JP2001136616A - Switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a switchgear capable of miniaturization and cost reduction. SOLUTION: This switchgear is equipped with a main circuit switching part 71 which is installed in a vessel and has a moving electrode 27 and a fixed electrode 26, and a ground switching part 172 which is installed in the vessel and has a moving electrode 129 and a fixed electrode 128. The electrodes 27 and 26 close and open a part between a bus side conductor 30 and a load side conductor 32. The electrodes 129 and 128 close and open a part between the load side conductor 32 and a ground side earthed conductor 33, and are smaller than the electrodes 27 and 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switchgear having, for example, a main circuit opening / closing section for connecting / disconnecting a bus-side conductor and a load-side conductor, and a grounding opening / closing section for connecting / disconnecting a load-side conductor and a ground-side conductor. .

[0002]

2. Description of the Related Art A switchgear (closed switchboard) used to distribute power received from a bus to various load devices and other electrical rooms is provided with a bus-side conductor for connection to the bus and a connection between the bus and the load. A main circuit switch for connecting and disconnecting the load-side conductor, a ground switch for grounding the load-side conductor and the ground-side conductor,
Control devices and the like necessary for monitoring and control are arranged in a container made of grounded metal.

FIG. 5 is an example of an electric circuit diagram of a switchgear. The switchgear is a container 1 filled with an insulating gas.
Inside, a circuit breaker 2 and first to third switches 3, 4, and 5 are provided. In this switchgear, for example, when performing maintenance and inspection of the load-side substation equipment, after the circuit breaker 2 is shut off, the first to third switches 3, 3,
Release 4 and 5. Then, the first switch 3 is operated to electrically connect the bus-side conductor 6 and the grounding conductor 8 to ground the bus-side conductor 6, and the second switch 4 and the third switch 3 5, the load side conductor 7 is electrically connected to the ground conductor 8 to ground the load side conductor 7. By doing so, the residual charge and the induced current on the bus side and the load side flow to the ground, and re-application from the power supply is prevented, thereby protecting the safety of the operator.

FIG. 6 is a front sectional view of a main part of another example of a conventional switchgear. The switchgear has a main circuit opening / closing section 71 and a grounding opening / closing section 72 in the metal container main body 21. The main circuit opening / closing portion 71 includes a fixed electrode 26 and a movable electrode rod 31 fixed to the fixed electrode rod 30 which is a busbar side conductor.
And a movable electrode 27 fixed to the movable electrode 27. The fixed electrode rod 30 is fixed to the container body 21 through a first sealing portion 39 made of metal, a first insulating portion 22 made of ceramics, and a second sealing portion 43 made of metal. And is electrically insulated. The movable electrode rod 31 includes an insulating rod 73
Is connected to the operation rod 35 via the. The operation rod 35 is
It is connected to a drive mechanism for operating the main circuit opening / closing section 71 to the closed position, the closed position, and the disconnected position. Further, the operating rod 35 is connected to the third sealing part 40 via the bellows 34. The third sealing section 40 is connected to the container body 21 via the second insulating section 23 and the fourth sealing section 44.

The main circuit opening / closing section 71 is operable while maintaining airtightness by the bellows 34. The insulating rod 73 includes an insulating portion 53 and shield portions 54 attached to both ends of the insulating portion 53. The shield part 54 is used to alleviate the electric field at the joint boundary between the insulating part 53 and the shield part 54, protect the creeping surface of the insulating part 53, and insulate the metal circuit of the electrodes 26 and 27 generated when the main circuit switching part 71 switches the current. The purpose is to protect the bellows 53 and the bellows 34. Around the main circuit opening / closing section 71, an arc shield section 37 for suppressing scattering of metal vapor on the electrodes 26 and 27 at the time of current opening / closing is fixed to the first insulating section 22 and provided. The opening / closing section 71 is provided in the container body 2
1 and electrically insulated. In the vicinity of the brazed joint between the first to fourth sealing portions 39, 43, 40, and 44 serving as the charged portion and the first and second insulating portions 22 and 23 made of ceramic, an electric field for relaxing the electric field is provided. First to third rings 4
7, 49, and 50 are provided. The first to third rings 47, 49, and 50 are located inside the first and second insulating portions 22 and 23, and are provided with insulating portions 2 made of metal vapor.
Stain on the inner wall surfaces of 2, 23 is suppressed.

