SWAGED CONNECTORS FOR A GROUNDING GRID

CONNECTEURS EMBOUTIS DESTINES A UN RESEAU DE MISE A LA TERRE

English Abstract

A family of swaged connectors has particular application for joining segments of copper cable that make up a subterranean grounding grid in an electrical utility substation. The connectors have a body member with at least one swage region having a trough for receiving an electrical conductor. The swage region has an opening extending the length of the trough to allow insertion, in a radial direction, of the electrical conductor into the trough. An insert is configured for mating engagement with the opening in the swage region, such that, when the insert is mated with the body member, an electrical conductor disposed within the trough is radially entrapped in the connector. The connector body and insert have a cylindrical outer surface in the swage region to facilitate swaging the connector to secure it to the electrical conductor. The connector may be configured as a lap splice, tee or elbow.

French Abstract

Une famille de connecteurs emboutis présente une application particulière pour joindre des segments d'un câble de cuivre composant un réseau de mise à la terre souterrain dans un poste de service électrique. Les connecteurs comprennent un élément de corps ayant au moins une région d'emboutissage ayant un creux pour recevoir un conducteur électrique. La région d'emboutissage comprend une ouverture s'étendant sur la longueur du creux pour permettre l'insertion dans un sens radial du conducteur dans le creux. Une pièce rapportée est configurée pour l'accouplement avec l'ouverture dans la région d'emboutissage, de sorte qu'un conducteur électrique placé dans le creux soit pris en relation radiale dans le connecteur lorsque la pièce rapportée est accouplée à l'élément de corps. Le corps de connecteur et la pièce rapportée ont une surface extérieure cylindrique dans la région d'emboutissage pour faciliter l'emboutissage du connecteur afin de le fixer au conducteur électrique. Le connecteur peut être configuré en épissure, en té ou en coude.

Claims

CLAIMS
What is claimed is:
1. A connector comprising:
a body member with first and second swage regions having respective first and
second troughs for receiving respective electrical conductors, the body member
having
first and second openings extending a length of the respective troughs to
allow insertion,
in a radial direction, of respective electrical conductors into the respective
troughs;
first and second inserts, each configured for mating engagement with a
respective
one of the openings such that, when the inserts are mated with the body
member, the
electrical conductors disposed within the troughs are radially entrapped in
the connector.
2. The connector of claim 1 wherein the first and second swage regions are
disposed
at right angles to one another.
3. The connector of claim 1 wherein the first and second swage regions are
coaxial
and wherein the body member further comprises a tap portion having a
cylindrical
opening for receiving an additional electrical conductor.
4. The connector of claim 3 wherein the tap portion is disposed
perpendicular to the
two swage regions in a tee configuration.
5. The connector of claim 1 wherein the first and second troughs are
oriented
parallel to one another.
6. The connector of claim 1 wherein a transverse cross-section of the
trough defines
a first circular arc.
7. The connector of claim 6 wherein each insert has a trough with a
transverse cross-
section defining a second circular arc complementary to the first circular
arc.
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8. The connector of claim I wherein the body member and inserts have
corresponding keying surfaces such that the inserts are axially insertable
into the body
member and are radially retained therein.
9. A method of attaching the connector of claim 1 to first and second
electrical
conductors comprising:
inserting the first electrical conductor into the first trough of the body
member;
inserting the second electrical conductor into the second trough of the body
member;
inserting the two inserts into the respective openings;
compressing the swage regions radially inwardly with a swaging tool.
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Description

