JPH019061Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field This invention relates to a terminal cover in a switch.
For example, a pair of fixed electrodes are fixed to the machine frame for each phase, and a conductive member with a pair of movable electrodes protruding from both ends corresponding to the fixed electrodes is connected to a movable insulator for each phase and a common electrode for each phase. In an air load switch which is vertically movably supported on the machine frame via a movable body, and this movable body is moved vertically by external operation, the movable electrodes are brought into contact with and separated from the fixed electrodes all at once. The present invention relates to a terminal cover that covers a connection terminal for connecting an output wire connected to the fixed electrode.

Purpose The purpose of this invention is to reduce the arc gas pressure generated within the machine frame when a large fault current flows into the power supply side of the air load switch from the distribution line by using a gas guide section protruding from the outer peripheral surface of the terminal cover. This allows the terminal cover to be removed from the main body insulator that covers the fixed electrode, exposing the internal connection terminals, allowing the arc to smoothly transfer from the power supply side to the load side, and preventing arc buildup inside the machine. An object of the present invention is to provide a structure of a terminal cover in a switch which can prevent damage to the porcelain of the switch due to arc heat.

Embodiment Below, an embodiment embodying the present invention is shown in Fig. 1~
To explain according to FIG. 7, as shown in FIGS. 1 and 2, the machine frame 1 includes an upper frame 4 on which a mounting bracket 3 is attached to an armrest 2, and It is composed of four hanging pillars 5 and a rectangular lower frame 6 fixed to the lower ends of the pillars 5. This lower frame 6 includes a pair of stabilizing plates 7 arranged on both the front and rear sides (left and right sides in FIG. 2) and bolted to the pillars 5, respectively, and a connecting rod installed between the left and right sides of each stabilizer plate 7. It consists of 8. Further, below both connecting rods 8, the entire space between both stabilizing plates 7 is closed by a scattering prevention member 9 constructed of a net shape or a plate shape with holes, etc., installed therebetween. Further, both the front and rear sides of the machine frame 1 are closed off by side plates 10 with holes.

A pair of fixed electrodes 12 and an arc extinguishing chamber 13 are provided in the main body insulator 11 fixedly installed on both left and right sides of the upper frame 4 of the machine frame 1 for each phase, and a lead wire 15 connected to the fixed electrode 12 A connection terminal 14 for connection protrudes from one side of the main insulator 11.

A pair of guide rods 16 are fixed at positions corresponding to the center between the pair of main body insulators 11 on both front and rear sides between the upper and lower frames 4 and 6, and the guide rods 16 have movable rods common to each phase. Both ends of the body 17 are supported so as to be movable up and down. And this movable body 1
7 is designed to be opened and closed in the vertical direction by an operating handle 18 via an operating mechanism M shown in FIG. On the lower surface of the movable body 17, movable insulators 19 for each phase are fixedly suspended at positions corresponding to the main body insulators 11 for each phase. As shown in FIG. 1, a conductive member 20 is fixed to the lower end of each movable insulator 19 so as to form an inverted T-shape together with the movable insulator 19. Further, at both ends of each conductive member 20, movable contact blades 21 as movable electrodes that correspond to the fixed electrodes 12 for each phase so as to be able to come into contact with and separate from them are provided to protrude upward.

The connection terminal 14 shown in FIG. 1 is shown in FIGS.
It is covered with a terminal cover 22 shown in the figure, and the lead wire 15 is drawn out from the tip opening 23 of this terminal cover 22. An engaging protrusion 25 is formed on a part of the inner circumference of the proximal opening edge of the terminal cover 22.
When the terminal cover 22 is attached to the main insulator 11, it is removably engaged in an engagement recess 26 formed on one side of the main insulator 11.

On the other hand, a gas guide portion 27 is formed to protrude downward on the lower surface of the base end of the terminal cover 22, and when an arc occurs, the inner surface 27a receives arc gas pressure, so that the terminal cover 22 becomes a main body insulator. It is starting to leave from 11th.

Further, a butterfly-shaped plate-shaped terminal horn 31 made of a conductive material is attached to the lower central surface of both the power supply side and load side connection terminals 14 with screws (not shown), and as shown in FIG. The protruding pieces 32 protrude toward the main insulator 11 with their tips open. When the terminal cover 22 is removed, as shown in FIG.
1 is exposed to the outside.

Next, the effect will be explained.

Now, a major fault current flows into the power supply side of the air load switch constructed as described above from the distribution line.
When the current flows in the direction of arrow I shown in Figure 4, the weakest ground insulation of the switch, that is,
An arc occurs between the power supply side connection terminal 14 and the upper frame 4, and from this state, a short circuit occurs between different phases, and an arc occurs.
A ₁ occurs. In that case, since the lower part and both front and rear sides of the machine frame 1 are respectively blocked by the anti-scattering member 9 and the side plates 10, the arc gas tends to get trapped inside the machine frame 1, and the gas pressure can escape toward the connection terminal. becomes. Due to the gas pressure, the gas guide section 27 is attached to the terminal cover 22 on the power supply side and the load side.
Pressure is applied through the inner surface 27a of the main body insulator 1.
The engagement protrusion 25 of the terminal cover 22 is disengaged from the engagement recess 26 of the terminal cover 22, and the terminal horn 31 of each phase connection terminal 14 is largely exposed.

