Retrofittable panel board for electric apparatus

A retrofittable panel board (8) for an electric apparatus is provided. A bracket assembly (10) is affixed to a backwall (1004) of an enclosure (1002) of the panel board. Bracket assembly (10) includes guide tracks (12) defining restraint locations (14) to provide an adjustable height. A mount assembly (50), providing mounting support to an interior assembly (13) and in turn to circuit breakers 18, is movable by way of the guide tracks with respect to the bracket assembly. An affixing element (16) is disposed in each guide track and connected to the mount assembly. When loosened, affixing element 16 may be arranged to travel connected with the mount assembly along the guide track to a desired restraint location. When tightened, affixing element 16 may be arranged to fixedly secure the mount assembly to the bracket assembly at the desired restraint location to provide a desired height position to the mount assembly with respect to the backwall of the enclosure.

BACKGROUND

Disclosed embodiments are generally related to panel boards or enclosures for electric apparatuses, and, more particularly, to a retrofittable panel board.

2. Description of the Related Art

Circuit breakers for branch circuits at sites served by an electric power distribution system are typically housed in a panel board, control center or load center, with the first two designations commonly used for units designed to meet the more demanding service requirements of industrial and commercial installations while the latter term is commonly used for residential and relatively light commercial applications. As the main difference between panel boards, control panels and load centers is the service rating, for the sake of simplicity of description, just the term “panel board” will be used throughout the present disclosure, but it should be understood that the term “panel board” will also encompass control panels and load centers, unless otherwise stated.

Often it is desirable to replace or update the electrical functionality provided by components (e.g., interior assembly and circuit breakers) in a panel board already in use at a given site. The enclosure of the panel board is usually still quite adequate in quality, and, in the case of recessed panel board enclosures, installing a new panel board enclosure would involve wall repairs to remove and replace the existing panel board enclosure. Thus, replacing the existing panel board enclosure with a new panel board enclosure may turn into a costly and burdensome operation. U.S. Pat. No. 7,209,343 describes an adjustable riser assembly for retrofitting an existing panel board enclosure.

DETAILED DESCRIPTION

The inventor of the present invention has recognized certain issues that can arise when retrofitting certain prior art electrical panel boards or enclosures, such as described below with reference toFIG. 1. A typical panel board1000includes an enclosure1002having a backwall1004and four side walls. Mounted within the enclosure is a structure typically referred to as an interior assembly1006for mounting one or more circuit breakers1008, as may include respective manually-actuated levers1010extending from a face1009of respective circuit breakers. As will be appreciated by one skilled in the art, interior assembly1006typically includes bus bars electrically insulated by a supporting insulating structure and terminal blocks to which electrical conductors are connected.

Panel board1000may also include a cover assembly1020(also referred to as a trim assembly) that may include a cover plate (e.g., trim)1022that may be attached (at a fixed location) to enclosure1002by way of threaded fasteners1025inserted into threaded holes1027located in respective front edges of enclosure1002. Cover plate1022may define a window like opening1024and may include a dead front plate1026that may be configured to provide one or more access openings1028arranged to register with each respective face1009of installed circuit breakers1008and respective manually-actuated levers1010. Removable plates1030, commonly referred to as knock-outs or twist-outs, may be provided as part of dead front plate1026to arrange quantity and location of the one or more access openings1028that may be involved in a given application. A hinged door1032with a latch1034may be connected to cover plate1022to cover dead front plate1026when in the closed position.

In replacing or updating electrical functionality provided by equipment originally installed in a panel board, it has been found that in many cases the replacement equipment providing the same or expanded electrical functionality may not physically match the originally installed equipment. Consequently, the access openings1028in dead front plate1026may no longer register (e.g., be flush) with the manually-actuated levers on the respective faces of the replacement circuit breakers. As noted above, the existing enclosure of the panel board is usually still quite adequate in quality. Thus, replacing the existing enclosure of the panel board with a new panel board enclosure may not be desirable in view of the cost of the new board plus concomitant expenses, such as involving wall repair.

