JP3175703B2 - Insulated switchgear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated switchgear in which one or more of a circuit breaker, a disconnector, a load switch, and a grounding device are assembled or combined.

[0002]

2. Description of the Related Art Generally, a power receiving and transforming apparatus receives power from a power company, for example, by a disconnector and a circuit breaker, changes the voltage to a voltage optimal for a load by a transformer, and supplies power to a load, such as a motor. . To maintain and inspect the substation equipment, turn off the circuit breaker, open the disconnector provided separately from the circuit breaker, and ground the earthing switch to prevent residual charge on the power supply side.
The induced current is allowed to flow to the ground, and re-application from the power supply is prevented, thereby protecting the worker. Further, if the grounding switch is grounded while the bus is charged, an accident may occur. Therefore, an interlock is provided between the disconnecting switch and the grounding switch.

[0003]

Problems to be Solved by the Invention For example, Japanese Patent Application Laid-Open No. 3-27380
In the gas insulated switchgear described in Japanese Patent Publication No. 4 (1995), a circuit breaker, two disconnectors and a grounding switch are individually manufactured and housed in a unit room and a bus room in which a distribution box is filled with insulating gas. When a vacuum circuit breaker is used as a circuit breaker, the movable contact moves up and down with respect to the fixed contact by the operation device of the vacuum circuit breaker, and is turned on and off, or described in JP-A-55-143727. In the vacuum circuit breaker, the movable contact is turned left and right with the main shaft as a fulcrum, and is brought into and out of contact with the fixed contact to make and break.

In order to perform maintenance and inspection of the gas insulated switchgear, after disconnecting the circuit breaker, two disconnecting switches provided separately from the circuit breaker are opened, and the grounding switch is grounded, so that the residual voltage on the power supply side is reduced. The electric charge and induced current flow to the ground to prevent re-application from the power supply side, and protect the safety of workers. At the end of maintenance and inspection, after opening the earthing switch, the circuit breaker must be turned on, and a series of operations cannot be performed continuously, making operation difficult.
Not easy to use.

Further, the circuit breaker, the two disconnectors, and the grounding switch are individually arranged, and accordingly, the size of the device is increased, and it is difficult to operate the device separately. There are drawbacks such as the possibility of erroneous operation. In addition, if the grounding switch is grounded while the bus is charged, an accident may occur.Therefore, a complicated and robust interlock is provided between the disconnecting switch and the grounding switch, which restricts the arrangement of the equipment. The device becomes larger.

An object of the present invention is to provide a compact and easy-to-use insulated switchgear which performs a series of operations continuously.

Another object of the present invention is to provide an insulated switchgear which is further miniaturized by reducing the operating force of the operating device by utilizing electromagnetic force.

[0008]

According to the present invention, there is provided an insulated switchgear according to the present invention, wherein a fixed conductor and a ground conductor correspondingly arranged in a vacuum valve are opened and closed with both conductors with a main shaft serving as a fulcrum between the conductors, and one side is a vacuum valve. A movable conductor extending to the outside, and the movable conductor moves from the fixed conductor to the ground conductor, and is operated in one of four positions of a closed position, an open position, a disconnection position, and a ground position, or three positions excluding the disconnection position. Was performed continuously.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows the internal structure of the insulated switchgear. The details of the insulating gas container 1 are shown in FIGS. FIGS. 4 and 5 are external views as viewed from the left and right sides of FIG. 6 and 7 are sectional views taken along lines DD and EE in FIG. Other FIGS. 8 to 1
2 will be explained as needed.

A description will be given mainly with reference to FIGS. Insulating gas container 1 is arranged a vacuum valve 11 into the interior of the insulating gas 1G example SF ₆ is configured as follows. The insulating container body 2 is integrally molded of epoxy resin between two insulating partition plates 3 via three vacuum valve arrangement locations 2S. The main body insulating plate 4B and the fixed insulating plate 4A are provided on the lower side and the upper side of the insulating container main body 2 to form a hollow box having a substantially rectangular hollow shape. The bus insulating plate 6 is detachably disposed in the three openings 4D penetrating the three-phase bus in the fixed insulating plate 4A. The insulating cover 7A and the back side insulating cover 7B are detachably fixed to the front and rear surfaces of the hollow container insulating container body 2 with the fastening screws 5 to form an insulating gas container 1 filled with an airtight insulating gas 1G. are doing.

