Abstract:
A power transfer arrangement is provided for supplying power from a generator the electrical system of a building. The power transfer arrangement includes a power transfer switching mechanism adapted for interconnection with the building electrical system. The power transfer switching mechanism includes a cabinet having panel structure provided with various electrical components for transferring power to various load circuits. A transparent cover assembly is movably mounted to the cabinet for selectively preventing and permitting access to the electrical component and the front panel while simultaneously allowing constant visual monitoring of the components of the panel structure.

Description:
FIELD OF THE INVENTION 
     This invention relates to a power transfer arrangement for providing power to the electrical system of a building, such as power supplied from a standby generator, and more particularly, pertains to a power transfer arrangement provided with a protective cover assembly. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Portable generators may be used in certain situations to feed electrical power to residential and commercial load circuits during a utility power outage. These systems in their most basic form include a generator or other auxiliary source of power positioned exteriorly of a building. The generator is connected to a transfer switching mechanism which continues the electrical path through integral overcurrent protectors associated with the transfer switching mechanism to supply power to certain selected circuits of the load center as determined by the transfer switching mechanism circuit breakers. 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 load center and the transfer switching mechanism. 
     The present invention relates to a power transfer switching mechanism for interposition between an auxiliary power source and electrical load center of a building. Such a switching mechanism typically includes a cabinet having a front panel which may be provided with an opening for accommodating power input structure, such as a socket-type power input receptacle. The power input receptacle may also be remotely mounted at a distance from the transfer mechanism and interconnected by cabling. The input receptacle is adapted to selectively receive a plug connector electrically interconnected with a source of auxiliary power such as a generator, and is interconnected with a bus bar within the cabinet. Overcurrent protectors are mounted to the bus bar for receiving power from the generator through the input receptacle to provide auxiliary power to selected circuits of the load center. A set of switches associated with the overcurrent protectors is mounted to the panel for controlling the supply of generator power from the switching mechanism to the building load center. A power outlet receptacle may also provided in the panel for selectively delivering generator power to a load plugged into the receptacle. A pair of watt meters may be further included in the panel for displaying the amount of power provided by the generator. 
     Certain or all of the switches associated with the overcurrent protectors on the panel of the power transfer switching mechanism are connected to a particular load such as a furnace blower, sump pump, refrigerator, light circuit, freezer or other device normally driven by a utility power source. With utility power available, each of the switches connected to a particular load is manually set to a LINE position. However, in the event of a power outage, once the generator is connected to the power transfer switching mechanism, the switches connected to the loads are manually set to a GENERATOR position to effect the actual transfer of power from the generator to the loads. If any of these switches were to be moved from their intended setting due to accidental or inadvertent contact, it would cause a cut off in power to the connected load(s). For example, if a child playing in the vicinity of the power transfer switching mechanism were to actually hit the switch which controls power to a freezer, it would result in the unplanned thawing of food which might not become immediately known such that the thawed food may need to be disposed of. 
     Accordingly, it would be desirable to provide the power transfer switching mechanism with a cover assembly which would prevent accidental or inadvertent contact with the switches on the panel of the power transfer switching mechanism so as to preserve the continuous transfer of power to selected loads. It would also be desirable to provide such a cover assembly which would permit easy access to the panel of the power transfer switching mechanism and simultaneously provide constant visual inspection of the components on the panel. 
     It is one object of the present invention to provide a power transfer switching mechanism equipped with a cover assembly for selectively permitting and preventing access to the front panel of the power transfer switching mechanism. 
     It is also an object of the present invention to provide a power transfer switching mechanism with a cover assembly which is easy to install and simple to operate. 
     It is a further object of the present invention to provide a power transfer switching mechanism having a hinged cover assembly which can be mounted on new equipment or retrofit on existing equipment. 
     It is another object of the present invention to provide a power transfer switching mechanism having a transparent cover assembly which enables unobstructed monitoring of the front panel of the power transfer switching mechanism when the cover is in a closed position overlying the front panel. 
     It is an additional object of the present invention to provide a power transfer switching mechanism having a cover assembly which ensures that a reliable connection between a power source and one or more loads is maintained without accidental contact with the switches on the front panel of the power transfer switching mechanism. 
