The present invention relates to electrical cable connectors, such as splicing connectors for joining two or more electrical cables, loadbreak connectors, and deadbreak connectors. More particularly, aspects described herein relate to an electrical cable connector that includes a feature for enabling personnel to confirm that the connector is de-energized.
High and medium voltage electrical connectors and components typically operate in the 15 to 35 kilovolt (kV) range. Because such voltages are potentially very dangerous, it is typically necessary for personnel to confirm that the power is disconnected before commencing work or repair. Known methods of visual or physical de-energizing confirmation include “spiking the cable,” in which a grounded spike is driven thru the cable and into the conductor or a grounded hydraulic cable cutter is used to physically cut or sever the cable in half.
Problematically, after a cable is “spiked,” the utility is required to replace or re-terminate the cable or increase its length by adding a splice and additional cable in order to reconnect to the system. This is costly and time consuming.
The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements.
One or more embodiments disclosed herein relate to a power cable connector, such as an elbow or T-connector having a sacrificial component. More specifically, the connector may include a power cable receiving body and at least one T-end projecting substantially perpendicularly from the receiving body. The power cable receiving portion is configured to receive a power cable and the T-end is configured to receive an equipment bushing. The power cable operates by enabling current to flow between the bushing and the cable.
Power cables for use with the described embodiments include a terminating component, such as a spade connector affixed to a free end thereof. In normal operation, the end of the spade connector projects through the power cable receiving body into proximal relationship with the bushing positioned within the T-end. In some implementations, a bolt or other component may be inserted through an opening in the end of the spade connector and into a corresponding threaded aperture on the bushing. This facilitates conductive coupling of the power cable to the bushing by providing a securable conductive interface on an end of the power cable.
Consistent with embodiments described herein, a conductive, sacrificial bar (also referred to as a “link” or “bridge”) may be interposed between the power cable terminating component (e.g., the spade connector) and the T-end. One end of the sacrificial bar may coupled to the terminating component and the other end of the sacrificial bar may project into the T-end for coupling with the bushing. An elbow housing having an extended length may accommodate insertion of both the terminated power cable elbow and the sacrificial bar and may include a marked portion corresponding to a position of the sacrificial bar. The marked portion may indicate that a cut of the connector at a marked location may be performed to verify that the power cable has been de-energized.
After being severed, the power cable may be removed from the cut elbow housing and the cut portion of the sacrificial bar may be removed or disassembled from the power cable terminating component. The T-end of the connector may be also disassembled from the bushing. A replacement sacrificial bar may be connected to the power cable terminating component and the power cable/sacrificial bar may be inserted into a replacement elbow housing. The connector may then be attached to the equipment bushing.
As shown, conductor receiving end 104 may extend along a main axis of connector 100 and may include a bore 112 extending therethrough. First and second T-ends 108/110 may project substantially perpendicularly from conductor receiving end 104 in opposing directions from one another. First and second T-ends 108/110 may include bores 114/116, respectively, formed therethrough for receiving equipment, bushings, and/or plugs. A contact area 118 may be formed at the confluence of bores 112, 114, and 116.
Power cable elbow connector 100 may include an electrically conductive outer shield 120 formed from, for example, a conductive peroxide-cured synthetic rubber, commonly referred to 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.
In one exemplary implementation, combined power cable elbow connector 100 may include a voltage detection test point assembly 126 for sensing a voltage in connector 100. Voltage detection test point assembly 126 may be configured to allow an external voltage detection device, to detect and/or measure a voltage associated with connector 100.
For example, as illustrated in
A test point cap 130 may sealingly engage a portion of test point terminal 128 and outer shield 120. In one implementation, test point cap 130 may be formed of a semi-conductive material, such as EPDM. When test point terminal 128 is not being accessed, test point cap 130 may be mounted on test point assembly 126. Because test point cap 130 is formed of a conductive or semi-conductive material, test point cap 130 may ground test point terminal 128 when in position.
Consistent with embodiments described herein, main housing body 102 of power cable elbow connector 100 may include a sacrificial portion 134 formed therein. As shown in
Conductor receiving end 104 of power cable elbow connector 100 may be configured to receive a prepared end of power cable 106 therein. For example, a forward end of power cable 106 may be prepared by connecting power cable 106 to a conductor spade assembly 140. More specifically, conductor spade assembly 140 may include a rearward sealing portion 142, a crimp connector portion 144, and a spade portion 146.