A ground layer 9 is provided on the outer surface of the insulating gas container 1 to increase the withstand voltage of the insulating gas container 1 and reduce the size thereof. In addition, even if the insulation performance deteriorates due to leakage of the insulation gas 1G, a so-called double insulation structure that can be insulated by the insulation gas container 1 such as the insulation partition plate 3 is used to prevent accidents from spreading and maintain safety. I have. When the fastening screws 5 are removed and both insulating covers 7A and 7B are removed, the location 2S between the insulating partition plates is removed.
In addition, since each vacuum valve 11 can be easily stored on either the front surface or the rear surface, the efficiency of assembling and disassembling operations can be significantly improved. Both insulating covers 7A and 7B and insulating gas 1
Since the dielectric constant is different from that of G, a partial discharge is likely to occur when the insulation distance is reduced, so that the insulation gas container 1 close to the insulation gas container 1 of the vacuum valve 11 and the operation mechanism 38 is formed.
A concave portion 7C is provided on the inner surface to alleviate the electric field and prevent the occurrence of partial discharge. 5A is a screw insertion hole.

The vacuum valve 11 shown in FIGS. 1 and 4 to 7 has a metal case 12 and a metal case
Insulating bushings 13 and 14 of ceramic members protruding upward and downward are provided. A fixed conductor 16 and a ground conductor 17 are attached to a sealing metal 15 provided outside the upper insulating bushing 13 and the lower insulating bushing 14, respectively. Arc extinguisher 18 and movable conductor 19 are provided on the left and right sides of vacuum valve 11 between the conductors.
, The vacuum valve 11 having a substantially cross shape is formed.

The width of the sealing member 15 is W1, and the arc extinguishing device 1
When the width of the metal case 12 at the position of the electrode such as 8 or the movable conductor 19 is W2 and the length of the metal case 12 is W3,
W2 is equal to or larger than W1, and W3 is W
The size is equal to or larger than 2. While the entire voltage is applied to the sealing metal 15 (this width W is 1) through which the conductor 16 having a small cross-sectional area passes, the voltage of the metal case 12 (this width W2) covering the arc extinguishing device 18 is A voltage smaller than the full voltage is applied (this voltage is an intermediate voltage of the full voltage, ie, theoretically half). W3 is an arc extinguishing device 18 and a movable conductor 19
And a contact center point at which the fixed conductor 16 contacts.

When these vacuum valves 11 are arranged in three phases, the vacuum valves 11 of each phase are arranged as shown in FIG. 4 in a direction perpendicular to the movable conductor 19 projecting outside the vacuum valves. As a result, the width W2 between the vacuum valves 11 is mutually different.
, The insulation distance of W1 can be sufficiently set, and the width W2 direction can be reduced.

A fixed contact 16A made of a high melting point metal member, for example, a Pb-Cu alloy is provided at the tip of the fixed conductor.
The fixed conductor 16 extends from the inside of the vacuum valve 11 to the outside, and the bus-side conductor 23A is connected to the outside.
The fixed conductor 16 is fixed to the supporting portion 4C of the fixed insulating plate 4A by tightening it with bolts 22. The bus-side conductor 23A is connected to a bus 23B of the bus insulating plate 6. That is, the bus insulating plate 6 is formed by integrally casting the bus-side conductor 23A and the bus 23B with an insulating resin such as epoxy.

