Bucket assemblies for motor control centers (MCC) with disconnect assemblies and related MCC cabinets and methods
10541092 ยท 2020-01-21
Assignee
Inventors
- Stephen W. Oneufer (Fayetteville, NC, US)
- Robert A. Morris (Fayetteville, NC, US)
- Daniel B. Kroushl (Clayton, NC, US)
Cpc classification
H01H2071/565
ELECTRICITY
H01H9/22
ELECTRICITY
H02B1/00
ELECTRICITY
International classification
H02B1/00
ELECTRICITY
H01H9/22
ELECTRICITY
Abstract
Circuit breakers with a rotary handle attached to an inwardly oriented shaft that connects to a gear assembly that translates rotational input to linear input also include a trip assist spring in communication with the rack gear so that, in operation, the trip assist spring applies a force to the operator slider and forces the handle to a consistent trip position.
Claims
1. A Motor Control Center (MCC) cabinet with bucket units, the bucket units having a common size external rotary handle that each communicates with a respective internal disconnect assembly that engages a respective toggle or switch of an internal circuit breaker or a fused disconnect switch, wherein different ones of the bucket units can have different frame sizes associated with different amperage ratings, and wherein the rotary handle of each of the bucket units rotate 90 degrees between OFF and ON positions, and wherein the rotary handle of each of the bucket units have a common trip orientation, wherein the bucket units have first and second configurations, with the second configuration being larger than the first configuration, wherein the first configuration is associated with bucket units having frame sizes/amperage ratings in a range of about 125 A to about 250 A, and wherein the second configuration is associated with bucket units having frame sizes/amperage ratings above 250 A, including 400 A and 600 A.
2. The MCC cabinet with bucket units of claim 1, wherein at least one of the bucket units comprises the fused disconnect switch, and wherein the disconnect assembly of the at least one bucket unit with the fused disconnect switch comprises a gear system having a rack gear and disconnect slider that engages the fused disconnect switch.
3. A Motor Control Center (MCC) cabinet with bucket units, the bucket units having a common size external rotary handle that each communicates with a respective internal disconnect assembly that engages a respective toggle or switch of an internal circuit breaker or a fused disconnect switch, wherein different ones of the bucket units can have different frame sizes associated with different amperage ratings, and wherein the rotary handles all rotate 90 degrees between OFF and ON positions and have a common trip orientation, wherein at least one of the bucket units comprises the fused disconnect switch, wherein the disconnect assembly of the at least one bucket unit with the fused disconnect switch comprises a gear system having a rack gear attached to a disconnect slider that engages the fused disconnect switch, and wherein the disconnect slider of the at least one bucket unit with the fused disconnect switch moves vertically up and down in response to rotation of the handle, and wherein the handle is attached to a drive gear that is coupled to the rack gear.
4. The MCC cabinet with bucket units of claim 3, wherein the disconnect assembly of the at least one bucket unit with the fused disconnect switch comprises a pivoting arm that has a lower end portion that extends into a slot or aperture of the slider and a switch contact member or feature that engages the toggle or the switch of the fused disconnect switch.
5. A Motor Control Center (MCC) cabinet with bucket units, the bucket units each having at least one external rotary handle of a common size and each at least one external rotary handle communicates with a respective internal disconnect assembly that engages a respective toggle or switch of an internal circuit breaker or a fused disconnect switch, wherein different ones of the bucket units can have different frame sizes associated with different amperage ratings, and wherein each of the at least one rotary handle rotates 90 degrees between OFF and ON positions and have a common trip orientation, wherein at least one of the bucket units has dual side-by-side external rotary handles aligned in horizontal and vertical directions as the at least one rotary handle, with a load side facing outward and an incoming side between the dual rotary handles facing inward.
6. The MCC cabinet with bucket units of claim 5, wherein the bucket units are provided in different sizes with a plurality of different amperage ratings including at least two of 250 A, 400 A and 600 A.
7. The MCC cabinet with bucket units of claim 1, wherein the bucket units are configured to position the rotary handles aligned along a left hand side of the MCC cabinet.
