of FIGS. 4A and 4B in an unoperated state, according to one example.

[0019] FIG. 7B is a side view of a dropout mechanism included in the actuator assembly of FIGS. 4A and 4B in an unoperated state, according to one example.

[0020] FIG. 8A is a perspective view of a link included in the dropout mechanism of FIGS. 7A and 7B, according to one example.

[0021] FIG. 8B is a perspective view of a retainer spring included in the dropout mechanism of FIGS. 7A and 7B, according to one example. [0022] FIG. 8C is a perspective view of a release plate included in the dropout mechanism of FIGS. 7A and 7B, according to one example.

[0023] FIG. 8D is a perspective view of an actuating rod included in the dropout mechanism of FIGS. 7A and 7B, according to one example.

[0024] FIG. 8E is a perspective view of an actuator spring included in the dropout mechanism of FIGS. 7A and 7B, according to one example.

[0025] FIG. 8F is a perspective view of a latch included in the dropout mechanism of FIGS. 7A and 7B, according to one example.

[0026] FIG. 8G is a perspective view of a latch plate included in the dropout mechanism of FIGS. 7A and 7B, according to one example.

[0027] FIG. 8H is a perspective view of a release linkage included in the dropout mechanism of FIGS. 7A and 7B, according to one example.

[0028] FIG. 81 is a perspective view of a hinge holder included in the dropout mechanism of FIGS. 7A and 7B, according to one example.

[0029] FIG. 9 is a close-up perspective view of the circuit interrupter assembly of FIG. 2 in an unoperated state, according to one example.

[0030] FIG. 10 is a close-up perspective view of the circuit interrupter assembly of FIG. 2 in an operated state, according to one example.

[0031] FIG. 11 is a side view of a dropout mechanism included in the actuator assembly of FIGS. 4A and 4B in an operated state, according to one example.

[0032] FIG. 12 is a side view of a dropout mechanism included in the actuator assembly of FIGS. 4A and 4B in an operated state, according to one example.

[0033] FIG. 13 is a perspective view of a dropout mechanism included in the actuator assembly of FIGS. 4A and 4B in an operated state, according to one example. [0034] FIG. 14 is a perspective view of the circuit interrupter assembly of FIG. 2 dropped out from the industry standard cutout of FIG. 1, according to one example.

DETAILED DESCRIPTION

[0035] Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Use of "including" and "comprising" and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of "consisting of' and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

[0036] In general, the present disclosure relates to a replaceable circuit interrupter assembly that includes a current limiting fuse and a reusable actuator assembly for mounting the current limiting fuse to an industry standard cutout.

[0037] FIG. 1 illustrates a perspective view of an indsutry standard cutout 100 that is used to mount and electrically connect protective equipement, such as circuit interrupting devices, in a power distribution system. The cutout 100 includes a first, or upper, terminal 105 and a second, or lower, terminal 110 that electrically connect a circuit interrupting device to the power distribution system. The upper and lower terminals 105, 110 are disposed on opposing ends of an insulator 115 included in the cutout 100, thereby giving the cutout 100 a “C” shape. In the illustrated example, the cutout 100 is supported by and mechanically coupled to a bracket 120, which may be mounted to a structure, such as a utility pole or tower, included in the power distribution system. [0038] FIG. 2 illustrates a perspective view of a circuit interrupter assembly 200 used in a power distribution system, according to one example of the present disclosure. The circuit interrupter assembly 200 includes a current limiting fuse 205 and an actuator assembly 210. As shown, the circuit interrupter assembly 200 is configured to be mounted to an industry standard cutout, such as the cutout 100. With reference to FIG. 3 A, the current limiting fuse 205 is an industry standard current limiting fuse that includes, a top terminal, or cap 305, an offset cap 307, a fuse tube 310, and a bottom terminal, or cap, 315. The offset cap 307 is used to electrically and mechanically connect the current limiting fuse 205 to the upper terminal 105 of the cutout 100. FIG. 3B illustrates a perspective view of the offset cap 307.

