Abstract:
A power transfer device adapted for interconnection with the electrical system of a building includes a cabinet, a set of switches mounted to an upper panel of the cabinet, and wires adapted to connect the switches to an electrical distribution panel associated with a building electrical system. The power transfer device includes an upper compartment and a lower compartment partitioned from one another by an intermediate wall. The upper panel closes the upper compartment and a lower panel is adapted to selectively close the lower compartment. A strain relief member is mounted in the lower compartment and tightly holds the wires against the housing to prevent the unintentional disconnection of the wires from the switches.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention relates to a power supply arrangement for providing auxiliary power to the electrical system of a building, such as from a standby generator or the like. 
     Portable generators are used in certain situations to supply electrical power to residential and commercial load circuits during a utility power outage. A system for interconnecting the generator with the load center of a building typically includes a power inlet box having a receptacle for receiving a plug extending from the generator. 
     The power inlet box is typically mounted to the exterior of a building, and is adapted for connection to a transfer switching mechanism which establishes an electrical path between the generator and the load center. The transfer switching mechanism typically includes a series of switches and circuit breakers, which are operable to supply power to certain selected circuits of the load center. The circuits of the transfer switching mechanism are wired to selected circuits of the load center, through wiring housed within a conduit extending between the transfer switching mechanism and the load center. 
     A typical transfer switching mechanism includes a housing provided with a power input receptacle. The remote power inlet box is wired to a power cord connected to a junction box, and the power cord is engageable with the power input receptacle of the transfer switching mechanism so as to provide power to the transfer switching mechanism from the generator. An alternative arrangement is illustrated in Flegel U.S. Pat. No. 5,895,981 issued Apr. 20, 1999, the disclosure of which is hereby incorporated by reference. In the &#39;981 patent, the transfer switching mechanism includes a terminal compartment within which a set of terminals is located. The terminals are wired to the switches of the transfer switching mechanism. A set of power input wires extends from the power inlet box, and into the terminal compartment of the transfer switching mechanism. The ends of the power input wires are connected to the terminals, to establish a direct, non-plug type connection between the power inlet box and the transfer switching mechanism. 
     U.S. Pat. No. 6,414,240 issued to Flegel on Jul. 2, 2002 describes a power transfer switching mechanism that includes a cabinet defining an internal cavity within which a series of switches are mounted. One or more lead wires are connected to the switches, and define ends which extend into a compartment. The compartment is accessible through an opening associated with the cabinet, and a cover is selectively positionable over the opening to provide or prevent access to the compartment. With the cover removed, the lead wires can be connected to power input wires in a conventional manner, e.g., wire-to-wire connectors, and the wires and the connectors may then be placed within the compartment and concealed by attaching the cover to the cabinet. The internal cavity is segmented into upper and lower compartments by a transverse wall that is integrally formed with a front panel of the cabinet. More particularly, the front panel is bent rearwardly at its lower end to form the transverse wall. 
     The present invention provides a power transfer switching mechanism that improves upon the advancements to the art provided by the &#39;240 patent to Flegel. More particularly, in accordance with one embodiment of the present invention, a power transfer switching mechanism includes a cabinet defining an internal cavity that is segmented into first and second compartments by an intermediate and removable transverse wall member. The cabinet is generally defined by a back wall and a pair of sidewalls extending transversely outwardly from the back wall, and which may be integrally formed with the back wall. A mating engagement arrangement is interposed between the base and the intermediate wall member. The mating engagement arrangement may be in the form of a channel formed along the inner surface of the back wall and along facing inner surfaces of the sidewalls. The intermediate wall member may be configured for engagement within the channel, and functions to partition the cabinet into first and second sections. In one embodiment, a first (or upper) panel engages portions of the sidewalls and the intermediate wall member, and is configured to fit over the first section to define the first or upper compartment. In a similar fashion, a second (or lower) panel engages portions of the sidewalls and the intermediate wall member, and is configured to fit over the second or lower section to define the second or lower compartment. 
