JPS61109403A - Bushing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to improvements in insulating bushings for bus bar penetrations in closed switchboards.

[Background of the invention]

In the conventional bushing, insulation and mechanical strength were increased by surrounding the conductor 5 with insulating pleats 21 and 22, as disclosed in Japanese Patent Laid-Open No. 52-118227, but the conductor was arranged in a straight line. Because of this, many folds were required to ensure insulation from adjacent busbars, and insufficient consideration was given to miniaturization.

[Purpose of the invention]

An object of the present invention is to provide a through-type bushing that is small, has strong electrical insulation strength, and has strong mechanical strength.

[Summary of the invention]

The bushing of the present invention divides three-phase conductors into halves when arranging them on a rectangular insulating plate, and makes the area where one conductor is arranged smaller than the area with the other two. The aim is to arrange the conductors in such a way that reinforcing ribs are inserted between the rectangular conductors on the side containing the book conductors, thereby increasing the electrical insulation and the strength of the material.

[Embodiments of the invention]

EMBODIMENT OF THE INVENTION Hereinafter, an embodiment of the present invention will be explained using a closed switchboard 1 shown in FIG.

When a door 2 attached to one end of the closed switchboard 1 is opened, a partition plate 3 is attached inside the closed switchboard 1 to form an electrical chamber 4 and a conductor chamber 5 within the closed switchboard. The circuit breaker 6 enters and exits the electrical room and electrically connects and disconnects from fixed disconnecting sections 7A and 7B attached to the partition wall plate 3. Both fixed disconnecting sections 7A and 7B are separated by conductor chamber side partition plates 8. A lower fixed disconnector 7A disposed in the lower conductor chamber is connected to a cable head 10 via a current transformer 9. The upper fixed disconnector 7B arranged in the upper conductor chamber connects the three-phase bus 12A via the conductor 11.

12B and 12C, and the three-phase busbar is supported by a bushing 13. The bushing 13 is attached to the closed switchboard 1 and the detailed structure will be explained with reference to FIG. 2.3.

The bushing 13 has an insulating plate body 14, and the insulating plate body 1
A screw hole 15 is formed in the even corner part of 4, and the insulating plate main body 14 is attached to the closed switchboard 1 using bolts and nuts through the screw hole 15. The outer ring 16 surrounds the inner insulating plate main body 14 of the screw hole 15 and is formed to protrude to one side.

The first rib 17 is formed on the intermediate insulating plate main body 114 of the outer circumferential rib 16, and the position of the first rib 17 is such that the distance between the first rib 17 and the corresponding left and right outer circumferential ends 14A, 14B is 1.
, 1! If so, 1. >1. There is a relationship between 1. The three-phase bus 12A is connected to the side insulating plate main body 14X1 at t! Side insulating plate main body 14 Two-phase three-phase bus 1 on X2 and X3
2B and 12C penetrate through each. These three-phase busbars 12. A circular rib 18 protruding to one side along lines A to 12C is formed on the insulating plate main body 14. Insulating plate main body portion 14 Xs between the first rib length 7 and the outer peripheral end 14A
, A second rib 20 is formed at Xs. 2nd rib 2
0 forms an inclined surface 21 whose height increases sequentially from the lower end side of the first rib 17 toward the upper end side of the outer peripheral rib end 14A.

With this configuration, the area of each of the insulating plate main bodies X! , if the area of Xs is narrow, the 211th ′ of the inclined surface 21
Since the insulation distance between the bus bar 12B and the bus bar 12C is substantially increased by providing the bus bar 20, it is possible to reduce the size of each insulating plate main body portion 14Xs, 14Xs, and increase the mechanical strength. Can be done.

Further, as shown in FIG. 3, when providing the second rib 20,
If it is provided at a weak boundary between the equipotential lines 22 of both bus bars 12B and 12C, the insulation layer of the second rib 20 will not be thinned or dielectric breakdown will not occur due to electric field concentration.

〔Effect of the invention〕

As described above, according to the bushing of the present invention, it is possible to reduce the size and increase the mechanical strength.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a closed switchboard that is an embodiment of the present invention;
Figure 2 is a perspective view of the bushing used in Figure 1, and Figure 3 is a perspective view of the bushing used in Figure 1.
The figure is a plan view of FIG. 2. 12A, 12B, 12C...Three-phase bus bar, 13...Bushing, 14...Insulating plate, 14A, 14B...Outer circumferential ring, 17...First rib, 18A-18C...Circular Rib, 20...second rib.

Claims (1)

[Claims] 1. In an insulating plate having a bushing through which conductors of at least three phases pass through, a first rib formed in the insulating material and partitioning one bushing and two bushings on the left and right; and 2 formed in the insulating plate on the second bushing side.
A bushing comprising: a second rib which divides each bushing into an upper part and a lower part and which is inclined; 2. The bushing according to claim 1, wherein the second rib is formed at a location where the equipotential lines of each conductor are weak.