A metal fitting 15 provided on the lower bushing 14
The grounding conductor 17 attached to the elastic sealing metal 25 is supported by an insulating guide 24 and a fixed guide 29, and is axially moved by a spring 26 in accordance with the contact of the movable conductor 19. Moving. The grounding conductor 17 is fixed by fastening a stopper plate 27 compressing a spring 26 provided in the middle or a copper plate 28 made of a plurality of thin copper plates with a grounding nut 31 fitted to a protruding end thereof. Therefore, at the time of grounding, the movable conductor 19 comes into contact with the pressing force for pressing the ground conductor 17 and the compressive force of the spring 26, and the ground current flows to the external ground terminal 32 via the copper plate 28. Since the external ground terminal 32 protrudes in a direction opposite to the protruding side of the movable conductor 19, the connection end of the movable conductor 19 is not hindered when the ground cable is connected to the external ground terminal 32, and the attaching / detaching operation is easy. I can do it.

The movable conductor 19 extending at right angles rotates between the fixed conductor 16 and the ground conductor 17 with the main shaft 35 as a fulcrum, and opens and closes with both. Fixed contact 16A and movable contact
An arc extinguishing device 18 that extinguishes the arc in the direction of arc discharge generated between the two when 19A is opened is provided.

In order to mount the arc extinguishing device 18, as shown in FIG. 8, a mounting bracket 18B is mounted on a mounting groove 18A which is cut into the inside from one side of the fixed conductor 16 by tightening a screw 18C. Arc device 18 and shield 1
8D is attached with a screw 18X. Screw 18C,
The screw 18X allows the arc extinguishing device 18 to be easily attached to and detached from the outside of the fixed conductor 16 and the movable conductor 19.

The structure of the arc extinguishing device 18 is such that a connection portion 18H connects a coil electrode 18E and a main electrode 18F between a shield 18D and a movable conductor 19; A cutout groove extending from the outer peripheral end of the electrode to the through hole was provided.

A movable contact 19 provided on a part of the movable conductor 19
When A moves away from the fixed contact 16A, an arc A is generated between the two contacts as shown in FIGS. 9 and 10, and when the movable contact 19A moves near the through hole 18G, the arc current is applied to the main electrode 18F and the coil. The magnetic field generated by this current flows in the same direction along the circumferential portion with the electrode 18E, becomes a vertical magnetic field in the same direction near the arc through-hole, and becomes a loop magnetic field on the outer peripheral side. And the arc is magnetically driven to extinguish the arc of the circumference of the main electrode 18F in the loop magnetic field, so that the breaking performance can be remarkably improved.

As another arc extinguishing device, as shown in FIG. 14, the movable conductor 19 rotates counterclockwise around the main shaft 35, and when it moves to a position corresponding to the arc horn 100, the movable conductor 19 is turned to the cut position. A between the contact and the movable contact
Arc A moves to a pair of arc horns 100, 101 closest to the tip of the movable contact, and the arc horns 100, 1 of the arc extinguishing device 102 arranged in the arc discharge direction.
The arc A is connected by an arc, and the arc A is extinguished by the projections and depressions 103 made of a plurality of ceramic insulating materials or zircon porcelain material of the arc extinguishing device 102. Therefore, the arc A is interrupted at the current zero point, and the conventional arc A
May cause a so-called cutting current that cuts off just before the current zero point. However, according to the present invention, the cutting current can be reduced, so that it is not necessary to take an overcurrent measure. FIG. 15 shows a vacuum valve in which the ground conductor is omitted, 11X is a ceramic insulator, and 19D is a movable arc conductor.

The movable conductor 19 extends from the inside of the vacuum valve 11 to the outside, and penetrates the bellows 36 on the way. The bellows 36 causes the movable conductor 19 to pivot upward and downward, and the movable contact 19A provided at the tip of the movable conductor to move between the fixed contact 16A and the ground conductor 17. The material of the movable contact 19A is the same as that of the above-mentioned fixed contact 16A. The bellows 36 is fixed by the sealing fitting 15. The movable conductor 19 is sandwiched between the connection conductors 37, and is fixed to a screw at the tip of the main shaft 35 inserted into a through hole of both conductors by a nut fastening portion (not shown).

