US20100096962A1

US20100096962A1 - Electrical Insulation Barriers Having Knock Out Features

Info

Publication number: US20100096962A1
Application number: US12/400,196
Authority: US
Inventors: Rahul Rajvanshi; Jason Parkerson; Thomas Hawkins
Original assignee: Siemens Energy and Automation Inc
Current assignee: Siemens Industry Inc
Priority date: 2008-10-20
Filing date: 2009-03-09
Publication date: 2010-04-22
Also published as: WO2010047728A1

Abstract

The present invention relates generally to a switchgear apparatus. More particularly, the invention encompasses an electrical insulation barrier having knock-out features for a switchgear apparatus. The present invention also relates to enclosures for switchgear, panel boards, circuit breakers, and more particularly to an enclosure for low voltage switchgear and switchboard assemblies. The enclosure can be a walk-in type enclosure or a non-walk-in type enclosure. This invention further provides a rear barrier for switchgear vertical (section) bus insulation assembly. The rear barrier is made from a brittle material, such as, for example, a thermoset insulating material, a glass reinforced polyester laminate (GPO-2 or GPO-3) material, and has a plurality of knock-out pass-through-openings for the bus bars and other hardware. These inventive knock-out design features have been incorporated in the rear barrier to produce openings in these rear barriers by knocking-out pre-defined shapes to allow a clearance for intersecting electrical parts. With this invention a single master or universal-type part can be made and used in many configurations and locations dependant on the design of the switchgear. This invention also consolidates many single use barriers into a few master parts where an assembly technician can customize the rear barrier to fit the desired application.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The instant patent application claims priority to and the benefit of the filing date of pending U.S. Provisional Patent Application Ser. No. 61/106,659, filed on Oct. 20, 2008, titled “Electrical Insulation Barriers Having Knock Out Features,” the entire disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

