JPH0156612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a connecting portion between an electrical device and a cable, which is useful, for example, when electrically connecting a plurality of cubicles housing electrical devices.

[Technical Background of the Invention and Problems Therewith] Electrical equipment including switching devices such as circuit breakers and disconnectors, and switchboards equipped with meters, relays, etc., is housed in the cubicle.

As shown in FIG.
Inverted T-shaped branch bushings 2a, 2 installed inside
They are electrically connected by busbars 3ab and 3bc that communicate between them.

Note that the connection between the bus bar and the branch bushing is
As shown in the figure, this is accomplished by press-fitting a wedge 6 attached to the tip of a cable conductor 5 into an intermediate closed cylindrical shielding electrode 4 built into the center of the base of the branch bushing 2.

In the figure, 7 indicates a conductor pull-out rod, and 8 indicates a mold stress cone.

By the way, the conductor connections between electrical devices are usually exposed, and therefore the insulation distance between the live parts and the case (in the case of three-phase, between different phases) must be increased in proportion to the voltage.

However, if the insulation distance is increased, the cubicle etc. will become larger and the required space will become larger.

For this reason, mini-clad cubicles have been developed in which sulfur hexafluoride gas (SF ₆ gas) is sealed in the cubicles 1a, 1b, and 1c.
In such a mini-clad type cubicle, the gas pressure is high (approximately 2.5 kg/cm ² ), so the cubicle case wall must be thick, which makes the cubicle heavy, making it difficult and expensive to transport. There was a problem.

Therefore, a low gas pressure (approximately 0.5
A so-called low gas pressure cubicle has been proposed, which is filled with SF ₆ gas of Kg/cm ² ), shortens the insulation distance, downsizes the entire cubicle, and makes the cubicle easier to transport.

However, in such low gas pressure type cubicles, as the cubicles become smaller, the length of the busbars that electrically connect each cubicle becomes shorter, and it becomes proportionately difficult to bend the busbars. The connection method shown in Figure 2 has the disadvantage that it is difficult to bend the busbar and insert the wedges attached to both sides of the busbar into the branch bushings, making it difficult to make electrical connections between the cubicles. Ta.

[Object of the Invention] The present invention was made based on the above-mentioned circumstances, and an object of the present invention is to provide a connection portion between an electric device and a cable that can easily establish electrical connections between cubicles even when the cubicles are downsized.

[Summary of the Invention] That is, the electrical equipment and cable connection part according to the present invention has a receiving port for receiving a cable terminal on its side, and a cylindrical shielding electrode is built in the center of its base. and at least two branch bushings in which only the tips of the conductor pull-out rods protruding in the radial direction from a part of the outer periphery of the shielding electrode are exposed, and each conductor end with both ends exposed by step stripping. at least two branch bushings are formed by passing each plug of the cable through the receiving port and fitting tightly into a contact disposed on the inner periphery of each of the shielding electrodes. In a connecting portion between an electrical device and a cable that are electrically connected, the inner diameter of the contact and the diameter of the receiving port are larger than the finished outer diameter of the cable.

[Embodiments of the invention] Next, examples of the present invention will be described.

In FIG. 3, cases 10a and 10, such as cubicles, house electrical equipment (not shown) such as switchgears and switchboards, and contain SF ₆ gas 9 inside.
b, 10c Inverted T-shaped branch bushing 1 on the wall side
1a, 11b, and 11c are cases 10a, 10b, and 10, respectively, where the tips of conductor pull-out rods 13, which will be described later, are
It is installed airtight so that it is located within c.

The branch bushings 11a, 11b, 11c are the fourth
As shown in the figure, a cylindrical shielding electrode 12, a conductor pull-out rod 13 protruding in the radial direction from the outer periphery of the central part of the shielding electrode, a contactor 14 disposed on the inner periphery of the shielding electrode 12, and On the outer periphery of the charging member, there is a receptacle 1 for a cable terminal connected to the tip of the conductor pull-out rod 13 and the end of the contactor 14 or the shield electrode 12.
It is comprised of an inverted T-shaped bushing 16 that is molded and coated with epoxy resin or the like, except for part 5. The contactor 14 is formed by inserting an elastic conductive plate with a large number of punched holes into a groove 17 provided on the inner periphery of the shield electrode 12 along the inner wall of the groove.