When the operating mechanism 38 connected to the outer end of the movable conductor 19 is driven to rotate the movable conductor 19 upward and downward via the main shaft 35, it stops at the four positions in FIG.
That is, as the movable conductor 19 rotates, the movable contact 1
An entry position Y1 at which the 9A contacts the fixed contact 16A, an interruption position Y2 that pivots downward from the entrance position to cut off current, a pivoting position further downward to prevent insulation breakdown due to lightning, etc. There is a disconnection position Y3 where a sufficient insulation distance is provided on the side so that the worker does not receive an electric shock, and a ground position Y4 where the movable contact 19A contacts the ground conductor 17 by pivoting further downward.

In each of these positions, four positions are continuously performed by one operation while the movable conductor 19 rotates from the fixed contact 16A to the ground conductor 17 in a vacuum which is a higher insulator than SF gas or the like. In addition to the ease of operation and the ease of use, the movable contact 19A and the fixed contact 1
Since the 6A and ground conductors 17 are gathered in one place, the size can be further reduced as compared with the above-described conventional technology. Further, when the disconnection position Y3 is provided, the load-side conductor is connected when the insulated switchgear of one circuit is operating at the on-position Y1 and the insulated switchgear of the other circuit is in standby at the disconnection position Y3, for example, in two circuits with different power sources. It is not only safe for workers to come in contact with
In addition, since the operation can be performed continuously even when the operation is switched from standby to operation or from operation to standby, the operation speed is high and the operation is easy. Further, as described above, the vacuum valve 11
When the insulation performance deteriorates due to a vacuum leak inside and discharges to ground, this current is detected by the current transformer 42 and the protection relay 42
By operating X and tripping the operating mechanism 38 so as not to operate the movable conductor 19, the vacuum valve 11 is prevented from being damaged.

The U fitting 38A of the operating mechanism 38 is connected to the distal end of the movable conductor 19 inserted therein by a pin 38B.
The U bracket is attached to the insulating operation rod 38C,
An operation lever 38D connected to the other end of the insulated operation rod is attached to the rotation shaft 38E, and operation levers 38D for each phase are attached to the rotation shaft 38E. Is omitted.

The rotating shaft 38E is connected to the fixed insulating plate 4 as shown in FIG.
Since the bearing 38F was molded integrally with the insulating resin at the time of forming the A, an O-ring was inserted into the recess 38G on the inner wall surface of the bearing 38F.
In contrast to the conventional structure in which the bearing 38F is not molded, two rings are required for the bearing, whereas a conventional seal structure in which the bearing 38F is not molded is sufficient.

Support plate 40 connected to one end of connection conductor 37
Are integrally fixed to the fixed insulating plate 4A, and the other end is connected to the load-side conductor 41. A current transformer 42 and a capacitor 43 are integrally molded on the load-side conductor 41 in the body insulating plate 4B. When the current transformer 42 detects an accident current flowing through the load-side conductor 41 or a ground current generated when a vacuum abnormality occurs in the vacuum valve, the protection relay operates, the trip mechanism of the operation mechanism 38 operates, and the above-described operation mechanism is operated. Part 3
8 is released, the movable conductor 19 is rotated downward, and the movable contact 19A is opened from the fixed contact 16A and cut off. Further, the capacitor 43 divides the voltage of the main circuit, takes in the main circuit voltage and phase, and causes a detection unit (not shown) to detect the power flow state and the direction of the grounding accident. In the present invention, when the vacuum abnormality of the vacuum valve 11 occurs, the insulation performance in the vacuum valve 11 is reduced, and the vacuum relay 11 is discharged to ground.
The use of X makes it possible to detect a vacuum abnormality and to take measures against it, which could not be easily performed conventionally.

Further, the load-side conductor 41 in the main body insulating plate 4B has a vertical portion 41A extending in the axial direction and
A so-called L-shaped current-carrying portion which is bent in the opening / closing position side where 9A and the fixed contact 16A come into contact is formed, and the leading end is connected to the cable head 45 and the load cable 43.

The cable head 45 is connected to the load cable terminal 4
3 and the reverse bent portion 41B and the end surface screw hole are tightened with the tightening nut 49, and the adjusting screw head 47 supported by the insulating holding portion 46.
When rotated, the insulating holding portion 46 is pressed correspondingly and swells outward and spreads, pressing the adjusting screw 47, the tightening nut 49, and the insulating rubber cover 50 surrounding the load cable terminal 43, thereby insulating. The adhesion between the holding portion 46 and the insulating rubber cover 50 is sufficient, there is no gap between them, and it is difficult for moisture to enter inside, and the dielectric strength can be significantly improved. Since these are all publicly known, the description of the detailed structure is omitted.