BACKGROUND INFORMATION

Switchgear and switchboard are general terms which cover metal enclosures, housing switching and interrupting devices, such as, fuses, circuit breakers, relays, along with associated control, instrumentation and metering devices, such as, bus bar, inner connections, and supporting structures, including, assemblies of these devices with associated buses, interconnections and supporting structures used for distribution of electric power.
There are High Voltage switchgear and switchboards, Medium Voltage switchgear and switchboards, and Low Voltage switchgear and switchboards. This invention is primarily geared towards the Low voltage switchgear and switchboards.
Low voltage switchgear and switchboards operate at voltages up to about 635 volts, and with continuous currents that can exceed about 5000 amperes. These Low voltage switchgear and switchboards are designed to withstand short-circuit currents up to about 200,000 amperes.
Low voltage switchgear equipment typically comprises of an assembly composed of multiple metal enclosed sections. Each section may have several circuit breakers stacked one above the other vertically in the front of the section with each breaker being enclosed in its own metal compartment. Each section has a vertical or section bus which supplies current to the breakers within the section via short horizontal branch buses that extend through insulated openings in the rear wall of the breaker compartments. The vertical buses in each section are supplied with current by a horizontal main bus that runs through the line-up. The rear of the section is typically an open area for the routing of cables.
The standard metal-enclosed switchgears have a rear insulation barrier that typically has pre-determined openings for an assortment of electrical and mechanical connections. These pre-determined openings are created in the rear insulation barrier while the rear insulation barrier is being manufactured. Due to a large number of possible design configurations many single use rear barriers are needed with these pre-determined openings. Thus, there is a need to have a rear insulation barrier that can be customized or modified in the field as demanded by the switchgear configuration.
U.S. Pat. No. 4,032,030 (David L. Bass, et al.) the entire disclosure of which is incorporated herein by reference discloses a modifiable utility outlet box cover element formed of thin, metallic sheet material useable without modification in a substantially square form in closing a substantially square utility outlet box including slots through which screws may be passed into engagement with screw receiving means carried by such utility outlet box. The four corner portions of such utility outlet box cover element, two of which include such slots, are readily separable from the remainder thereof along slots cut deeply into one of the surfaces of such utility outlet box cover element; such remainder of such utility outlet box cover element being shaped and proportioned to close octagonally shaped or round utility outlet boxes and including knock-out portions which, when readily separated from the remainder of such utility outlet box cover element, provide openings through which screws may be passed into engagement with screw receiving means carried by such octagonal or round utility outlet boxes.
U.S. Pat. No. 4,296,740 (Milton Meckler) the entire disclosure of which is incorporated herein by reference discloses a modular system of solar insolation panels having sun tracking capability and adapted to be installed directly upon a roof structure and integrated with the surrounding roofing, and comprised of prismatic lenses embodied in a multiplicity of transparent tubes disposed in normal relation to the traverse plane of the sun, and arranged upon an insulation panel and with corner fittings and knock-out plugs to be employed as circumstances require.
U.S. Pat. No. 4,825,339 (Douglas M. Boudon, et al.) the entire disclosure of which is incorporated herein by reference discloses a knock-out in the wall of the housing for electronic equipment is selectively removed to provide a knock-out opening. A wall includes first and second slits positioned along the boundary of the knock-out and separated by a land. The wall includes a break out opening adjacent to each land. Break portions of the wall separate the break out opening from the first and second slits. These break portions are severed to interconnect the first and second slits through the break out opening and permit removal of the knock-out. Plural such slits and break out openings are provided and arranged to provide a knock out of rectangular or other desired geometric shape. The slits and break out openings are sized to provide electromagnetic interference shielding. Also, the break portions are of a length which is approximately no greater than the thickness of the wall and are positioned to facilitate removal of the knock-out without deforming the wall and without leaving burrs in the knock-out opening.
U.S. Pat. No. 5,058,414 (Fred M. Hayes) the entire disclosure of which is incorporated herein by reference discloses a method of removing electrical box knock-outs which includes utilizing a hand tool which has elongated jaws, one with a ring and the other with a punch directed toward the center of the ring. By positioning the jaws on opposite sides of a box wall and closing the jaws, the punch and ring close on the knock-out and the punch deflects the knock-out through the ring so that the knock-out can then be twisted and removed by needle nose pliers, for example.
U.S. Pat. No. 5,462,169 (Douglas M. Dygert, et al.) the entire disclosure of which is incorporated herein by reference discloses a novel composite package including a rectangular, outer, paperboard box and a rectangular, thin-walled, lightweight, molded plastic bottle within the box suitable for use with hazardous liquid materials. At its upper end, the bottle has a pouring spout adjacent its front wall and an elongated hollow handle extending from the pouring spout to the rear wall and defining an air passageway between the pouring spout and the liquid containing chamber within the bottle. A vent spout is provided at the rear of the hollow handle. The top flap assembly of the box includes knock-out flap portions which overlie the pouring spout, the hollow handle, and the vent spout, those knock-out portions being removable when it is desirable to pour liquid from the package. A pair of paperboard reinforcing pads are placed between the underside of the top flap assembly and the top of the plastic bottle, the pads enhancing the crush resistance and impact strength of the package.
Thus there is a need for a master or a universal-type electrical insulation barrier having knock-out features for a switchgear.
This invention overcomes the problems of the prior art and provides a novel method and an apparatus for switchgear assemblies by providing a master or universal-type electrical insulation barrier having knock-out features for a switchgear.

PURPOSES AND SUMMARY OF THE INVENTION

The invention is a novel method and an apparatus for switchgear assemblies having an electrical insulation barrier having knock-out features.
Therefore, one purpose of this invention is to provide a novel method and an apparatus for switchgear assemblies by providing an electrical insulation barrier having knock-out features.
Another purpose of this invention is to provide a master or universal-type electrical insulation barrier having knock-out features.
Yet another purpose of this invention is to use a brittle material to provide a master or universal-type electrical insulation barrier having knock-out features.
Still yet another purpose of this invention is to use a thermoset insulating material, or a glass reinforced polyester laminate (GPO-2 or GPO-3) material to provide a master or universal-type electrical insulation barrier having knock-out features.
Therefore, in one aspect this invention comprises an insulation barrier for a switchgear, comprising an insulation panel, wherein at least a portion of the insulation panel is secured to the switchgear, and wherein the insulation panel has at least one knock-out feature.
In another aspect this invention comprises an insulation barrier for a switchgear, comprising an insulation panel, wherein the insulation panel has at least one knock-out feature, and wherein at least one of the at least one knock-out feature is removed to provide access to at least one component of the switchgear, and thereby forms the insulation barrier for the switchgear.

