Breaker secondary terminal block isolation chamber

Abstract

The disclosed concept pertains generally to secondary terminal blocks and, more particularly, to apparatus and methods for isolating the secondary terminal blocks and associated wiring in electrical switching assembly enclosures. The apparatus includes a housing having an outer surface structured to form a cavity therein. The apparatus is positioned in an enclosure which includes an electrical switching apparatus and one or more secondary terminal blocks. The one or more secondary terminal blocks are positioned in the cavity such that the apparatus at least substantially isolates the one or more secondary terminal blocks from the electrical switching apparatus. Further, the apparatus is effective to substantially isolate the secondary terminal blocks from temperature and pressure effects resulting from an arcing fault occurring in the enclosure.

Claims

1. An electrical switching apparatus, comprising: an enclosure having an interior space; a housing positioned within the interior space of the enclosure, the housing comprising: an outer surface structured to form a cavity therein; at least one slot formed through the outer surface, the at least one slot structured to receive a plurality of connecting wires; and one or more electrical connector devices positioned in the cavity of the housing, the one or more electrical connector devices comprising: a plurality of connection apertures to correspondingly receive and, electrically and mechanically engage the plurality of connecting wires, wherein, the housing isolates the one or more electrical connector devices from the interior space of the enclosure of the electrical switching apparatus which surrounds the housing.

2. The electrical switching apparatus of claim 1, wherein the housing is structured to substantially isolate the one or more electrical connector devices from temperature and pressure conditions released into the enclosure as a result of an arc fault occurring in the enclosure.

3. The electrical switching apparatus of claim 2, wherein said conditions comprise high temperature and pressure gas.

4. The electrical switching apparatus of claim 1, comprising: a rectangular member having a front side opening, a top side, bottom side, back side, and a pair of opposing end walls; and at least one slot formed in at least one of the pair of opposing end walls, wherein said at least one slot is adjustable.

5. The electrical switching apparatus of claim 4, wherein the housing comprises: at least one vane for mounting the housing to an inner surface of the enclosure.

6. The electrical switching apparatus of claim 1, wherein the housing is constructed of a material selected from the group consisting of rigid and semi-rigid materials.

7. The electrical switching apparatus of claim 6, wherein the housing is constructed of a molded plastic component.

8. The electrical switching apparatus of claim 1, wherein the housing is effective to provide access to the one or more electrical connector devices while maintaining arc resistant rating.

9. The electrical switching apparatus of claim 4, wherein the front side opening allows access to the one or more electrical connector devices positioned therein.

10. A method of isolating one or more electrical connector devices in an enclosure of an electrical switching apparatus, comprising: installing a housing in the enclosure which is structured to house the one or more electrical connector devices, the housing comprising: an outer surface structured to form a cavity therein; at least one slot formed through the outer surface and structured to receive a plurality of connecting wires; and positioning the one or more electrical connector devices within the cavity of the housing, the one or more electrical connector devices comprising: a plurality of connection apertures to correspondingly receive and, electrically and mechanically engage the plurality of connecting wires.

11. The method of claim 10, wherein the housing is effective to withstand increased temperature and pressure gas resulting from an electrical arcing fault occurring in the enclosure.

12. The method of claim 10, wherein the housing is effective to prevent the increased temperature and pressure gas from escaping the enclosure.

13. An electrical switching apparatus, comprising: a molded case having walls forming a first cavity including an outer wall and an inner wall, and components positioned in the first cavity comprising: an electrical switching mechanism; a chamber comprising: an outer surface structured to form a second cavity; at least one slot formed through the outer surface, the at least one slot structured to receive a plurality of connecting wires; a mounting means to couple said chamber to the inner wall of the molded case; and one or more electrical connector devices positioned in the second cavity of the chamber, the one or more electrical connector devices comprising: a plurality of connection apertures to correspondingly receive and, electrically and mechanically engage the plurality of connecting wires.

14. The electrical switching apparatus of claim 13, wherein said electrical switching mechanism is a circuit breaker.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:

(2) FIG. 1 is a perspective view of an isolation apparatus to house secondary terminal blocks in a circuit breaker enclosure, in accordance with certain embodiments of the invention.

(3) FIG. 2 is a side view of a circuit breaker enclosure including the isolation chamber of FIG. 1, in accordance with certain embodiments of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) Direction phrases used herein, such as, for example and without limitation, top, bottom, left, right, upper, lower, front, back and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.

(5) As employed herein, the statement that two or more parts are connected or coupled together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. Further, as employed herein, the statement that two or more parts are attached shall mean that the parts are joined together directly.

(6) The disclosed concept is described in association with electrical switching apparatus, such as circuit breakers, although it will become apparent that the disclosed concept could also be applied to other types of electrical switching apparatus, e.g., without limitation, other circuit switching devices and other circuit interrupters such as contactors, motor starters, motor controllers and other load controllers.

(7) In certain embodiments, the disclosed concept includes an apparatus, e.g., chamber or compartment, for housing and/or isolating one or more secondary terminal blocks in electrical switching apparatus, such as circuit breaker, enclosures. Secondary terminal blocks are generally not isolated from other components and wiring in a typical circuit breaker enclosure.

(8) In certain other embodiments, the disclosed concept further includes a method of installing or incorporating an apparatus, e.g., chamber or compartment, into an electrical switching apparatus enclosure. One or more secondary terminal blocks and their associated wiring are positioned within the apparatus to isolate the one or more secondary terminal blocks from other components and wiring located in the electrical switching apparatus enclosure.