     A series of switches is mounted to the first panel, and in a preferred method of manufacturing the power transfer switching mechanism, the switches are mounted to the first panel before the first panel is secured to the back wall. Lead wires are interconnected with the switches. The lead wires define ends which extend into and are located within the second compartment. The ends of the lead wires are adapted for engagement with a power input interconnected with the auxiliary power source, such that the lead wires establish an electrical path between the power input and the switches. 
     The power input may be in the form of a series of power input wires which extend from a remote power inlet box, which includes a power input receptacle for receiving a plug-type connector extending from the auxiliary power source, such as a portable generator. In this embodiment, the power input wires are connected to the ends of the lead wires, such as by twist-on connectors. Once the appropriate connections have been made, the wire ends and connectors are placed within the second compartment of the power transfer device housing. The second panel is secured in place over the second compartment, so as to enclose the second compartment within which the wire ends and the connectors are located. 
     A strain relief arrangement may be engaged with the wire leads at a location spaced from the switches. The strain relief arrangement includes a clamp that is fastened to the back wall of the second compartment by a pair of threaded fasteners. As the fasteners are tightened using a suitable driver, the clamp is driven toward the back wall. In doing so, the wire leads extending into the second compartment are pushed toward, and eventually held tight against, the back wall of the second compartment. This arrangement prevents the inadvertent or unintentional disconnection of the wires from the switches as the wires are being connected to a power input. 
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the best mode presently contemplated of carrying out the invention. 
       In the drawings: 
         FIG. 1  is a schematic representation showing a prior art transfer switch arrangement for interconnecting an auxiliary power source, such as a portable generator, with a load center or electrical panel associated with a building; 
         FIG. 2  is a front isometric view of a power transfer device constructed according to the invention, adapted for connection in an auxiliary power supply arrangement for transferring power from an auxiliary power source to the load center of a building, and shown with a cover mounted to the housing of the power transfer device in a raised position; 
         FIG. 3  is a rear isometric view of the power transfer device of  FIG. 2 ; 
         FIG. 4  is an exploded isometric view of the power transfer device of  FIG. 2 ; 
         FIG. 5  is a section view of the power transfer device of  FIG. 2  taken along line  5 - 5  of  FIG. 2 ; 
         FIG. 6  is an enlarged view, partially in section, of a portion of the power transfer device of  FIG. 2 , with reference to line  6 - 6  of  FIG. 5 ; 
         FIG. 6A  is a partial section view taken along line  6 A- 6 A of  FIG. 2 ; 
         FIG. 7  is a front elevation view of the power transfer device of  FIG. 2 ; 
         FIG. 8  is a front elevation view of the lower portion of the power transfer device of  FIG. 2 , shown with the cover and a lower panel removed, and engagement of lead wires with power input wires; 
         FIG. 9  is a partial exploded isometric view of the lower portion of the power transfer device of  FIG. 2 , illustrating the lower panel adapted for engagement with the power transfer device housing over the lower compartment; 
         FIG. 10  is a view similar to  FIG. 9 , showing an alternative embodiment in which a power input receptacle is mounted to the lower panel and a set of power input or connection wires are interposed between the power input receptacle and the lead wires; and 
         FIG. 11  is a view similar to  FIG. 10 , showing an alternative embodiment in which the lead wire ends are engaged directly with the power input receptacle. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a prior art power inlet arrangement for interconnecting a portable generator  10  with a main electrical panel or load center  12  located in the interior of a building  14 . In the prior art power inlet arrangement of  FIG. 1 , a manual power transfer panel  16  is mounted adjacent main panel  12 , and is interconnected therewith via a series of wires enclosed by a conduit  18  extending between main panel  12  and transfer panel  16 . Transfer panel  16  may illustratively be a panel such as that manufactured by Reliance Controls Corporation of Racine, Wis. 