[0039] As will be described in more detail below, the actuator assembly 210 is used to electrically and mechanically connect the bottom cap 315 to the lower terminal 110 of the cutout 100. FIG. 3C illustrates a perspective view of the current limiting fuse 205 in which the fuse tube 310 is removed to expose the fusible elements 320 included in the current limiting fuse 205. The fusible elements 320 melt to open a circuit in the power distribution system in response to the occurrence of an overload and/or short circuit fault condition. For example, the current limiting fuse 205 electrically disconnects the upper terminal 105 of the cutout 100 from the lower terminal 110 of the cutout 100 when an electrical fault occurs in the power distribution system to which the circuit interrupter assembly 200 is connected.

[0040] Furthermore, as shown in FIG. 3C, the current limiting fuse 205 includes a striker 325. The striker 325 may be a component of a striker assembly included in the current limiting fuse 205, the striker assembly including components (not shown), such as a spring, an explosive charge, and/or one or more wires, that operate to eject the striker 325 from the current limiting fuse 205 in response to the occurrence of an electrical fault. The striker 325 is positioned within the current limiting fuse 205 to align with an aperture formed in the bottom cap 315. Thus, when the fusible elements 320 melt to disconnect the circuit in response to an electrical fault, one or more components of the striker assembly are also operated to eject the striker 325 from the bottom cap 315 through the aperture. For example, upon the occurrence of an electrical fault, a spring included in the striker assembly is released and/or a small charge included in the striker assembly is detonated to eject the striker 325 from the bottom of the current limiting fuse 205. Moreover, the striker 325 is ejected from the bottom of the current limiting fuse 205 after the fusible elements 320 included in the current limiting fuse 205 are melted in response to the occurrence of a fault.

[0041] As described above, the current limiting fuse 205 is mounted to the cutout 100 using the actuator assembly 210. In particular, the current limiting fuse 205 is electrically and mechanically coupled to the lower terminal 110 of the cutout 100 by the actuator assembly 210. FIGS. 4 A and 4B illustrate perspective views of the actuator assembly 210 according to one example of the present disclosure. The coupling mechanism includes a housing 400, a hinge 405 coupled to the housing 400, and a dropout mechanism 410 positioned within the housing 400.

[0042] FIG. 5A illustrates a perspective view of the housing 400. As shown, the interior of the housing 400 includes, or defines, a first internal cavity 505 that is arranged to receive and contain the dropout mechanism 410. In the illustrated example, the first internal cavity 505 is rectangular in shape. However, it should be understood that in some instances, the first internal cavity 505 has a different shape. Furthermore, the interior of the housing 400 includes, or defines, a second internal cavity 510 that is disposed above the first internal cavity 505 and arranged to receive the bottom cap 315 of the current limiting fuse 205. That is, when the actuator assembly 210 is coupled to the current limiting fuse 205, the bottom cap 315 of the current limiting fuse 205 is received by and positioned within the second internal cavity 510. Moreover, when the bottom cap 315 of the current limiting fuse 205 is received by the second internal cavity 510 of the housing 400, the dropout mechanism 410 positioned within the first internal cavity 505 is disposed underneath the bottom cap 315 of the current limiting fuse 205. In the illustrated example, the second internal cavity 510 is cylindrical in shape and has a larger circumference than the bottom cap 315 of the current limiting fuse 205. However, in some instances, the second internal cavity 510 has a different shape.