Next, in the insulated switchgear 1 of the present invention, a current flowing from the bus-side conductor 23A to the load cable 43 causes an electromagnetic force to act outward in all the L-shaped reversely bent portions 41B. In the present invention, an electromagnetic force F is generated as shown in FIG. This electromagnetic force F is changed from the outward electromagnetic force F generated by the movable conductor 19 to the outward electromagnetic force F1 of the reverse bent portion 41B.
Is reduced. The movable contact 19A is a fixed contact 16A
The contact pressure that comes into contact with the operating mechanism 3 is such that it can overcome the electromagnetic repulsion force F due to the short-circuit current and continue to apply and keep energizing.
8, the prior art requires a large contact force,
A large operation mechanism was required.

In the present invention, the electromagnetic force F1 generated by the reverse bending portion 41B cancels the outward electromagnetic force F generated by the movable conductor 19, so that the driving force of the operating mechanism can be reduced by this amount, and the operating mechanism 38 can be reduced. Is the movable conductor 19 and the fixed conductor 16
Since only the contact force between the operating mechanism 38 and the ground conductor 17 is sufficient, the operating mechanism 38 requires only a greatly reduced operating force, and the operating mechanism 38 of the present invention can be compared with the conventional operating mechanism.
Can be greatly reduced in size and weight.

Considering the length of the reverse bent portion 41B, the width dimension L1 of the movable conductor 19 from the main shaft 35 to the contact position of the movable contact 19A with the fixed contact 16A, and the main shaft 35
Assuming that the width dimension L2 of the reverse curved portion 41B from the contact point to the contact position is L1 = L2, the electromagnetic force F = F1, and the operating force of the operating mechanism 38 is only the contact pressure.
8 can be reduced. In short, in order to obtain an appropriate operation force, the electromagnetic force F1 must have a width L in the direction of canceling the electromagnetic force F.
It is sufficient to adjust 2.

Further, the insulated switchgear of the present invention has the following features.
A switch such as a circuit breaker in which the movable conductor 19 opens and closes with the fixed conductor 16, a disconnector in which the movable conductor 19 is moved from the fixed conductor 16 to the disconnection position Y3, a ground switch using the movable conductor 19 and the ground conductor 17, and the like. It can be used as a switch alone product. It can also be used when the vacuum valve 11 is not housed in the insulating gas container 1.

Further, in the vacuum valve shown in FIG. 13, a movable conductor 19 that opens and closes a fixed contact 16A of a fixed conductor 16 and a movable contact 19A with a main shaft as a fulcrum is arranged in the vacuum valve. A spiral groove 1 for guiding arc A is provided at each contact.
8S is provided. The fixed conductor 16 and the movable conductor 19 are L
Since an L-shaped current flows in the shape of a letter, a large electromagnetic repulsive force acts between both conductors when an accident current flows. The arc A, which has been ignited between the movable contact 19A and the fixed contact 16A due to the electromagnetic repulsion, always has an arc A outside the electrode surfaces due to the current flowing through the L-shaped conductor and the arc current i flowing between the two contacts. Electromagnetic force H in the direction in which it protrudes acts.

On the other hand, in the present invention, when the movable conductor 19 is separated from the fixed conductor 16 and cut off, as the gap between the fixed contact 16A and the movable contact 19A increases, the distance from the outer electrode side to the inner electrode side increases as the gap between the fixed contact 16A and the movable contact 19A increases. Since the movable contact 19A is rotated in an inclined state so that the gap is gradually narrowed,
In the arc A, a force acts to move to the inner peripheral electrode surface having a smaller arc resistance than the outer peripheral electrode surface.