In the prior art, retrofitting an existing panelboard with a replacement interior assembly and replacement circuit breakers has involved shimming up the replacement interior assembly or fabricating risers to, for example, bring the replacement (e.g., physically smaller) circuit breakers into registry with the dead front access openings. This latter practice may require the contractor to supply measurements of the existing enclosure, which are often not accurate and/or not timely provided. The approach described in U.S. Pat. No. 7,209,343 is believed to involve cumbersome and time-consuming alignment of rows of holes and removal and insertion of fasteners into the aligned rows of holes.

In view of such recognition, the present inventor proposes innovative retrofitting assemblies (e.g., a kit) effective to provide, in a user-friendly manner, a reliable and relatively low-cost technical solution to solve at least the issues mentioned above in connection with the retrofit of an existing electric panel board.

In the following detailed description, various specific details are set forth in order to provide a thorough understanding of such embodiments. However, those skilled in the art will understand that disclosed embodiments may be practiced without these specific details that the aspects of the present invention are not limited to the disclosed embodiments, and that aspects of the present invention may be practiced in a variety of alternative embodiments. In other instances, methods, procedures, and components, which would be well-understood by one skilled in the art have not been described in detail to avoid unnecessary and burdensome explanation.

Furthermore, various operations may be described as multiple discrete steps performed in a manner that is helpful for understanding embodiments of the present invention. However, the order of description should not be construed as to imply that these operations need be performed in the order they are presented, nor that they are even order dependent, unless otherwise indicated. Moreover, repeated usage of the phrase “in one embodiment” does not necessarily refer to the same embodiment, although it may. It is noted that disclosed embodiments need not be construed as mutually exclusive embodiments, since aspects of such disclosed embodiments may be appropriately combined by one skilled in the art depending on the needs of a given application.

The terms “comprising”, “including”, “having”, and the like, as used in the present application, are intended to be synonymous unless otherwise indicated. Lastly, as used herein, the phrases “configured to” or “arranged to” embrace the concept that the feature preceding the phrases “configured to” or “arranged to” is intentionally and specifically designed or made to act or function in a specific way and should not be construed to mean that the feature just has a capability or suitability to act or function in the specified way, unless so indicated.

FIG. 2is an exploded view of a disclosed retrofittable panel board8including respective embodiments of a bracket assembly10, a mount assembly50and a cover assembly20that may be used for retrofitting the panel board to accommodate a replacement interior assembly13and replacement circuit breakers18. Bracket assembly10may be affixed to backwall1004of enclosure1002of panel board8. Without limitation, as may be better appreciated inFIG. 5, bracket assembly10may include a plurality of guide tracks12′,12″,12′″,12″″. Each guide track12defines a plurality of restraint locations14arranged to provide an adjustable height with respect to the backwall of the enclosure. It will be appreciated that restraint locations14may alternatively be functionally described as providing an adjustable depth with respect to the front of the enclosure.

Mount assembly50is movable (schematically represented by twin-headed arrows15inFIGS. 2 and 4) by way of the plurality of guide tracks12with respect to bracket assembly10. A respective affixing element16(FIGS. 4 and 5), such as without limitation, a threaded affixing element, may be disposed in each respective one of the plurality of guide tracks and connected to the mount assembly in a loosened condition or in a tightened condition. When in the loosened condition, each respective affixing element16may be arranged to travel connected with mount assembly50along the respective one of the plurality of guide tracks12to a desired restraint location of the plurality of restraint locations14.

When in the tightened condition, each respective affixing element16may be arranged to fixedly secure mount assembly50with respect to bracket assembly10at the desired restraint location of the plurality of restraint locations14. The desired restraint location of the plurality of restraint locations provides a desired height position to mount assembly50with respect to the backwall1004of enclosure1002.

As may be appreciated inFIG. 3, mount assembly50includes a base pan52configured to support interior assembly13. In one non-limiting embodiment, mount assembly50includes an end wall54(also seen inFIG. 4) arranged to extend away opposite the backwall1004of the enclosure1002of panel board8. End wall54may extend from a distal edge56of base pan52at a right angle with respect to base pan52. In one non-limiting embodiment, end wall54includes a flange58extending outwardly from end wall54and parallel with respect to base pan52.

