Patent ID: 12206223

The reference symbols used in the drawings, and their meanings, are listed in summary form in the list of reference symbols. In principle, identical parts are provided with the same reference symbols in the figures.

DETAILED DESCRIPTION

In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings.

As used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. The terms “optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

As used herein, the term “switchgear” refers to an electrical enclosure that houses electrical disconnect switches, (such as fused switches or circuit breakers). The switchgear includes a busbar assembly to carry electrical current from an external, main power source to downstream switches. The busbar assembly includes separate copper or aluminum laminations for each phase and additional laminations for a neutral to form an electrical circuit. Opening and closing of the phases is controlled by a main electrical disconnect switch (referred to herein as a “main”) which has a line-side connection to the upstream external power source (such as a service entrance connection) and a load-side connection to downstream electrical disconnect switches (referred to herein as “branch switches”) positioned within the switchgear enclosure. Branch switches downstream from the main can provide power to electrical equipment and components of an electrical system connected to the branch switches by way of cable conduit or busway extending from the switchgear enclosure. As used herein, the term “line-side connection” shall refer to an upstream connection of the element or component and “load-side connection” shall refer to a downstream connection of the element or component.

As used herein, the term “hot” refers to an electrical element, such as a switch, cable, busway or termination point of the present disclosure which has a voltage potential that deviates from ground. The term “cold” refers to an electrical element of the present disclosure that does not have a voltage potential. The term “closed” refers to an electrical circuit, a system, a component, feature, or element, such as a switch of the present disclosure in which electricity passes through and flows uninterrupted. The term “open” refers to a describes an electrical circuit, a system, a component, feature, or element, such as a switch of the present disclosure in which continuity is broken such that current is interrupted and does not flow. An open circuit is cold, and a closed circuit is hot.

Embodiments of the present disclosure are directed to an electrical distribution enclosure having compartmentalized and isolated power connection terminals. The electrical distribution enclosure can be integrated with a switchgear system, or the electrical distribution enclosure can be a standalone cabinet. An electrically insulated panel separates the enclosure into an access portion of the enclosure and a load portion, and the access portion is further separated by at least one electrically insulated compartment. Each electrically insulated compartment has a front-accessible neutral connection and a front-accessible phase connection such that a user can connect downstream components to the front connections of the compartment without being exposed to hot connections of adjacent compartments. Each electrically insulated compartment also has a phase connection extending into the load portion which is not accessible by the user when connecting downstream components to the front connections. During initial installation of the electrical distribution enclosure, the rear phase connection and the neutral of each compartment is connected to a corresponding branch switch. The branch switch can selectively be opened such that the front-accessible phase connection is cold, and the user can subsequently connect the front-accessible phase connection to downstream components without having to completely de-energize the switchgear.

FIGS.1and2illustrate schematic front views of an exemplary switchgear enclosure100.FIG.1illustrates an electrical distribution enclosure200integral to the switchgear enclosure100, andFIG.2illustrates the electrical distribution enclosure200as a standalone cabinet or enclosure. The terms “cabinet” and “enclosure” shall be used interchangeably in the present disclosure. In the exemplary embodiment, switchgear enclosure100is a low-voltage switchgear100. The term “low-voltage” refers to switchgear operating at voltages lower than 2 kV.

The switchgear enclosure100has a rectangular structure defining an interior space102within. The interior space102includes support structures for maintaining rigidity of the enclosure100and further support structures for positioning electrical switches (122,132) within the interior space102. The electrical switches (122,132) are operable from a front104of the switchgear enclosure100. However, in other embodiments, the switchgear100may have an alternative orientation, and is not intended to be limited to the orientation shown inFIG.1. The electrical switches (122,132) in the illustrated embodiments are three-phase power switches having three poles, however in other embodiments, the electrical switches (122,132) can be single pole, double pole, or quad pole switches.