     A power inlet box  20  is mounted to the wall of building  14 , shown at  22 . Power inlet box  20  includes an external housing including a series of walls such as  24 , and a receptacle  26  mounted to a front wall of the housing. A cover  28  is mounted to the front wall of the housing via a hinge structure, and is movable between an open position as shown in  FIG. 1  and a closed position in which cover  28  encloses receptacle  26  when not in use. A conduit  30  extends between inlet box  20  and a junction box  32 , and a flexible cord  38  is attached at one end to junction box  32 . At its opposite end, flexible cord  38  has a connector  42  engageable with a power inlet receptacle provided on transfer panel  16 . Appropriate wiring and connections are contained within inlet box  20 , conduit  30  and junction box  32  for providing an electrical path between inlet box  20  and transfer panel  16  when cord  38  is engaged with the inlet receptacle of transfer panel  16 . 
     A power cord  44  extends between generator  10  and power inlet box  20 . Cord  44  includes a plug  46  at one end, which is engageable with the power outlet of generator  10 . Cord  44  further includes a connector  48  at the end opposite plug  46 . Connector  48  is engageable with receptacle  26  for transferring power generated by generator  10  to power inlet box  20 , which is then supplied through the wiring in conduit  30 , junction box  32 , cord  38  and connector  42  to transfer panel  16 , and from transfer panel  16  through the wiring in conduit  18  to main panel  12 . In this manner, generator  10  functions to provide power to selected circuits of main panel  12  during a power outage. In this arrangement, the user first connects cord  38  to the power input of transfer panel  16  utilizing connector  42 , and then exits the building, connects cord  44  between generator  10  and power inlet  20 , and then commences operation of generator  10 . 
     The present invention provides a power transfer switching mechanism having generally the same function and construction as in the prior art power transfer arrangement of  FIG. 1 . 
     Turning now to  FIGS. 2-5 , a power transfer switching mechanism  50  according to one embodiment of the present invention includes a housing  51  defined by base  52 , a first, or upper, panel  54 , a second, or lower panel  56 , and a cover  58 . The base and the first and second panels collectively define an interior volume that can be further compartmentalized, as described further herein. The base  52  is defined by a back wall  60 , a pair of sidewalls  62 ,  64  and a lower wall  66 , which in one embodiment, are integrally formed as a single unitary structure. A hanging tab  68  extends from an upper end of the back wall  60  for mounting the power transfer switching mechanism  50  to a wall (not shown) or other mounting structure. 
     The construction of the back wall  60  and the sidewalls  62 ,  64  forms a series of planar surfaces that provide a seat for the first panel  54 . More particularly, sidewalls  62 ,  64  extend outwardly from the back wall  60  generally along a plane that is perpendicular to the plane of the back wall  60 . As a result, each sidewall  62 ,  64  has a first outer edge  68 ,  70 , respectively, and a second outer edge  72 ,  74 , respectively. The second outer edges  72 ,  74  may be generally perpendicular to the first outer edges  68 ,  70 , respectively, or may be formed so as to have an incline from front-to-back. The upper end of the back wall  60  also defines an outer edge  76  that is generally perpendicular to the first outer edges  68 ,  70 . The first outer edges  68 ,  70  extend along the length of the sidewalls  62 ,  64 , respectively, and therefore run from the upper end of the back wall  60  to the lower wall  66 . 
     An intermediate transverse wall  78  is located within the housing  51  and partitions the interior volume into an upper cabinet section or compartment  80  and a lower cabinet section or compartment  82 . While the construction of the back wall  60  and the intermediate wall  78  is shown and described in connection with intermediate wall  78  separating the interior volume into upper and lower sections or compartments, it is also understood that intermediate wall  78  may be in any other satisfactory orientation as desired in order to form the separate interior sections or compartments. For example, intermediate wall  78  may be oriented vertically so as to form separate side-by-side (left-right) sections or compartments. 
     The first, or upper, panel  54  is constructed to fit against an upper portion of the base  52  to define the aforementioned upper compartment  80 . The first panel  54  has a pair of sidewalls  84 ,  86  interconnected by a planar face  88 . The upper end of the first panel  54  has a generally planar top  90  that extends rearward from the sidewalls  84 ,  86 , and ultimately, fits against the upper end, e.g., edges  72 ,  74 , and  76 , of the base  52  when the first panel  54  is secured to the base  52 . The front face  88  carries the various electrical components of the power transfer switching mechanism  50 , which may include switches  92 , meters  94 , a light bar  96 , and circuit breakers  98 . In one embodiment, the switches, meters, light bar, and breakers are mounted to the first panel  54  in a conventional manner before the first panel  54  is secured to the base  52 . 
