Abstract:
A circuit breaker mounting assembly comprises an enclosure for holding at least one circuit breaker, with the circuit breaker being mounted within said enclosure; a terminal block mounted within the enclosure at a location remote from the circuit breaker, the terminal block including a plurality of input connections and a plurality of output connections; a plurality of control wires extending from the circuit breaker to the terminal block; and a mounting bracket for positioning the terminal block in a first position within the enclosure and for permitting the terminal block to be moved to a second location outside of the enclosure.

Description:
CROSS REFERENCE TO A RELATED PATENT APPLICATION 
     A commonly assigned United States patent application titled “Circuit Breaker Mounting Assembly With Remote Terminal Block” filed on the same date as this application discloses a circuit breaker mounting assembly having an remote terminal block for connection to the auxiliary wiring of circuit breakers. 
     BACKGROUND OF THE INVENTION 
     This invention relates to circuit breaker mounting assemblies, and more particularly to such mounting assemblies having an auxiliary terminal block for connection to the auxiliary wiring of a circuit breaker. 
     Circuit breakers are generally used to protect electrical circuitry from damage due to an overcurrent condition, such as an overload fault or a relatively high level short circuit condition. Molded case circuit breakers, for example, include at least one pair of separable contacts which may be operated either manually by way of a handle disposed on the outside of the case or automatically in response to an overcurrent condition. In the automatic mode of operation, an electronic trip unit, for example, controls an operating mechanism that opens the separable contacts. In the manual mode of operation, the handle cooperates with the operating mechanism in order to open the separable contacts. Circuit breakers have at least one line terminal for connection to a power source and at least one load terminal for connection to a load, such as a motor. The separable contacts of the circuit breakers are internally connected to the line and load terminals. Circuit breakers may also have one or more auxiliary terminals. Such auxiliary terminals may be utilized as inputs to provide an external signal for tripping the circuit breaker. Furthermore, other such auxiliary terminals may be utilized as outputs to externally indicate the trip status of the circuit breaker. Input auxiliary terminals may include, for example, connections to a shunt trip mechanism or an undervoltage trip relay which trips the circuit breaker whenever the line voltage falls below a predetermined value. 
     An external auxiliary terminal block can be utilized to provide terminals for connection of the circuit breaker with such external trip mechanisms. Output auxiliary terminals may include, for example, connections to a bell alarm and other external circuits for enunciating or monitoring the open/closed/tripped status of the circuit breaker. An external auxiliary terminal block can also be utilized to provide terminals for interconnection of two circuit breaker status relay contacts having a common reference node with such external status monitoring circuits. Combinations of input and output auxiliary terminals may be provided by auxiliary terminal blocks having plural (e.g., six, nine, etc.) terminals. Circuit breakers having auxiliary terminal blocks are shown in U.S. Pat. Nos. 5,483,213 and 5,652,698. 
     When circuit breakers are mounted in cabinets or panelboards, the auxiliary terminal blocks shown in the above patents may not be readily accessible. There is a need, therefore, for a circuit breaker assembly having an auxiliary terminal block that improves the accessibility for connection to the internal wiring of the circuit breaker. 
     SUMMARY OF THE INVENTION 
     This and other needs are satisfied by the invention that is directed to a circuit breaker mounting assembly comprising an enclosure for holding at least one circuit breaker, with the circuit breaker being mounted within said enclosure; a terminal block mounted within the enclosure at a location remote from the circuit breaker, the terminal block including a plurality of input connections and a plurality of output connections; a plurality of control wires extending from the circuit breaker to the terminal block; and a mounting bracket for positioning the terminal block in a first position within the enclosure and for permitting the terminal block to be moved to a second location outside of the enclosure. 
     In the preferred embodiment, the first position is in a gutter area of the enclosure that houses electrical power conductors. Movement of the terminal block out of the gutter area permits easy access to the terminal block connection points and to the power conductors in the gutter area. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A full understanding of the invention can be gained from the following description of the preferred embodiment when read in conjunction with the accompanying drawings in which: 
     FIG. 1 is an isometric view of a circuit breaker mounting assembly having an auxiliary terminal block in accordance with the invention; 
     FIG. 2 is an isometric view of a circuit breaker that may by used in the assembly of FIG. 1; 
     FIG. 3 is a top view of the terminal block of FIG. 3 with the cover shown in phantom lines; 
     FIG. 4 is an exploded isometric view of a terminal block used in the assembly of FIG. 1; 
     FIG. 5 is an isometric view of the terminal block of FIG. 3; 
     FIG. 6 is an isometric view of the terminal block of FIG. 3 with the cover shown in phantom lines; 
     FIG. 7 is another isometric view of the terminal block of FIG. 3 with the cover shown in phantom lines; 
     FIG. 8 is an isometric view of the terminal block of FIG. 3 attached to a hinged mounting bracket; 
     FIG. 9 is an isometric view of the hinged mounting bracket shown in FIG. 8; and 
     FIG. 10 is an end view of the terminal block mounted on the enclosure. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, FIG. 1 is an isometric view of a circuit breaker mounting assembly having an auxiliary terminal block in accordance with the invention. The circuit breaker mounting assembly  10  includes an enclosure  12 , also referred to as a cabinet, that is capable of housing various electrical devices. The cabinet is constructed in accordance with the prior art, and in the illustrated embodiment includes a pair of doors  14  and  16  covering channels, also referred to as gutters, on either end of the cabinet. A plurality of front panels  18 ,  20 ,  22 ,  24 ,  26  and  28  extend between the channels. The panels include openings for exposing the faces of various electrical components that arc mounted in the cabinet. In this sample embodiment, five circuit breakers  30 ,  32 ,  34 ,  36  and  38  are shown to be mounted in the cabinet. A pair of terminal block assemblies  40  and  42  are shown to be mounted such that they extend into channel  44 . The terminal block assemblies provide connection points for control circuitry in the circuit breakers as described below. While only two terminal block assemblies are shown in FIG. 1, it should be understood at more or less terminal blocks may be used in accordance with the invention. 