The electrical switches (122,132) include a main switch122and a plurality of branch switches132electrically connected to the main switch122by a busbar assembly (not shown). In some embodiments, a dual feed power distribution unit (PDU) is electrically connected to the branch switches132such that two incoming sources of power are tied together. The PDU can transfer between the two incoming sources, or distribute both incoming sources to the branch switches132. The main switch122has a line-side connection (not shown) which receives power from a utility power main or an upstream switch and a load-side connection (not shown) which branches out by the busbar assembly and electrically connects to all of the plurality of branch switches132located within the switchgear100. Likewise, each of the plurality of branch switches132have a line-side connection (not shown) electrically connected to the main switch122and a load-side connection134. Opening the main switch122will cut power to all of the plurality of branch switches132, and opening and closing of the plurality of branch switches132will cut power to a downstream electrical system attributed to each of the plurality of branch switches132. The load-side connection134of the each of the plurality of branch switches132can electrically connected to a corresponding downstream electrical system by power cables136(as shown inFIG.1) or by a busway assembly138(as shown inFIG.2).

In some embodiments, the main switch122is positioned within a main compartment110and at least some of the plurality of branch switches132are positioned within a sub-compartment112adjacent to the main compartment110. Branch switches132of a larger power rating may not fit within a single sub-compartment112, and thus, are separated into additional sub-compartments112positioned adjacent to one another. The busbar assembly can extend across adjacent sub-compartments through either an upper portion114or a lower portion116of the sub-compartment112to connect to the plurality of branch switches132of the adjacent sub-compartment112. Additional sub-compartments can be positioned to the either side of the main compartment110. As shown inFIGS.1and2, the sub-compartment112is adjacent to the main compartment110, however in other embodiments, switchgear100may have an alternative configuration, and is not intended to be limited to the orientation shown inFIGS.1and2.

A neutral busbar142extends from the external power source across the switchgear enclosure100to a side edge106of the switchgear enclosure100for connection to adjacent cabinets. In the illustrated embodiment, the side edge106is a right-side edge106, however in other embodiments, switchgear100may have an alternative orientation, and is not intended to be limited to the orientation shown inFIGS.1and2. In some embodiments, opening and closing of the neutral busbar142is controlled by electrical switches (122,132). In some embodiments, the neutral busbar142is independent from the electrical switches (122,132) and extends to the side edge106of the switchgear enclosure100without any associated disconnect points or means. The neutral busbar142includes an L-shaped termination plate144at the side edge106of the switchgear enclosure100to connect to a corresponding neutral busbar of an adjacent cabinet or enclosure. By way of example, the termination plate144can connect to a corresponding termination plate272of a neutral busbar270of the electrical distribution enclosure200as shown inFIG.4In embodiments where the electrical distribution enclosure200is connected to the plurality of branch switches132by the busway assembly138, a neutral bus can be included with the busway assembly138to transfer the neutral along with the phases to the electrical distribution enclosure200.

The main switch122, plurality of branch switches132and the busbar assembly connecting the switches are pre-assembled before shipment to a jobsite and the user can terminate the utility power main to the main switch122. The user can also terminate the power cables136to the plurality of branch switches132prior to energizing the main switch122. Under national and local electrical codes, these terminations must occur when the system is cold and the switchgear enclosure100is de-energized to prevent a user from coming into contact with a hot connection. To terminate the utility power to the main switch122, a discrete switch feeding the main switch122must be opened. Likewise, to terminate a discrete system to the load-side connection134of any one of the plurality of branch switches132, the user must open the main switch122, thereby de-energizing all of the plurality of branch switches132and cutting power to the downstream electrical systems of all of the plurality of branch switches132. Stated differently, connecting cables to a load-side connection134of a single branch switch132requires opening the main switch122because all termination points of the branch switches132are within the same interior space102.

FIGS.3-8illustrate the electrical distribution enclosure200having compartmentalized and isolated power connection terminals such that a user can terminate downstream electrical components for a single branch switch without having to de-energize the entire switchgear100.FIGS.3,7and8illustrate perspective front views of the electrical distribution enclosure200showing the exterior of the electrical distribution enclosure200,FIG.4illustrates a front view of the electrical distribution enclosure200,FIG.5illustrates a side view of the second side210andFIG.6illustrates a side view of the first side208.

As shown inFIG.3, the electrical distribution enclosure200is defined by a rectangular frame202having a front204and a rear206defining a depth D, a first side208and a second side210defining a width W. The depth D is generally equal to a depth of the switchgear enclosure100, and the first side208is positioned adjacent to the side edge106of the switchgear enclosure100. As best shown inFIG.1, the width W of the electrical distribution enclosure200can vary depending on the size, amperage, and number of plurality of branch switches132corresponding to the isolated power connection terminals as explained in further detail below.