(9) In general the apparatus of the invention includes a chamber or compartment for housing one or more secondary terminal blocks. The chamber or compartment has an opening to provide access to the secondary terminal blocks. The secondary terminal blocks include connection apertures formed therein. Each of the connection apertures is structured to receive an end of a connection wire. Thus, the chamber or compartment can also at least partially house one or more connection wires. Further, the chamber or compartment includes at least one adjustable slot to allow one or more connection wires to be received into the chamber or compartment from outside thereof. The chamber or compartment is positioned in an enclosure which houses an electrical switching apparatus. The chamber or compartment isolates the secondary terminal blocks from the electrical switching apparatus and from other components that may be positioned in the electrical switching apparatus enclosure. In the event of an arcing fault occurring in the electrical switching apparatus enclosure, the chamber or compartment isolates the secondary terminal blocks from high temperature and pressure gas that typically results from the arcing fault. The chamber or compartment can also prevent the gas from exiting the electrical switching apparatus enclosure and being dissipated into the external atmosphere or environment.

(10) FIG. 1 is an isometric view of an isolation chamber 1 in accordance with certain embodiments of the disclosed concept. The isolation chamber 1 includes a housing in the form of a rectangular member 5 having generally a trough shape which is open at a front side 7 and closed at a top side 9, bottom side 11, back side 13 (opposite to the front side 7) and a pair of opposing end walls 15, which define the rectangular member 5. The particular rectangular member 5 is not meant to be limiting and it should be understood that other types of housing members, e.g., having various shapes and sizes, may be substituted for the rectangular member 5. The particular housing member can depend on the size and configuration of the circuit breaker, the switchgear and/or the other components positioned in the circuit breaker enclosure.

(11) The isolation chamber 1 of the disclosed concept can be constructed of a wide range of materials. Suitable materials may be selected from those materials that are known in the art for use in electrical switching assembly enclosure. The isolation chamber 1, in particular, the rectangular member 5, is typically made of a substantially rigid material. In certain embodiments, the isolation chamber 1 is at least partially constructed of a polymer and/or polymer-containing material. In particular, the isolation chamber 1 can be constructed of molded plastic. The isolation chamber can be prepared using conventional molding methods that are known in the art, such as but not limited to, injection molding.

(12) As shown in FIG. 1, the front side 7 of the rectangular member 5 defines an opening which can function to provide access to the interior cavity defined by rectangular member 5.

(13) Positioned within the rectangular member 5 is a pair of secondary terminal blocks 17. The two secondary terminal blocks 17 are shown in FIG. 1, however, it is contemplated that various designs and configurations of electrical switching apparatus may include one or more secondary terminal blocks 17. Each of the pair of secondary terminal blocks 17 includes a plurality of connection apertures 19. Each of the connection apertures 19 is adapted for receiving an end portion of a connection wire (not shown) and, electrically and mechanically engaging the end portion of the connection wire (not shown). An adjustable slot 21 is formed within each of the opposing end walls 15 of the rectangular member 5. Each of the adjustable slots 21 is adapted for receiving at least one connection wire (not shown), e.g., a wire harness, that is received by the plurality of apertures 19 formed in the pair of secondary terminal blocks 17. Further, as shown in FIG. 1, a vane 23 having a plurality of mounting apertures 25 formed therein is coupled to the rectangular member 5 to provide for connecting or attaching the isolation chamber 1 to a circuit breaker enclosure (shown in FIG. 2). One vane 23 is shown in FIG. 1, however, it is contemplated that various designs and configurations of electrical switching apparatus may include more than one vane 23 for mounting the isolation chamber 1 to the circuit breaker enclosure (shown in FIG. 2). Each of the mounting apertures 25 is adapted to receive an associated mounting mechanism, such as a screw or bolt (not shown). Although the vane 23 and the associated mounting mechanism (not shown) are used to couple or attach the isolation chamber 1 to the circuit breaker enclosure, e.g., interior wall, the disclosed concept contemplates using any suitable coupling and mounting mechanisms to accomplish this function.

(14) The open front side 7 provides personnel the capability to access the secondary terminal blocks 17 and associated connection wires which are contained in the isolation chamber 1, e.g., rectangular member 5.

(15) FIG. 2 is a side view of a circuit breaker enclosure 10 in accordance with certain embodiments of the disclosed concept. The circuit breaker enclosure 10 includes the isolation chamber 1 as shown in FIG. 1 including the rectangular member 5, one of the pair of secondary terminal blocks 17 and the connection apertures 19. FIG. 2 also includes a front portion 30, a personnel access point 32, a circuit breaker 12 and an arcing fault 14. The arcing fault produces increased, e.g., high, temperature and pressure gas 16. The circuit breaker enclosure 10 may house other components and equipment which are not shown in FIG. 2. As demonstrated in FIG. 2, the isolation chamber 1 is effective to house the secondary terminal blocks 17 and to at least substantially isolate the secondary terminal blocks 17 from the circuit breaker 12 and other components (not shown) which are positioned in the interior cavity or space of the enclosure 10. In the event of the arcing fault 14, the isolation chamber 1 is effective to isolate and protect the secondary terminal blocks 17 from the gas 16 which is released into the circuit breaker enclosure 10 as a result of the arcing fault 14. The gas 16 is prevented from entering the isolation chamber 1 and thereby prevented from escaping through the personnel access point 32 to the environment outside of the enclosure 10. Thus, access to the secondary terminal blocks 17 is provided while the arc resistant rating is maintained.

(16) While specific embodiments of the disclosed concept 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. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.