     FIG. 2 is an isometric view of a circuit breaker  46  that may by used in the assembly of FIG.  1 . The circuit breaker  46  includes a molded cover  48  and a molded base  50 . A plurality of control wires  52  emerge form an opening in the base and are contained within an insulting sleeve  54 . The control wires are used in accordance with the prior art to monitor various parameters associated with the circuit breaker and to control the operation of the breaker. The individual control wires are coated with an insulating layer, but the voltage rating of the control wires is less than that required for exposed wire within the cabinet. Therefore, the control wires are contained within an outer sleeve  54  of insulation having a higher voltage rating. The control wires, within the sleeve pass within the cabinet to one of the remote terminal blocks, for example terminal block  40 . In the preferred embodiment, the outer sleeve insulation is rated at 600 volts, while the insulation of the individual wires within the sleeve is rated at less than 600 volts. 
     FIG. 3 is a top view of the terminal block  40  with the cover shown in phantom lines. The terminal block  40  includes a terminal strip  56  having two offset rows  58  and  60  of connection points as generally indicated by item numbers  62  and  64 . Control wires  52  are shown to be connected to connection points  62  in row  58 . Insulating sleeve  54  passes through a grommet  66  in an opening in a plate  68  that forms a portion of an enclosure that houses row  58  of connection points of the terminal strip  56 . In the illustrated embodiment, additional control wires  70  are also connected to connection points  62 . These additional control wires are contained within insulating sleeve  72  that passes through another grommet  74  in another opening in plate  68 . These additional control wires can be connected the same circuit breaker as control wires  52 , or they can be connected to another circuit breaker or other device. 
     FIG. 4 is an exploded isometric view of a terminal block used in the assembly of FIG.  1 . In this figure, terminal strip  56  is shown to comprise two separable components  76  and  78  that contain the rows of terminals  62  and  64 . A mounting bracket  80  is used to mount the terminal strip  56  to plate  68 . A cover  82  having an opening  84  is attached to plate  68  by posts  86  and  88 , and bolts  90  and  92  to form an enclosure that houses connection points  62 . When the terminal block is assembled, connection points  64  extend through the opening  84  in the cover  82  such that connections can be made to connection points  64  without removing cover  82 . 
     FIG. 5 is an isometric view of the terminal block of FIG.  3 . This figure shows the terminal block with the cover  82  attached to the plate  68  so as to from an enclosure  94  that houses the lower row of connection points  62 . 
     FIG. 6 is an isometric view of the terminal block of FIG. 3 with the cover shown in phantom lines. FIG. 7 is another isometric view of the terminal block of FIG. 3 with the cover shown in phantom lines. 
     FIG. 8 is an isometric view of the terminal block of FIG. 3 attached to a hinged mounting bracket  96 . The hinged mounting bracket includes a hinge member  98  having a pair of flanges  100  and  102  that pivot about pin  104 . A plate  106  is connected to flange  100  and extends generally perpendicularly therefrom. The plate includes an elongated opening  108  that permits an adjustment in the vertical direction when the terminal block is mounted in the cabinet of FIG. 1. A pair of projections  110  and  112 , shown in FIG. 9, extend from flange  102  for connection to the Terminal block. 
     FIG. 9 is an isometric view of the hinged mounting bracket shown in FIG.  8 . Holes  114  and  116  are provided for receiving bolts  90  and  92  to couple the terminal block to the hinged mounting bracket. The distance between the holes and the pin  104  is large enough such that when flange  106  is attached to and internal surface of the cabinet of FIG. 1, the terminal block can swing out of the gutter area and in front of one of the cabinet panels. This provides improved access to the gutter area, as well as improved access to the connection points in the terminal block. 
     FIG. 10 shows how the terminal block can be mounted to the enclosure using one or more bolts  118  passing through the elongated slot in plate  106 , and can move from a first position  120  within the gutter portion of the enclosure to a second position  122  outside of the enclosure. To be able to move the terminal block as shown in FIG. 10, the control wires, not shown in this view, that would be connected to the terminal block will have to have sufficient slack or flexibility to permit movement of the hinged mounting bracket. 
     This invention permits easy access to terminal block connection points as well as improved access to line terminal connections on the circuit breakers, which require occasional tightening checks. While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. For example, while the preferred embodiment of the invention utilizes circuit breakers, it should be understood that the present invention is applicable to a wide variety of electrical devices which are considered to be equivalent where such devices are connected to the terminal block by auxiliary or control wires. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.