The electrical distribution enclosure200includes an electrically insulated panel220extending from the first side208to the second side210separating the interior space of the electrical distribution enclosure200into an access portion222of the enclosure200and a load portion224of the enclosure200. In the illustrated embodiment, the access portion222is positioned in the front204of the electrical distribution enclosure200and the load portion224is positioned at the rear206of the of the electrical distribution enclosure200. However, in other embodiments, electrical distribution enclosure200may have an alternative orientation, and is not intended to be limited to the orientation shown inFIG.3. Generally, where the electrical switches (122,132) of the switchgear enclosure100are operable from the front104, the access portion222of the electrical distribution enclosure200is also in the front204of the electrical distribution enclosure200. The electrically insulated panel220is positioned a distance Di from the rear206of the frame202. The access portion222is further separated by at least one electrically insulated compartment panel240extending from the electrically insulated panel220to the front204of the frame202and defining two or more compartments250. As shown inFIGS.3and4, in some embodiments, the electrical distribution enclosure200includes three electrically insulated compartment panels240defining four compartments250. As shown inFIG.1, the electrical distribution enclosure200can include any number of compartments250. In some embodiments, the electrically insulated compartment panel240extends the entire height of the frame202. In some embodiments, each compartment250includes an associated removable front panel280configured to provide access to the respective associated compartment250. In some embodiments, the front204of each compartment250includes an associated removable lower panel282, removable middle panel284and removable upper panel286configured to provide access to the compartment250. Each compartment also includes a bottom access panel288covering a bottom access opening290and a top access panel292(as shown inFIG.7) for covering a top access opening294for top-fed power cable configurations and bottom-fed power cable configurations respectively.

As shown inFIGS.3through5, the electrically insulated panel220includes an opening226for each compartment250. The opening226of each compartment250is positioned such that the rear phase connection254of each compartment250is accessible from the rear load portion224through the opening226. For each phase, the compartment250includes a front-accessible phase connection258such that a user can terminate cables of a discrete system to front power connection terminals260by opening the removable front panel280(ofFIG.2) and feeding the power cables of the discrete system to the front-accessible phase connection258. In some embodiments, the front-accessible phase connection258include lug termination points259configured to receive and secure individual power cables (not shown) of the discrete system.

A neutral busbar270extends across each of the two or more compartments250and is positioned in the front access portion222of the electrical distribution enclosure200. For each compartment250, a front-accessible neutral connection256is accessible from the front204. Similar to the phase connections, the neutral busbar270includes neutral power connection terminals274for each compartment250. In some embodiments, the neutral power connection terminals274include lug termination points275configured to receive and secure individual power cables (not shown) for the neutral of the discrete system. As best shown inFIG.4, the neutral busbar270includes a termination plate272positioned at the first side208of the frame202. When the switchgear enclosure100is adjacent to the electrical distribution enclosure200, the neutral termination plate144of the switchgear enclosure100can be electrically connected to the neutral termination plate272of the electrical distribution enclosure200. In some embodiments, the termination plate144of the switchgear enclosure100and the corresponding termination plate272of the electrical distribution enclosure200are L-shaped bus plates that can be bolted or otherwise fastened together. The front power connection terminals260and the neutral power connection terminals274for each compartment250are configured for top-fed cable entry. In some embodiments, one or more of the compartments250are configured for bottom-fed cable entry.

As best shown inFIGS.5and6, power cables136from a branch switch132are terminated at the corresponding rear phase connection254of each compartment for each phase. The power cables136extend from each branch switch132of the plurality of branch switches132(illustrated inFIG.5as an upstream power cable end137) and terminate at the rear phase connection254(as shown inFIG.5). In the illustrated embodiments, each rear phase connection254includes lug termination points255for receiving the power cables136. In embodiments where the electrical distribution enclosure200is adjacent and integral to the switchgear enclosure100(as shown inFIG.1), the power cables136pass from the front104of the switchgear enclosure100to the rear206(and in particular the load portion224) of the electrical distribution enclosure200to terminate at the lug termination points255for each rear phase connection254. In embodiments where the electrical distribution enclosure200is positioned a distance from the switchgear enclosure100, the power cables136can be top-fed or bottom fed-into the load portion224to connect to the lug termination points255for each rear phase connection254. The power cables136can be enclosed within a cable conduit in accordance with national and local electrical codes. In some embodiments, the rear phase connection254can include bus plates (not shown) for terminating busbar from the branch switches132.