8. A Motor Control Center (MCC) cabinet with bucket units, the bucket units having a common size external rotary handle that each communicates with a respective internal disconnect assembly that engages a respective toggle or switch of an internal circuit breaker or a fused disconnect switch, wherein different ones of the bucket units can have different frame sizes associated with different amperage ratings, and wherein the rotary handle of each of the bucket units rotate 90 degrees between OFF and ON positions, and wherein the rotary handle of each of the bucket units have a common trip orientation, wherein the bucket units have a substantially common width irrespective of height and the height and/or frame size of the bucket units is provided in modular 6 inch increments in a range of about 6 inches to about 72 inches.
9. The MCC cabinet with bucket units of claim 1, wherein at least one of the bucket units comprises the internal circuit breaker and further comprises a shaft attached to the rotary handle and extending into the bucket unit, wherein the disconnect assembly comprises a gear assembly that engages the shaft and comprises a rack gear that linearly moves an operator slider in communication with the toggle or switch of the circuit breaker, and wherein the disconnect assembly further comprises a trip assist spring that is held on a rod that is parallel to the rack gear, wherein the trip assist spring cooperates with the rack gear to move the external rotary handle to a defined consistent orientation when the circuit breaker trips, and wherein the trip assist spring and rod are parallel to a side of a primary body of the rack gear comprising gear teeth.
10. The MCC cabinet with bucket units of claim 9, wherein the trip assist spring and rod are both held in a fixed lateral orientation over their respective lengths, wherein the fixed lateral orientation is parallel to a long side of the side of the primary body as the side of the primary body comprising gear teeth, and wherein the rod extends through the trip assist spring and has a length that is greater than the trip assist spring, and wherein the trip assist spring is in a compressed state when the toggle or the switch is in the ON and OFF positions to be able to bias the operator slider to a center of its travel path.
11. The MCC cabinet with bucket units of claim 9, wherein the trip assist spring is held above the rack gear in a fixed horizontal orientation on the rod, wherein the rod has a length that is greater than the trip assist spring, and wherein the trip assist spring extends over a sub-length of the rod in a compressed configuration and applies a force to bias the operator slider to reside at a location that is at a medial position of its sliding travel path.
12. A Motor Control Center (MCC) cabinet with bucket units, the bucket units having a common size external rotary handle that each communicates with a respective internal disconnect assembly that engages a respective toggle or switch of an internal circuit breaker or a fused disconnect switch, wherein different ones of the bucket units can have different frame sizes associated with different amperage ratings, and wherein the rotary handle of each of the bucket units rotate 90 degrees between OFF and ON positions, and wherein the rotary handle of each of the bucket units have a common trip orientation, wherein the disconnect assembly of at least one of the bucket units comprises a slider that engages the toggle or the switch and moves vertically up and down in response to rotation of the rotary handle.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
(25) The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. Like numbers refer to like elements and different embodiments of like elements can be designated using a different number of superscript indicator apostrophes (e.g., 10, 10, 10, 10).
(26) In the drawings, the relative sizes of regions or features may be exaggerated for clarity. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
(27) It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
(28) Spatially relative terms, such as beneath, below, lower, above, upper and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as below or beneath other elements or features would then be oriented above the other elements or features. Thus, the exemplary term below can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
(29) The term about refers to numbers in a range of +/20% of the noted value.
(30) As used herein, the singular forms a, an and the are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms includes, comprises, including and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being connected or coupled to another element, it can be directly connected or coupled to the other element or intervening elements may be present. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items.
(31) Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
(32) The term escutcheon refers to a cover residing about the operator handle.
(33) The terms operating mechanism and operator mechanism are used interchangeably and refer to an assembly for opening and closing separable main contacts in a circuit breaker and/or for turning power ON and OFF using a switch associated with a fuse (e.g., a fused disconnect). The circuit breaker can be for a motor starter unit or feeder unit, for example.