In one non-limiting embodiment, mount assembly50further includes two spaced-apart mount assembly members60arranged to extend away opposite the backwall1004of the enclosure1002of panel board8. Spaced-apart mount assembly members60may extend from a proximate edge62of base pan52at a right angle with respect to base pan52. Proximate edge62of base pan52is opposed to distal edge56of base pan52.

In one non-limiting embodiment, spaced-apart mount assembly members60each includes a respective flange64′,64″ extending outwardly from each of the two spaced-apart mount assembly members60and parallel with respect to base pan52. Flange58, extending outwardly from end wall54, and the respective flanges64′,64″ extending outwardly from each of the two spaced-apart mount assembly members60, are coplanar with one another. The two spaced-apart mount assembly members60define an opening66arranged to provide access to interior assembly13(e.g., a front region of interior assembly13).

In one non-limiting embodiment bracket assembly10includes an end bracket piece26(FIG. 5) disposed in abutting relationship and in correspondence with end wall54of mount assembly50. InFIG. 4, end bracket piece26is behind end wall54of mount assembly50and therefore is not visible. As can be appreciated inFIG. 5, end bracket piece26includes a first guide track12′ and a second guide track12″ of the plurality of guide tracks12. The first and second guide tracks12,12″ may be disposed at mutually opposed sides of end bracket piece26.

In one non-limiting embodiment bracket assembly10further includes two spaced apart bracket assembly members28disposed in abutting relationship and in correspondence with the two spaced-apart mount assembly members60. The two spaced apart bracket assembly members28may each respectively include a third guide track12′″ and a fourth guide track12″″ of the plurality of guide tracks12. The third guide track12′″ and the fourth guide track12″″ are respectively aligned with the first12′ and second guide tracks12″.

As can be further appreciated inFIG. 5, the respective plurality of restraint locations14may be arranged at mutually opposed edges of guide tracks12. Without limitation, a respective one of the mutually opposed edges of the plurality of guide tracks12may be arranged to provide a first set of height locations with respect to the backwall of the enclosure. Conversely, the other one of the mutually opposed edges of the plurality of guide tracks may be arranged to provide a second set of height locations with respect to the backwall of the enclosure. In one non-limiting embodiment, the first and second set of height locations may be arranged to provide different height locations relative to one another.

As can be further appreciated inFIG. 6, the respective plurality of restraint locations14need not be arranged at mutually opposed edges of guide tracks12. For example, the restraint locations14could be arranged just on one edge of guide tracks12. Also, in lieu of guide tracks, a plurality of discrete holes31could be used in the bracket assembly to provide variable height locations with respect to the backwall of the enclosure.

In one non-limiting embodiment, as may be conceptualized from the view shown inFIG. 2and the foregoing description, the desired height position of mount assembly50with respect to the backwall1004of the enclosure1002of panel board8can be chosen so that when circuit breakers18are assembled in retrofittable panel board8, respective manually-actuated levers19of circuit breakers18are in registration with circuit breaker access openings1028.

In one non-limiting embodiment, as may be appreciated inFIG. 3, a retrofit cover plate22of cover assembly20may be connected by way of respective threaded fasteners67insertable into threaded holes68in the respective co-planar flanges58,64′,64″. Without limitation, the height of co-planar flanges58,64′,64″ may be chosen so that when mount assembly50is at the desired height position with respect to the backwall1004of enclosure1002, the respective front edges of cover assembly20are flush with respective edges69(FIG. 2) of a wall that define a recess where panel board8is installed.

In operation, disclosed kit assemblies are effective to provide, in a user-friendly manner, a reliable and relatively low-cost technical solution to solve at least the issues mentioned above in connection with the retrofit of an existing electrical panel board. Without limitation, disclosed kit assemblies avoid or reduce the possibility of having to install a new panel board enclosure and thus save costs that otherwise would be involved in wall repairs to remove and replace the existing panel board enclosure. Additionally, disclosed kit assemblies avoid cumbersome and time-consuming operations involved in certain prior art techniques, such as may involve alignment of rows of holes in a riser assembly and removal and insertion of fasteners into the aligned rows of holes in the riser assembly.