As shown inFIG.7, a removable dead front panel222covers the removable front panels280ofFIG.2, and removable side panels (282,284,286) ofFIG.2cover the second side210of the frame202and top access panel292cover the top access opening294for each of the two or more compartments250. In embodiments where the electrical distribution enclosure200is positioned a distance from the switchgear enclosure100, side panels also cover the first side208of the frame202. The side panels214can be bolted to the frame. In some embodiments, the side panels214include a tab and latch system whereby the user can pull a latch to remove an entire panel.

As shown inFIGS.3and6, in some embodiments, a movable cable support member278is positioned within the load portion224of the electrical distribution enclosure200. The cable support member278is affixed to the top of the frame202and extends at least to the openings226of the electrically insulated panel220. In some embodiments, the cable support member278is positioned a distance Ls from the electrically insulated panel220. The cable support member278is configured to support the power cables136. The distance Ls can be selected depending on the gauge and bend radius of the power cables136and the cable support member278.

As shown inFIGS.8and9, the electrical distribution enclosure200can include horizontal electrically insulated panel276separating the access portion222into a top portion and a bottom portion having compartments250. The compartments250above the horizontal electrically insulated panel276include front-accessible phase connections254in a top-fed configuration and compartments250include front-accessible phase connections258in a bottom-fed configuration.

In operation, each branch switch of the plurality of branch switches132is electrically connected to a corresponding rear phase connection254of each compartment of the two or more compartments250for each phase of the branch switch132. As shown inFIGS.1,5and6, the power cables136are electrically connected to the load-side connection134of the plurality of branch switches132and to the rear phase connections254of each of the two or more compartments250. Connection of the power cables136can occur at the factory, or the cables can be connected at the jobsite by removing the side panels222(ofFIG.5) prior to energizing the switchgear enclosure100(i.e., prior to closing the main switch122). To install a power cable of a discrete system into one of the two or more compartments s250, the user opens the corresponding branch switch of the plurality of branch switches132. Because each of the two or more compartments250is electrically isolated from adjacent compartments250, the user opens one of the removable front panels280. Auxiliary components such as such as controls, relays, communication devices, indicators, and the like can be installed onto the front-accessible phase connection258in the same manner.

Each compartment250can vary in size depending on the amperage rating of the corresponding branch switch132. By way of example, a branch switch132of a higher amperage will require a wider compartment250due to heat generation of the components within. In general, in order for the compartment250to be considered properly heat rated for operation, the heat generated in each of the circuit components must not cause a temperature of the component to exceed a predetermined temperature rise limit, which may be governed or otherwise determined by regulatory standards.

Electrically insulating materials of the electrically insulated panel220, at least one electrically insulated compartment panel240and the horizontal electrically insulated panel276can include, for example, an epoxy or fiberglass sheet. In some embodiments, the electrically insulated panel220, at least one electrically insulated compartment panel240and the horizontal electrically insulated panel276are made of fiberglass reinforced thermoset polyester material (Glastic), Vulcanized paper (fishpaper), Nomex or Formex.

A method of connecting a downstream branch connection to an electrical branch switch is described. The method includes opening the electrical switch, the electrical switch positioned within a first enclosure, the electrical switch having at least one load connection, the first enclosure having a neutral connection; connecting one or more cables to a front-accessible neutral connection of a second enclosure, the second enclosure comprising an electrically insulated panel defining an access portion and a load portion, at least one electrically insulated compartment panel positioned within the access portion, the at least one electrically insulated compartment panel extending from the electrically insulated panel defining two or more compartments, the two or more compartments having the front-accessible neutral connection, at least one front-accessible phase connection and at least one rear phase connection; and, connecting one or more cables to at least one front-accessible phase connection, the at least one front-accessible phase connection coupled to the at least one rear phase connection, the at least one rear phase connection connected to the at least one load connection of the electrical switch.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from the study of the drawings, the disclosure, and the appended claims. In the claims the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the claims.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.

The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.