The grounding switch 72 includes a fixed electrode 28 fixed to a fixed electrode rod 32 as a load-side conductor, and a movable electrode 2 fixed to a movable electrode rod 33 as a grounded-side conductor.
9. The fixed electrode rod 32 is fixed to the container body 21 via the first sealing part 41, the first insulating part 24, and the second sealing part 45. The movable electrode rod 33 is connected to a third sealing part 42 via a bellows 36.
The third sealing portion 42 is connected to the vacuum container main body 21 via the second insulating portion 25 and the fourth sealing portion 46.

[0007] The grounding opening / closing section 72 is operable by the bellows 36 while maintaining airtightness in the vacuum vessel main body 21. First to fourth sealing portions 41 and 4 serving as charging portions
First to third rings 48, 51, and 52 are provided in the vicinity of the brazed joints between the first, second, and fifth insulating members 24, 25 made of ceramics. Have been. In addition, the first to third rings 4
Reference numerals 8, 51, and 52 are inside the first and second insulating portions 24 and 25, and suppress contamination of the inner wall surfaces of the insulating portions 24 and 25 by metal vapor.

A flexible conductor 38 is provided between the movable electrode bar 31 of the main circuit switch 71 and the fixed electrode bar 33 of the ground switch 72.
Are electrically connected. Then, the main circuit switch 71
Is closed, and when the grounding switch 72 is open, the current from the bus side flows to the load side through the fixed electrode rod 30, the flexible conductor 38, and the fixed electrode rod 32.

Next, the operation of the switchgear having the above configuration will be described. During normal operation, the operating rod 35 is moved downward in FIG. 6 to bring the movable electrode 27 into contact with the fixed electrode 26. Further, the movable electrode rod 33 is moved upward to separate the movable electrode 29 from the fixed electrode 28. For this reason, power supply from the bus side is performed by the fixed electrode rod 30 and the movable electrode rod 3.
1. Power is distributed to various load devices on the load side via the flexible conductor 38 and the fixed electrode rod 32.

At the time of maintenance and inspection of various load devices,
The operation rod 35 is moved upward in FIG. 6 to move the movable electrode 27 away from the fixed electrode 26 to the cutoff position, and further to the disconnection position. Thereafter, the movable electrode rod 33 in FIG. 6 is moved downward, and the movable electrode 29 is brought into contact with the fixed electrode 28. Therefore, the grounded movable electrode rod 33 and the fixed electrode rod 32
Are electrically connected to each other, the residual charge of the load-side conductor and the induced current flow to the ground through the fixed electrode rod 32 and the movable electrode rod 33, and the movable electrode 27 and the fixed electrode 26 are separated from each other up to the disconnection position. Therefore, power supply from the bus side to the various load devices on the load side is prevented, and the operator can safely perform maintenance and inspection.

[0011]

In the switchgear having the above structure, the movable electrode 29 and the fixed electrode 2 of the ground opening / closing section 72 are provided.
8 denotes a movable electrode 27 and a fixed electrode 2 of the main circuit opening / closing section 71.
6, the entire device is enlarged, and the movable electrode 29 and the fixed electrode 28 of the grounding switch are made of, for example, a Cu-W alloy, so that the entire device is large and expensive. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem, and an object of the present invention is to provide a switchgear capable of reducing the size of an apparatus and reducing costs.

[0013]

In the switchgear according to the present invention, the movable electrode and the fixed electrode of the grounding switch are smaller than the movable electrode and the fixed electrode of the main circuit switch.

In the switchgear according to the second aspect of the present invention, the movable electrode and the fixed electrode of the disconnection opening / closing section, and the movable electrode and the fixed electrode of the grounding opening / closing section are smaller than the movable electrode and the fixed electrode of the cutoff opening / closing section. .

