The present invention is directed to high voltage, separable connector systems. In particular, the present invention is directed to a 200 amp, hotstick operable, separable deadbreak connector used to directly connect electrical apparatus with a bushing well male interface.
The increasingly widespread use of underground power distribution systems has led to the development of larger systems utilizing components designed to handle greater amounts of power. Electrical power is typically distributed through cables that are connected to other cables and electrical equipment in the system. Separable loadbreak and deadbreak connectors and accessories provide a convenient method to connect and disconnect cables and equipment in underground power distribution systems.
A variety of different connectors and accessories are used in power distribution systems, such as separable elbow connectors, cable joints, bushings, inserts, links, cable terminations and other mating components. Electrical connectors developed for use in such systems can accommodate approximately 5 kV to 35 kV. Loadbreak elbows include provisions for energized operation using standard hotstick tools, allowing load-make and break operation and a visible disconnect. Components can be isolated with insulated caps, plugs and parking bushings. Optional accessories allow system grounding, testing, bypass, lightning surge protection and current limiting fusing. Additional connecting points and taps can be provided using junctions or feed-thrus.
The connectors for high voltage power distribution systems must be designed so that they can be manipulated by an operator at a safe distance from the connection to the high voltage electrical apparatus. To accomplish this, an insulated tool known as a “hot-stick” is used to install and service the connectors. The hot-stick allows the operator to connect, disconnect and maintain the various components in the system from a safe distance of at least 4 or 5 feet.
Proper maintenance procedures in high voltage cable systems require a circuit to be de-energized and isolated by opening switches or disconnecting the cable at both ends of the cable run. The circuit is then tested to ascertain that it is actually de-energized and each phase is grounded at both ends to prevent injury should the cable system accidentally become energized. Finally, the cables are removed from the switch or transformer bushings to achieve a visible break between the cables and their respective bushings.
In underground power distribution systems, electrical power is typically transmitted from substations through cables which interconnect other cables and electrical apparatus in a power distribution network. The cables are typically terminated on bushings that may pass through walls of metal encased equipment such as capacitors, transformers or switchgear. High voltage, separable connector systems have been developed that allow disconnection of the electrical path from a deadfront apparatus to the feeder cables connected to the apparatus bushings without moving the feeder cables and while providing visible-break isolation. The connector systems typically include a removable link or connector located between a deadfront junction mounted to the electrical apparatus and a mating connector (such as an elbow connector) joined to a cable.
The connectors (also referred to herein as “links”) presently in use have bushing inserts (i.e., male connectors) that require a bushing extender and a reducing tap well in order to connect to a bushing or a feed-thru insert. One end of the reducing tap well is connected to the male interface of the bushing or feed-thru insert and the other end is connected to a bushing extender. The bushing extender is then connected to a bushing insert on a link connector.
The multiple components in the link connectors presently being used require additional assembly time and increase the length of the connector assembly. In applications where space is limited, the increased length of the connector assembly can be a problem when installing and maintaining the connector assembly. Therefore, there is a need for a connector assembly with fewer components and a shorter overall length.
In accordance with the present invention, a hotstick operable electrical connector assembly with integral bushing well is provided. The connector for use in a power distribution system includes: a housing, first and second frustoconical members and a well. The housing has a perimetrical side wall extending between first and second surfaces. Each of the first and second frustoconical members extends from the first surface of the housing to a distal end and has an axial bore that extends from the distal end into the housing. Preferably, the axial bore in the second frustoconical member is substantially parallel to the axial bore in the first frustoconical member.
The well includes a wall, a base and a tapered cavity. The tapered cavity extends from the second surface into the housing and has a longitudinal axis that is aligned with the axial bore of the first frustoconical member. The wall extends above the second surface of the housing and surrounds the tapered cavity. The base is located in the housing and has an aperture that provides communication between the cavity and the axial bore of the first frustoconical member.
The well provides a means for directly receiving a male interface of an insert device, for example a bushing insert or a feed-thru insert, without the use of an adapter, such as a bushing extender. The integrally formed well in the connector which allows for direct connection with an insert device provides a connector assembly with a reduced overall axial height. The well further includes an electrical contact assembly that extends through the aperture in the base of the well between the cavity and the axial bore. The wall surrounding the cavity can be substantially circular and can have an exterior surface and a pair of anchors extending therefrom for engaging a hold down bail. A lever arm can be attached to the perimetrical side wall of the housing for connecting and disconnecting the connector. The lever arm has a first end attached to the housing and a second end with an aperture for operation of the lever arm with a hotstick.
The preferred embodiments of the hotstick operable electrical connector assembly with integral bushing well of the present invention, as well as other objects, features and advantages of this invention, will be apparent from the accompanying drawings wherein:
The present invention is a hotstick operable electrical connector assembly, which includes a connector link with an integral bushing well that provides an easier to operate and more compact connector. The design of the electrical connector eliminates the need for a bushing extender/reducing tap or other type of adapter to provide a means for receiving a male end of an insert device so that a bushing or feed-thru bushing insert can be inserted directly into the connector (also referred to as a “link”). The electrical connector with the integral bushing well conforms to ANSI/IEEE Standard 386. The bushing well in the link can have a design similar to the bushing disclosed in U.S. Pat. No. 7,556,540 to Siebens et al., which is incorporated herein in its entirety. Preferably, the connector link is constructed from a solid dielectric material, most preferably ethylene propylene diene monomer (“EPDM”) rubber. High voltage electrical equipment housings constructed using high dielectric strength EPDM rubber insulation is described in U.S. Pat. Nos. 5,667,060; 5,808,258; and 5,864,942 to Luzzi, all of which are incorporated herein in their entirety. In addition to EPDM rubber, a metalized epoxy material can also be used for constructing the connector.
The electrical connector system of the present invention is a deadbreak connector. As used herein, the term “deadbreak connector” is used to refer to a connector that is designed to be separated and engaged when the equipment is de-energized. In contrast, the term “loadbreak connector” is used to refer to a connector that is designed to close or interrupt current on energized circuits.
The electrical connector link with integral bushing is now described in more detailed with respect to the drawings. As discussed above,
Thus, while there have been described the preferred embodiments of the present invention, those skilled in the art will realize that other embodiments can be made without departing from the spirit of the invention, and it is intended to include all such further modifications and changes as come within the true scope of the claims set forth herein.
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