     The sidewalls  84 ,  86  of the first panel  54  have respective forward facing surfaces  100 ,  102  and rearward facing surfaces  104 ,  106  that are defined by lip portions of the sidewalls  84 ,  86 , respectively, that extend rearwardly past the planar face  88  of the first panel  54 . The forward facing surfaces  100 ,  102  provide a seat for the front cover  58  when the cover  58  is attached to the first panel  54 . The rearward facing surfaces  104 ,  106 , however, overlap and abut against the exterior sides of the sidewalls  62 ,  64  of the base  52 . The peripheral edge of the top  90  of the first panel  54  has a lip  108  that extends downwardly from the top  90  along a plane that is generally perpendicular to the plane of the top  90 . When the first panel  54  is mounted to the base  52 , the upper end of the base  52  sits against the inner surface of the lip  108 . In this regard, when the panel  54  is mounted to the base  52 , surfaces  72 ,  74 , and  76  abut against the underside of the top  90 . The lip  108  and the rearward lip portions of the sidewalls  84 ,  86  therefore wrap around the respective upper and side portions of the base  52  to provide an overlapping snug fit of the panel  54  onto the base  52 . At its central area, a notch is formed in the lip  108  to accommodate the hanging tab  68 . 
     A pair of spaced apart ribs  110  is formed along the interior surface of the back wall  60  and the side walls  62 ,  64 . The ribs  110  collectively define a channel or groove  112  sized to receive the intermediate wall  78 . In this regard, the intermediate wall  78  may be slid into the channel  112  to be mounted to the base  52 . When mounted into place, the intermediate wall  78  effectively partitions the interior volume into the aforedescribed upper and lower cavities or compartments. Alternatively, one of the ribs  100  may be eliminated so that the other rib forms a ledge that supports the intermediate wall  78 , or the edges of intermediate wall  78  may be formed with a channel and the back wall  60  and side walls  62 ,  64  may include mating ribs that are engaged by the channel. It is understood that intermediate wall  78  may be engaged with the back wall  60  and/or the side walls  62 ,  64  in any other satisfactory manner that maintains intermediate wall  78  in position relative to base  52 . As described above, the lower compartment  82  is defined by the intermediate wall  78  in combination with back wall  60  and the lower portions of the sidewalls  62 ,  64 . This lower compartment  82  is accessible through an opening that is available when second panel  56  is removed. It will thus be appreciated that the second panel  56  is sized so as to enclose the access opening of lower compartment  82 . 
     The second panel  56  has a generally L-shaped configuration that is defined by a generally planar front surface  114 , a generally flat or planar bottom surface  116 , and a curved surface  118  interconnecting the front and bottom surfaces  114 ,  116 . In one embodiment, the second panel  56  is formed as a single unitary member. The width of the second panel  56  is defined by curvilinear sidewalls  120 ,  122  that align with sidewalls  84 ,  86  of the first panel  54  when the housing  51  is assembled. The sidewalls  120 ,  122  extend past the planar front surface  114  of the second panel  56 , to define rearwardly extending lip portions of the sidewalls  120 ,  122 . 
     The peripheral edge of the bottom surface  116  of the second panel  56  has an upturned lip  124  that fits around the lower end of the base  52  when the second panel  56  is mounted to the base  52 . More particularly, the lower wall  66  of the base  52  abuts against the underside of the bottom surface  116  when the second panel  56  is mounted to the base. The lip  124  overlaps and wraps around the lower end of the base  52 , as best shown in  FIG. 3 , and the rearwardly extending lip portions of the sidewalls  120 ,  122  overlap the lower side portions of the base sidewalls  62 ,  62 , to provide a relatively snug fit of the second panel  56  to the base  52 . In a manner to be explained, the second panel  56  is attached to the base  52  by a pair of fasteners  126  and the first panel  54  is attached to the base  52  by a pair of fasteners  127 . 