In the switchgear according to a third aspect of the present invention, a magnetic field generating section for generating a magnetic field for attracting the movable electrode and the fixed electrode to each other when the electrode is closed is provided on the back surface of the movable electrode and the fixed electrode of the grounding switch. Have been.

In the switchgear according to a fourth aspect of the present invention, the movable electrode and the fixed electrode of the disconnection opening / closing section and the movable electrode and the fixed electrode of the grounding opening / closing section are formed of the same shape and the same material.

In the switchgear according to the fifth aspect of the present invention, the movable electrode and the fixed electrode of the main circuit opening / closing section are made of a different material from the movable electrode and the fixed electrode of the grounding opening / closing section.

In the switchgear according to the sixth aspect of the present invention, the movable electrode and the fixed electrode of the cutoff opening / closing section are made of a different material from the movable electrode and the fixed electrode of the disconnection opening / closing section and the movable electrode and the fixed electrode of the grounding opening / closing section. It is configured.

In the switchgear according to claim 7 of the present invention, the container is a vacuum container.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described. Parts that are the same as or equivalent to those in FIGS. 5 and 6 are denoted by the same reference numerals. Embodiment 1 FIG. FIG. 1 is a front sectional view of a main part of a first embodiment of a switchgear according to the present invention. The switchgear has a main circuit opening / closing section 71 and a grounding opening / closing section 72 in the metal container main body 21. The main circuit opening / closing section 71 includes a fixed electrode 26 fixed to the fixed electrode rod 30 which is a busbar side conductor and a movable electrode 27 fixed to the movable electrode rod 31. The fixed electrode rod 30 is formed of a first sealing portion 3 made of metal.
9, is fixed to the container body 21 via the first insulating portion 22 made of ceramics and the second sealing portion 43 made of metal, and is electrically insulated from the container body 21. Movable electrode rod 31
Is connected to the operation rod 35 via the insulating rod 73. The operation rod 35 is connected to a drive mechanism for operating the main circuit opening / closing unit 71 to a closed position, a cutoff position, and a disconnection position. Further, the operating rod 35 is connected to the third sealing part 40 via the bellows 34. The third sealing part 40 is connected to the container body 2 via the second insulating part 23 and the fourth sealing part 44.
1 connected.

The main circuit opening / closing section 71 is operable while maintaining airtightness by the bellows 34. The insulating rod 73 includes an insulating portion 53 and shield portions 54 attached to both ends of the insulating portion 53. The shield part 54 is used to alleviate the electric field at the joint boundary between the insulating part 53 and the shield part 54, protect the creeping surface of the insulating part 53, and insulate the metal circuit of the electrodes 26 and 27 generated when the main circuit switching part 71 switches the current. The purpose is to protect the bellows 53 and the bellows 34. Around the main circuit opening / closing section 71, an arc shield section 37 for suppressing scattering of metal vapor on the electrodes 26 and 27 at the time of current opening / closing is fixed to the first insulating section 22 and provided. The opening / closing section 71 is provided in the container body 2
1 and electrically insulated. In the vicinity of the brazed joint between the first to fourth sealing portions 39, 43, 40, and 44 serving as the charged portion and the first and second insulating portions 22 and 23 made of ceramic, an electric field for relaxing the electric field is provided. First to third rings 4
7, 49, and 50 are provided. The first to third rings 47, 49, and 50 are located inside the first and second insulating portions 22 and 23, and are provided with insulating portions 2 made of metal vapor.
Stain on the inner wall surfaces of 2, 23 is suppressed.

The grounding switch 72 includes a fixed electrode 128 fixed to the fixed electrode rod 32 as a load-side conductor, and a movable electrode 129 fixed to the movable electrode rod 33 as a grounded-side conductor. I have. The fixed electrode 128 and the movable electrode 129 are formed smaller than the fixed electrode 26 and the movable electrode 27 of the main circuit opening / closing section 71. Fixed electrode rod 32
Is fixed to the container body 21 via a first sealing portion 41, a first insulating portion 24, and a second sealing portion 45. The movable electrode rod 33 is connected to a third sealing part 42 via a bellows 36. The third sealing part 42 is a second insulating part 2
Fifth, it is connected to the vacuum vessel main body 21 via the fourth sealing portion 46.