(34) The terms bucket assembly, bucket and unit are used interchangeably and refer to a structure (typically a protective metal shell) that contains either a fuse or a circuit breaker for turning power ON and OFF to a motor, or feeder circuit, typically for controlling power to motor starters. As is well known, the bucket can be, for example, a feeder unit or a starter unit. The bucket assembly can include other components such as a power transformer, a motor starter to control a single motor and PLCs (programmable logic controllers), drives and the like. The bucket assembly can be configured as a modular device to allow the internal components to be assembled as a unit that can be easily installed into a Motor Control Center (MCC) compartment. As is well known, the bucket can have power stabs in the back that connect to vertical bus bars that carry power (current) to the compartments of a vertical section in an MCC cabinet. The vertical bus bars are connected to the larger horizontal bus bars that bring power to the vertical sections. The horizontal bus bars are usually in the top, but some MCC designs may have them in the center or bottom. MCCs usually have a wire way for wires to the motors and other loads and control wires.
(35) MCCs can be configured in many ways. Each compartment can have a different height to accept different frame sizes of respective bucket assemblies or units 10, typically in about 6-inch increments. The vertical bus can be omitted or not run through the full height of the section to accommodate deeper buckets for larger items like variable frequency drives. The MCC can be a modular cabinet system for powering and controlling motors or feeder circuits. Several may be powered from main switchgear which, in turn, gets its power from a transformer attached to the incoming line from the power company.
(36) A typical MCC cabinet is an enclosure with a number of small doors arranged in rows and columns along the front and flat, mostly featureless, back and sides. The buckets can be provided in varying sizes. For starter units, the size can be based on the size of the motor they are controlling. The bucket assembly can be configured to be relatively easily removable for repair, service or replacement. MCCs can have, for example, regular starters, reversing starters, soft start, and variable frequency drives. MCCs can be configured so that sections can be added for expansion if needed.
(37) The term compact refers to bucket units 10 (also known as buckets) in a very condensed configuration (package) relative to conventional units/buckets. The MCC structure or cabinet 100 (
(38) Referring now to the figures,
(39) In some embodiments, the bucket assembly 10 can comprise a molded case circuit breaker. Molded case circuit breakers are well known to those of skill in the art, as exemplified by U.S. Pat. Nos. 4,503,408 and 5,910,760, the contents of which are incorporated herein by reference as if recited in full herein. In other embodiments, the bucket assembly 10 can be configured to house a fuse disconnect with a fuse disconnect switch to turn power on and off (
(40) The unit 10 includes a handle mechanism 20 with a rotary handle 20h. For the circuit breaker unit 10C, the unit 10 includes a shaft 25 that communicates with the handle 20h can be rotated through defined translations of rotation from circuit breaker conduction to circuit breaker non-conduction. Typically, there is about a 90 rotation from conduction to non-conduction (OFF to ON) but other defined rotational stroke distances may be used including, for example, about 45 degrees, about 120 degrees, or about 180 degrees. The handle 20h can be configured to turn about 90 degrees in all different breaker sizes in a single MCC cabinet 100 (
(41) The rotary handle 20h can be attached to an inwardly extending shaft 25 (
(42) In operation, the orientation of the rotary handle 20h can provide a visual indication of the conduction status of the operator disconnect, e.g., breaker 60 (
(43) If the handle 20h is in a generally horizontal position, i.e., with the nose, lever or thumb knob straight across the front of the circuit breaker as shown in
(44) The handle 20h can be circular with a protruding thumb or finger segment 21 and/or a T shaped member or feature (e.g., an insert) 23 residing substantially inside the circular profile with the small cross-end of the T on the outer perimeter as shown in
(45) The handle can have a rectangular lever or arm and this end can be oriented to reside on the handle 20h to provide a clean visual indicator of handle position (e.g., ON and OFF) readily visible from a distance (e.g., 5-20 feet away) in a room holding the MCC 100 (
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(48) As is shown in
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(50) The biasing member 33 is shown as a coil spring, but other biasing members may also be used including, for example, a leaf spring, belleville or stacked dome washers and elastic plugs or combinations of the same. The door 22 can include a hinge 22h that attaches to the frame 11f of the housing and supports the bolt 31 and biasing member 33.
(51) The interlock assembly 30 can be integrated in the operator envelope or operator mechanism 40 and can be an automated mechanism. Thus, the interlock assembly 30 can reside inside the operator mechanism envelope 40 that comprises a laterally extending spring 33 residing over a door interlock bolt 31 configured so that the bolt can be electronically directed to automatically slidably extend to lock the door bracket 44.