     From the foregoing description of the first and second panels  54 ,  56 , respectively and the base  52 , it will be appreciated that during the assembly process, the first panel  54  slides onto an upper portion of the base  52  in a direction along a longitudinal axis defined by base  52 , and the second panel similarly slides onto a lower portion of the base  52  in a direction along a longitudinal axis defined by base  52 . It will be appreciated that the construction of the base  52  and, more particularly, the manner in which the first and second panels fit around the base, simplifies the assembly process and avoids exposed seams through which moisture may enter when the power transfer switching mechanism  50  is used in outdoor applications. 
     The power transfer switching mechanism  50  is usable in both indoor and outdoor applications. Accordingly, the power transfer switching mechanism  50  may be used with cover  58 , which is pivotally mounted to the first panel  54 . The cover  58  has an upper planar section  126  and a lower curved section  128 . A pair of tabs  130  is formed at the upper end of the upper section  126  and are designed to be received in notches  132  formed in the sidewalls  84 ,  86  of the first panel  54 . The notches  132  are shaped such that the cover  58  may pivot about a pivot axis  134 ,  FIG. 7 , when the tabs  130  are fully seated in the notches  132 . The cover  58  may be rotated or pivoted upward about pivot axis  134  to expose the circuit breakers  98 , switches  92 , light bar  96 , meters  94 , and the second panel  56 . It will therefore be appreciated that the cover  58  is sized to fit over the first and second panels  54 ,  56  when pivoted to the closed position. It will be appreciated that the curvature of the lower section  128  is substantially matched to the curvature of the second panel  56 , and particularly surface  118 , so that the lower section of the cover  58  sits flat against the second panel  56  when the cover is fully lowered. 
     The lower wall  66  of the base  52  has a knockout  136  that allows wires to be routed from the housing  51 , as will be described in greater detail below. In one embodiment, the base  52  may have additional knockouts  138 ,  140  that facilitate the routing of wires to and from the housing  51 . In one embodiment, which is best illustrated in  FIGS. 7 and 8 , an elbow fitting  142  is mounted to the base  52  in a conventional manner via knockout  136 . The elbow fitting  142  interfaces with conduit, such as conduit  18 , to route wires carried within the conduit  18  to the housing  51 . The second panel  54  has a U-shaped cutout  144  that matches the location of knockout  136  and that receives the elbow fitting  142  to allow the second panel  54  to be slid onto or from the base  52  when the elbow fitting  142  is coupled to the base  52 . In this regard, the fitting  142  does not need to be disconnected from the base  52  to remove the second panel  56  in order to expose compartment  82 . 
     Referring particularly now to  FIG. 4 , the intermediate transverse wall  78  includes a generally planar body  146  having a thickness that allows the body to be slid into the groove  112  formed in the base  52  as described above. An opening or passageway  148  is formed in body  146 . The passageway  148  may be generally centered on the back wall  60  and the switches  92 . The passageway  148  is designed to enable lead wires to pass from compartment  80  to compartment  82 , as will be described further herein. 
     The power transfer switching mechanism  50  has a strain relief member  150  that includes a clamp  152  that is aligned with the passageway  148  so that wires passing through the passageway  148  may be engaged by the clamp  152  and forced toward the portion of the back wall  60  generally below the intermediate wall  78 . The clamp  152  has a guide member  154  that fits within a guide slot  156  formed adjacent the passageway  148  in the body  146  of the wall  78 . The guide member  154  and guide slot  156  cooperate to define a desired fixed range of movement for the clamp  152  and to center the clamp  152  about the passageway  148 . 
     The intermediate wall  78  includes two pairs of elongated bores  158  and  160  that extend through bosses formed on the underside and topside of the body  146 , respectively. Bores  158  align with nut receivers  162  formed in the backside of wall  60 , as shown in  FIG. 3 . Similarly, bores  160  align with nut receivers  164  also formed in the backside of the wall  60 . The elongated bores  158 ,  160  also align with openings  166 ,  168  formed in the first and second panels  54 ,  56 , respectively. In this manner, as shown in  FIG. 6A , elongated fasteners  126 ,  127  may be passed through openings  166 ,  168 , elongated bores  158 ,  160 , and threadingly engaged with nuts that are non-rotatably placed in nut receivers  162 ,  164  to couple the first panel  54 , the second panel  56 , and the intermediate wall  78  to the base  52 . 
