Patent Application
20220285055
This invention relates to a dielectric cover for high voltage power line insulators and conductors (wires) and, in particular, to an insulator cover system that has a separate shell for certain types of insulators having a metal end. The shell is not used for standard insulators.
A wood or metal utility pole is typically used for supporting high voltage (HV) conductors (e.g., twisted wire strands) in a power distribution system. Each pole has secured to it one or more crossarms that support insulators which, in turn, support the HV conductors. The insulators are typically ceramic or a polymer. A conductor is typically secured over the top of each insulator, or along its side, via a metal tie wire, a bracket, a clamp, or other means.
One known problem with exposed insulators and conductors is that large birds or other wildlife may alight on the grounded crossarm and short out phases or short a conductor to ground. Insulating (e.g., plastic) covers that cover the insulator 12 and a portion of the conductor 16 extending from the insulator 12 are known.
Holes 36 extend through the cover 24 and arms 28/30 and below the conductor 16. Retaining pins, described later, are inserted through the holes 36 and pass through corresponding holes on the opposite side under the conductor 16, which secures the cover 24 in place. The pins and the cover 24 may be manipulated by a hot stick while high voltage is conducted by the conductor 16 so there is no loss of power to the consumer when the cover 24 is installed.
The bottom of the insulator cover 26 rests on the wide skirt 20 of the insulator 12, or the top of the insulator abuts against the ceiling of the insulator cover 26, depending on the type of insulator used.
Limited (K-Line™). The insulator 36 is available in various forms depending on the voltage and use. The lengths L vary between about 1-2 feet. The insulator 36 has a robust metal base 38 that is bolted to a base, a porcelain or polymer insulator 40, and a metal top 42. The metal top 42 may include a clamp for a wire. The metal top 42 provides a robust support for the wire. In order to protect wildlife, the entire high voltage metal top 42 must be covered by a suitable dielectric cover. The metal top 42 may be on the order of 3-6 inches in length.
What is needed is a dielectric cover for an insulator supporting a high voltage conductor, where the same cover can be used for standard insulators and for K-Line type insulators with a metal top.
Applicant manufactures an insulator cover designed for standard insulators. The standard insulator supports a high voltage conductor and has either no metal on top or a relatively small metal connector/support on top that contacts the wire. Occasionally, a utility company uses a K-Line type insulator having a relatively large metal top that extends down by, for example, 2-6 inches. The size depends on the voltage and the purpose of the insulator. Such a large metal top extends below Applicant's insulator cover by at least one inch, thus exposing wildlife to the high voltage.
Rather than Applicant manufacturing a specially designed insulator cover for the K-Line insulator, Applicant has designed an inexpensive dielectric shell that fits over Applicant's existing insulator cover. The shell effectively extends the cover downward by about two inches to completely cover the metal top of the K-Line insulator. In one embodiment, the bottom of the shell rests on the top rib of the K-Line insulator so lateral coverage of the metal top is assured.
The shell securely connects to the existing cover and may be connected by a lineman in the field or in a factory as required. Accordingly, inventory requirements are greatly eased since the same insulator cover can be used with standard insulators as well as a K-Line insulator. Only the inexpensive shell needs to augment the existing insulator cover.
The K-Line insulator may simply support a high voltage conductor or may be a bushing, where a conductor through the middle of the insulator connects between a top connector and a bottom connector.
Although the term K-Line has been used to describe the type of insulator with a large metal top, other insulators not manufactured by K-Line may also use large metal tops, and Applicant's cover and shell can fully cover such large metal tops. Different shells may be provided for different types of insulators, potentially extending the effective depth of the cover by four or more inches.
The cover includes attachable dielectric arms to cover the wire extending from the insulator. The coverage is sufficient to prevent birds from directly contacting exposed wires when spreading their wings while perched on the utility pole.
The cover and arms are secured over the insulator and wire by retaining pins that extend through holes in the cover and under the wire. The shell for the K-Line type insulator may be affixed to the cover by plastic bolts or other connectors. Thus, the cover and shell cannot be blown off the insulator in high winds. The pins may be easily removed by a lineman using a hot stick.
Other features of the cover system are also described.
Elements labeled with the same numerals in the various figures may be identical or similar.
Holes 52 extend through the cover 46 and below the conductor. Identical retaining pins 54 are inserted through the holes 52 and pass through corresponding holes on the opposite side under the conductor, which secures the cover 46 and arms 48 in place. The pins 54 and the cover 46 may be manipulated by a hot stick while high voltage is conducted by the conductor so there is no loss of power to the consumer when the cover 46 is installed. The hot stick has a hook that engages holes in the cover 46, or the top handle 55, and a ring in the pins 54. More detail of the pins is described in Applicant's U.S. Pat. No. 10,679,815, incorporated herein by reference, describing a dielectric cutout cover held in place using dielectric retaining pins.
The shell 58 may be provided in various sizes to accommodate insulators with varying metal top lengths.
Although the shell 58 and cover 46 are open near the bottom in the direction of the conductor (wire), birds would not come in contact with any high voltage metal exposed along that direction and below the cover 46.
Accordingly, the cover 46 is effectively supported by the top rib 62 of the insulator 40, and is prevented from being blown off by the retaining pins 54. Depending on the height of the cover 46 above the insulator 40, any suitable hole in the cover 46 may be used for the pins 54.
As seen in the perspective view of
Rounded fenders 66 over the pin 54 areas act as arched roofs or shields. The fenders 66 extend out from the cover 46 by about one inch to shield the rings of the pins 54 and still allow the lineman to grasp the ring of the pins 54 by a hot stick. The fenders 66 have multiple purposes. The fenders 66 effectively prevent birds roosting on the pin 54 (whose shafts are directly below the HV conductor), increase the dielectric surface length between the top of the cover 46 and the electrical conductor above the pins 54, and protect the pins 54 from contamination issues which would reduce the dielectric properties of the pins 54. Contamination issues include birds defecating on the pins 54, which can create a conductive path between the bird and the inside of the cover 46, and atmospheric moisture such as rain, snow, and ice on the pins 54.
There are a variety of insulator shapes, and the insulator 36 is just an example. The insulator cover 46, arms 48, and shell 58 may be molded to accommodate any standard insulator shape and any K-Line type insulator shape while still retaining all aspects of the invention.
Having described the invention in detail, those skilled in the art will appreciate that, given the present disclosure, modifications may be made to the invention without departing from the spirit of the inventive concept described herein. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described.