[0043] The housing 400 further includes a plurality of holes and/or receptacles that are used for coupling the housing 400 to the bottom cap 315 of the current limiting fuse 205 and the hinge 405. In the illustrated example, the housing 400 includes a lip 515 in which a plurality of holes 520A-520D are formed for fastening the housing 400 to the bottom cap 315 of the current limiting fuse 205. When the bottom cap 315 is received by the second internal cavity 510, the plurality of holes 520A-520D may be aligned with corresponding holes formed in the bottom cap 315 such that fasteners (e.g., screws, bolts, washers, etc.) can be inserted into the holes 520A- 520D to couple the bottom cap 315 to the housing 400. In addition, the housing 400 includes a coupling mechanism 525 for coupling the hinge 405 to the housing 400. In the illustrated example, the coupling mechanism 525 includes first and second holes 530A, 530B that are used to couple the hinge 405 to the housing 400. In some instances, the housing 400 is constructed from an electrically conductive metal(s), such as copper/copper alloy or aluminum and/or steel. In some instances, the housing 400 is formed of a different conductive material.

[0044] The housing 400 further includes a current bridge assembly 535. FIG. 5B illustrates a perspective view of the current bridge assembly 535, which includes a copper plate 540 and a steel plate 545 that are fixed to the housing 400 (for example, by a stud and/or nuts). As shown, the copper plate 540 is disposed on top of the steel plate 545. The current bridge assembly 535 is configured to transfer current, via the copper plate 540, from the housing 400 to the hinge 405, when the dropout mechanism 420 is in the unoperated state. As will be described in more detail below, the unoperated state of the dropout mechanism 410 is the state of the dropout mechanism 410 before the dropout mechanism 410 is operated to disconnect the current limiting fuse 205 from the upper terminal 105 of the cutout 100. As will also be described in more detail below, the current bridge assembly 535 is mechanically compressed by the hinge 405 and engages prongs of the hinge 405 with a hinge holder, such that there is a force acting on the hinge 405 against the engagement of the hinge 405 with the hinge holder. When the dropout mechanism 410 is operated and the hinge holder starts to move downwards, the compressed force from current bridge assembly 535 assists with decoupling the hinge 405 from the hinge holder 745. In some instances, the copper plate 540 is used for transferring current from the housing 400 and the steel plate 545 is used to provide the mechanical compressive force.

[0045] FIG. 6 illustrates a perspective view of the hinge 405. As shown, the hinge 405 includes first and second pivots 605A, 605B that are used to electrically and mechanically connect the actuator assembly 210, and thus the circuit interrupter assembly 200, to the lower terminal 110 of the cutout 100. The first and second pivots 605 A, 605B are rounded such that when the first and second pivots 605A, 605B are respectively received by and positioned in openings, or slots, of the lower terminal 110, the hinge 405 is operable to rotate about the first and second pivots 605 A, 605B relative to the lower terminal 110 of the cutout 100. The hinge 405 further includes first and second holes 610A, 61 OB that are used to couple the hinge 405 to the housing 400. For example, the first and second holes 610A, 610B are arranged to align with the first and second holes 530A, 530B of the housing 400 such that the housing 400 and the hinge 405 may be mechanically coupled by a pin or similar mechanical component that extends through the first and second holes 530A, 530B and the first and second holes 610A, 610B. In some instances, the first and second holes 530A, 530B of the housing and/or the first and second holes 610A, 610B of the hinge 405 are replaced with one or more different fastening elements for coupling the hinge 405 to the housing 400. As will be described in more detail below, the hinge 405 further includes prongs 615 that are used to mechanically couple the hinge 405 to one or more components of the dropout mechanism 410. In some instances, the hinge 405 is constructed from electrically conductive metal(s), such as copper/copper alloy or aluminum or steel. In some instances, the hinge 405 is formed of a different conductive material.