BRIEF DESCRIPTION OF THE DRAWINGS

Although the scope of the present invention is much broader than any particular embodiment, a detailed description of the preferred embodiment follows together with drawings. The features of the invention that are novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The drawings are for illustration purposes only and are not drawn to scale. Furthermore, like numbers represent like features in the drawings. The invention itself, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:

FIG. 1 is a novel switchgear assembly which is used to illustrate an embodiment of the present invention.

FIG. 2 illustrates a rear view of the novel switchgear assembly with housing covers removed to reveal a section bus compartment which is used to illustrate an embodiment of the present invention.

FIG. 3 illustrates a rear view of the novel switchgear assembly with the vertical wall insulation barrier removed to show at least one vertical bus to further illustrate the invention.

FIG. 4 illustrates a vertical wall insulation barrier.

FIG. 5 illustrates a vertical wall insulation barrier having knock-out features which is used to illustrate an embodiment of the present invention.

DETAILED DESCRIPTION

This invention provides a method and apparatus for an improved switchgear apparatus. This invention further provides an electrical insulation barrier having knock-out features for a switchgear. This invention also provides a master or universal-type electrical insulation barrier having knock-out features for a switchgear apparatus.
The rear barrier in a switchgear apparatus is used in conjunction with inner isolation barriers and side-wall barriers to insulate the vertical bus in a switchgear section. The power connectors are attached to the vertical buses and the horizontal buses. Short horizontal branch buses are typically provided where they run from the circuit breakers, which are in the front through the vertical bus and into the rear of the section. Therefore, the rear barrier must be provided with a multitude of openings for the power connectors and horizontal branch buses. Openings are also provided in the rear barrier, such as, for example, for screws, other hardware, to name a few.
The location of the horizontal main bus and the breakers in the section determines the number of the openings or slots requirements for the power connectors and the horizontal branch buses in the rear insulation barriers. To satisfy all the different configurations that might be needed at these locations one has to have many different variations of these vertical wall insulation barriers. With this invention one can now consolidate these rear barriers by making knock-out features for power connectors and horizontal branch busses in a master part. These knocked-out features can be popped or pried out in various combinations for the power connectors and for the placement of the horizontal branch busses. With this invention instead of assembling multiple parts in the assembly line and having them in the field one can now have a lesser number of master parts which can be adapted to the desired configuration either during assembly or in the field. With this invention having a master part saves time on fabrication and as well as it reduces time during assembly as well as repairs in the field.
As stated earlier that the master part contains a multitude of knock-out features and can be shaped to fit various locations during assembly of the switchgear. Additionally, an assembly technician can create the correct rear insulation barrier for the situation as they encounter. For example, the assembly technician can determine where openings are required in the rear barrier by observing the locations of the intersecting parts. Then all they have to do next is to remove the knock-out feature to create the openings.
This invention applies to fully enclosed shapes, shapes that join with the edge of part to create a notch, knock-outs within knock-outs, to name a few. Also, various different designs and shapes can be employed for the knock-out feature itself. A knock-out when left in its original location or place means that there is no need for an opening at that location. The slits or weakened area around the perimeter of the knock-out are sufficiently small to provide a proper electrical barrier.
With this invention one gets a master electrical insulation barrier, such as, a glass polyester barrier, which can be used in multiple application by using the knock-out features in the rear barrier.
It should be appreciated that the knock-outs in the insulation barriers should be used or provided where slots or openings are needed for the intersecting parts.
FIG. 1 is a novel switchgear assembly 23, which is used to illustrate an embodiment of the present invention. As shown in FIG. 1, the switchgear assembly 23, comprises of a plurality of switchgear sections 40. For some applications the switchgear section 40, may be assembled on at least one mounting base or sill channel 41. Each switchgear section 40, can contain up to six compartments 17, such as, a circuit breaker compartment 17, containing one circuit breaker 18, per each circuit breaker compartment 17. The switchgear assembly 23, further comprises of an enclosure or housing 10, which has a bottom or base 11, a top panel or cover 12, a first side panel or cover or wall 3, a second side panel or cover or wall 14, a back panel or cover 15, and a frontal panel or cover or assembly 16. For some applications the bottom or base 11, may have a bottom panel 11 or a base panel 11 or a floor plate 11. One or more of the compartments 17, may also contain electronic devices or electronic device modules 19. In some situations the breaker compartment may contain an electronic device module 19, instead of a circuit breaker 18. The switchgear assembly 23, is preferably provided with at least one ventilation means or structure 45, in the top panel or cover 12.