Next, apply 66kV to 77kV between the above branch bushings.
This section describes a method for connecting cables made of grade cross-linked polyethylene insulated cables.

As shown in FIG. 5, first, both ends of the cable 18 are stripped in steps to expose the cable conductors 19, 19 and the cable insulators 20, 20, and a cable shielding layer 21 is formed on the outer periphery of each exposed cable insulator or on the outer periphery of the cable. Stress cones 22, 22 for alleviating the electric field at the ends, pressing members 23, 23 such as springs for pressing the stress cones toward the receiving port 15 of the cable terminal, protective tubes 24, 24 for protecting the cable terminals, etc. are attached. .

Next, attach a contact 1 to one end C of the cable conductor 19 with a diameter that is approximately equal to or larger than the outer diameter of the cable before step stripping, that is, the finished outer diameter D of the cable.
4, and then connect the other end B of the cable conductor 19, to which the plug 25 is not attached, to the contact 14 in the other branch bushing 11b. In this state, the same plug 25 as described above is attached to the other end B of the cable conductor 19.

Then, pull back the cable 18 in the direction of the arrow, tightly fit each plug 19, 19 into each contactor 14, 14 in each branch bushing, and apply required parts such as each stress cone 22, 22, which has been installed in advance. are placed in a predetermined position and assembled by conventional means.

Branch bushing 11a and branch bushing 11b
The connection with the cable is also made in the same manner, and the connection between the electric device and the cable according to the present invention is thus completed.

In the figure, 26 is a case side wall, 27 is a seal, 28
2 indicates an outer semiconducting layer, and 29 indicates a shield.

[Effects of the Invention] In the present invention described above, the branch bushing and the cable conductor are connected by a plug-in method,
In addition, the inner diameter of the contact and the diameter of the receiving port of the cable terminal are made larger than the finished outer diameter of the cable so that the cable can fit loosely inside the contact, so even if the distance between the branch bushings is short, the cable can be easily inserted between the branch bushings without bending. can be electrically connected.

Therefore, in the present invention, the length of the cable for communication between cubicles can be shortened to a length sufficient to attach necessary parts such as stress cones, so that it is possible to shorten the length of the cable for connecting between cubicles, so that it is possible to shorten the length of the cable for connecting between cubicles. Connections can be provided.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the connection between a conventional electric device and a cable, Fig. 2 is a sectional view of a main part showing the connection between a conventional branch bushing and a bus bar, and Fig. 3 is an explanatory diagram showing the connection between a conventional electric device and a cable. FIG. 4 is a cross-sectional view of the main part showing the connection between the branch bushing and the cable in the present invention, and FIG. 5 is a schematic explanatory diagram showing the method of connecting the branch bushing and the cable in the present invention. be. 11, 11a, 11b, 11c...branch bushing, 12...shielding electrode, 13...conductor pull-out rod,
14... Contact, 15... Receiving port, 16... Bushing, 18... Cable, 19... Cable conductor, 20... Cable insulator, 22... Stress cone.

Claims (1)

[Claims] 1. It has a receiving port for receiving a cable end on its side, and has a cylindrical shielding electrode built in the center of its base, and extends radially from a part of the outer periphery of the shielding electrode. The cable consists of at least two branch bushings with only the tips of the conductor pull-out rods protruding from the outside exposed, and a cable with a plug attached to each conductor end exposed by step stripping at both ends. An electrical device and a cable, each of which is electrically connected to at least two branch bushings by tightly fitting each plug of the cable through the receiving port and into a contact disposed on the inner periphery of each of the shielding electrodes. A connecting portion between an electrical device and a cable, characterized in that, in the connecting portion, an inner diameter of the contact and a diameter of the receiving port are larger than a finished outer diameter of the cable. 2. The electrical equipment according to claim 1, wherein the branch bushing is airtightly attached to a side wall of a case housing the electrical equipment so that the tip of the conductor pull-out rod is located within the case. and cable connections.