With respect to the electromagnetic force H in the direction of projecting to the outside of both electrode surfaces, a moving force acts from the outer electrode surface to the inner electrode surface. The breaking performance can be improved without breaking through the vacuum valve. In particular, the fixed conductor 16 is set so that the electromagnetic force H in the direction in which the arc A projects to the outside of both electrode surfaces acts.
When the conductor 16X and the movable conductor 19 corresponding to the conductor 16X are arranged in the direction perpendicular to the above, the use of the electrode shown in FIG. 13 can more effectively prevent the arc A from jumping out of both electrode surfaces. . This is the same as described above in the case of the reverse bending portion 41B.

Further, the insulated switchgear of the present invention is provided with the above-described FIG.
In addition, the fixed contact 16 of the fixed conductor 16 with the main shaft as a fulcrum
A movable conductor 19 that opens and closes the A and the movable contact 19A may be arranged in the vacuum valve, and a coil electrode that generates a magnetic field parallel to the arc on the back of each contact may be used. That is, a coil electrode and a main electrode may be used on one side of the fixed contact 16A and the movable contact 19A in FIG. 9 as shown in FIG.

[0038]

As described above, according to the insulated switchgear of the present invention, the following effects can be obtained.

(1) While the movable conductor 19 rotates between the fixed conductor 16 and the ground conductor 17, four positions of a closed position, an open position, a disconnection position, and a ground position (or three positions where the disconnection position is removed) ) Can be continuously performed by one operation, so that not only the operation is easy and the usability is good, but also the movable conductor 19, the fixed conductor 16, and the ground conductor 17 are gathered in one place. Therefore, the size can be reduced by reducing the number of components. In addition, if the disconnection position is provided, for example, when one line is operating with two lines receiving power and the other line is waiting at the disconnection position, it is safe even if an operator touches the load-side conductor in the standby state.

(2) Inverted portion 41 provided in the middle of the load-side conductor
Since the electromagnetic force of the movable conductor is canceled by B, the operating mechanism 38 needs only the operating force of the contact pressure (or the contact pressure slightly larger than the contact pressure). The operating mechanism 38 of the present invention can be made much smaller, and the insulated switchgear can also be made smaller.

(3) Since the movable conductor 19 is rotated in an inclined state, the arc on the outer electrode surface can be forcibly moved to the inner electrode surface, so that the arc A breaks through the vacuum valve. Without this, the breaking performance can be improved.
In particular, a configuration in which a conductor 16X arranged in a direction perpendicular to the fixed conductor 16 and a movable conductor 19 corresponding to the conductor 16X are arranged correspondingly.
Arc A can be effectively prevented from breaking through the vacuum valve.

(4) Since the vacuum valve of the present invention is provided with an arc extinguishing device for extinguishing an arc, the breaking performance can be remarkably improved as compared with the case where no arc extinguishing device is provided. In addition, the size of the insulated switchgear can be further reduced.

(5) The fixed conductor and the ground conductor arranged inside the present invention are opened and closed with both conductors around the main shaft as a fulcrum, and one side of the movable conductor projects outside the vacuum valve. Since the valves are arranged, the installation area in the width direction between the vacuum valves of a plurality of phases can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an insulated switchgear according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the insulating gas container used in FIG.

FIG. 3 is a partial perspective view of the insulating gas container used in FIG.

FIG. 4 is a front view of FIG. 1 as viewed from the left side.

FIG. 5 is a front view of FIG. 1 as viewed from the right side.

FIG. 6 is a sectional view taken along line DD of FIG. 1;

FIG. 7 is a sectional view taken along line EE in FIG. 1;

FIG. 8 is a detailed view of the vicinity of the arc extinguishing device used in FIG. 1;

FIG. 9 is an explanatory diagram of a simplified electrode for explaining arc extinction used in FIG. 8;

FIG. 10 is an explanatory view for extinguishing an arc of an electrode shown as another embodiment.

FIG. 11 is an equivalent circuit diagram illustrating the operation of the movable conductor of FIG.

FIG. 12 is an explanatory diagram showing an operation of an electromagnetic force acting on the insulated switchgear of FIG. 1;

FIG. 13 is a perspective view showing an electrode of a vacuum valve according to another embodiment of the present invention.

