GB2315166A - Arc protection clamping connector - Google Patents

Abstract

The invention relates to an electrical connector for overhead power lines. The connector has a two part construction with an arc protection device permanently attached to one of the parts. When fitting an arc protection device to overhead lines, the apparatus of the present invention provides the advantage that workers need only to carry a few items and offer them up to the overhead lines giving greatly simplified fitting of the parts since only minimal alignment time is required. In this way, connectors in accordance with the present invention are more user friendly and parts are much less likely to be dropped or mislaid.

Description

ELECTRICAL CONNECTOR The invention relates to electrical connectors. In particular, the invention relates to connectors for connecting to conductors such as those which are used in overhead electricity distribution systems. Particularly, although not exclusively, the invention is directed towards such a connector for use as an arc protection device.

In many circumstances it is required to provide a connection to overhead power lines. Prime considerations when making such connections are naturally that the connection should be made in a safe and reliable manner.

To improve the safety and reliability of overhead lines, insulated lines are in use and this invention is primarily (although not exclusively) directed towards forming a connection to such insulated lines.

Arc protection devices (also known as spark protection devices) need to be provided at any location where an over voltage causing damage to the lines is possible or likely.

Arc protection devices are commonly fitted to overhead lines adjacent to support structures.

In order to provide a connection to an insulated overhead line, it is necessary to pierce or remove the insulation surrounding the conductor. In the piercing type of connector, such piercing is typically carried out by providing a two piece clamping arrangement to fit around the overhead line, the two pieces being joined together by a bolt or the like which, as it is tightened, brings opposing jaws of the clamping arrangement together. As the jaws close, teeth on the jaws pierce the insulating layer and establish a connection.

A disadvantage with known connectors is that because of their multipart construction, they can often be awkward to attach to the overhead lines.

Furthermore, because of the insulation piercing nature of the connectors, the electrical connection to the line can prove unreliable since such connection is often made by a limited number of points.

According to an aspect of the present invention, there is provided an electrical connector for connection to a conductor, the connector comprising first and second parts for fitment to the conductor, whereby the first part is an integrated portion comprising a first clamping member and an external connection and the second part comprises a second clamping portion, the connector being arranged such that the first part may be clamped to the second part around the conductor.

Preferably, the external connection comprises an arc protection device.

The external connection and the first clamping member may be manufactured as a single item or may be manufactured separately and thereafter joined together prior to deployment. The external connection and the first clamping member may be welded together.

The arc protection device preferably comprises a combined arcing horn/current conducting wire.

Preferably, the two clamping members are especially adapted to be bolted to one another around the conductor.

Preferably, the two clamping members are joined together by one or more shear head torque controlling bolts. The bolt or bolts are preferably double-headed such that a first head is arranged to shear when a given tightening torque has been reached and the second head may be utilised to remove the connector if required at a later date for servicing etc.

A pair of such double-head bolts may be provided for each electrical connector. However any suitable alternative fixing could be utilised.

Preferably, the arc protection device incorporates a current conducting wire which may be approximately one meter long. The current conducting wire is preferably of high conductivity material.

When used on insulated overhead conductors, the insulation on the overhead conductor must be removed prior to application of the electrical connector. By removing the insulation at this connection point, and clamping the connector thereto, a very reliable connection may be made.

Preferably, the two clamping members are provided with internal serrations or the like so as to provide a reliable mechanical and electrical connection between the connector and the overhead line.

By providing the electrical connector in a two-part construction with the external connection (in preferred embodiments the arc protection device) permanently attached to one of the clamping members, the number of parts which need to be taken up to overhead lines is reduced and handling of the equipment is significantly simplified. Previously, operatives needed to carry three or four separate items up to the overhead lines and spend a significant amount of time aligning the different parts before bolting them together. This procedure often led to parts being dropped or mislaid causing considerable inconvenience. The connector of the present invention may be taken up to the conductor in an already loosely assembled form, so that attachment can be reliably and speedily made by placing the two clamping members around the locally stripped conductor and then simply clamping the first and second parts together. In this manner, only a single entity is needed to be carried to the conductor and handling problems are reduced.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which: Figure 1 shows an integrated electrical connector and arc protection device according to an embodiment of the invention; Figure 2 is a cross-sectional exploded view along line A-A' of the electrical connector; and Figure 3 shows a typical application of the electrical connector.

