Abstract:
A connection system for providing auxiliary electrical power to electrical loads of a building may include a meter box having one or more load receptacles connectable with the electrical loads of the building and one or more power grid receptacles connectable to a power grid and a connection unit with one or more load stabs configured for engagement with the load receptacles and for electrical interconnection with the auxiliary power source. The one or more load stabs may be positioned to be electrically isolated from the power grid receptacles.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/328,997 filed Apr. 28, 2010. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to systems for connecting auxiliary power sources such as emergency electrical generators to provide distribution of electrical power within a building. 
         [0003]    Typically, electrical power may be supplied to one or more buildings from a power grid operated by an electrical power supplier. Occasionally power delivery to a building may be temporarily interrupted because of storm damage or other accidental damage within the power grid. In such circumstances, building owners may elect to connect portable generators to their building&#39;s wiring system in order to maintain availability of electrical power. When such a generator connection is made, it is imperative to avoid back-feeding of power from the portable generator to the power grid. 
         [0004]    In a typical residential building back-feed prevention may be provided with specially designed interlocking switching devices which may allow some portion, but not all, of the building&#39;s wiring system to be electrically energized. 
         [0005]    As can be seen, there is a need for a system which permits connection of a generator to provide power for an entire wiring system of a building. Such a system must be capable of preventing back-feeding from the generator to the power grid. 
       SUMMARY OF THE INVENTION 
       [0006]    In one aspect of the present invention, a connection system for providing auxiliary electrical power to electrical loads of a building through a meter box with load receptacles and power grid receptacles, the system may comprise a connection unit with a cast resin body configured in a shape of a meter that fits the meter box, the connection unit including load stabs partially embedded in the cast resin body and configured for engagement with the load receptacles and for electrical interconnection with the auxiliary power source, and the load stabs being positioned to be electrically isolated from the power grid receptacles. 
         [0007]    In another aspect of the present invention, a connection unit for connecting an auxiliary power source to a wiring system of a building, the connection unit may comprise: a body formed of cast resin and configured to enclose a meter socket of a meter box of the building; load stabs configured to engage with load receptacles of the meter box; and auxiliary power attachment cables electrically interconnected with the load stabs so that the auxiliary power source is electrically interconnectable with the load receptacles of the meter box, the load stabs and the auxiliary power attachment cables being partially embedded in the cast resin of the body and held in position by the cast resin. 
         [0008]    In still another aspect of the invention, a method for interconnecting an auxiliary power source with a wiring system of a building comprising the steps of: removing an electrical meter from a meter socket of a meter box of the building; connecting a first end of neutral wire to a neutral terminal of the meter box; passing a second end of the neutral wire through a connection unit; placing the connection unit into the meter socket so that load stabs of the connection unit engage with load receptacles of the meter box; connecting the auxiliary power source to load attachment cables attached to the load stabs, removing the connection unit when power is restored to power grid receptacles of the meter box; and coiling the neutral wire inside the meter box while leaving the neutral wire connected to the neutral terminal. 
         [0009]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of a connection system in accordance with an embodiment of the invention; 
           [0011]      FIG. 2  is an exploded perspective view of the system of  FIG. 1  in accordance with an embodiment of the invention; and 
           [0012]      FIG. 3  is a cross sectional view of a connection unit in accordance with an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
         [0014]    Various inventive features are described below that can each be used independently of one another or in combination with other features. 
         [0015]    Broadly, embodiments of the present invention generally provide a system for interconnecting an auxiliary power source such as a portable generator to a meter box of a building in a manner that precludes back-feeding of power from the generator to the power grid. 
         [0016]    Referring now to  FIGS. 1 and 2 , it may be seen that an exemplary embodiment of a generator connection unit  10  may comprise a connector body  12 , load attachment cables  18  for an auxiliary power source (not shown), lugs  20  of cables  18 , a neutral wire  22 , a lug  24  of neutral wire  22 , load stabs  26  and alignment stabs  30 . The body  12  of the connection unit  10  may be configured in the same shape as a conventional electric meter (not shown). 
         [0017]    In the event of a power failure from the power grid, an electric meter may be removed from a meter socket  11  of a meter box  14  and the connection unit  10  may be placed into the vacated meter box  14 . As seen in  FIG. 2 , the load stabs  26  may be engageable with load receptacles  28  of the meter box  14 . The alignment stabs  30  may be engageable with power grid receptacles  32  of the meter box  14 . The neutral wire  22  may be connectable to a neutral terminal (not shown) in the meter box  14 . 
         [0018]    Referring now to  FIG. 3 , it may be seen that the body  12  of the connection unit  10  may be constructed from a cast resin  13  (e.g., polyester, acrylic or epoxy). Each of the load stabs  26  may partially embedded in the cast resin  13  and may be completely supported by the cast resin  13 . In an exemplary embodiment, the load stabs  26  may be lugs which may be crimp-connected to the load attachment cables  18 . The load stabs  26  may be electrically isolated from one another. The alignment stabs  30  may be embedded and the cast resin and may be electrically isolated from one another. Additionally, the alignment tabs  30  may be electrically isolated from the load stabs  26 . 
         [0019]    It may be seen that the connection unit  10  may be constructed without use of fasteners to hold the load stabs  26  and alignment stabs  30  in their respective position. The load stabs  26  and alignment stabs  30  may be held securely in position by the cast resin  13  in which they may be embedded. 
         [0020]    In an exemplary embodiment of the connection unit  10 , the load attachment cables  18  may comprise 2/0 copper stranded shielded wire, the neutral wire  22  may comprise #5 shielded soft copper welding wire (flexible). The load stabs  26  and the lugs  20  and  24  may be UL listed crimped tinned copper lugs. In this exemplary configuration, the connection unit  10  may be employed to connect auxiliary power of up to 200 amps. 
         [0021]    In a typical building wiring system, the load receptacles  28  may be electrically interconnected with a circuit breaker panel (not shown). Thus the load receptacles  28  may be connectable to all of the electrical loads of the building. 
         [0022]    It can be seen that when the lugs  20  of the load attachment cables  18  are connected to an auxiliary power source such as a portable generator, power from that auxiliary source may be directed to any and/or all electrical loads in the building. It may also be seen that, since the alignment stabs  30  may be electrically isolated from the load stabs  26 , there may be no electrical back-feed from the auxiliary power source to the power grid receptacles  32 . 
         [0023]    The connection unit may be employed to connect a conventional 240 volt auxiliary power source by connecting the source to both of the load attachment cables  18 . Alternatively, the connection unit  10  may be employed to connect a 120 volt auxiliary power source to the building wiring by connecting the source to only one of the load attachment cables  18 . In the case of a single load cable connection for a typical residential building, only about 50% of the electrical loads may be connectable to the auxiliary power source. 
         [0024]    In an exemplary employment of the connection unit  10  the following steps may be performed. An electrical meter may be removed from a meter socket of a meter box of the building. A first end of neutral wire  22  may be connected to a neutral terminal of the meter box  14 . A second end of the neutral wire  22  may be passed through the connection unit  10 . The connection unit  10  may be placed into the meter socket  11  so that load stabs  26  of the connection unit  10  engage with load receptacles  26  of the meter box  14 . The auxiliary power source may be connected to load attachment cable  18  attached to the load stabs  26 . The connection unit  10  may be removed when power is restored to power grid receptacles  32  of the meter box  14 . The neutral wire  22  may be coiled inside the meter box  14  while leaving the neutral wire  22  connected to the neutral terminal so that subsequent use of the connection unit  10  may be made without a need for re-connecting the neutral wire. 
         [0025]    It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.