Note: Descriptions are shown in the official language in which they were submitted.
CA 02766633 2014-04-03
ELECTRICAL CONNECTOR WITH SACRIFICIAL COMPONENT
BACKGROUND OF THE INVENTION
[0001] 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.
[0002] 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.
[0003] 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.
SUMMARY OF THE INVENTION
[0004] In accordance with one aspect of the present invention, there is
provided an
electrical connector assembly, comprising a housing body that includes a cable
receiving end
having a first bore extending therethrough, and at least one equipment end
projecting
perpendicular to the cable receiving end, wherein the at least one equipment
end includes a
second bore extending therethrough that communicates with the first bore in
the cable
receiving end, wherein the cable receiving end includes a sacrificial portion,
and a sacrificial
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bar configured to be received within the cable receiving end in a position
proximate to the
sacrificial portion, wherein the sacrificial bar includes a first end for
coupling to an end of a
prepared electrical power cable and a second end configured to project into
the second bore
and conductively couple with an electrical device received within the at least
one equipment
end, wherein the sacrificial portion of the housing body and the sacrificial
bar are configured
to be cut through to confirm that the electrical connector is de-energized.
[0004.1] In accordance with another aspect of the present invention, there is
provided a
medium or high voltage electrical connector assembly, comprising a housing
body having a
longitudinal bore extending therethrough for receiving a prepared power cable
therein, a first
T-end projecting perpendicularly from the housing body and including a second
bore that
communicates with a forward end of the longitudinal bore, a second T-end
projecting
perpendicularly from the housing body in a direction opposite to the first T-
end, wherein the
second T-end includes a third bore that communicates with the second bore and
the forward
end of the longitudinal bore, a sacrificial bar assembly configured to be
received within the
longitudinal bore, wherein the sacrificial bar assembly includes a first end
for coupling to an
end of the prepared power cable and a second end configured to project into
the second bore
of the first T-end and the third bore of the second T-end, wherein the
sacrificial bar assembly
is configured to be cut through to confirm that the electrical connector
assembly is de-
energized.
[0004.2] In accordance with a further aspect of the present invention, there
is provided a
method, comprising coupling a first end of a sacrificial bar assembly to a
prepared end of an
electrical power cable, wherein the sacrificial bar assembly includes a second
end configured
to be coupled to an electrical equipment bushing, inserting the sacrificial
bar assembly and
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the prepared end of the electrical power cable into a longitudinal bore of a
power cable
electrical connector housing body, wherein the power cable electrical
connector housing
body includes at least one equipment end projecting perpendicular to the
longitudinal bore,
wherein the at least one equipment end includes a second bore extending
therethrough that
communicates with the longitudinal bore in the power cable electrical
connector housing
body, wherein the second end of the sacrificial bar assembly projects into the
second bore,
coupling the second end of the sacrificial bar assembly to an electric device
received in the
second bore of the at least one equipment end, cutting through the power cable
electrical
connector housing body and the sacrificial bar assembly to confirm that the
power cable
electrical connector is de-energized, removing the prepared end of the
electrical power cable
and a cut portion of the sacrificial bar assembly from the longitudinal bore
of the power cable
electrical connector, decoupling the cut portion of the sacrificial bar
assembly from the
prepared end of the electrical power cable, removing the cut portion of the
sacrificial bar
assembly and the power cable electrical connector housing body, coupling a
replacement
sacrificial bar assembly to the prepared end of the electrical power cable,
inserting the
prepared end of the electrical power cable and the replacement sacrificial bar
assembly into
the longitudinal bore of a replacement power cable electrical connector
housing body, and
coupling the second end of the replacement sacrificial bar assembly to the
electrical device
received in the second bore of the at least one equipment end of the
replacement power cable
electrical connector housing body.
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,
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Figures 1A and 1B are schematic cross-sectional and side views,
respectively,
illustrating a sacrificial power cable elbow connector configured in a manner
consistent with
implementations described herein;
[0006] Figures 2A and 2B are schematic side and end views, respectively, of
the sacrificial
bar of Fig. 1A;
[0007] Figures 3A and 3B are schematic side and end views, respectively, of an
other
exemplary sacrificial bar assembly;
[0008] Figure 4 is a flow diagram of an exemplary method for using the
sacrificial power
cable elbow connector of Fig. 1; and
[0009] Figs. 5A-8 are schematic illustrations of the process of Fig. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] The following detailed description refers to the accompanying drawings.
The same
reference numbers in different drawings may identify the same or similar
elements.
[0011] 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.
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. ,
=
[0012] 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.
[0013] 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.
[0014] 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.
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[0015] Fig. lA is a schematic cross-sectional diagram illustrating a power
cable elbow
connector 100 configured in a manner consistent with implementations described
herein.
Fig. 1B is a side view of elbow connector 100. As shown in Fig. 1A, power
cable elbow
connector 100 may include a main housing body 102 that includes a conductor
receiving end
104 for receiving a power cable 106 therein and first and second T-ends
108/110 that include
openings for receiving an equipment bushing, such as a deadbreak transforming
bushing 111
or other high or medium voltage terminal, such as an insulating plug 113, a
grounding plug,
or other power equipment.
