Abstract:
A circuit breaker is provided with a case having a groove on the load end and a groove on the side. The grooves are sized and positioned on the case to allow several isolation accessories to be mounted to the circuit breaker. The isolation accessories include at least a terminal cover and a phase separator which electrically isolate adjacent circuit breaker poles.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to circuit breakers, and more particularly to a pull-out circuit breaker case intended for use with a circuit breaker capable of attaching multiple isolation accessories.  
         BACKGROUND OF THE INVENTION  
         [0002]    Molded case circuit breakers are well known in the art. Circuit breakers of this type are connected to an electrical circuit between a power source and a circuit which requires protection against electrical faults. To connect the circuit breaker, cabling or solid busbar is connected to one side of the circuit breaker, and a second set of cables or busbar exit the opposite end of the circuit breaker. An internal switching mechanism allows the protected circuit to be coupled and decoupled from the power source. The circuit breaker also includes a sensing device that automatically switches the circuit breaker to the open or decoupled position in the event of an electrical fault.  
           [0003]    Industrial molded case circuit breakers typically handle three or four phase circuits. Each phase of the circuit is carried through the circuit breaker in an individual pole. Some regulatory agencies such as the International Electrotechnical Commission (IEC) require that accessories be used to increase the effective distance between the poles. These distances, usually referred to as “through air” or “over surface” distances reduce the probability of electrical current flowing between adjacent phases. The most common accessories include phase barriers and terminal covers which fit between the cables mounted on each end of the circuit breaker. In the case of the terminal cover, a shield also extends over the top of the cables. Typically, installation of the terminal cover is difficult especially when the circuit breaker is already installed. Additionally the terminal cover usually requires multiple fasteners. It is thought to be advantageous to provide a terminal cover that easily installs on the circuit breaker and overcomes other disadvantages of the prior art devices.  
         SUMMARY OF THE INVENTION  
         [0004]    In an exemplary embodiment of the present invention relates to a circuit breaker having a case. The case includes a first and second groove arranged on an end and a side respectively. The grooves are positioned and sized to receive a plurality of isolation accessories including phase separators and terminal covers. The terminal covers include a plurality of knockouts that allow electrical conductors to exit the circuit breaker.  
           [0005]    Other advantages and features will become more clearly apparent from the following description of an illustrative embodiment of the invention, given as a non-restrictive example only and represented in the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0006]    [0006]FIG. 1 illustrates an exploded perspective view of a circuit breaker with its accessories;  
         [0007]    [0007]FIG. 2 illustrates a perspective view of a circuit breaker case;  
         [0008]    [0008]FIG. 3 illustrates an exploded perspective view of a circuit breaker having the upper portion of the case removed with its accessories. 
     
    
     DETAILED DESCRIPTION  
       [0009]    With reference to FIG. 1, circuit breaker  1  has a general parallelepiped shape with upper case  2  and four lateral sides, of which only large side  3  and load side  4  are visible.  
         [0010]    Large side  3  is generally flat and is provided with two parallel grooves  7  and  8 , one arranged in the vicinity of load side  4  and the other in the vicinity of the line side of the circuit breaker, which is not visible. The side opposite side  3  (not visible) is preferably identical to side  3  including a pair of corresponding grooves  7 ,  8 .  
         [0011]    Load side  4  is generally flat and is provided with three holes  9 ,  10  and  11 , one for each pole of the circuit breaker  1 . As shown in FIG. 1, the circuit breaker is configured to protect a three phase electrical circuit. Each of the holes  9 - 11  is sized to receive electrical conductors (not shown), which can be attached inside circuit breaker  1 . The load side  4  also includes two parallel grooves  12  and  13 . The groove  12  is arranged between holes  9  and  10 , and groove  13  is arranged between holes  10  and  11 . The line side of the circuit breaker (not shown) is preferably identical to load side  4  including grooves corresponding to grooves  11 ,  13 . In general, for every n holes are provided, n- 1  grooves will be produced.  
         [0012]    Grooves  7 ,  8 ,  12 ,  13  have the same cross section with an opening, and a bottom wider than the opening. At least one longitudinal end of each groove  7 ,  8 ,  12 ,  13  is open. In the preferred embodiment, both longitudinal ends are open.  