     In one aspect of the invention, a power transfer arrangement is provided for supplying power from a generator to the electrical system of a building. The power transfer arrangement has a power transfer&#39;switching mechanism adapted for interconnection with the building electrical system and includes a cabinet having panel structure provided with various electrical components for transferring power to various load circuits. The invention is improved by a transparent cover assembly movably mounted to the cabinet for selectively preventing and permitting access to the electrical components and the front panel while simultaneously allowing constant visual monitoring of the components of the panel structure. The electrical components of the power transfer switching mechanism include a set of switches mounted to the panel structure controlling the supply of power from the power transfer switching mechanism to the building electrical system. The transparent cover assembly is pivotally mounted about a horizontal axis to a top edge of the panel structure for movement between a closed position against the panel structure for preventing access to the electrical components, and an open position swung away from the panel structure for permitting access to the electrical components. The panel structure includes a front panel defining a mounting surface for the electrical components. The cabinet includes a base having a pair of side panels interconnected by a top panel and a rear panel. The preferred cover assembly includes a transparent front cover, a hinge arrangement attached to the front cover and a support bracket joining the hinge arrangement with the panel structure. The front cover includes a front wall integrally formed with a pair of side walls, the side walls having rear edges engagable with the front panel and exterior surfaces which are received inside interior surfaces of the side panels when the cover assembly is in the closed position. The hinge arrangement includes a first leaf and a second leaf interconnected with the first leaf by knuckle structure, and a horizontal pivot pin passing through the knuckle structure. The support bracket has a horizontal portion connected to one of the first and second leaves and a vertical portion attached to a mounting anchor depending from the panel structure. An alternative cover assembly includes a transparent front cover, and a combination, U-shaped hinge and support bracket pivotally joining the front cover to the panel structure. The front cover has a pair of side walls with upper edges formed with aligned holes, and the combination hinge and support bracket has cylindrical bosses which are pivotally received in the holes. 
     In another aspect of the invention, a power transfer arrangement is provided for supplying power from a generator to the electrical system of a building. The power transfer arrangement has a power transfer switching mechanism adapted for interconnection with the building electrical system and includes a cabinet having panel structure provided with various electrical components for transferring power to various load circuits. The invention is improved by a pre-assembled cover assembly having a transparent front cover and a hinge and support structure pivotally mounted relative to the cover, the hinge and support structure being mounted to the cabinet. 
     Various other objects, features and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The drawings illustrate the best mode presently contemplated of carrying out the invention. 
     In the drawings: 
     FIG. 1 is an isometric view showing the power transfer switching mechanism provided with a hinged, pre-assembled, transparent cover assembly constructed according to the invention; 
     FIG. 2 is an isometric, exploded view of the pre-assembled cover assembly relative to the switching mechanism shown in FIG. 1; 
     FIG. 3 is an isometric, exploded view of the individual components of the cover assembly; 
     FIG. 4 is a partial, enlarged, sectional view of the installed cover assembly taken on line  4 — 4  of FIG. 1; 
     FIG. 5 is an exploded view like FIG. 3 showing an alternative cover assembly for the power transfer switching mechanism; and 
     FIG. 6 is a sectional view similar to FIG. 4 of the alternative cover assembly shown in FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Although not shown, a power supply arrangement interconnects a portable generator with a main electrical panel or load center located in the interior of a building. As is well known, the load center is equipped with a plurality of circuit breaker switches, each of which is associated with a particular load circuit for normally running a load such as a furnace blower, sump pump or other device from a utility power source. In such a power inlet arrangement, a manual power transfer switching mechanism  10  constructed in accordance with the invention is mounted adjacent the main panel, and is interconnected therewith via a series of wires enclosed in a conduit  12  extending between the main panel and the transfer switch  10 . The general construction of the power transfer switching mechanism  10  may be such as manufactured by Reliance Controls Corporation of Racine, Wis. under the designation Gen/Switch (e.g. Model 30216 or any other satisfactory model). 
     As seen in FIGS. 1 and 4, the power transfer switching mechanism  10  includes a cabinet having a base defined by a pair of parallel, upwardly diverging side panels  14 ,  16 , each having an inwardly extending flange  18  with holes  20  formed therein at their lower ends. A top panel  22  extends between and interconnects the upper ends of the side panels  14 ,  16 , and a rear panel  24  joins the side panels  14 ,  16  and the top panel  22  together. Running vertically along the exterior surface of the rear panel  24  is a pair of rigid metal straps  26 ,  28  formed with fastener holes  30  to facilitate mounting of the base to a building wall  32 . The interior surface of the top panel  22  is provided with an L-shaped mounting anchor  34  having a rearwardly extending portion  36  joined, such as by welding, to a forward portion of the top panel interior surface, and a downwardly extending portion  38  formed with a pair of spaced apart, threaded cover mounting apertures  40 . 