In this state, the arc _A1 attempts to move in the direction of arrow P due to the action of electromagnetic force. Also, in the direction between the same phases, as shown in Fig. 4, an arc is generated below the switch (in the direction of arrow S) due to the action of electromagnetic force.
_A1 tries to migrate. Therefore, the arc as a whole tends to move in the direction of arrow Q in FIG. 4, that is, diagonally downward on the load side of the switch.

Therefore, as shown in FIGS. 2 and 4, the arc is extended diagonally downward on the load side, and as shown in FIG. ₂ occurs. The arc A ₂ is similarly transferred diagonally downward on the load side of the switch, and as shown in Fig. 3, it transfers to a phase-to-phase short circuit between the load side movable contact blades 21 of different phases, causing an arc.
It becomes _A3 . Furthermore, the arc A ₃ is similarly shifted diagonally downward on the load side of the switch, and shifts to an interphase short circuit with the upper and lower terminal horns 31 of the load side connection terminal 14 as the firing point, as shown in FIG. arc like
It becomes A ₄ and stops. Therefore, in this state, the arc A ₄ is stationary outside the machine frame 1 of the switch, so there is no fear that the surface of the main insulator 11 will be exposed to the arc and destroyed by uneven heat.

However, if the terminal cover 22 on the load side is not removed, the terminal horn 31 is not exposed, so that the arc A ₃ becomes difficult to move from the movable contact blade 21 on the load side to the connection terminal 14 on the load side. As a result arc A ₃
stops, and the surface of the main insulator 11 is exposed to the arc, causing damage to the porcelain. Needless to say, when such a large fault current flows in, the distribution line is opened by the substation OCR operation.

Another Embodiment FIGS. 8 to 10 show a modified example of the gas guide part, in which an opening 29 is cut out on the lower surface of the base end of the terminal cover 22, and the opening 2
A plate-shaped gas guide portion 30 is provided to protrude downward from the tip edge of the gas guide portion 9 . The pressure receiving surface 30a inside the gas guide section 30 is curved toward the main insulator 11 side so that the center of curvature is on the main insulator 11 side, and is formed in an oblique shape so that the tip approaches the main insulator 11 side. There is.

Note that the shape and attachment location of the terminal horn 31 are not limited to this embodiment, and can be changed as desired. Furthermore, the gas guide section 27 and the terminal horn 31 are provided on both the power supply side and the load side in consideration of the fact that the power supply side and the load side may be reversely arranged when equipment is mounted on a pole. .

Effects The present invention described in detail above enables the movable electrode 21 to be moved into and out of contact with the fixed electrode 12, covers the connection terminal 14 for connecting the lead wire 15 connected to the fixed electrode 12 with the terminal cover 22, and covers the terminal cover 22. In a switch in which a cover 22 is attached to a main body insulator 11 that covers a fixed electrode 12, the terminal cover 22 is removably attached to the main body insulator 11, and a gas guide portion 27 is provided on the outer peripheral surface of the terminal cover 22. By providing the arc gas pressure, the terminal cover 22 is
The connecting terminal 14 can be largely exposed by separating it from the device, and as mentioned above, the transition of the arc from the power supply side to the load side is performed smoothly, preventing arc buildup inside the machine, and preventing arcing outside the device. By keeping the switch stationary, damage to the porcelain of the switch due to arc heat is prevented, which has the effect of preventing public disasters.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing an air load switch with a terminal cover attached, which is the first embodiment of the present invention, Fig. 2 is a side sectional view, and Fig. 3 is a schematic plan sectional view. , FIG. 4 is a schematic front sectional view, FIG. 5 is a front sectional view of the terminal cover according to the first embodiment, FIG. 6 is a plan view, FIG. 7 is a left side view, and FIG. 8 is a terminal. It is a perspective view showing a horn. 9 to 11 show another embodiment, in which FIG. 9 is a front sectional view of the terminal cover, FIG. 10 is a plan view, and FIG.
The figure is also a left side view. Machine frame 1, upper frame 4, lower frame 6, scattering prevention member 9, side plate 10, main body insulator 11, fixed electrode 12, connection terminal 14, lead wire 15, movable insulator 19, movable contact blade (movable electrode) 21, Terminal cover 22, engagement protrusion 25, engagement recess 26, gas guide section 27, inner surface 27a thereof, and terminal horn 31.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A main body in which a movable electrode can be moved into and out of contact with a fixed electrode, a connecting terminal for connecting an output wire connected to the fixed electrode is covered with a terminal cover, and the terminal cover covers the fixed electrode. In a switch attached to an insulator, the terminal cover is removably attached to the main insulator, and the outer peripheral surface of the terminal cover is exposed to arc gas pressure to separate the terminal cover from the main insulator and connect the connecting terminal. A structure of a terminal cover characterized by a protruding exposed gas guide portion. 2. The structure of a terminal cover in a switch according to claim 1, wherein the gas guide portion is formed as a bulge on the lower surface of the base end of the terminal cover.