FIG. 14 is a sectional view of a vacuum valve with an arc extinguishing device according to another embodiment of the present invention.

FIG. 15 is a sectional view of a vacuum valve with an arc extinguishing device according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating gas container, 11 ... Vacuum valve, 16 ... Fixed conductor, 17 ... Ground conductor, 19 ... Movable conductor, 35 ... Main shaft, 4
1 ... load side conductor, 41B ... reverse bending part.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoru Kajiwara 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside the Kokubu Plant of Hitachi, Ltd. (72) Inventor Masayoshi Hayakawa 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Kokubu Plant (72) Inventor Ayumu Morita 7-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Power and Electricity Development Division (72) Inventor Fumio Shibata Chiyoda, Tokyo 4-6, Kanda-surugadai, Ward Inside Hitachi, Ltd. (56) References JP-A-55-143727 (JP, A) JP-A-5-20983 (JP, A) JP-A-54-143840 (JP, A) JP-A-59-75527 (JP, A) JP-A-6-12948 (JP, A) JP-A-5-62572 (JP, A) Japanese Utility Model Application No. 55-171931 (JP, U) Japanese Utility Model Application No. Sho 59-186934 (JP U) JitsuHiraku Akira 52-93473 (JP, U) British Patent 451963 (GB, A) UK Patent 1329725 (GB, A) (58 ) investigated the field (Int.Cl. ^7, DB name) H01H 33/66 H01H 33/42

Claims (4)

(57) [Claims] 1. A fixed conductor disposed in a vacuum valve and having a fixed contact, a ground conductor connected to an external ground terminal, and disposed between the two conductors and movable with the main shaft as a fulcrum. A movable conductor having a contact; and an operation mechanism for driving the movable conductor, wherein the movable position moves between the fixed conductor and the ground conductor, and the input position Y1, the cut position Y2, the disconnect position Y3, and the ground position An insulated switchgear, wherein the movable conductor is operated by a driving mechanism so as to take four positions of Y4 or three positions other than Y4, the movable conductor is connected to a load conductor, and the fixed conductor is connected to a bus-side conductor. 2. A fixed conductor having a fixed contact disposed in a vacuum valve, a ground conductor connected to an external ground terminal, and disposed between the two conductors, and movable with the main shaft as a fulcrum. A movable conductor having a contact, and an operating mechanism for driving the movable conductor, wherein the movable conductor is connected to a load conductor, and the fixed conductor is connected to a bus-side conductor to form an insulation switchgear for one phase. An insulating switchgear having a configuration in which the insulating switchgear is arranged in a plurality of phases in an insulating gas container, wherein the front and back sides of the insulating gas container are hermetically sealed by detachable insulating covers. 3. A fixed conductor having a fixed contact and disposed in a vacuum valve, a ground conductor connected to an external ground terminal, and a movable conductor which is disposed between the two conductors and which opens and closes with respect to the two conductors with the main shaft as a fulcrum. A movable conductor having a contact, an operating mechanism for driving the movable conductor, the movable conductor is connected to a load conductor, and the fixed conductor is connected to a bus-side conductor to form an insulation switch for one phase; This insulated switchgear is arranged in parallel in three phases in an insulating gas container, and the front and back sides of the insulating gas container are sealed by detachable insulating covers, respectively, and the head of the insulating gas container is detachable bus insulating plate. An insulated switchgear having a configuration sealed by a seal. 4. A fixed conductor disposed in a vacuum valve and having a fixed contact, a ground conductor connected to an external ground terminal, and disposed between the two conductors and movable with the main shaft as a fulcrum. A movable conductor having a contact, an operating mechanism for driving the movable conductor, the movable conductor is connected to a load conductor, and the fixed conductor is connected to a bus-side conductor to form an insulation switch for one phase; This insulated switchgear is arranged in parallel in a plurality of phases in an insulating gas container, and the front and back sides of the insulating gas container are sealed by detachable insulating covers, respectively, and the head of the insulating gas container is a detachable bus insulating plate. An insulated switchgear having a configuration sealed by a seal.