Abstract:
A cover for use with a panelboard enclosure. The cover includes a cover element for mounting onto a panelboard enclosure. The cover element includes an insert for insertion into a cover opening. A plate section is attached to the insert along peripheral edges of the plate section by a thin wall section to form a cover suitable for use with a main lug panelboard configuration. The thin wall section is sized relative to the plate section to enable separation of the plate section from the insert by a user to then form a cover suitable for use with a main breaker panelboard configuration.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/302,287 entitled BREAKER TRAY, filed on Feb. 8, 2010 which is incorporated herein by reference in its entirety and to which this application claims the benefit of priority. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to panelboards, and more particularly, to a breaker tray for a panelboard cover that enables conversion of the cover from one that is suitable for use with a main lug panelboard to a cover suitable for a main breaker panelboard. 
     BACKGROUND OF THE INVENTION 
     Panelboards and load centers used in electrical distribution systems typically include a deadfront, door, trim or other type of cover which is mounted to an enclosure. The cover is typically fabricated from sheet metal and includes removeable sections known as twistouts each of which, when removed, provide an opening for a handle of a device such as a circuit breaker to enable operation of the circuit breaker. 
     The twistouts are generally configured as rectangularly shaped sheet metal blanks. Each twistout is attached to the cover by a metal tab. During installation, the twistouts are manually removed from the cover by a contractor or electrician by repeatedly bending or twisting the metal tab until the tab breaks thus separating the twistout from the cover and forming an opening. This allows the circuit breaker handle to protrude through the opening and enables assembly of cover to the panelboard enclosure. Removal of the twistouts is a difficult and labor intensive operation and requires the use of special tools. 
     A panelboard may be configured as either a main lug panelboard or a main breaker panelboard each having different cover configurations. In particular, the cover used in a main breaker panelboard includes an opening for accommodating a breaker handle whereas the cover used in a main lug panelboard does not have the opening. Therefore, manufacturers typically provide two different types of covers in order to accommodate each panelboard configuration. 
     During on-site installation of an electrical distribution system, it is frequently desirable to convert a cover originally configured for a main lug panelboard to a cover which is suitable for a main breaker panelboard. This requires that an opening be manually cut into the main lug cover by an installer. However, this is also labor intensive and in many instances cannot be done in the field. In order to facilitate the conversion, manufacturers also supply covers having a twistout section for creating an opening in the cover. These types of covers may be used in either a main lug panelboard configuration wherein the twistout is left in place, or in a main breaker configuration wherein the twistout is removed to form an opening for accommodating a breaker handle. As previously described however, removal of a twistout is a difficult and labor intensive operation and requires the use of special tools. 
     Therefore, there is a need for a cover which reduces the amount of labor needed to form openings for accommodating a handle of a device, such as a circuit breaker, and wherein the opening may be formed without the use of special tools. 
     SUMMARY OF THE INVENTION 
     A cover for use with a panelboard enclosure is disclosed. The cover includes a cover element for mounting onto the panelboard enclosure. The cover element further includes an insert which is inserted into a cover element opening. A plate section is attached to the insert along peripheral edges of the plate section by a thin wall section sized to enable separation of the plate section from the insert to thereby provide a tray opening to accommodate a handle of an electrical device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1   a - 1   c  depict front, side and bottom views of a breaker tray. 
         FIG. 1   d  depicts a front view of the breaker tray and a tray opening. 
         FIG. 1   e  is an enlarged view of balloon section  1  in  FIG. 1   c  and depicts a snap. 
         FIGS. 2   a - 2   b  depict left and right rear perspective views of the breaker tray. 
         FIGS. 2   c - 2   d  depict left and right rear perspective views of an alternate embodiment of the breaker tray. 
         FIGS. 3   a - 3   b  depict front and side views, respectively, of the breaker tray assembled into a cover for use with a panelboard. 
         FIG. 3   c  depicts the cover and a cover opening for receiving the breaker tray. 
         FIG. 4  is a bottom cross sectional view of the breaker tray installed in the cover. 
         FIG. 5  is an enlarged view of balloon section  5  of  FIG. 4  and depicts an edge of the cover inserted into a tray gap. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     Before any embodiments of the invention are explained in detail, it should be understood that the invention 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 invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it should be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. In the description below, like reference numerals and labels are used to describe the same, similar or corresponding parts in the several views of  FIGS. 1-5 . 