[0016] 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.
[0017] 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.
[0018] 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
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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.
[0019] For example, as illustrated in Fig. 1A, voltage detection test point
assembly 126
may include a test point terminal 128 embedded in a portion of insulative
inner housing 122
and extending through an opening within outer shield 120. In one exemplary
embodiment,
test point terminal 128 may be formed of a conductive metal or other
conductive material. In
this manner, test point terminal 128 may be capacitively coupled to the
electrical conductor
elements (e.g., power cable 106) within connector 100.
[0020] 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.
[0021] 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 Fig. 1B, in one embodiment, sacrificial portion 134 may be positioned in a
region of main
housing body 102 between test point assembly 126 and T-ends 108/110 and
corresponding to
a location of a sacrificial bar 200, described below. As shown in Fig. 1B, an
outer surface of
main housing body 102 in sacrificial portion 134 may include surface markings
138
indicating that sacrificial portion 134 may be cut to verify that connector
100 has been de-
energized.
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[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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 Fig. 1A, spade portion
146 may
include a bore 150 extending perpendicularly therethrough.
[0026] Consistent with embodiments, described herein, a sacrificial bar 200
may be
provided in connector 100. As shown in Fig. 1A, sacrificial bar 200 may be
removably
coupled to conductor spade assembly 140 and may project axially into contact
area 118
between T-ends 108 and 110. Fig. 2A is a side view of an exemplary embodiment
of
sacrificial bar 200. Fig. 2B is an end view of sacrificial bar 200 taken along
the line A-A in
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Fig. 2A. As shown in Fig. 2A, sacrificial bar 200 may include a first spade
end 202, a central
bar portion 204, a forward conductor portion 206, and a second spade end 208.
[0027] As shown in Fig. 2A, sacrificial bar 200 may be formed or machined from
a single
conductive body, such as a brass or aluminum material. First spade end 202 may
be
configured to engage spade portion 146 of conductor spade assembly 140, as
shown in Fig.
1A. For example, first spade end 202 may include a threaded bore 210 extending
perpendicularly therethrough. Bore 210 is configured to align with bore 150 in
spade portion
146. As shown in Fig. 1A, a connector bolt 154 may be inserted through bore
150 and into
threaded bore 210 in first spade end 202. Tightening of bolt 154 secures
sacrificial bar 200
to conductor spade assembly 140. Although Fig. lA illustrates first spade end
202 of
sacrificial bar 200 as being positioned below (or radially outside of) spade
portion 146 of
conductor spade assembly 140, in other embodiments, this relationship may be
reversed.
[0028] As shown in Figs. lA and 2A, central bar portion 204 of sacrificial bar
200 may
include a generally cylindrical configuration extending between first spade
end 202 and
forward conductor portion 206. As shown in Fig. 2A, in one embodiment, central
bar portion
204 may include an outside diameter that is smaller than an outside diameter
of either first
spade end 202 or forward conductor portion 206. Further, as shown in Fig. 1A,
central bar
portion 204 may be configured to underlay surface markings 138 in sacrificial
portion 134 of
main housing body 102. The reduced diameter of central bar portion 204 may
facilitate
efficient severing of sacrificial bar 200 by field personnel.
[0029] As shown in Fig. 2A, forward conductor portion 206 may include a
generally
cylindrical configuration having an outside diameter that is larger than the
outside diameter
of central bar portion 204. Second spade end 208 may be conductively coupled
to forward
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conductor portion 206 of sacrificial bar and may extend axially therefrom. As
shown in Fig.
1A, upon insertion of sacrificial bar 200 into connector 100, second spade end
208 may
project into contact area 118. As shown in Fig. 2A, second spade end 208 may
include a
perpendicular bore 212 extending therethrough. Once second spade end 208 is
seated within
contact area 118, bore 212 may allow a stud (e.g., stud 115 in Fig. 1A) or
other coupling
element (e.g., a pin, rod, bolt, etc.) to conductively couple second spade end
208 to an
equipment bushing or other device received within bores 114 and/or 116 in T-
ends 108 and
110, respectively.
[0030] Fig. 3A is a side view of an alternative implementation of sacrificial
bar 200 that
includes a sacrificial bar assembly 300 of. Fig. 3B is an end view of
sacrificial bar assembly
300 taken along the line A-A in Fig. 3A. As shown in Fig. 3A, sacrificial bar
assembly 300
may be formed or machined from three modular conductive components, that
include a first
spade end component 302, a central bar component 304, and a second spade end
component
306. As shown in Fig. 3A, consistent with this embodiment, central bar
component 304 may
be replaceable with respect to a remainder of sacrificial bar assembly,
thereby reducing an
amount of material necessary to replace sacrificial bar 200 upon re-assembly
of connector
100 following cut-through.
[0031] 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.
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[0032] 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 Fig. 3B,
first threaded aperture 310 may be diametrically opposed to second threaded
aperture 312.