     The power transfer switching mechanism  10  also includes a front panel unit having a vertically extending front panel  42  integrally formed with a rearwardly extending bottom panel  44 . The upper end of the front panel  42  is provided with two through holes  46  adapted to be aligned with the apertures  40  in the mounting anchor  34 . The side edges of the bottom panel  44  are formed with a series of screw threaded openings  48  which are aligned with the holes  20  and the flanges  18  at the lower end of the side panels  14 ,  16 . A set of screws  50  is passed through the holes  20  and screwed into the threaded openings  48  to hold the front panel unit together with the base. When the front panel  42  is secured to the base, a front portion of top panel  22  and the upper portions of side panels  14 ,  16  project forwardly of the plane of the front panel  42  as seen in FIGS. 2 and 4. 
     As is well known, the front panel  42  functions as a flat mounting surface for supporting various electrical components including a power output receptacle  52 , a pair of watt meters  54 ,  56 , a power input receptacle  58  and a linear array of identical adjacently disposed switches  60   a-f . Also positioned on the front panel  42  and positioned above each of the switches  60   a-f  in association therewith is a respective, resettable overcurrent protective device  62   a-f  which corresponds to a particular load circuit. Power output receptacle  52  is selectively used in a plug type connection to deliver generator power, while watt meters are selectively employed to monitor generator power delivered to the electrical loads in the system. Power input receptacle  58  is also a plug type connection, also selectively employed, which enables generator power to be received in the cabinet and connected to all the other components mounted on the front panel  42 . The power input receptacle may also be remotely mounted at a distance from the transfer mechanism and interconnected by cabling. In addition, switches  60   a-f  are employed to effect the actual transfer of power from the generator to various loads. For example, the first switch  60   a  may control power to a furnace blower, the second switch  60   b  may control power to a sump pump, the third switch  60   c  may control power to a refrigerator. Fourth, fifth and sixth switches,  60   d-f  may control power to a freezer, a light circuit, and an air conditioner, respectively. Overcurrent protective devices  62   a-f  protect individual circuits from an abnormality by breaking the circuit such as in the event of a current overload. 
     Each of the switches  60   a-f  on front panel  42  is of triple throw construction having a respective lever which is manually actuable to a LINE position when utility power is available, a GEN position when auxiliary or generator power replaces utility power and an OFF position which signifies no electrical power is being transferred to the load circuits. Switches  60   a-f  are designated such that each lever must move to the OFF position before being placed either in the GEN or LINE positions. Although not shown, in the case of double-pole circuits a tie bar interconnects two switches together. 
     Because the power transfer switching mechanism  10  and the setting of switches  60   a-f  is critical to preserving the transfer of either utility or generator power to the various load circuits, it is important to maintain the intended setting of the switch so as to avoid any power cut off such as to appliances defining the load. 
     In accordance with the invention, the power transfer switching mechanism  10  includes a pre-assembled, transparent cover assembly  64  which selectively prevents and permits access to the electrical components on the front panel  42  and, in particular, the switches  60   a-f  movably mounted thereon. At the same time, the cover assembly  64  provides complete and constant visual inspection of the components on the front panel  42 . Cover assembly  64  is hingedly or pivotally mounted about a horizontal axis to the top edge of the front panel  42  for movement between a closed position (FIGS. 1 and 4) and an open position (shown in phantom lines at FIG.  4 ). 
     Referring to FIG. 3, cover assembly  64  is typically comprised mainly of three elements, namely, a transparent cover  66  preferably formed of extremely durable plastic, a hinge arrangement preferably formed of metal, and a support bracket  70  also preferably fabricated from metal. 
     Cover  66  has a planar front wall  72  integrally formed with rearwardly extending side walls  74 ,  76 , the rear edges of which engage the front panel  42  and the planar surfaces of which side walls  74 ,  76  are adapted to be positioned inside the interior surfaces of the side panels  14 ,  16  when the cover assembly  64  is in the closed position. The height of the cover front wall  72  and the side walls  74 ,  76  is substantially coextensive with the height of the front panel  42 . The front wall  72  is formed with two apertures  78  spaced apart along the top edge thereof to facilitate mounting of the cover assembly  64  to the mounting anchor  34  depending from the top panel  22 . Each of these apertures  78  is friction fit with a plastic receiver  80  which accommodates a headed plastic fastener  82  in a pop-in fit. 