[0046] When the current limiting fuse 205 and the actuator assembly 210 are mechanically coupled to each other (e.g., fastened together using the plurality of holes 520A-520D and corresponding holes formed in the bottom cap 315) and installed on the cutout 100, the offset cap 307 mechanically and electrically connects the current limiting fuse 205 to the upper terminal 105 of the cutout 100 and the hinge 405, and more particularly the first and second pivots 605 A, 605B, mechanically and electrically connect the current limiting fuse 205 to the lower terminal 110 of the cutout 100. As will be described in more detail below, the actuator assembly 210 is configured to perform an operating action that disconnects the offset cap 307 of the current limiting fuse 205 from the upper terminal 105 of the cutout 100 in response to the occurrence of an electrical fault. After the actuator assembly 210 performs the operating action to disconnect the offset cap 307 from the upper terminal 105 of the cutout 100, the current limiting fuse 205 drops out from the cutout 100. For example, the current limiting fuse 205 and the actuator assembly 210 rotate downward about the first and second pivots 605 A, 605B, such that the current limiting fuse 205 and the actuator assembly 210 hang from the lower terminal 110 of the cutout 100 to provide a visual indication that the current limiting fuse 205 has disconnected the circuit in response to an electrical fault.

[0047] In particular, the dropout mechanism 410 included in the actuator assembly 210 performs the operating action to disconnect the current limiting fuse 205 from the upper terminal

the circuit interrupter assembly 200 is connected. As described above, the striker 325 is ejected downward from the bottom of the current limiting fuse 205 when the current limiting fuse 205 is operated in response to an electrical fault. When ejected, the striker 325 exits the current limiting fuse 205 through an aperture formed in the bottom cap 315 and enters the actuator assembly 210. In particular, the striker 325 enters the first internal cavity 505 of the actuator assembly 210 and exerts a force (e.g., 22 lbs) on the dropout mechanism 410 thereby triggering the dropout mechanism 410 to perform the operating action that disconnects the offset cap 307 of the current limiting fuse 205 from the upper terminal 105 of the cutout 100.

[0048] FIGS. 7A and 7B respectively illustrate perspective and side views of the dropout mechanism 410 in an unoperated state, according to one example of the present disclosure. The unoperated state of the dropout mechanism 410 is the state of the dropout mechanism 410 before the dropout mechanism 410 is operated to disconnect the current limiting fuse 205 from the upper terminal 105 of the cutout 100. As will be described in more detail below, the dropout mechanism 410 includes a link 705, a retainer spring 710, a release plate 715, an actuating rod 720, an actuator spring 725, a latch 730, a latch plate 735, a release linkage 740, and a hinge holder 745. Perspective views of the components included the dropout mechanism 410 are respectively illustrated in FIGS. 8A-8I.

[0049] The link 705 is biased, or supported, in the unoperated state by the retainer spring 710. The retainer spring 710 is arranged coaxially around the length of the link 705 such that the retainer spring 710 is compressed between a top surface 805 of the link 705 and the release plate 715. Exertion of a force on the top surface 805 of the link 705 is resisted by the retainer spring 710. Moreover, downward movement of the link 705 towards the release plate 715 results in compression of the retainer spring 710. In the illustrated example, the top surface 805 of the link 705 is cap-shaped and includes a flat surface that is designed to engage the striker 325 when the striker 325 is ejected from the current limiting fuse 205. The link 705 is arranged in such a way, the axis of link 705 and the axis of striker 325 are approximately aligned in the same line.

[0050] The actuating rod 720 is maintained, or latched, in the unoperated state by the latch 730. As shown, a notch 810 formed in the first end 815 of the actuating rod 720 is configured to receive and engage an arm 820 of the latch 730. When the arm 820 of the latch 730 is engaged with the notch 810 formed in the actuating rod 720, the actuating rod 720 is prevented from downward linear movement (e.g., movement in the direction of the hinge holder 745). The latch 730 is mechanically coupled to and supported by a latch plate 735. In the illustrated example, the latch 730 is coupled to the latch plate 735 by a pin such that the latch 730 is operable to rotate relative to the latch plate 735 about the pin.

[0051] When the dropout mechanism 410 is in the unoperated state, the actuator spring 725 is compressed between the latch plate 735 and a cap 825 formed on the actuating rod 720. When compressed, the actuator spring 725 exerts a downward on the cap 825 in the direction of the hinge holder 745. However, as described above, the latch 730 prevents the actuator spring 725 from pushing the actuating rod 720 in the direction of the hinge holder 745. The latch 730 is supported in the unoperated state by the release linkage 740. As shown, a notch 830 formed in the latch 730 is configured to engage a tab 835 extending from the release linkage 740.