The grounding opening / closing section 172 is operable by the bellows 36 while maintaining the airtightness in the container body 21. First to fourth sealing portions 41 and 45 serving as charging portions;
Near the brazing joint between the first and second insulating portions 24 and 25 made of ceramics, first to third rings 48, 51 and 52 for reducing electric field are provided. I have. Also, the first to third rings 48,
Reference numerals 51 and 52 are located inside the first and second insulating portions 24 and 25, and suppress the contamination of the inner wall surfaces of the insulating portions 24 and 25 by metal vapor.

A flexible conductor 38 is provided between the movable electrode bar 31 of the main circuit switch 71 and the fixed electrode bar 33 of the ground switch 72.
Are electrically connected. Then, the main circuit switch 71
Is in a closed state and the grounding switch 172 is in an open state, the current from the bus side flows to the load side through the fixed electrode rod 30, the flexible conductor 38, and the fixed electrode rod 32. The container body 21 includes sealing portions 39, 22, 43,
44, 40, 41, 45, 46, 42 and the insulating part 22,
Together with 23, 24, and 25, these components are components of a container, and a vacuum is secured inside the switchgear by the container.

Next, the operation of the switchgear having the above configuration will be described. During normal operation, the operating rod 35 is moved downward in FIG. 1 to bring the movable electrode 27 into contact with the fixed electrode 26. Further, the movable electrode rod 33 is moved upward to separate the movable electrode 129 from the fixed electrode 128. Therefore, power supply from the bus side is distributed to various load devices on the load side via the fixed electrode rod 30, the movable electrode rod 31, the flexible conductor 38, and the fixed electrode rod 32.

In addition, during maintenance and inspection of various load devices,
The operation rod 35 is moved upward in FIG. 6 to move the movable electrode 27 away from the fixed electrode 26 to the cutoff position, and further to the disconnection position. Thereafter, the movable electrode rod 33 in FIG. 6 is moved downward, and the movable electrode 129 is brought into contact with the fixed electrode 128. Therefore, the grounded movable electrode rod 33 and the fixed electrode rod 32 are electrically connected to each other, and the residual electric charge of the load-side conductor,
The induced current flows to the ground through the fixed electrode rod 32 and the movable electrode rod 33, and the movable electrode 27 and the fixed electrode 26 are separated from each other up to the disconnection position, so that power is supplied from the bus side to various load devices on the load side. Is prevented, and the operator can perform maintenance and inspection safely.

In the switchgear having the above configuration, the grounding switch 172 does not need the fault current interruption performance and the load current switching performance required for the main circuit switch 71. In this embodiment, focusing on this point, the electrode 12 of the grounding switch 172 is
8 and 129 are configured to have a smaller diameter and a smaller thickness than the electrodes 26 and 27 of the main circuit opening / closing section 71, and the amount of use of the Cu—W-based alloy, which is a constituent material of the movable electrode 129 and the fixed electrode 128, is reduced. Manufacturing costs are reduced. In addition, the overall size of the apparatus can be reduced by reducing the size of the grounding switch 172.
The miniaturization of the electrodes 128 and 129 may be either one of a reduction in diameter and a reduction in thickness. The electrode 128 of the ground switch 172,
129, like the electrodes 26 and 27 of the main circuit opening / closing section 71, requires high welding resistance (easiness of separation between the electrodes) and high withstand voltage, but does not require the fault current interruption performance and the load current switching performance. Therefore, the fixed electrode 26 and the movable electrode 2
Unlike the Cu-Cr alloy used in 7, a Cu-W alloy is used.

Further, since the main circuit switch 71 and the ground switch 172 are formed in a vacuum having good insulation performance, the insulation distance between the two switches 71 and 172 can be shortened, and the inside of the vacuum vessel can be reduced. Even if an arc short-circuit occurs, there is no possibility that the arc short-circuit will cause an explosion because no gas exists inside the vacuum vessel, and high safety is ensured.

