Patent Application
20220285056
The invention relates to a dielectric cover for a high voltage fuse cutout that protects birds and other animals from electrocution, which may also trigger an over-current condition that causes a power outage. The invention more particularly relates to a customizable cover that can cover a variety of types of fuse cutouts while ensuring protection for the wildlife.
In
The conventional fuse cutout 70 includes a fuse 73 that blows when a current exceeds a threshold. This causes the blown fuse to pivot downward to electrically disconnect the top of the fuse 73 from a high voltage connector 72. The fuse 73 can be manually disconnected using a hot stick or a load breaker tool by pulling down on the ring 74. The cutout 70 also includes an insulator 76, which is attached to a utility pole using a bracket 78.
To prevent birds and other wildlife from creating a flashover between a high voltage component and another wire or a grounded structure, a molded polymer cutout cover 140 is affixed over the cutout 70. Retaining pins 80 extend through holes in the cover 140 and under the high voltage connector 72 to prevent the cover 140 being blown off in high winds.
The cover 140 includes an integral molded roof 144 that is adequate to cover the tops of fuses in certain types of fuse cutouts.
During high voltage testing of the structure of
What is needed is a low cost solution to the above flashover problem in a fuse cutout cover or other high voltage cover that employs a cruxiform-hole connector for connecting together dielectric parts.
In one embodiment of the invention, a fuse cutout cover is provided that has a molded roof that is suitable for covering the top of a fuse in certain types of fuse cutouts. A separate roof extension is provided for covering larger types of fuse cutouts, such as a Fault Tamer™ cutout. The roof has molded male cruxiform connectors that tightly fit into aligned holes in the roof extension.
In order to prevent flashovers through the air gaps between the cruxiform connector and the side of the holes, the holes are sealed at the bottom. There is no extra cost to sealing the hole since the roof extension is a single molded piece. The roof and the roof extension surfaces are flush so there is no significant air gap between them.
By sealing the bottom of the holes, there is no air gap created with the connection, and flashover is prevented between the roof and the roof extension.
The invention may be applied to any high voltage cover that connects dielectric pieces together using a cruxiform connector.
Elements in the various figures that are the same or equivalent are labelled with the same numeral.
The present invention prevents flashover via the connection between dielectric pieces in a high voltage cover by sealing the bottoms of any holes that receive a male connector. In one example, the male connector is a cruxiform, forming a polymer plus sign or a cross, and the hole has sides that form a tight fit when the cruxiform is pressed into the hole. Typically, the hole has an open bottom, which creates an air gap, forming a weak link in high voltage protection. Flashover occurs through this air gap. By sealing the bottom of the hole, there is no air gap, and no weak link, so the dielectric properties of the high voltage cover are improved.
The example shown is a fuse cutout cover, and a modification of the Applicant's own design is shown in
The sealing of the bottom 22 of the hole 24 prevents an air gap occurring in the connection between the cruxiform connector 145 and the hole 24 in the roof extension 142.
In one embodiment, the cruxiform connector 145 is about one-quarter to one inch in diameter (depending on the size of the cover) and protrudes about one-half inch from the bottom surface of the roof 144. The hole 24 in the roof extension has about the same diameter as the cruxiform connector 145 for a tight fit and protrudes downward from the bottom surface of the roof extension 20 by a depth so that the bottom surface of the roof 144 is flush with the top surface of the roof extension 20 so there is no or an insignificant air gap between the two pieces. The bottom of the cruxiform connector 145 may or may not contact the bottom 22 of the hole 24.
The modified roof extension 20 incurs no additional cost, yet its insulating properties are greatly enhanced.
There may be multiple roofs for different types of fuse cutouts, and one or more of the roofs may have cruxiform connectors for attaching a roof extension.
Other types of covers, such as for high voltage insulators supporting an energized wire, may also have attachments that use a cruxiform connector and a hole. All such covers will benefit from sealing the bottom of the hole to prevent an air gap forming.
Other embodiments are envisioned.
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.