[0052] When the tab 835 extending from the release linkage 740 is engaged with the notch 830 formed in the latch 730, the tab 835 prevents the latch 730 from rotating in the clockwise direction. Moreover, the tab 835 prevents, via the latch 730, the actuator spring 725 from pushing the actuating rod 720 in the downward direction towards the hinge holder 745. As described above, the actuator spring 725 exerts the downward force on the actuating rod 720 while the dropout mechanism 410 is in the unoperated state. Thus, the release linkage 740 supports the latch 730 in the unoperated state such that the latch 730 is prevented from disengaging the actuating rod 720 and rotating in the clockwise direction in response to the force exerted by the actuator spring 725 on the actuating rod 720. The release linkage 740 includes a first aperture 840 that mechanically couples the release linkage 740 to the bottom end 845 of the link 705. The release linkage 740 further includes a second aperture 850 that is used to mechanically couple the release linkage 740 to the release plate 715. As will be described in more detail below, the release linkage 740 is rotatably coupled to the release plate 715.

[0053] The hinge holder 745 is mechanically coupled to the second end 855 of the actuating rod 720. In the illustrated example, the second end 855 of the actuating rod 720 includes an aperture 860 that is used to couple the actuating rod 720 to the hinge holder 745. Furthermore, in the illustrated example, the hinge holder 745 includes a first aperture 865 that is configured to receive the second end 855 of the actuating rod 720 and a second aperture 870 that is arranged to align with the aperture 860 formed in the second end 855 of the actuating rod 720. In some instances, a fastener such as a pin, is inserted into the aperture 860 and the second aperture 870 while the second end 855 of the actuating rod 720 is received by the first aperture 860 of the hinge holder 745. As shown in FIG. 9, a groove 875 formed in the hinge holder 745 is configured to receive and engage the prongs 615 extending from the hinge 405 when the dropout mechanism 410 is in the unoperated state.

[0054] FIG. 9 illustrates a close-up perspective view of the current limiting fuse 205 coupled, by the actuator assembly 210, to the lower terminal 110 of the cutout 100 when the dropout mechanism 410 is in the unoperated state. That is, FIG. 9 illustrates a close-up perspective view of the bottom of the current limiting fuse 205, the actuator assembly 210, and the lower terminal 110 of the cutout 100 during normal operating conditions in the power distribution system to which the circuit interrupter assembly 200 is connected (e.g., before an electrical fault has occurred). While in the unoperated state, the prongs 615 extending from the hinge 405 are engaged with and supported by the groove 875 formed in the hinge holder 745.

[0055] In contrast, FIG. 10 illustrates a close-up perspective view of the bottom of the current limiting fuse 205, the actuator assembly 210, and the lower terminal 110 of the cutout 100 after the current limiting fuse 205 and the dropout mechanism 410 are operated in response to the occurrence of an electrical fault in the power distribution system to which the circuit interrupter assembly 200 is connected. That is, FIG. 10 illustrates a perspective close-up view of the dropout mechanism 410 in the operated state. The operated state of the dropout mechanism 410 is the state of the dropout mechanism 410 after the dropout mechanism 410 is operated to dropout the current limiting fuse 205 from the cutout 100 (e.g., disconnect the current limiting fuse 205 from the upper terminal 105 of the cutout 100). While in the operated state, the hinge holder 745 is no longer engaged with the prongs 615 extending from the hinge 405.