Embodiment 2 FIG. 2 is a front sectional view of a main part of a second embodiment of the switchgear according to the present invention. In addition,
In the following description of the embodiment, components different from those of the first embodiment will be described.

In the second embodiment, the movable electrode 12 in the container cuts off the electric circuit by separating the fixed electrode rod 30 as the bus-side conductor and the fixed electrode rod 32 as the load-side conductor.
7 and a blocking opening / closing section 171 having a fixed electrode 126, and electrically connected to the blocking opening / closing section 171 by a flexible conductor 38,
A disconnection opening / closing section 200 having the movable electrode 58 and the fixed electrode 57, which is separated after the movable electrode 127 and the fixed electrode 126 are separated, electrically connected to the disconnection opening / closing section 200 by the conductor 68, and connected to the fixed electrode rod 32; A ground switch 172 having a movable electrode 129 and a fixed electrode 128 is provided for moving the movable electrode rod 33, which is a grounded-side conductor, into and out of contact with the ground. The movable electrode 58 of the disconnection opening / closing unit 200 is fixed to the tip of the movable electrode rod 75. The fixed electrode 57 is fixed to a fixed electrode rod 74. The fixed electrode rod 74 and the fixed electrode rod 32 are electrically connected by a conductor 68. Fixed electrode rod 7
4 is fixed to the container body 21 via an insulating support 65. The insulating support portion 65 includes a columnar insulating portion 66 and electric field relaxation shield portions 67 fixed to both ends thereof. The movable electrode rod 75 is fixed to the container body 21 with the same support structure as the movable electrode rod 31 on the blocking opening / closing section 171 side. This support structure and its peripheral structure are the same as the structure for supporting the movable electrode bar 31 on the blocking opening / closing part 171 side and its peripheral structure, and are denoted by the same reference numerals and description thereof is omitted. The movable electrode 58 and the fixed electrode 57 of the disconnection opening / closing unit 200
Is an electrode having a disconnection function, and is similar to the fixed electrode 128 and the movable electrode 129 of the grounding switch 172 in that the fault current blocking and load current breaking performances are unnecessary. And the same electrode as the movable electrode 129 is used.

In this embodiment, at the time of maintenance and inspection of various load devices, the operating rod 35 is moved upward in FIG.
The movable electrode 127 of the blocking opening / closing section 171 is separated from the fixed electrode 126 to the blocking position. Thereafter, the operation rod 35 connected to the movable electrode rod 75 is moved upward in FIG. 2, and the movable electrode 75 of the disconnection opening / closing unit 200 is separated from the fixed electrode 57 to the disconnection position. Thereafter, in FIG. 2, the movable electrode rod 33 is moved downward, and the movable electrode 129 is brought into contact with the fixed electrode 128 to electrically connect the grounded movable electrode rod 33 and the fixed electrode rod 32 as the load-side conductor. Connect to As a result, the residual charge and the induced current on the load side flow to the ground through the fixed electrode rod 32 and the movable electrode rod 33, and the fixed electrode rod 30 as the bus-side conductor and the fixed electrode rod 32 as the load-side conductor are movable. The electrode 58 and the fixed electrode 57 are separated and disconnected from each other, power supply from the bus side to various load devices is prevented, and the operator can safely perform maintenance and inspection.

In the above embodiment, the electrodes 57 and 58 of the disconnection opening / closing section 200 are in an open state at the time of disconnection and grounding, and the gap between the electrodes 126 and 127 of the disconnection opening / closing section 171 is added to the gap between the electrodes 57 and 58. Since the withstand voltage performance is obtained in the gap, the withstand voltage performance can be improved. In addition, disconnection opening / closing section 200
The movable electrode 58 and the fixed electrode 57 of the
As in the case of the electrodes 128 and 129 of the above, since the fault current breaking performance and the load current switching performance required for the breaking switching unit 171 are unnecessary, the electrodes 58 and 57 of the disconnection switching unit 200 are
The electrodes 28 and 29 of the grounding switch 172 can be shared.