FIG. 2 illustrates a rear view of the novel switchgear assembly 23, with housing covers removed to reveal a section bus compartment 20, which is used to illustrate an embodiment of the present invention. The section bus compartment 20, is preferably enclosed by at least one insulation side barrier 22, and a vertical wall insulation barrier 24. The section bus compartment 20, may also have one or more short horizontal branch bus 21, that extend through insulated openings 26, at least one horizontal main bus 28, and at least one power connector 25.
FIG. 3 illustrates a rear view of the novel switchgear assembly 23, with the vertical wall insulation barrier 24, removed to show at least one vertical bus 29, to further illustrate the invention. Also shown is an inner phase isolation barrier 27, that separate the section bus phases into at least one chamber, and preferably three separate chambers.
FIG. 4 illustrates a vertical wall insulation barrier 24. The vertical wall insulation barrier 24, comprises an upper vertical wall insulation barrier 42, a middle vertical wall insulation barrier 44, and a lower vertical wall insulation barrier 46. The vertical wall insulation barrier 24, may have one or more slots or openings 47, for horizontal branch buss 21, at least one slot or opening 49, for at least one power connectors 25, and at least one hardware hole, or opening or vent 48. The vertical wall insulation barrier 24, could be comprise of a single panel or it could comprise of several panels, such as, for example, the upper vertical wall insulation barrier 42, the middle vertical wall insulation barrier 44, and the lower vertical wall insulation barrier 46.
FIG. 5 illustrates a vertical wall insulation barrier or panel 55, having knock-out features, which is used to illustrate an embodiment of the present invention. The vertical wall insulation barrier 55, comprises of an upper vertical wall insulation barrier 52, a middle vertical wall insulation barrier 54, and a lower vertical wall insulation barrier 56. The vertical wall insulation barrier 55, has at least one knock-out feature 57, for a horizontal branch buss 28, and at least one knock-out feature 59, for at least one power connector 25. The vertical wall insulation barrier 55, could be comprise of a single panel or it could comprise of several panels, such as, for example, the upper vertical wall insulation barrier 52, the middle vertical wall insulation barrier 54, and the lower vertical wall insulation barrier 56. As one can see in FIG. 5, that the insulation barrier or panel 55, has a plurality of knock-out features 57 and 59, and these knock-out features 57 and 59, can be knocked-out as needed which gives this single insulation barrier or panel 55, a large number of possible design configurations, whereas in the past many single use rear barriers were needed with pre-determined openings for each application.
As stated earlier that these knock-out features of this invention can be knocked-out or removed as needed. For example, the same upper vertical wall insulation barrier 52, can be used when there is a need to have an opening for power connector 25, and the slot or slots for the power connector 25, can be simple created by knocking-out or removing the knock-out feature 59, for the power connector 25. Similarly, the same upper vertical wall insulation barrier 52, can be used when there is a need to have an opening for at least one horizontal branch buss 21, and where the slot or slots for the horizontal branch buss 21, can be created simply by knocking-out the knock-out feature 57, for the horizontal branch buss 21. Thus for some applications the same upper vertical wall insulation barrier 52, can be used for both the power connector 25, and the horizontal branch buss 21, by knocking-out both the knock-out features 57 and 59. Thus with one vertical wall insulation barrier 55, one can have a master part or a universal part that can be used in multiple scenarios and applications.
The insulation barrier or panel 55, is preferably selected from a group comprising of a brittle material, a thermoset insulating material, a glass reinforced polyester laminate material, to name a few. A brittle material is defined as a material that is liable to fracture when subjected to stress, i.e., it has a little tendency to deform (or strain) before fracture. A brittle material usually fails in tension rather than shear and there is little or no evidence of plastic deformation before failure. When a brittle material has reached the limits of its strength, it usually either deforms or fractures.
The inventive knock-out features in the insulation barrier 55, could be made for a horizontal branch bus, a power connector, to name a few. The inventive knock-out features could be formed by a plurality of serrations around the periphery of the knock-out feature, or they could be formed by a weakened area around the periphery of the knock-out feature. These knock-out features could also be formed by having a notch around the periphery of the knock-out feature or could be formed by a plurality of discrete connections around the periphery of the knock-out feature and the insulation barrier 55. The shape for the knock-out feature could be selected from a group comprising a triangular shape, a rectangular shape, a circular shape, a polygonal shape, an odd shape, to name a few.
While the present invention has been particularly described in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.