CA 02920762 2016-02-09
SWAGED CONNECTORS FOR A GROUNDING GRID
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
100011 This invention relates to the field of connectors for electrical
conductors, and,
more particularly to swaged connectors for use in a grounding grid.
BACKGROUND
[0002] Substations in electrical power distribution systems require a
properly
designed and installed grounding system to insure reliable performance.
Grounding is
typically accomplished with a grid of electrical conductors buried in the
soil. The
substation equipment is connected to the grounding grid by means of cables,
rods or bars
that are securely connected to the grid.
[0003] Connections within and to the grid are typically made using special
purpose
connectors that are crimped to a grid conductor. The crimping process used to
secure a
connector concentrates the compressive force at one or a few locations around
the
circumference of the conductor. This localized concentration of force can
result in a poor
electrical connection. Swaging is a process that distributes compressive force
evenly
around the circumference of a cylindrical body. Therefore, a properly swaged
connector
will generally provide a superior connection in comparison to a crimped
connector.
SUMMARY OF THE INVENTION
100041 The present invention provides a family of swaged connectors with
particular
application for joining segments of copper cable that make up a subterranean
grounding
grid in an electrical utility substation. Removable inserts or "lids" allow
the connectors
to join onto existing continuous cables prior to installation.
[0005] The connectors comprise a body member with at least one swage region
having a trough for receiving an electrical conductor, the swage region having
an opening
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0 .
=
extending the length of the trough to allow insertion, in a radial direction,
of the electrical
conductor into the trough. An insert is configured for mating engagement with
the
opening in the swage region, such that, when the insert is mated with the body
member,
an electrical conductor disposed within the trough is radially entrapped in
the connector.
The connector body and insert have a cylindrical outer surface in the swage
region to
facilitate swaging the connector to secure it to the electrical conductor. The
connector
may be configured as a lap splice, tee or elbow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 is perspective view of a connector in accordance
with a first
embodiment of the invention.
[0007] Figure 2 is a side elevation view of the connector shown
in Figure 1.
[0008] Figure 3 is an elevation view of one end of the connector
shown in Figure 1.
[00091 Figure 4 is a perspective view of a connector in
accordance with a second
embodiment of the invention.
[0010] Figure 5 is an elevation view of one end of the connector
shown in Figure 3.
[0011] Figure 6 is a perspective view of a connector in
accordance with a third
embodiment of the invention.
[0012] Figure 7 is an elevation view of one end of the connector
shown in Figure 5.
DETAILED DESCRIPTION OF THE INVENTION
[0013] In the following description, for purposes of explanation
and not limitation,
specific details are set forth in order to provide a thorough understanding of
the present
invention. However, it will be apparent to one skilled in the art that the
present invention
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may be practiced in other embodiments that depart from these specific details.
In other
instances, detailed descriptions of well-known methods and devices are omitted
so as to
not obscure the description of the present invention with unnecessary detail.
[0014] Figures 1-3 illustrate a split tee grounding connector 10. The
purpose of this
connector is to join cable (copper-clad, copper stranded or solid copper)
and/or ground
rod (solid copper or copper clad/bonded) or rebar in a 900 configuration.
Connector 10
comprises a body member 12 and a pair of inserts or "lids" 14. The body member
and
inserts are preferably made of high-purity copper, such as electrolytic tough
pitch copper.
With the inserts removed, connector body 12 has a nearly semi-cylindrical
trough 16 for
receiving a conductor cable 17. In one specific example, the diameter of the
cylindrical
trough is 0.594".
[0015] Inserts 14 are configured with a complementary cylindrical inner
surface 18
such that the assembled connector has a complete cylindrical inner surface
surrounding
the cable in swage regions 24. Inserts 14 have flanges 20 that are received in
corresponding slots 22 in body member 12. These flanges and slots define
keying
surfaces that assist axial insertion of the inserts into the body member and
prevent the
inserts from being removed radially. The flanges and slots may also be
configured with
an axial taper toward the center of the body member to prevent the inserts
from sliding all
the way through the slots and to temporarily wedge the inserts in the slots
during
installation prior to swaging.
[0016] Connector 10 is attached to a cable by first removing the inserts 14
and then
placing the cable into trough 16. Inserts 14 are then inserted axially into
slots 22. Swage
regions 24 of the connector are then inserted into a suitable swage tool and
uniformly
radially compressed to retain the cable. In one specific example, the swage
regions of the
connector are 1.00" wide and have an outside diameter of 1.25". The swaging
operation
is preferably performed using the 360 Radial Swage Tool manufactured by DMC
Power,
Inc. of Gardena, Calif.
[0017] The center section 26 of the body member between the two swage
regions 24
does not fully encircle the cable for the purpose of reducing the volume of
material in the
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connector. The resulting shorter lengths of the inserts 14 increase the
strength of the
connector by minimizing the overturning moment created under a tensile load
between
the 900 portions of the connector.
[0018] Bottom tap 28 does not require an insert since the cable, rod or
rebar can be
inserted axially. The outside diameter of the bottom tap is sized for the
swaging tool and
will generally have the same outside diameter as swaging regions 24. A hole 30
is drilled
to the center of the connector. This hole serves to verify proper insertion
depth during
installation and allows moisture to escape after installation.
[0019] Figure 4 and 5 illustrate an offset split elbow/tee/cross connector
40. This
connector is designed to join cable and/or ground rod or rebar in a 90 offset
configuration. The construction and assembly of connector 40 is essentially
the same as
for connector 10 described above. As with connector 10, the area behind the
two swage
regions 44 of body member 42 has been removed for material reduction and to
minimize
the overturning moment between the 90 portions.
[0020] Figure 6 and 7 illustrate a split parallel grounding connector 50.
Two parallel
holes 54 and 56 allow the connector to be used in various geometries with
flexible cable,
such as tee, offset cross, splice, or parallel continuous cable. As with the
above-described
connectors, connector 50 can be used with cable, ground rod and/or rebar. Two
cutaway
sections 58 and 60 on either side of connector body 52 serve dual purposes.
First, they
reduce the amount of material in the connector, allowing a smaller required
force to
plastically deform during swaging. Second, they provide an area where the
fitting can
further compress, even after the cable and connector interface have been fully
compressed. This allows for range taking, i.e., the ability to accommodate
various cable
sizes with a single hole diameter.
[0021] Unlike the previously described embodiments, connector 50 does not
have
separate swage regions for the connected conductors. Instead, the entire
connector body,
with inserts 14, is inserted into a suitable swage tool and uniformly radially
compressed
to retain both of the conductors. In one specific example, the outside
diameter of
connector 50 is 2.00".
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[0022] It will
be recognized that the above-described invention may be embodied in
other specific forms without departing from the spirit or essential
characteristics of the
disclosure. Thus, it is understood that the invention is not to be limited by
the foregoing
illustrative details, but rather is to be defined by the appended claims.
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Representative Drawing