     Hinge arrangement  68  includes a first leaf  84  and a second leaf  86 , each of which has a series of interlocking knuckles  88  through which an elongated hinge pin  90  is passed. The first leaf  84  is formed with a pair of openings  92  aligned with apertures  78  in the cover front wall  72  so that the receivers  80  are frictionally held in the openings  92  and the apertures  78  is best seen in FIG.  4 . 
     Support bracket  70  is a generally L-shaped bracket having a horizontal segment  94  integrally formed with a vertical segment  96  having spaced apart holes  98  aligned with the through holes  46  in the top edge of the front panel  42  and the threaded apertures  40  in the mounting anchor  34 . A pair of screws  100  are used to fasten the support brackets  70  against the top of the front panel  42  and to the mounting anchor  34 . The front of the horizontal segment  94  is slightly recessed as shown in FIG. 4 to receive the knuckles  86  and hinge pin  90  of the hinge arrangement  68 . Further, the upper surface of the second leaf  86  is fixed, such as by spot welding, to a lower surface of the horizontal portion  94  of the support bracket  70 . 
     With the cover assembly  64  hingedly mounted to the power transfer switching mechanism  10  in the closed position, the front wall  72  of cover  66  is spaced forwardly of the switches  60   a-f  on the front panel  42  and the cover  66  is open at the bottom. In the closed position, the setting of the switches  60   a-f  cannot be accidentally or inadvertently bumped as could be the case without the cover assembly  64 . That is, with the cover assembly  64 , a switch  60   d  associated with a freezer circuit, for example, will remain in a position transferring power to keep the freezer running. Without the cover  66 , bumping of the switch  60   d  associated with the freezer could lead to a shut off of power resulting in the unwanted and likely unknown thawing of food. The pre-assembled cover assembly  64  can be attached to new power transfer switching mechanisms  10  or can be easily retrofit to existing power transfer switching mechanisms simply by using the through holes  46  in the front panel  42  and the threaded apertures  40  in the mounting anchor  34  along with the two screws  100 . When it is desired to engage the switches  60   a-f  or other components on the front panel  42 , the cover  66  is simply pivoted upward to allow complete, unobstructed access to the front panel  42 . It should be appreciated that because of the transparent cover  66 , the front panel  42  is able to be constantly visually monitored especially when in the closed position. 
     FIGS. 5 and 6 illustrate an alternative embodiment of the transparent cover assembly  64 ′. In this version, the front cover  66 ′ is formed with a pair of aligned holes  102  at the top of the side walls  74 ′,  76 ′. In addition, the cover assembly  64 ′ includes a generally U-shaped, combination hinge and support bracket  104  having a base strip  106  integrally formed with a pair of forwardly projecting ears  108 , each of which includes an inwardly extending, cylindrical hinge boss  110 . Each boss  110  is designed to snap fit into one of the holes  102  in the front cover side wall  74 ′,  76 ′ so that the cover  66 ′ may freely pivot relative to the base strip  106 . The pre-assembled cover assembly  64 ′ is attached to the top edge of the front panel  42  by passing fasteners  112  through a pair of spaced through holes  114  on the base strip  106  and threading the fasteners  112  into engagement with the threaded apertures  40  on the mounting anchor  34  depending from the cabinet top panel  22 . 
     It should be appreciated that the present invention provides a hinged transparent cover assembly  64 ,  64 ′, for a power transfer switching mechanism  10  which ensures that a reliable connection between the power source and one or more loads is maintained without accidental contact with the switches  60   a-f  on the front panel  42  of the power transfer.switching mechanism  10 . The cover assembly  64 ,  64 ′, is simple in construction, low in cost and easy to install and operate. The cover assembly  64 ,  64 ′, allows the front panel  42  to be viewed at all times and can be conveniently installed on both new and old power transfer switching mechanisms. 
     While the invention has been described with reference to a preferred embodiment, those skilled in the art will appreciate that certain substitutions, alterations and omissions may be made without departing from the spirit thereof. Accordingly, the foregoing description is meant to be exemplary only, and should not be deemed limitative on the scope of the invention set forth with the following claims.