Embodiment 3 FIG. 3 is a front sectional view of a main part of a third embodiment of a switchgear according to the present invention, and FIG. 4 is a perspective view of a main part of FIG.

In this embodiment, a magnetic field generator 81 for generating a magnetic field in the axial direction of the fixed electrode rod 32 is fixed to the back of the fixed electrode 128 of the grounding switch 272. A magnetic field generator 82 that generates a magnetic field in the axial direction of the movable electrode bar 33 is fixed to the back surface of the movable electrode 129 of the grounding switch 272. If the external pressure in the direction in which the movable electrode 129 contacts the fixed electrode 128 is insufficient at the time of grounding when the grounding opening / closing part 272 closes, the movable electrode 129 is fixed after the fixed electrode 128 contacts the movable electrode 129. Electrode 1
The gap between the movable electrode 129 and the fixed electrode 128 is generated by the repulsive force acting between the movable electrode 129 and the fixed electrode 128.
Not only does the metal vapor scatter, but the melting area of the movable electrode 129 and the fixed electrode 128 increases due to arcing, and when the grounding switch 272 is opened accordingly, the movable electrode rod 3
3 requires a large separating force. To prevent this arcing phenomenon, the movable electrode 129 and the fixed electrode 12
After the contact with the movable electrode rod 33, a sufficient external pressing force is required to prevent a gap from being generated. However, an increase in the external pressing force requires reinforcement of the driving mechanism connected to the movable electrode rod 33. In addition, adverse effects such as an increase in manual operation load occur.

In this embodiment, a current flows from the fixed electrode bar 32 to the movable electrode bar 33 through the grounding switch 272 when the grounding switch 272 is closed and the ground is closed. Flow through the portions 81 and 82, and the magnetic field generated at this time causes the electrode 12
8, 129 are attracted to each other, and there is no gap between the fixed electrode 128 and the movable electrode 129 after the contact.
Therefore, after the fixed electrode 128 and the movable electrode 129 come into contact with each other, the scattering of metal vapor on the electrodes 128 and 129 due to the arcing phenomenon between the two is suppressed, and the amount of welding is reduced.
When the ground opening / closing part 272 is opened by that much, it can be opened with a small force, and the driving mechanism of the ground circuit part 272 can be downsized.

[0036]

As described above, according to the switchgear according to the first aspect of the present invention, the movable electrode and the fixed electrode of the grounding switch are smaller than the movable electrode and the fixed electrode of the main circuit switch. Therefore, the size of the entire apparatus can be reduced, and the cost can be reduced.

According to the switchgear according to the second aspect of the present invention, the movable electrode and the fixed electrode of the disconnecting opening / closing section, and the movable electrode and the fixed electrode of the grounding opening / closing section are made smaller than the movable electrode and the fixed electrode of the blocking opening / closing section. Since the device is also small, the size of the entire device can be reduced, and the cost can be reduced.

According to the switchgear of the third aspect of the present invention, the magnetic field for generating a magnetic field for attracting the movable electrode and the fixed electrode to each other when the electrode is closed is provided on the back surface of the movable electrode and the fixed electrode of the grounding switch. Since the generating portion is provided, the metal vapor of the electrode is prevented from being scattered by the arcing phenomenon between the fixed electrode and the movable electrode, and the amount of welding is reduced,
When the ground switch is opened, the contact can be opened with a small force, and the drive mechanism of the ground circuit can be downsized.

According to the switchgear of the fourth aspect of the present invention, the movable electrode and the fixed electrode of the disconnection opening / closing section are
Since the movable electrode and the fixed electrode of the grounding switch are formed of the same shape and of the same material, the movable electrode and the fixed electrode of the disconnection switch and the movable electrode and the fixed electrode of the grounding switch can be shared.

According to the switchgear of the fifth aspect of the present invention, the movable electrode and the fixed electrode of the main circuit switching section are excellent in fault current interruption performance, load current switching performance, welding resistance performance and withstand voltage performance. For the movable electrode and the fixed electrode of the grounding switch, a material having excellent welding resistance and withstand voltage performance can be selected.