[0056] As further shown in FIG. 10, the striker 325 has been ejected from the bottom of the current limiting fuse 205 and into the actuator assembly 210. As described above, the striker 325 is ejected from the current limiting fuse 205 when the current limiting fuse 205 is operated to interrupt the circuit to which the circuit interrupter assembly 200 is connected. For example, one or more components of the striker assembly are also operated to eject the striker 325 from the bottom cap 315 when the fusible elements 320 are melted to disconnect the circuit in response to an electrical fault. Upon being ejected, the striker 325 enters the first internal cavity 505 of the actuator assembly 210 and exerts a downward force D on the top surface 805 of the link 705 (FIG. 11). In the illustrated example, the striker 325 travels 5-7 millimeters (mm) before contacting the top surface 805 of the link 705 when ejected from the current limiting fuse 205. In some instances, the striker 325 travels a different distance before contacting the top surface 805 of the link 705. For example, in some instances, the striker 325 travels a distance that is less than 5 mm before contacting the top surface 805 of the link 705. In other instances, the striker 325 travels a distance that is greater than 7mm before contacting the top surface 805 of the link 705.

[0057] In some instances, the striker 325 is ejected from the bottom cap 315 of the current limiting fuse 205 with an initial force of approximately 26 pounds (lbs). In other instances, the striker 325 is ejected from the bottom cap 315 of the current limiting fuse 205 with a different amount of force. In some instances, by the time the striker 325 contacts the top surface 805 of the link 705 after being ejected from the current limiting fuse 205, the force D exerted on the top surface 805 by the striker 325 is less than the force with which the striker 325 is ejected from the bottom of the current limiting fuse 205. For example, if it is assumed that the striker 325 is ejected from the current limiting fuse 205 with an initial force of 26 lbs, the force D that the striker 325 exerts on the top surface 805 of the link 705 may be less than 26 lbs. In such an example, the striker 325 may exert a force D of 22 lbs on the top surface 805 of the link 705 when the striker 325 is ejected from the current limiting fuse 205 with an initial force of 26 lbs. In some instances, the striker 325 exerts a force D that is less than 22 lbs on the top surface 805 of the link 705. In some instances, the striker 325 exerts a force D that is greater than 22 lbs on the top surface 805 of the link 705. In some instances, the striker 325 exerts a force D that is between 20-30 lbs on the top surface 805 of the link 705. In some instances, the striker 325 exerts a force D that is less than 20 lbs on the top surface 805 of the link 705. In some instances, the striker 325 exerts a force D that is greater than 30 lbs on the top surface 805 of the link 705. [0058] With reference to FIG. 11, the link 705 moves linearly downward (e g., in a direction towards the release linkage 740) when the striker 325 exerts the force D on the top surface 805 of the link 705. When the link 705 moves linearly downward, the release linkage 740, which is coupled to the bottom end 845 of the link 705, rotates in the counterclockwise direction. When the release linkage 740 rotates in the counterclockwise direction, the tab 835 extending from the release linkage 740 rotates away from the notch 830 formed in the latch 730. As described above, the tab 835 supports the latch 730 in the unoperated state when engaged with the notch 830 formed in the latch 730. However, when the tab 835 of the release linkage 740 rotates away from the latch 730, the latch 730 is no longer supported in the unoperated state.

[0059] Furthermore, as described above, the actuating rod 720 is supported in the unoperated state by the latch 730. For example, the arm 820 extending from the latch 730 engages the notch 810 formed in the first end 815 of the actuating rod 720 such that the arm 820 supports the actuating rod 720 in the unoperated position. However, when the latch 730 is no longer supported by the release linkage 740 after the release linkage 740 rotates in the counterclockwise direction, the latch 730 is unable to support the actuating rod 720 in the unoperated position. For example, the latch 730 is unable to prevent the actuator spring 725 from pushing the actuating rod 720 downward in the direction of the hinge holder 745. Thus, as shown in FIG. 12, the force T exerted by the actuator spring 725 on the cap 825 of the actuating rod 720 pushes the actuating rod 720 downward in the direction of the hinge holder 745. As the hinge holder 745 is coupled to the second end 855 of the actuating rod 720, the hinge holder 745 also moves in the downward direction when the actuating rod 720 moves in the downward direction. As further shown in FIG. 13, the downward movement of the actuating rod 720 forces the latch 730 to rotate in the clockwise direction.

