The present invention relates to electrical cable connectors, such as loadbreak connectors and deadbreak connectors. More particularly, aspects described herein relate to an electrical cable connector, such as a power cable elbow or T-connector connected to electrical switchgear assembly.
High and medium voltage switch assemblies may include sub-atmospheric or vacuum type circuit interrupters, switches, or circuit breakers for use in electric power circuits and systems. Insulated vacuum bottles switches in such systems typically do not provide means for visual inspection of the contacts to confirm whether they are open (visible break) or closed. Non-vacuum bottle type switches previously used were designed to include contacts in a large gas or oil filled cabinet that allowed a glass window to be installed for viewing the contacts. However, with vacuum type switches, there is typically provided no means of directly viewing contacts in the vacuum bottles since the bottles are made of metal and ceramic non-transparent materials.
Typically, conventional insulated switches using vacuum technology are sealed inside the vacuum bottle and hidden from view. The voltage source and the load are connected to the switch, but the switch contacts are not visible. The only means for determining the status of the switch contacts is the position of a switch handle associated with the switch. If the linkage between the handle and the switch contacts is inoperative or defective, there is no positive indication that allows the operating personnel to accurately determine the position of the contacts. This can result in false readings, which can be very dangerous to anyone operating the switch or working on the lines/equipment.
The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements.
First T end 108 and second T end 110 may include a flange or elbow cuff 118 surrounding the open receiving end thereof. Body portion 102 may extend substantially axially and may include a bore extending therethrough. First and second T ends 108/110, link access opening 114, and visible open port 116 may project substantially perpendicularly from body portion 102, as illustrated in
Power cable elbow connector 100 may include an electrically conductive outer shield 120 formed from, for example, a conductive or semi-conductive peroxide-cured synthetic rubber, such as EPDM (ethylene-propylene-dienemonomer). Within shield 120, power cable elbow connector 100 may include an insulative inner housing 122, typically molded from an insulative rubber or epoxy material. Within insulative inner housing 122, power cable elbow connector 100 may include a conductive or semi-conductive insert 124 that surrounds the connection portion of power cable 106 and visible open linking assembly 112.
Conductor receiving end 104 of power cable elbow connector 100 may be configured to receive power cable 106 therein. As shown in
Rearward sealing portion 128 may include an insulative material surrounding a portion of power cable 106 about an opening of conductor receiving end 104. When conductor spade assembly 126 is positioned within conductor receiving end 104 (e.g., within insert 124), rearward sealing portion 128 may seal an opening of conductor receiving end 104 about power cable 106.
Crimp connector portion 130 may include a substantially cylindrical assembly configured to receive a center conductor 134 of power cable 106 therein. Upon insertion of center conductor 134 therein, crimp connector portion 130 may be crimped onto or otherwise secured to center conductor 134 prior to insertion of power cable 106 into conductor receiving end 104.
Spade portion 132 may be conductively coupled to crimp connector portion 130 and may extend axially therefrom. In one implementation, spade portion 132 may have substantially planar upper and lower surfaces and may include a perpendicular bore 136 extending therethrough.
As shown in
In one embodiment, visible open linking assembly 112 may include a housing 138, a rearward spade assembly 140, a cavity 142, a linking pin 144, a rack and pinion housing 145, a forward insulative portion 146, a conductive rack and pinion assembly 148, a flexible conductor 150, and a forward spade portion 152.
Housing portion 138 may be formed of, for example, insulative rubber or epoxy material and may be substantially cylindrical in one implementation. Housing portion 138 may by sized to fit within insert 122 in connector 100.
Rearward spade assembly 140 may include a conductive insert 154 maintained within housing portion 138 and a rearward spade 156. Conductive insert 154 may be formed of a conductive material, such as copper or aluminum and may be secured within a rearward portion of housing portion 138. As shown in
Rearward spade 156 may project axially from housing portion 138 in a rearward direction (e.g., toward power cable 106). In one implementation, spade 156 may be formed integrally with conductive insert 154 in a one-piece construction. Similar to spade portion 132 described above, rearward spade 156 may also have substantially planar upper and lower surfaces and may include a perpendicular bore 160 extending therethrough. As shown in
Cavity 142 may be formed around rearward spade assembly 140 and may form an air gap between conductive rearward spade assembly 140 and forward insulative portion 146. As shown in
Linking pin 144 may include an insulative tip portion 164 and a conductive portion 166 and may be secured to rack and pinion assembly 148 at an end proximate to conductive portion 166. Linking pin 144 may through cavity 142 and into cylindrical cavity 158 in rearward spade assembly 140. Linking pin 144 may be movable between an isolated or de-energized position (shown in
In the energized state, linking pin 144 may be moved (e.g., drawn further into cavity 158 in rearward spade assembly 140), such that conductive portion 166 of linking pin 144 conductively couples rearward spade assembly 140 and conductive rack and pinion assembly 148. This allows for conductive linking between cable 106 and first and second T ends 108/110.