Referring initially to Figures 1 and 2, the electrical connector comprises an external connection such as an arc protection device comprising a combined arcing horn and current conducting wire 1 (sometimes known as a trace wire) forming an integral part of a first clamping member 2, a second clamping member 3 and a pair of double-headed shear head torque controlling bolts 4, 5.

The connector further comprises a captive nut 6 corresponding to bolt 4 and a further captive nut (not shown) corresponding to the bolt 5, both provided on the first clamping member 2, and a pair of spring washers and washers 7, 8 provided associated with each bolt 4, 5.

As mentioned previously, the arc protection device 1 forms an integral part of the first clamping member 2. This may be achieved in various ways.

For instance, it may be manufactured as a single item. Alternatively, upon assembly the arc protection device 1 could be welded to the first clamping member 2 or fixed thereto by, for instance, compression fixing at the manufacturing site. It will be appreciated that many different types of connection may be employed to fix the arc protection device/current conducting wire 1 to the first clamping member 2 prior to its deployment upon an overhead conductor system.

Clamping members 2 and 3 each comprise an internal serrated region 9, 9' for connection to an overhead conductor. These serrated regions 9, 9' are adapted to make a strong mechanical connection with the overhead line after that line has been locally stripped of its insulating layer. The clamping member 3, in the embodiment shown, also has a serrated region 10 for cooperation with the arc protection device 1 but it will be appreciated that this is not an essential feature of all embodiments.

An application of the electrical connector will now be described with reference to Figures 1, 2 and 3.

In order to apply the electrical connector to an overhead line, an operator first selects an appropriate position for the connector, close to a support structure 11. The operator then ascends the structure and removes the electrical insulation from the point of the line to which it is desired to connect the connector. Then, the operative takes the first and second clamping members 2, 3, already loosely assembled, and places them around the appropriate portion of the conductor so that serrated portions 9, 9' of clamping members 2, 3 enclose the overhead conductor. Then the bolts 4, 5 which are already engaged with their corresponding nuts 6 are tightened to bring the two clamping members 2, 3 together. Tightening is carried out to an appropriate torque, at which point, the outer heads 41, of the bolts 4, 5 will shear. The device is now attached to the correct torque.

If during servicing or due to a failure, it is necessary to remove the connector from the line, then secondary heads 42 may be utilised to separate the two clamping members 2, 3.

The arrangement shown in Figure 3 represents a typical arrangement of electrical connector/arc protection device when utilised with an overhead conductor system.

It will be appreciated that the connector may be utilised with the external connection being other than an arc protection device. For instance, the external connection may be for a personal earth.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (13)

1. An electrical connector for connection to a conductor, the connector comprising first and second parts for fitment to the conductor, whereby the first part is an integrated portion comprising a first clamping member and an external connection and the second part comprises a second clamping portion, the connector being arranged so that the first part may be clamped to the second part around the conductor.

2. A connector according to claim 1, wherein the external connection comprises an arc protection device.

3. A connector according to claim 1 or 2, wherein the external connection and the first clamping member are manufactured as a single item.

4. A connector according to claim 1 or 2, wherein the external connection and the first clamping member are manufactured separately and thereafter joined together prior to deployment.

5. An electrical connector according to claim 4, wherein the external connection and the first clamping member are welded together.

6. A connector according to claim 2, or any of claims 3 to 5 as dependent upon claim 2, wherein the arc protection device comprises a combined arcing horn/current conducting wire.

7. A connector according to any of the preceding claims, wherein the two clamping members are especially adapted to be bolted to one another around the conductor.

8. A connector according to any of the preceding claims, wherein the two clamping members are joined together by one or more shear head torque controlling bolts.

9. A connector according to claim 8, wherein the bolt or bolts are double headed such that a first head is arranged to shear when a given tightening torque has been reached and the second head may be utilised to remove the connector if required at a later date for servicing etc.

10. A connector according to claim 2, or any of claims 3 to 9 as dependent thereon, wherein the arc protection device comprises a current conducting wire of approximately one meter long.

11. A connector according to claim 10, wherein the current conducting wire is of a high conductivity material.

12. A connector according to any of the preceding claims, wherein the clamping members are provided with internal serrations or the like so as to provide a reliable mechanical and electrical connection between the connector and the overhead line.

13. An electrical connector substantially as hereindescribed with reference to the accompanying drawings.