Claims

1. An insulation barrier for a switchgear, comprising an insulation panel, wherein at least a portion of said insulation panel is secured to said switchgear, and wherein said insulation panel has at least one knock-out feature.

2. The insulation barrier for a switchgear of claim 1, wherein material for said insulation panel is selected from a group consisting of a brittle material, a thermoset insulating material, and a glass reinforced polyester laminate material.

3. The insulation barrier for a switchgear of claim 1, wherein said knock-out feature is selected from a group consisting of a knock-out for a horizontal branch bus, and a knock-out for a power connector.

4. The insulation barrier for a switchgear of claim 1, wherein said knock-out feature is formed by a plurality of serrations around the periphery of said knock-out feature.

5. The insulation barrier for a switchgear of claim 1, wherein said knock-out feature is formed by a weakened area around the periphery of said knock-out feature.

6. The insulation barrier for a switchgear of claim 1, wherein said knock-out feature is formed by a notch around the periphery of said knock-out feature.

7. The insulation barrier for a switchgear of claim 1, wherein said knock-out feature is formed by a plurality of discrete connections around the periphery of said knock-out feature and said insulation barrier.

8. The insulation barrier for a switchgear of claim 1, wherein shape for said knock-out feature is selected from a group consisting of a triangular shape, a rectangular shape, a circular shape, a polygonal shape, and an odd shape.

9. The insulation barrier for a switchgear of claim 1, wherein said switchgear has at least one equipment compartment.

10. The insulation barrier for a switchgear of claim 1, wherein said switchgear has at least one equipment compartment, and wherein said equipment compartment accommodates at least one equipment selected from a group consisting of a circuit breaker, an electronic device, and an electronic module.

11. The insulation barrier for a switchgear of claim 1, wherein said switchgear has at least one vent opening.

12. The insulation barrier for a switchgear of claim 1, wherein said switchgear has at least one vent opening, and wherein said at least one vent opening is located on the upper surface of said switchgear.

13. An insulation barrier for a switchgear, comprising an insulation panel, wherein said insulation panel has at least one knock-out feature, and wherein at least one of said at least one knock-out feature is removed to provide access to at least one component of said switchgear, and thereby forming said insulation barrier for said switchgear.

14. The insulation barrier for a switchgear of claim 13, wherein material for said insulation panel is selected from a group consisting of a brittle material, a thermoset insulating material, and a glass reinforced polyester laminate material.

15. The insulation barrier for a switchgear of claim 13, wherein said knock-out feature is selected from a group consisting of a knock-out for a horizontal branch bus, and a knock-out for a power connector.

16. The insulation barrier for a switchgear of claim 13, wherein said knock-out feature is formed by a plurality of serrations around the periphery of said knock-out feature.

17. The insulation barrier for a switchgear of claim 13, wherein said knock-out feature is formed by a weakened area around the periphery of said knock-out feature.

18. The insulation barrier for a switchgear of claim 13, wherein said knock-out feature is formed by a notch around the periphery of said knock-out feature.

19. The insulation barrier for a switchgear of claim 13, wherein said knock-out feature is formed by a plurality of discrete connections around the periphery of said knock-out feature and said insulation barrier.

20. The insulation barrier for a switchgear of claim 13, wherein shape for said knock-out feature is selected from a group consisting of a triangular shape, a rectangular shape, a circular shape, a polygonal shape, and an odd shape.