[0060] In some instances, the actuator spring 725 exerts a downward force T on the actuating rod 720 that is greater than the downward force D that the striker 325 exerts on the top surface 805 of the link 705. In some instances, the downward force T exerted on the actuating rod 720 by the actuator spring 725 is approximately 100 lbs. In some instances, the actuator spring 725 exerts a downward force T that is less than 100 lbs. In some instances, the actuator spring 725 exerts a downward force T that is greater than 100 lbs on the actuating rod 720. [0061] When the actuating rod 720 and the hinge holder 745 are pushed downward in response to the downward force T exerted by the actuator spring 725, the actuating rod 720 exerts, via the hinge holder 745, a corresponding downward force onto the prongs 615 of the hinge 405. It should be understood that the force exerted by the actuating rod 720 onto the prongs 615 of the hinge 405 is approximately equal to and/or slightly less than the downward force T exerted by the actuator spring 725. This downward force exerted by the hinge holder 745 onto the prongs 615 of the hinge 405 causes decoupling between the prongs 615 of the hinge 405 and the hinge holder 745. The decoupling between the prongs 615 of the hinge 405 and the hinge holder 745 is further aided by a pushing force from the current bridge assembly 535. For example, the compressive force applied by the current bridge assembly 535 onto the hinge 405 causes the hinge 405 to rotate partially from its pivot, thereby resulting in disengagement of current limiting fuse 205 from the upper terminal 105. In addition, as shown in FIG. 10, the hinge holder 745 becomes decoupled from the prongs 615 of the hinge 405 after the dropout mechanism 410 is operated.

[0062] When the offset cap 307 of the current limiting fuse 205 is disconnected from the upper terminal 105 of the cutout 100, the circuit interrupter assembly 200 “drops out” from the cutout 100. That is, the circuit interrupting assembly 200 (e.g., the current limiting fuse 205 coupled to the actuator assembly 210) rotates downward and away from the upper terminal 105 of the cutout 100 about the first and second pivots 605 A, 605B of the hinge 405. FIG. 14 illustrates the circuit interrupter assembly 200 “dropped out” from the cutout 100. As shown, the circuit interrupter assembly 200 hangs downward from the lower terminal 110 of the cutout 100 by the first and second pivots 605 A, 605B of the hinge 405. The circuit interrupter assembly 200 hanging in the dropped out position from the cutout 100 provides a visual indication to service technicians that the current limiting fuse 205 has been operated to interrupt an electrical fault occurring in the power distribution system.

[0063] After the circuit interrupting assembly 200 is operated to interrupt an electrical fault occurring in the power distribution system, the current limiting fuse 205 cannot be reused. However, the actuator assembly 210 can be reused when a new current limiting fuse 205 is installed in the circuit interrupting assembly 200. That is, a service technician can disconnect the operated current limiting fuse 205 from the actuator assembly 210 and connect a new, unoperated current limiting fuse 205 to the previously used actuator assembly 210. Accordingly, the present disclosure provides a reusable device (e g., the actuator assembly 210) for connecting an industry standard current limiting fuse, such as the current limiting fuse 205, to an industry standard distribution cutout, such as the cutout 100.

[0064] Although aspects have been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope of one or more independent aspects as described.

Claims

CLAIMS What is claimed is:

1. A circuit interrupter assembly comprising: a current limiting fuse including: a terminal that connects the current limiting fuse to a first terminal of a cutout; and a striker that is ejected from the current limiting fuse in response to an occurrence of an electrical fault; and an actuator assembly including: a housing that couples the actuator assembly to the current limiting fuse; a hinge that connects the actuator assembly to a second terminal of the cutout; and a dropout mechanism that operates to disconnect the current limiting fuse from the first terminal of the cutout when the striker is ejected from the current limiting fuse.