(52) In some embodiments, the circuit breaker 10 can include a handle escutcheon 227 (
(53) Referring to
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(55) The circuit breaker unit 10C also includes a rotary to linear translating operator mechanism 40. The operator mechanism 40 can be integrally and/or permanently mounted to the unit housing or body 11.
(56) As shown in
(57) Referring to
(58) It is noted that the lever 90 (also known as a toggle) can move laterally as shown or the circuit breaker or fuse switch may be oriented to move vertically.
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(60) For units with circuit breakers 60, the operating mechanism 40 can also include a trip assist spring 43 that is in communication with the rack gear 46 to assist the handle 20h to move to a consistent OFF position when the circuit breaker is tripped.
(61) As shown in
(62) The spring 43 can spring bias the operating mechanism 40 to a consistent trip position, independent of a breaker toggle trip position. That is, in the past, if tripped, the lever or breaker toggle 90 will move to a TRIP position with little force. Unfortunately, this may not be sufficient force to move the lever 90 to a consistent trip orientation/position.
(63) The spring 43 can be configured to provide a suitable trip-assist force. The spring 43 can be configured with a length and and/or k-factor such that the slider 52 is biased to a center of its travel path between ON and OFF positions. The length of the spring 43 can vary depending on the type or size lever 90 and/or associated breaker 60. Although shown as one spring 43, more than one spring can be used, alone or with other cooperating members, e.g., an elastically resilient plug, belleville washers, stacked resilient dome washers and the like, to provide a desired spring force and/or biasing action. In addition, the spring 43 may be omitted in favor of one or more different resilient members to provide a suitable trip assist force.
(64) In some embodiments, the spring 43 can have a length that is about 50% to about 100% of a length of the travel path of the operator slider 52 between ON and OFF positions.
(65) The spring 43 can reside between a mounting member 55 and the operator base 50. The mounting member 55 can be formed integral with the base member 50 or be provided as a separate component that can attach to the operator base 50. The mounting member 55 can hold the guide rod 41 above the lever 90. The mounting member 55 can include an end portion that turns inwardly to be substantially orthogonal to a primary surface 55p of the mounting member. The end portion 55e can include a slot, channel or aperture 55a that allows the rod 41 to extend through to support the rod. However, the mounting member 50 can hold the rod inside its body and does not require the aperture 55a. The mounting member 55 can be a monolithic member with a formed end portion 55e or may include attached cooperating components.
(66) The operator base 50 and be in communication with the rack gear 46 to can provide sufficient force to move the handle 20h to a consistent TRIP position/orientation.
(67) The handle 20h can be detented when the operating mechanism 40 is in the spring-biased TRIP position to be in an externally visible consistent TRIP position. The ON and OFF positions can be separated by about 90 degrees.
(68) While the circuit breaker bucket 10C is shown with the operating mechanism 40 having a guide rod 41 in the figures, it is contemplated that other configurations or components can be used to provide the desired controlled lateral path for the compression of the spring 43 and/or other biasing members and proper movement of the sliding base 52 and/or rack 46 to provide the desired trip assistance.
(69) In operation, the breaker 60 with the spring 43 can bias/force the slider 52 to move to a position at or proximate a center of a travel length. The spring 43 can be sized and configured to move the handle 20h to a middle position, e.g., about 45 degrees.
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(71) The guide rod 41, where used, can have a length that is greater than the length of the trip assist spring 43 and may have a length that is about the same as a long side width of the operator base 50. In some embodiments, the trip assist spring 43 can have a length that is between about 30-80% less than a length of a guide rod 43 extending therethrough.
(72) In some embodiments, the rear surface of the rotary handle 20h resides a distance d1 (
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(74) The mounting member 55 can have a primary upwardly extending surface 55s that is substantially planar and can include a cutout or shape that provides an open space 55o for the toggle or lever 90 and a portal and/or path 55p for the drive shaft 25.
(75) In some embodiments, the mounting member 55 resides a distance d2 (
(76) The operating mechanism 40 can include a blocking member 49 that resides about the rod 41 and that traps the spring to the left of the right half of the rod 41 and compresses at least a portion of the spring 43 as the rack gear 46 translates in one direction (e.g., toward the left).