     Referring to  FIGS. 1   a - 1   b , front and side views, respectively, of a breaker tray  10  in accordance with the present invention are shown.  FIG. 1   c  depicts a cross sectional bottom view of the breaker tray  10 . The breaker tray  10  has a substantially rectangular shape and includes a plate section  14  having a pull tab  12 . The plate section  14  covers a tray opening  21  (see  FIG. 1   d ) in the breaker tray  10  which is sized to enable a handle of a device used in an electrical distribution system, such as a handle of a main breaker, to protrude through the tray opening  21  to enable operation of the main breaker. 
     Referring to  FIGS. 2   a - 2   b , left and right rear perspective views of the breaker tray  10  are shown. The breaker tray  10  may be fabricated from a nonmetallic material that has suitable flexibility and impact properties such as plastic. Peripheral side  17  and bottom  19  edges of the plate section  14  are attached to the breaker tray  10  by a thin wall section that is sized and configured relative to the plate section  14  such that pulling on the pull tab  12  in a downward direction causes the plate section  14  to separate from the breaker tray  10  to thus provide the tray opening  21 . A panel gap  38  may be formed between a top edge  15  of the plate section  14  and the breaker tray  10  to assist in removal of the plate section  14 . In one embodiment, the plate section  14  may include perforations to assist in removal of the plate section  14 . Referring to  FIGS. 2   c - 2   d , an alternate embodiment of the breaker tray  10  is shown wherein the plate section  14  does not include the pull tab  12 . In this embodiment, an operator simply pushes on the plate section  14  with a finger to thus separate the plate section  14  from the breaker tray  10  and provide the tray opening  21 . 
     Referring to  FIGS. 3   a - 3   b , front and side views, respectively, are shown of the breaker tray  10  assembled into a cover  16  for use with a panelboard. The panelboard may be either a main lug panelboard or a main breaker panelboard. The cover  16  may be either metallic or non-metallic and serves as a barrier between electrical elements within an enclosure and an operator. The cover  16  includes a cover opening  22  (see  FIG. 3   c ) defined by edges  30  to form a substantially rectangular shape for receiving the breaker tray  10 . The cover opening  22  is formed by a die or tool during manufacture of the breaker tray  10  at a factory. 
       FIG. 3   a  depicts the cover  16  in a configuration suitable for use with a main lug panelboard wherein the plate section  14  is not removed from the breaker tray  10 . Removal of the plate section  14  from the breaker tray  10  provides the tray opening  21  (see  FIG. 1   d ) through which a breaker handle protrudes to enable manual operation of the breaker (i.e. switching the breaker on/off) as needed without physically removing the cover  16 . This converts the cover  16  to a configuration which is suitable for use with a main breaker panelboard. 
     Therefore, the cover  16  may be used in either a main lug panelboard configuration wherein the plate section  14  is left in place, or in a main breaker configuration wherein the plate section  14  is removed to provide the opening  21  for accommodating a breaker handle. It is frequently desirable to convert a cover originally configured for a main lug panelboard to a cover which is suitable for a main breaker panelboard during an on-site installation of an electrical distribution system. The current invention enables the cover  16  to be quickly converted from a main lug application to a main breaker application without the use of specialized tools. As a result, a manufacturer only needs a single cover manufactured in accordance with the present invention rather than separate covers for each configuration, thus simplifying supply chain management. 
     Referring back to  FIG. 1   c , the breaker tray  10  further includes snap elements  18  located on sides  34  of breaker tray  10 . The snap elements  18  are used to secure the breaker tray  10  to the cover  16 .  FIG. 1   e  is enlarged view of balloon section  1  of  FIG. 1   c  and depicts an exemplary snap element  24 . The snap element  24  is spaced apart from a flange  26  to form a tray gap  36  having a height C for receiving the edge  30  of the cover  16 . The snap element  24  has a height H, width W and a sloping portion  32  having an angle A. In one embodiment, gap G is approximately 0.060 in., height H is approximately 0.312 in., width W is approximately 0.180 in. and angle A is approximately 22.6 degrees. In one embodiment, the breaker tray  10  includes four snap elements  18 . 
     Referring to  FIG. 4 , a bottom cross sectional view of the breaker tray  10  installed in the cover  16  is shown.  FIG. 5  is an enlarged view of balloon section  5  of  FIG. 4  and depicts the edge  30  of cover  16  inserted into the tray gap  36 . The breaker tray  10  is assembled into the cover  16  by applying a downward force to the breaker tray  10  in a direction substantially perpendicular to the cover  16 . This causes contact between sloping portion  32  and the edge  30 , thus causing the snap element  24  to deflect to enable insertion of the breaker tray  10  into the cover opening  22 . After the edge  30  moves past the sloping portion  32  and into the tray gap  36 , the snap element  24  returns to its original shape thus capturing the edge  30  within the tray gap  36  and securing the breaker tray  10 . 
     While the invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications, permutations and variations will become apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations.