Title:
Strap support barrier
Kind Code:
A1


Abstract:
A strap support barrier for an electrical cabinet, with the electrical cabinet including vertical and horizontal bus bars. The strap support barrier includes a planar member. A mounting portion coupled to the planar member. A pair of spacing portions coupled to the planar member, wherein the planar member, mounting portion and spacing portion are configured to provide electrical clearances for the bus bars. The strap support barrier can also include orifices defined on the planar member to facilitate mounting of a strap to at least one vertical bus bar. Another embodiment of the strap support barrier includes at least one guide pin coupled to the planar member and configured to align the straps with the vertical bus bar.



Inventors:
Packard III, Duan E. (Fort Worth, TX, US)
Melane, Marcus L. (Irving, TX, US)
Application Number:
10/969478
Publication Date:
04/20/2006
Filing Date:
10/20/2004
Assignee:
Siemens Energy & Automation, Inc.
Primary Class:
International Classes:
A47B81/00; A47B97/00
View Patent Images:
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Primary Examiner:
AYRES, TIMOTHY MICHAEL
Attorney, Agent or Firm:
FOLEY & LARDNER LLP (WASHINGTON, DC, US)
Claims:
What is claimed is:

1. A strap support barrier for an electrical cabinet, with the electrical cabinet including vertical and horizontal bus bars, the strap support barrier comprising: a planar member; a mounting portion coupled to the planar member; and a pair of spacing portions coupled to the planar member, wherein the planar member, mounting portion, and spacing portion are configured to provide electrical clearances for the bus bars.

2. The strap support barrier of claim 1, wherein the mounting portion and spacing portion are integral with the planar member as a single piece.

3. The strap support barrier of claim 1, including orifices defined on the planar member to facilitate mounting of a strap to at least one vertical bus bar.

4. The strap support barrier of claim 3, including at least one guide pin coupled to the planar member and configured to align and secure the straps with the vertical bus bar.

5. The strap support barrier of claim 1, wherein the planar member is configured to support electrical equipment.

6. The strap support barrier of claim 1, wherein the planar member, mounting portion and spacing portions are non-metallic and non-conductive.

7. An electrical cabinet for electrical equipment comprising: a housing; at least one pair of mounting rails mounted in the housing; at least one vertical bus bar mounted in the housing; and a strap support barrier coupled to the mounting rails, the strap support barrier comprising: a planar member; a mounting portion coupled to the planar member; and a pair of spacing portions coupled to the planar member, wherein the planar member, mounting portion, and spacing portion are configured to provide electrical clearances for the bus bars.

8. The electrical cabinet of claim 7, wherein the mounting portion and spacing portion are integral with the planar member as a single piece.

9. The electrical cabinet of claim 7, including orifices defined on the planar member to facilitate mounting of a strap to at least one vertical bus bar.

10. The electrical cabinet of claim 9, including at least one guide pin coupled to the planar member and configured to align and secure the straps with the vertical bus bar.

11. The electrical cabinet of claim 7, wherein the planar member is configured to support electrical equipment.

12. The electrical cabinet of claim 7, wherein the electrical cabinet is configured as one of a panelboard and a switchboard.

13. The electrical cabinet of claim 7, wherein the planar member, mounting portion and spacing portion are non-metallic and non-conductive.

14. An electrical equipment mounting kit for use in an electric cabinet, the cabinet including a plurality of vertical bus bars and at least two mounting rails, the mounting kit comprising: a planar member configured to couple to the mounting rails, with the planar member defining an orifice aligned with each vertical bus bar, a spacing portion coupled to the planar member separating the orifices, and a bus strap configured to couple to a vertical bus bar through one of the orifices, wherein the planar member and spacing portion maintain pre-selected distances between the bus strap and vertical bus bars.

15. The kit of claim 1, wherein the spacing portion is integral with the planar member as a single piece.

16. The kit of claim 14, including at least one guide pin coupled to the planar member and configured to align and secure the strap with the vertical bus bar.

17. The kit of claim 14, wherein the planar member is configured to support electrical equipment.

18. The kit of claim 14, wherein the planar member, mounting portion and spacing portion are non-metallic and non-conductive.

Description:

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of electrical switchboards and panel boards and more particularly to a device that facilitates spacing, alignment, and mounting of electrical equipment in switchboard and panel board cabinets.

Distribution panel assemblies such as switchboards and panel boards are general terms which cover metal enclosures, housing switching and interrupting devices such as fuses, circuit breakers, associated controls, instrumentation and metering devices. Such assemblies typically include associated supporting structures, interconnections and bus bars used for the distribution of electrical power. Voltage in switchboards operate at voltages up to 600 volts and with continuous currents up to 5000 amps or higher. Such devices are also designed to withstand short circuit currents ranging up to 200,000 amps (3 phase rms symmetrical).

Typical distribution panel equipment is composed of a lineup of several metal enclosures (hereinafter referred to as sections). Each section may have several circuit breakers stacked one above the other vertically in the front of the section. Each section has a vertical or sectional bus which supplies current to the breakers within the section via short horizontal branch busses or straps. The vertical bus bars in each section are supplied with current by a horizontal main bus bar that runs through the lineup of sections. A typical arrangement includes bus bars for each electrical phase of a multi-phase system which may include three power phases and a neutral.

The bus straps typically are directly attached to the vertical bus sections. If the straps are large, they may require additional support. Standards organizations and other electrical codes require that minimum over-surface and through-air clearances (hereinafter referred to as “electrical clearance”) be maintained between the straps and all other conductive components in a switchgear assembly. In a typical configuration, the circuit breakers that attach to the bus straps may wholly rely on the bus strap for the circuit breaker mounting location and support or may require an additional device or structure for attaching to the mounting rails of the cabinet.

Thus there is a need for a strap support barrier for an electrical cabinet that provides spacing, alignment and mounting of electrical equipment, such as circuit breakers. There is also a need for an apparatus that will provide support for circuit breakers and provide an isolation of connecting bus straps from each other to comply with electric clearance requirements.

SUMMARY OF THE INVENTION

There is provided a strap support barrier for an electrical cabinet, with the electrical cabinet including vertical and horizontal bus bars. The strap support barrier includes a planar member. A mounting portion coupled to the planar member. A pair of spacing portions coupled to the planar member, wherein the planar member, mounting portion and spacing portion are configured to provide electrical clearances for the bus bars. The strap support barrier can also include orifices defined on the planar member to facilitate mounting of a strap to at least one vertical bus bar. Another embodiment of the strap support barrier includes at least one guide pin coupled to the planar member and configured to align the straps with the vertical bus bar.

There is also provided an electrical cabinet for electrical equipment. The electrical cabinet includes a housing including at least one pair of mounting rails mounted in the housing. At least one vertical bus bar mounted in the housing and a strap support barrier coupled to the mounting rails. The strap support barrier comprises a planar member, a mounting portion coupled to the planar member, and a pair of spacing portions coupled to the planar member. The planar member, mounting portion and spacing portion are configured to provide electrical clearances for the bus bars.

There is also provided an electrical equipment mounting kit for use in an electrical cabinet. The electrical cabinet includes a plurality of vertical bus bars and at least two mounting rails. The electrical equipment mounting kit includes a planar member configured to couple to the mounting rails with the planar member defining an orifice aligned with each vertical bus bar. A spacing portion is coupled to the planar member separating the orifices. A bus strap is configured to couple to the vertical bus bar through one of the orifices. Wherein, the planar member and spacing portion maintain pre-selected distances between the bus strap and the vertical bus bars. Another embodiment of the kit includes at least one guide pin coupled to the planar member and configured to align the strap with the vertical bus bar. A planar member is configured to support electrical equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial perspective view of an electrical cabinet for electrical equipment, illustrating the housing frame members without exterior walls and including a strap support barrier.

FIG. 2 is a perspective view of an exemplary embodiment of a strap support barrier with a mounting portion, spacing portions, and planar member integral as one piece.

FIG. 3 is a perspective view of the strap support barrier illustrated in FIG. 2 coupled to mounting rails of an electrical cabinet and illustrating disposition of horizontal bus strap bars on the strap support barrier.

FIG. 4 is a perspective view of an exemplary embodiment of a strap support barrier mounted in an electrical cabinet, with electrical bus straps mounted on the barrier and coupled to vertical bus bars and an electrical circuit breaker aligned to mount on the barrier and coupled to the electrical bus straps.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Before describing the exemplary embodiments of a strap support barrier for electrical equipment in a distribution panel enclosure assembly, several comments are appropriate. Switchboard assemblies and panel board assemblies typically include vertical (section) bus bars to distribute electrical power within the assemblies. In a short circuit condition, extreme magnetic forces are created in bus bars as a result of the short circuit currents up to and including 200,000 amps symmetrical rms flowing through such bus bars. In a three phase power system (typically) as the short circuit currents flow through such bus bars, magnetic forces between adjacent bus bars tend to move such bus bars laterally (perpendicular) to the current flow. Such movement of the bus bars is typically prohibited or inhibited to avoid damage in arcing within enclosures by bus assemblies or arc barriers and equipment arrangements within the cabinet.