Rearward sealing portion 142 may include an insulative material surrounding a portion of power cable 106 about an opening of conductor receiving end 104. When conductor spade assembly 140 is positioned within connector body 102, rearward sealing portion 142 may seal an opening of conductor receiving end 104 about power cable 106.
Crimp connector portion 144 may include a substantially cylindrical conductive assembly configured to receive a center conductor 148 of power cable 106 therein. Upon insertion of center conductor 148 therein, crimp connector portion 144 may be crimped onto power center conductor 148 prior to insertion of cable 106 into conductor receiving end 104.
Spade portion 146 may be conductively coupled to crimp connector portion 144 and may extend axially therefrom. For example, in some implementations, spade portion 146 may be formed integrally with crimp connector portion 144 and be made of a conductive metal, such as steel, brass, aluminum, etc. As shown in
Consistent with embodiments, described herein, a sacrificial bar 200 may be provided in connector 100. As shown in
As shown in
As shown in
As shown in
Similar to first spade end 202 described above, first spade end component 302 may be configured to engage spade portion 146 of conductor spade assembly 140. For example, first spade end component 302 may include a threaded bore 308 extending perpendicularly therethrough. Bore 308 is configured to align with bore 150 in spade portion 146 to enable secure coupling of first spade end component 302 with spade portion 146 via connector bolt 154.
In addition, first spade end component 302 may include a first threaded aperture 310, a second threaded aperture 312, and a bar receiving cavity 314. As shown in
In one implementation, opposing sides of rearward end 316 of central bar component 304 may include flattened portions. Set screws 318 and 320 may engage the flattened portions, thereby providing a more secure attachment of central bar component 304 to first spade end component 302.
Central bar component 304 of sacrificial bar assembly 300 may include a generally cylindrical configuration extending between first spade end component 302 and second spade end component 306. As shown in
As shown in
As shown in
As described above with respect to rearward end 316 of central bar component 304, in one implementation, opposing sides of forward end 330 of central bar component 304 may also include flattened portions for engaging set screws 332 and 334.
When it is necessary for work to be performed on power cable 106 (or any device connected to power cables 106), a worker may cut through connector 100 in a location proximate to sacrificial portion 134 of main housing body 102 (e.g., with a hydraulic cable cutter, or similar tool) to ensure that the electrical system that splicing connector 100 is connected to has been properly de-energized and is, therefore, safe to work on (block 400). As described above, sacrificial portion 134 of main housing body 102 is configured to overlay central bar 204/304 in sacrificial bar 200/300. Consequently, severing connector 100 at sacrificial portion 134 also severs central bar 204/304. This operation is schematically illustrated in
After the work has been completed and it is time to re-energize, power cable 106 may be removed from housing body 102 (block 405—
Although not shown in
In any event, once removed from main housing 102, spade assembly 140 may be disassembled from the cut-through end of sacrificial bar 200 (block 415—
The cut-through portion of sacrificial bar 200 may be discarded, as shown schematically in
A new sacrificial bar 200 may be installed on spade assembly 140, as shown in
Power cable 106, spade assembly 140, and sacrificial bar 200 may be installed into a replacement main housing body 102 (block 430). For example, power cable 106, spade assembly 140, and sacrificial bar 200 may be inserted into bore 112 in main housing cable receiving end 104 of main housing body 102, with second spade end 208 extending into contact area 118 proximate bores 114/116 in first and second T-ends 108/110 respectively.
Connector 100 may be reinstalled on the equipment bushing (block 435) and re-energized (block 440).
By providing a replaceable sacrificial bar for coupling to a prepared power cable, significant time and expense savings are realized. For example, following a cut-through operation, power cable 106 and spade assembly 140 need not be re-terminated or re-prepared, an operation requiring both significant time expenditure and further requiring that sufficient cable slack be available to accommodate the new termination (e.g., new spade connector). In the event that a required length of slack is not available, a costly and time-consuming cable splice must be performed. In contrast, connector 100 provides for an easily replaceable elbow housing 102 and sacrificial bar 200 and does not require re-termination of power cable 106.
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 described herein may also be used in conjunction with other devices, such as high voltage switchgear equipment, including 15 kV, 25 kV, or 35 kV equipment.
For example, various features have been mainly described above with respect to electrical splicing connectors. In other implementations, other medium/high voltage power components may be configured to include the replaceable sacrificial bar configurations 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 is a non-provisional of U.S. Provisional Patent Application No. 61/558,204 filed on Nov. 10, 2011, the entirety of which is hereby incorporated by reference herein.
Number | Date | Country | |
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61558204 | Nov 2011 | US |