     The clamp  152  of the strain relief member  150  has openings  170  that align with nut receivers  172  formed in the backside of wall  60 , as shown in  FIG. 3 , when the clamp  152  is properly positioned within compartment  82 . Threaded fasteners  174  pass through the openings  170  and ultimately threadably engage nuts that are non-rotatably positioned in the nut receivers  172  to secure the clamp  152  to the base  52 . 
     As described above, the power transfer switching mechanism  50  is constructed to define first and second compartments, which are illustrated as upper and lower compartments  80  and  82  in the figures. Intermediate wall  78  is mounted to base  52  and separates the upper and lower compartments from one another. The upper compartment  80  is closed by first panel  54  that, as described above, carries various electrical components, such as switches  92 , meters  94 , light bar  96 , and circuit breakers  98 . The lower compartment  82  is designed to facilitate the connection of wires to these various electrical components. In this regard, the entire housing  51  does not need to be disassembled when making the necessary connections to the electrical components. The wires connected to the electrical components can simply be routed from the upper compartment  80  through passageway  148  formed in the intermediate wall  78  to the lower compartment  82  for connection to various output wires. 
     In this regard, and with reference to  FIGS. 5 ,  6 , and  8 , a series of lead wires  176  extend from the upper compartment  80  into the lower compartment  82 . Each lead wire  176  defines an upper end extending into upper compartment  80  for interconnection with one of the electrical components secured to first panel  54 , and a lower end located within lower compartment  82 . The upper ends of two of lead wires  176  may be connected to a pair of bus bars (not shown), and the switches  92  are mounted to each bus bar in a manner as is known. In one embodiment, two lead wires are connected to power input meters  94 , which in turn are interconnected with bus bars and switches  92 . In addition, two lead wires are connected to the light bar  96  and are then interconnected with the bus bar and switches  92 . The remaining two lead wires  176  may consist of a neutral wire connected in upper compartment  80  to a neutral wire extending through conduit  18  to main panel  12 , and a ground wire connected in upper compartment  80  to the frame of transfer switch  16  and to a ground wire extending through conduit  18  to main panel  12 . 
     Each lead wire  176  extends through the strain relief member  150 , which is mounted adjacent opening  148  formed in intermediate wall  78 . The strain relief member  150  securely clamps the lead wires  176  against the back wall  60 , so as to fix the length of wires  176  between strain relief member  150  and the upper connection of wires  176 . The length of wires  176  between their lower ends and strain relief member  150  forms a “tail” which can be freely moved about within compartment  82  or moved out of compartment  82 , with strain relief member  150  functioning to prevent disengagement of the upper ends of wires  176  from the upper connections upon such movement of the lower ends of wires  176 . With this arrangement, the lower ends of wires  176  extend into and are accessible from compartment  82 . As described above, the strain relief member  150  mounts to the base  52  by threaded fasteners  174  which allow the strain relief member  150  to move with the fasteners  174  until the fasteners  174  are tightened down to lock the strain relief member  150  in place. This allows the strain relief member  150  to be moved away from the back wall  60  and the ends of wires  176  to be pulled between the strain relief member  150  and the back wall  60 . Once the desired “tail” length is achieved, the fasteners  174  can be tightened down using a suitable tool to press the strain relief member  150  against the wires  176  to hold the wires  176  against the back wall  60 , as illustrated in  FIG. 6 . 
     Referring to  FIG. 7 , a conduit  178  may be mounted to sidewall  62  of base  52 . Conduit  178  extends between power transfer mechanism  50  and power inlet box  20 , and encloses a series of power input wires  180 . Conduit  178  extends through knockout opening  138  formed in the lower portion of sidewall  62  via a conventional nipple  182  and lock nut  184 . As can be appreciated, an input wire conduit such as  178  could also be connected through a knock-out opening in sidewall  64  or in a knock-out opening in back wall  60 . 