2. The circuit interrupter assembly of claim 1, wherein the dropout mechanism includes a link that is arranged to contact the striker when the striker is ejected from the current limiting fuse; and an actuating rod that is released to disconnect the current limiting fuse from the first terminal of the cutout when the link is contacted by the striker; wherein an axis through the striker is approximately aligned with an axis through the link.

3. The circuit interrupter assembly of claim 2, wherein the dropout mechanism further includes a spring that exerts a force on the actuating rod after the striker is ejected from the current limiting fuse, the force causing the actuating rod to disconnect the current limiting fuse from the first terminal of the cutout.

4. The circuit interrupter assembly of claim 3, wherein the force exerted on the actuating rod by the spring is greater than a second force exerted on the link by the striker.

5. The circuit interrupter assembly of claim 2, wherein the dropout mechanism further includes a latch that supports the actuating rod in an unoperated state before the striker is ejected from the current limiting fuse.

6. The circuit interrupter assembly of claim 5, wherein the dropout mechanism further includes a release linkage coupled to the link, the release linkage including a tab that supports the latch in the unoperated state before the striker is ejected from the current limiting fuse.

7. The circuit interrupter assembly of claim 6, wherein the release linkage rotates when the link is contacted by the striker; and wherein the tab disengages the latch when the release linkage rotates.

8. The circuit interrupter assembly of claim 1, wherein the dropout mechanism is contained in a first cavity formed in the housing of the actuator assembly and the current limiting fuse is received by a second cavity formed in the housing of the actuator assembly.

9. The circuit interrupter assembly of claim 8, wherein the dropout mechanism is disposed beneath the current limiting fuse when the current limiting fuse is received by the second cavity.

10. The circuit interrupter assembly of claim 1, wherein the current limiting fuse is an industry standard current limiting fuse and the cutout is an industry standard cutout.

11. An actuator assembly for mounting a current limiting fuse to a cutout, the current limiting fuse configured to eject a striker in response to an occurrence of an electrical fault, the actuator assembly comprising: a housing that couples the actuator assembly to the current limiting fuse; a hinge that connects the actuator assembly to a lower terminal of the cutout; and a dropout mechanism that operates to disconnect the current limiting fuse from an upper terminal of the cutout when the striker is ejected from the current limiting fuse.

12. The actuator assembly of claim 11 , wherein the dropout mechanism includes a link that is arranged to contact the striker when the striker is ejected from the current limiting fuse; and wherein the dropout mechanism includes an actuating rod that is released to disconnect the current limiting fuse from the upper terminal of the cutout when the link is contacted by the striker; wherein an axis through the striker is approximately aligned with an axis through the link.

13. The actuator assembly of claim 12, wherein the dropout mechanism further includes a spring that exerts a force on the actuating rod after the striker is ejected from the current limiting fuse, the force causing the actuating rod to disconnect the current limiting fuse from the upper terminal of the cutout.

14. The actuator assembly of claim 13, wherein the force exerted on the actuating rod by the spring is greater than a second force exerted on the link by the striker.

15. The actuator assembly of claim 12, wherein the dropout mechanism further includes a latch that supports the actuating rod in an unoperated state before the striker is ejected from the current limiting fuse.

16. The actuator assembly of claim 15, wherein the dropout mechanism further includes a release linkage coupled to the link, the release linkage including a tab that supports the latch in the unoperated state before the striker is ejected from the current limiting fuse.

17. The circuit interrupter assembly of claim 16, wherein the release linkage rotates when the link is contacted by the striker; and wherein the tab disengages the latch when the release linkage rotates.

18. The actuator assembly of claim 11, wherein the dropout mechanism is contained in a first cavity formed in the housing of the actuator assembly and the current limiting fuse is received by a second cavity formed in the housing of the actuator assembly.

19. The actuator assembly of claim 18, wherein the dropout mechanism is disposed beneath the current limiting fuse when the current limiting fuse is received by the second cavity.

20. The actuator assembly of claim 11, wherein the current limiting fuse is an industry standard current limiting fuse and the cutout is an industry standard cutout.