         [0013]    Different types of insulation accessories are used to provide electrical isolation between the electrical phases of the circuit breaker  1 . FIG. 1 shows two phase separators  14  and  15 . The phase separators  14 ,  15  include a generally rectangular flat plate  16  and an edge  17  arranged on one of the sides of plate  16 . The edge  17  has a shape that corresponds to of grooves  7 ,  8  such that the edge  17  can enter and slide in one of grooves  7 ,  8 . Phase separator  14 ,  15  are typically manufactured from a dielectric material, such as a flexible synthetic material. In the assembled position, the phase separators  14 ,  15  forms a barrier between two power connections of the circuit breaker, for example, between two connection accessories  18 - 22 . The connection accessories can receive lugs or bars which are not shown.  
         [0014]    Terminal cover  23  is also shown in FIG. 1. Terminal cover  23  is a single piece and has a front wall  24 , an upper wall  25  and two parallel lateral walls  26 . Terminal cover  23  can have phase separators parallel to the lateral walls and which are not visible in FIG. 1. A pair of edges, not visible in FIG. 1, are similar to edges  17  of phase separators  14 ,  15  and are arranged on the insides of the lateral walls of the terminal cover  23  so as to be housed respectively in groove  7  of large side  3  and in the corresponding groove opposite groove  7 . Terminal cover  23  makes it possible to increase the insulation and to protect the users by covering the holes  9 - 11 . The terminal cover  23  also includes a plurality of knockouts  40  arranged on the front face  24 . Each knockout is arranged to be removed from the terminal cover  23  to allow the electrical conductors (not shown) to pass out of the circuit breaker  1 . In addition, the terminal cover  23  includes a plurality of slots  41  arranged on the front wall  24  adjacent the knockouts  40 . The slots  41  are sized to allow the gases generated during an electrical fault to exit the circuit breaker  1 . The length of terminal cover  23  (in the direction of the length of wall  26 ) is suited to the connection accessories which are used.  
         [0015]    A user can thus have phase separators  14 ,  15  or terminal cover  23  on each load side  4  of circuit breaker  1 .  
         [0016]    In FIGS. 2 and 3, case  27  for a circuit breaker has a general a parallelepiped shape with upper side  28  and four lateral sides, two large sides  29  and  30  and two small sides  31  and  32 .  
         [0017]    Upper side  28  is hollow and can receive circuit breaker internal components, for example, a mechanism or interrupter (not shown).  
         [0018]    Large sides  29 ,  30  are generally flat and are provided with two parallel grooves  7 ,  8 . One groove  7  arranged in the vicinity of small side  31  and the other groove  8  arranged near side  32 . The distance between groove  7  of side  29 ,and groove  7  of side  30  is equal to the distance between the corresponding grooves of a circuit breaker having the same number of output connections and therefore of holes in small sides  31  and  32 . Thus, the terminal cover  23  can be attached to the two grooves  7  or to the two grooves  8  of support  27 . Terminal cover  23  can also be attached on grooves  37 - 39 ; see below.  
         [0019]    Sides  31 ,  32  are generally flat and are provided with four holes  33 ,  34 ,  35  and  36  in FIG. 2 and with three holes  33 ,  34  and  35  in FIG. 3. The holes  33 - 36  are sized to receive electrical conductors (not shown), which can be attached inside case  27 . The sides  31 ,  32  include three parallel grooves  37 ,  38  and  39  in FIG. 2 and two parallel grooves  37  and  38  in FIG. 3. Groove  37  is arranged between holes  33  and  34 , groove  38  is arranged between holes  34  and  35 , and groove  39  is arranged between holes  35  and  36 . In general, for every n holes provided, n- 1  grooves will be produced.  
         [0020]    The different grooves have the same cross section with an opening, and a bottom wider than the opening. At least one longitudinal end of each groove is open. In the preferred embodiment, both longitudinal ends are open. Phase separators  14 ,  15  are associated with case  27 .  
         [0021]    As shown in FIG. 3, an insulation plate  40  can be attached to case  27 . Plate  40  is provided with two holes  41  capable of receiving pegs, coming from the lower side of case  27  (not shown). Plate  40  makes it possible to increase the insulation with respect to the wall or to the wall or face on which the support is attached.  
         [0022]    While this invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.