     Power input wires  180  are connected at one end to power inlet receptacle  26  of inlet box  20 . The opposite ends of power input wires  180  extend through the open end of conduit  178  and into compartment  82  of power transfer mechanism  50 , where the power input wire ends are adapted for connection to the lower ends of lead wires  176 . The end of each power input wire  180  is paired with an appropriate one of lead wires  176 , and the paired wire ends are then exposed and connected in a conventional manner, such as by twisting together and securing the connection by use of conventional twist-on connectors  186 , in a manner as is known. This arrangement provides a direct, hard-wired, non-plug type connection between power inlet box  20  and power transfer mechanism  50 , without the need for a plug-type connector. In addition, this arrangement eliminates the cost and space required by the terminal arrangement illustrated in U.S. Pat. No. 5,895,981, thus reducing the overall cost of manufacture of power transfer mechanism  50 . 
     Power transfer mechanism  50  can be installed by an electrical contractor or a do-it-yourself homeowner, by first mounting power transfer mechanism  50  in a satisfactory location adjacent main panel  12 . Cover  58  of power transfer mechanism  50  is then raised or removed and the second panel  56  is then removed so as to expose lower compartment  82  and the ends of lead wires  176 . Conduit  178  is then installed in a known manner, and the ends of power input wires  180  are then pulled through the passage of conduit  178  so as to extend into compartment  82 . Lead wires  176  and power input wires  180  can then be cut to length as necessary, and the ends of lead wires  176  and power input wires  180  can be drawn out of compartment  82  to enable the installer to make the connections between lead wires  176  and power input wires  180 . Once connected using connectors  186 , lead wires  176 , power input wires  180  and connectors  186  are then placed into compartment  82  and second panel  56  is installed, so as to enclose compartment  82  and lead wires  176 , power input wires  180  and connectors  186  contained therein. This enables establishment of a direct electrical connection between remote power inlet box  20  and power transfer mechanism  50 , without the need for connecting a flexible cord to a power input receptacle as in the prior art. In this manner, the only step in operation of power transfer mechanism  50  to transfer power from generator  10  to main panel  12  is to place switches  92  in the appropriate position, so as to transfer power to main panel  12  as desired in response to operation of generator  10 . The cover  58  may then be pivoted downward or mounted into place. 
     In a known manner, output wires from switches  92  extend through compartment  82  and are connected to elbow fitting  142  secured to lower wall  60 , for routing through conduit  18  to main panel  12 . 
       FIG. 9  schematically illustrates the lower end of power transfer mechanism  50 . As shown, when the second panel  56  is removed, lower compartment  82  is exposed so as to enable power input wires  176  to be connected to lead wires  180  using connectors  186 . As explained previously, once the connections between lead wires  176  and power input wires  180  are made using connectors  186 , input wires  180  are placed into compartment  82  along with lead wires  176  and connectors  186 . Second panel  56  is then secured over the outwardly facing access opening of lower compartment  82 , so as to close lower compartment  82  and to prevent access to the connections between lead wires  176  and power input wires  180 . The U-shaped cutout  144  in the second panel  56  allows the second panel  56  to be placed over the lower compartment  82  and receive the elbow fitting  142 . The elbow fitting  142  connects to the base  52  via a conventional nipple  188  and lock nut  190 , which is illustrated in  FIG. 8 . 
       FIG. 9  illustrates conduit  178 , nipple  182  and lock nut  184  removed, and input wires  180  extending through the opening formed by a knock-out section in sidewall  62 . It is understood, however, that power input wires  180  are normally housed within a conduit or other sheath when located externally of the housing of power transfer mechanism  50 . 