At its forward end, linking pin 144 is conductively coupled to conductive rack and pinion assembly 148 within rack and pinion housing 145. In one embodiment, rack and pinion housing 145 may be formed of a conductive or semi-conductive material and may form a cavity that substantially surrounds rack and pinion assembly 148 and allows movement of rack and pinion assembly 148 therein.
Forward insulative portion 146 may be formed between rack and pinion housing 145 and cavity 142. As shown in
Conductive rack and pinion assembly 148 may be coupled to a forward end of linking pin 144 and may include a rack portion 170 aligned with link access opening 114. As shown in
Although an external tool 172 is shown in
Flexible conductor 150 may be secured to the forward end of rack portion 170 and may conductively couple rack portion 170 to forward spade portion 152. In one implementation flexible conductor 150 may be formed of a braided conductor (e.g., copper), a bellow, etc. Similar to spade portion 132 described above, forward spade portion 152 may extend axially from rack and pinion assembly 148 in a forward direction (e.g., toward T-ends 108/110). Forward spade portion 152 may also have substantially planar upper and lower surfaces and may include a perpendicular bore 174 extending therethrough. As shown in
Consistent with implementations described herein, insulative body 138 in visible open linking assembly 112 may include a visible open area 176 aligned with visible open port 116 in connector 100. In one implementation, visible open area 176 and visible open port 116 formed in connector shield 120, insulative inner housing 122, and semi-conductive insert 124, may be formed of a transparent or substantially transparent insulating material, such as glass, plastic, etc. In some implementations, visible open port 116 and/or visible open area 176 may be provided in only a portion of connector 100, as shown in
By forming visible open area 176 and visible open port 116 of a transparent material, a technician or worker may be able to visually confirm that linking pin 144 is in the isolated or de-energized state. For example, in one implementation, insulated tip portion 164 of linking pin 144 may be formed of a particular color, such as green. In such an implementation, insulated tip portion 164 may be provided in an area adjacent to visible open area 176 and visible open port 116 when the linking pin 144 is in the isolated state, as shown in
By providing an effective and safe mechanism for visibly identifying an open break in an electrical connector without requiring removal of switchgear components, various personnel may be more easily able to safely identify and confirm an isolated or de-energized condition in a switchgear assembly. More specifically, consistent with aspects described herein, personnel may be able to physically view the isolation element, and not merely an indicator of an open status, thereby more fully ensuring the personnel that the equipment is, in fact, de-energized. Furthermore, by providing the visible open on an elbow connector connected to the switchgear, existing or legacy switchgear may be easily retrofitted and the entire system may maintain a ground connection throughout operation.
The foregoing description of exemplary implementations provides illustration and description, but is not intended to be exhaustive or to limit the embodiments described herein to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the embodiments. For example, implementations may also be used for other devices, such as other medium or high voltage switchgear equipment, such as any 15 kV, 25 kV, 35 kV, etc., equipment, including both deadbreak-class and loadbreak-class equipment.
For example, various features have been mainly described above with respect to elbow power connectors. In other implementations, other medium/high voltage power components may be configured to include the visible open port configuration described above.
Although the invention has been described in detail above, it is expressly understood that it will be apparent to persons skilled in the relevant art that the invention may be modified without departing from the spirit of the invention. Various changes of form, design, or arrangement may be made to the invention without departing from the spirit and scope of the invention. Therefore, the above-mentioned description is to be considered exemplary, rather than limiting, and the true scope of the invention is that defined in the following claims.
No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.
This application claims priority under 35. U.S.C. §119, based on U.S. Provisional Patent Application No. 61/368,758 filed Jul. 29, 2010, the disclosure of which is hereby incorporated by reference herein.
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Number | Date | Country | |
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Number | Date | Country | |
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61368758 | Jul 2010 | US |