According to the switchgear according to the sixth aspect of the present invention, the movable electrode and the fixed electrode of the shutoff opening / closing section are:
Select a material that has excellent fault current interruption performance, load current switching performance, welding resistance and withstand voltage performance.Movable and fixed electrodes for disconnection switching parts and movable and fixed electrodes for ground switching parts have welding resistance. In addition, a material having excellent withstand voltage performance can be selected.

According to the switchgear according to the seventh aspect of the present invention, since the container is a vacuum container, it is possible to prevent explosion due to gas expansion due to an arc short circuit,
Safety can be improved.

[Brief description of the drawings]

FIG. 1 is a first embodiment of a switchgear according to the present invention;
It is a principal part front sectional view of FIG.

FIG. 2 is a second embodiment of the switchgear according to the present invention;
It is a principal part front sectional view of FIG.

FIG. 3 is a third embodiment of the switchgear according to the present invention;
It is a principal part front sectional view of FIG.

FIG. 4 is an exploded perspective view of a main part of the switchgear of FIG. 3;

FIG. 5 is an electric circuit diagram of a conventional switchgear.

FIG. 6 is a front sectional view of a main part of another conventional example of a switchgear.

[Explanation of symbols]

21 container body, 26, 126, 128 fixed electrode, 2
7, 127, 129 movable electrode, 30 fixed electrode rod (bus-side conductor), 32 fixed electrode rod (load-side conductor), 33 movable electrode rod (ground-side conductor), 81, 82 magnetic field generator, 2
72 Ground switch.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshifumi Sato 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Minoru Kobayashi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Rishi Electric Co., Ltd. (72) Inventor Seiichi Miyamoto 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. F-term (reference) 5G017 HH06 5G026 BA07 CB02 5G051 AA21 NB12

Claims (7)

[Claims] 1. A main circuit opening / closing portion provided in a container and having a movable electrode and a fixed electrode for connecting / disconnecting a bus-side conductor and a load-side conductor; and a load-side conductor and a ground provided in the container. A grounding switch having a movable electrode and a fixed electrode, for moving the grounded conductor in and out of the main circuit, wherein the movable electrode and the fixed electrode of the grounding switch are larger than the movable electrode and the fixed electrode of the main circuit switch. A small switchgear. 2. A shut-off switch having a movable electrode and a fixed electrode, wherein the shut-off switch is provided in a container and disconnects a bus-side conductor and a load-side conductor to cut off an electric circuit. A disconnection opening / closing portion electrically connected to a portion and a conductor and separated after the movable electrode and the fixed electrode separate from each other, the disconnection opening / closing portion having a movable electrode and a fixed electrode; And a grounding switch having a movable electrode and a fixed electrode, which are electrically connected with a conductor and separates the load-side conductor and the grounded ground-side conductor from each other. A fixed electrode, and the movable electrode and the fixed electrode of the grounding switch,
A switchgear smaller in size than the movable electrode and the fixed electrode of the blocking opening / closing section. 3. A magnetic field generator for generating a magnetic field for attracting the movable electrode and the fixed electrode to each other when the electrode is closed is provided on a back surface of the movable electrode and the fixed electrode of the grounding switch.
Or the switchgear according to claim 2. 4. A movable electrode and a fixed electrode of a disconnection opening / closing unit,
The switchgear according to claim 2 or 3, wherein the movable electrode and the fixed electrode of the grounding opening / closing part are formed of the same shape and the same material. 5. The switchgear according to claim 1, wherein the movable electrode and the fixed electrode of the main circuit opening / closing section are made of a different material from the movable electrode and the fixed electrode of the grounding opening / closing section. 6. The movable electrode and the fixed electrode of the shutoff opening / closing section,
The switchgear according to any one of claims 2 to 4, wherein the switchgear is made of a material different from the movable electrode and the fixed electrode of the disconnecting opening / closing section and the movable electrode and the fixed electrode of the grounding opening / closing section. 7. The switchgear according to claim 1, wherein the container is a vacuum container.