       FIG. 10  illustrates an alternative embodiment, in which a power input socket or receptacle  192  is mounted to the front wall of second panel  56 ′. Receptacle  192  may be constructed as shown and described in U.S. Pat. No. 6,293,821 issued Sep. 25, 2001, the disclosure of which is hereby incorporated by reference. In this version, power input wires  180 ′ are mounted to terminals or other electrical connections associated with receptacle  192 , extending rearwardly therefrom. The ends of power input wires  180 ′ are connected to the ends of lead wires  176  in the same manner as described previously with respect to connection of power input wires  180  to lead wires  176 . Once the connections between lead wires  176  and power input wires  180 ′ are made using connectors  186 , lead wires  176 , power input wires  180 ′ and connectors  186  are placed into lower compartment  82 . Second panel  56 ′, to which receptacle  192  is mounted, is then secured to the power transfer mechanism  50  in the same manner as described previously, to close lower compartment  82 . It will be appreciated that the cover  58  may modified to accommodate a plug engaged with receptacle  192 . 
       FIG. 11  illustrates an alternative arrangement utilizing second panel  56 ′ and power input receptacle  192  mounted thereto. In this version, lead wires  176  have a length sufficient to enable lead wires  176  to be manipulated so as to provide connection of the ends of lead wires  176  to the terminals or connectors associated with power input receptacle  192 . Once the ends of lead wires  176  are engaged with power input receptacle  192 , the length of lead wires  176  between strain relief member  150  and the connection to receptacle  192  is placed into lower compartment  82  and panel  56 ′ is then mounted in the same manner as described previously to enclose and prevent assess to lower compartment  82 . 
       FIGS. 9 through 11  illustrate that the connection arrangement of the present invention may be used to directly connect power transfer mechanism  50  with power inlet box  20 . Alternatively, the present invention may be used to connect a power input receptacle to power transfer mechanism  50 , for use in a plug-type system as illustrated in  FIG. 1 . 
     It will be appreciated that the present invention provides a power transfer mechanism  50  that can be manufactured more efficiently than conventional power transfer mechanisms. More particularly, and with reference to  FIG. 4 , the power transfer mechanism  50  is constructed such that switches  92 , circuit breakers  98 , power meters  94 , and the light bar  96  are mounted to upper panel  54  to form a fully assembled and integrated structure that is mounted as a single subassembly to the base  52 . Before the upper panel  54  is secured to the base  52 , the lead wires are connected to the breakers  98 , switches  92 , power meters  94 , and light bar  96 , and then the free ends of the wire leads are passed through the opening  148  formed in the intermediate wall member  78 . The intermediate wall  78  is then advanced into groove  112  and the upper panel  56  is then engaged with the base  52  using fasteners  127  as described above, which also results in fastening of the wall  78  to the base  52 . 
     The second panel  56  is then secured over the lower compartment  82  using fasteners  126 . As noted above, the second panel  56  is removable to expose the lower compartment  82  and the lead wires  176  extending therein. Such a construction allows an installer to make the connection between the power input wires  180  and the lead wires  176 , as described above. After the electrical connections have been made, the second panel  56  is again mounted to the base  52  using fasteners  126 . After the second panel  56  is placed over the opening to the lower compartment  82  and secured to the base  52 , the cover  58  may be installed by inserting the tabs  130  into the notches  132  formed in the upper panel  54 . Once the tabs  130  are fully seated in the notches  132 , the cover  58  may be pivoted or rotated downward to cover the upper and lower panels  54 ,  56 . 
     As described above, the power transfer switching mechanism  50  includes a set of lights or light bar  96  that illuminates the upper panel  54 . In one embodiment, the light bar  96  is fed electrical power from the auxiliary power source and thus illuminates the upper panel  54  when the auxiliary power source is supplying power to the power transfer mechanism  50 . In another embodiment, a battery (not shown) may provide electrical power to the light bar  96  when utility power is not providing electrical power to the power transfer mechanism. It is also contemplated that the light bar  96  could be supplied with utility power to provide illumination of the upper panel  54  when utility power is providing electrical power to the power transfer mechanism  50 . In one embodiment, the light bar  96  has a set of light emitting diodes, but other types of lighting elements could be used. 
     In one embodiment, the base  52 , intermediate wall  78 , upper and lower panels  54 ,  56 , and the cover  58  are made of rust-resistant or rust-free material, e.g., plastic. 
     Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.