Referring now to the figures, FIG. 1 is an illustration of an exemplary embodiment of a panelboard 10, without the outer panels for clarity purposes and without circuit breakers, or control apparatus. However, FIG. 1 does include a base assembly of circuit breaker type electrical equipment coupled to frame members 12 of the cabinet 10 by a mounting plate system 30. FIG. 1 specifically depicts a multi-phase assembly conventionally having power phases A B and C. A neutral bus or grounding bus can also be provided. Vertical bus bars 14 extend typically throughout the height of the panelboard assembly 10 for the distribution of power within the system. The equipment can be accessed from the front side 13 of the cabinet 10.

Referring now to FIG. 2, the strap support barrier 30 includes a planar member 32 with a mounting portion 34 coupled to the planar member 32. A pair of spacing portions 36 is coupled to the planar member 32 with the planar member 32, mounting portion 34 and spacing portion 36 configured to provide electrical clearances for the bus bars.

As illustrated in FIG. 3, the strap support barrier 30 is coupled to the mounting rails 12 of the electrical cabinet 10 (See FIG. 1). The strap support barrier 30 has mounting holes 44 which facilitate mounting of the barrier 30 to the mounting rails 11.

Strap support barrier 30 includes orifices 45 defined on the planar member 32 to facilitate mounting of a bus strap 40 to at least one vertical bus bar 14. The orifices 45 can be of any suitable configuration but typically are large enough to accommodate installation of the bus straps 40 as illustrated in FIG. 3. The location of the orifices 45 correspond to the spacings of the vertical bus bars 14 for a given switchgear cabinet configuration. Guide pins 50 are provided to assist in positioning and locating the bus straps on and affixing them to the barrier 30. Additional electrical clearances and barriers are provided by the spacing portions 36 which can be configured with ribbing 38 (FIG. 2) to comply with spacing requirements.

The guide pins 50 function to locate and latch the bus straps 40. The guide pins 50 enable a quick, efficient construction of a sub-assembly, comprised of the strap support barrier 30 and bus straps 40. Such sub-assembly can be shipped as a single entity for easy user installation, retrofits, or upgrades in the field. It should be understood that other guiding configurations are contemplated, for example, stakes with a hook feature, pegs, spaced apart ridges or similar structures.

The planar member 32, mounting portion 34, and spacing portions 36 can be composed of any suitable material that is non-metallic and non-conductive electrically. The mounting portion 34 and spacing portion 36 can be integral with the planar member 32 as a single piece.

To mount electrical equipment 20 such as a circuit breaker (See FIG. 4) an electrical equipment mounting kit 60 can be used in an electrical cabinet 10. The electrical equipment mounting kit 60 includes a planar member 32 configured to couple to the mounting rails 11, with the planar member 32 defining an orifice 45 aligned with each vertical bus bar 14. A spacing portion 36 is coupled to the planar member 32 separating the orifices 45. A bus strap 40 is configured to couple to a vertical bus bar 14 through one of the orifices 45. The planar member 32, spacing portions 32 and guide pins 50 maintain a pre-selected distance between the bus strap 40 and the vertical bus bars 14.

The bus straps 40 are configured to couple directly to the electrical equipment, such as a circuit breaker 20 with the circuit breaker mounted to mounting holes 44 provided in the strap support barrier 30 with fasteners 46 (See FIG. 4). Guide pins 50 are provided on the barrier 30 to position the bus straps 40. The bus straps 40 and the strap support barrier 30 that make up the electrical equipment mounting kit 60 are configured for each sized electrical equipment 20 so that additional mounting hardware will not be necessary to secure and support the electrical equipment 20 being mounted in the electrical cabinet 10.

Thus, there is provided a strap support barrier for an electrical equipment that provides guidance, securement, and phase isolation in a single device for mounting electrical equipment in the switchgear cabinet. The foregoing description of embodiments have been presented for purposes of illustration and description. It is not intended to be exhaustive nor to be limited to the precise forms disclosed, and modifications and variations are possible in light of the above teachings and may be acquired by practice of the invention. The embodiments are chosen and described in order to explain the principles and practical application to enable one skilled in the art to utilize the strap support barrier in various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the strap support barrier be defined by the claims appended hereto and their equivalents.