(77) The operating mechanism 40 can be configured so that the spring 43 has a compressed configuration when in use, e.g., when the lever is in both the OFF and ON position to be able to bias the slider 52 to a center of its travel path. Stated differently, the spring 43 is configured to have a compressed configuration irrespective of the position of the rack gear 46 and lever 90.
(78) The blocking member 49 can be a washer, nut, sleeve or other sufficiently rigid member and/or a protrusion on the outer surface of the rod itself that provides suitable obstruction with a cooperating component or feature on the rack gear 46 so as to compress the spring 43 and provide the desired biasing force.
(79) As shown, the blocking member 49 can contact the upper end portion 46u (e.g., arm 47) of the rack gear 46. The blocking member 49 and arm 47 thus cooperate to trap one end of the spring to thereby compress the spring 43.
(80) Embodiments of the invention provide circuit breakers 10 with a rotary position of the rotary handle 20h positioned on a centerline of the breaker 60, in-line with a corresponding center pole.
(81) As shown in
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(83) As shown, the unit 10 includes a fuse body or fuse assembly frame 250 with a fused switch 260.
(84) The unit 10 also includes a fuse disconnect assembly 140 that includes a primary drive gear 42 and a rack gear 46 that are in communication with the rotary handle 20h. The rack gear 46 can be attached to a slider 52 that translates to move a switch 260 in communication with a pivoting arm 262. The arm 262 includes an end portion 262e that extends through a slot 52s or opening in the slider 52. As shown, the pivoting arm 262 also includes a mounting end portion 265 which may optionally be substantially circular. The mounting end portion 265 can include an aperture that receives an attachment member to be pivotably attached to a fuse body frame and/or housing or housing frame. The arm 262 can also include a projection member 264 (which can be a discrete member or a monolithic shaped feature and/or portion of the arm) that contacts the switch 260 to force the switch between ON and OFF positions. In the embodiment shown, the projection feature/member 264 is inclined in an upward direction as it extends a distance above the arm primary body.
(85) The bucket unit 10F can be configured to have a visually similar appearance to the bucket unit 10C with the same handle 20h and exterior housing layout/appearance although the internal ON/OFF circuit components are different.
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(87) In some embodiments, one or more of the gears 42, 144, 46 of the operator mechanism 40 can be provided in different configurations, e.g., as first and second configurations, e.g., a small and larger version to work with bucket units having frame sizes/amperages from about 125 A, 225 A, 250 A, 400 A and 600 A, for example. The small version refers to circuit breakers rated between about 125 A and about 250 A. The larger bucket units 10 can have circuit breakers rated above 250 A, including 400 A and 600 A.
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(90) The trip unit module 60M is typically installed prior to the operating mechanism 40 and can be used only for adjustment access.
(91) The base 50 and cooperating slider 52 can be provided in different sizes with different length and width slots 50s to accommodate smaller and larger toggles or switches 90 associated with frames of different sizes/amperage rating. In some embodiments, when mounted in the MCC cabinet 100, the handles 20h can all substantially, if not totally, vertically align and have the same trip and/or ON/OFF positions.
(92) Similarly, an MCC cabinet 100 can be configured so the bucket units 10 all have the same handle 20h in the same position when mounted in the MCC cabinet 100 and the units 10 can have the same ON/OFF operative positions for both fuse and circuit breaker units 10F, 10C, respectively (
(93) In some embodiments, as shown in
(94) Each unit 10 with a circuit breaker 60 can have a mounting member 55 that has a rod support end 55e that extends inwardly away from the rotary handle 20h, away from the primary surface 55s as discussed above with respect to
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(96) The units 10 can have visual indicia 20v (
(97) Embodiments of the invention provide a handle detent to assist in positioning the handle to the defined tripped configuration, typically with the handle in a vertical orientation. Embodiments of the invention can include one or more of the below claims presented in this section of the application as an alternate claim listing although not formally presented in a claim section of the application at filing of the original application.
(98) A bucket assembly with a trip assist spring that cooperates with a rack gear and operator slider that communicate with an internal circuit breaker to move the external rotary handle to a defined consistent orientation when the circuit breaker trips.
(99) A bucket assembly with an automated latch assembly integrated into the operator system.
(100) The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the invention.