Further each of first threaded aperture 310 and second threaded aperture 312
may
communicate with bar receiving cavity 314. As shown, during assembly of
electrical
connector 100, a forward end 316 of central bar component 304 may be received
within bar
receiving cavity 314. Set screws 318 and 320 may be received within first
threaded aperture
310 and second threaded aperture 312, respectively, and may engage rearward
end 316 of
central bar component 304, thereby fixing central bar component 304 relative
to first spade
end component 302.
[0033] 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.
[0034] 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 Fig. 3A, in one embodiment, central bar
component 302
may include an outside diameter that is smaller than an outside diameter of
either first spade
end component 302 or second spade end component 306. Further, central bar
component
304 may be configured to underlay surface markings 138 in sacrificial portion
134 of main
housing body 102.
[0035] As shown in Fig. 3A, second spade end component 306 may include a
generally
cylindrical configuration having an outside diameter that is larger than the
outside diameter
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. ,
of central bar component 304. Similar to second spade end 208 described above,
second
spade end component 306 may project axially from sacrificial bar assembly 300.
As shown
in Fig. 3A, second spade end component 306 may include a perpendicular bore
322
extending therethrough. Upon insertion of sacrificial bar assembly 300 into
connector 100,
second spade end component 306 may project into contact area 118. Once second
spade end
component 306 is seated within contact area 118, bore 322 may allow a stud or
other
coupling element (e.g., a pin, rod, bolt, etc.) to conductively couple second
spade end
component 306 to an equipment bushing or other device received within bores
114 and/or
116 in T-ends 108 and 110, respectively.
[0036] As shown in Fig. 3A, second spade end component 306 may further include
a first
threaded aperture 324, a second threaded aperture 326, and a bar receiving
cavity 328. As
shown in Fig. 3B, first threaded aperture 324 may be diametrically opposed to
second
threaded aperture 326. Further, each of first threaded aperture 324 and second
threaded
aperture 326 may communicate with bar receiving cavity 328. As shown, during
assembly of
elbow connector 100, a forward end 330 of central bar component 304 may be
received
within bar receiving cavity 328. Set screws 332 and 334 may be received within
first
threaded aperture 324 and second threaded aperture 326, respectively, and may
engage
forward end 330 of central bar component 304, thereby fixing central bar
component 304
relative to second spade end component 306.
[0037] 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.
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,
[0038] Fig. 4 is a flow diagram of an exemplary method for using the
sacrificial power
cable elbow connector 100 consistent with embodiments described herein. Figs.
5A-8 are
schematic illustrations of the process of Fig. 4 and are described in
conjunction with the
description of Fig. 4.
[0039] 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 Figs. 5A (side view) and 5B (cross-sectional view).
[0040] 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 ¨ Fig. 6). For example, power
cable
106, spade connector assembly 140, and a cable-end 600 of cut-through
sacrificial bar 200
may be removed from main housing body 102 of connector 100.
[0041] Although not shown in Fig. 6, a forward end (e.g., a bushing-side end)
of the cut-
through main housing 102 and sacrificial bar 200 may also be removed from the
equipment
bushing and any other connected device, such as an insulated plug may be
removed (block
410). For example, a plug or stud securing the bushing to second spade end 208
may be
removed. In an embodiment using one-piece sacrificial bar 200, the cut-through
ends of
main housing 102 and sacrificial bar 200 may be discarded. However, in an
embodiment
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CA 02766633 2012-02-02
using modular sacrificial bar assembly 300, a cut-through end of sacrificial
bar assembly 300
may be removed from cut-through main housing 102, and forward spade end
component 306
may be removed from central bar component 304, e.g., by removing set screws
332 and 334.
[0042] 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 ¨ Fig.
7). For
example, connector bolt 154 may be removed from threaded bore 210 in first
spade end 202.
[0043] The cut-through portion of sacrificial bar 200 may be discarded, as
shown
schematically in Fig. 7 (block 420). In the embodiment of Fig. 3A and 3B,
rather than
discarding the entirety of sacrificial bar 300, the cut-through portion of
central bar
component 304 may be removed from first spade end component 302 (e.g., by
removing set
screws 318 and 320).
[0044] A new sacrificial bar 200 may be installed on spade assembly 140, as
shown in Fig.
8 (block 425). For example, a replacement sacrificial bar 200 may be installed
to spade
assembly 140 via connector bolt 154. Alternatively, in the embodiment of Figs.
3A and 3B,
a replacement central bar component 304 may be mounted within first spade end
component
302 and second spade end component 306, e.g., by tightening set screws 318,
320, 332, and
334. Sacrificial bar assembly 300 (with the replacement central bar component
304) may
then be reassembled to spade assembly 140 via connector bolt 154.
[0045] 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.
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[0046] Connector 100 may be reinstalled on the equipment bushing (block 435)
and re-
energized (block 440).
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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
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be modified. Various changes of form, design, or arrangement may be made to
the
invention. The scope of the claims should not be limited by the preferred
embodiments set
forth in the examples, but should be given the broadest interpretation
consistent with the
description as a whole.
[0051] 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.
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