KR20190001766A - Apparatus for indicating state of valve and gas insulated switchgear having the same - Google Patents

Abstract

The present invention relates to an apparatus for displaying a valve state and a gas insulated switchgear (GIS) including the same, capable of preventing the fatal error of equipment due to the erroneous flow of a fluid and a related accident, in advance. According to the present invention, the apparatus for displaying a valve state includes: a device body having a gear tooth provided on an inner surface thereof and including a state display window communicating with the outside; a bridge shaft received in the device body to be connected to a rotation shaft of a valve and having a gear tooth provided on an outer surface thereof; a planetary gear unit engaged with the gear tooth of the device body and the gear tooth of the bridge shaft to be rotated by the rotation of the bridge shaft; and a state display unit provided in the planetary gear unit to display, on the state display window, a state of the valve through an area exposed to the outside of the device body. The number of gear teeth of the planetary gear unit may be larger than the number of gear teeth of the bridge shaft.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a valve state indicating apparatus and a gas insulated switchgear having the same.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve state display apparatus and a gas insulated switchgear having the same.

Generally, Gas Insulated Switchgear (GIS) is a facility that insulates high pressure insulation gas into steel tanks and maintains insulation, and performs power supply and shutdown function.

The gas insulated switchgear is filled with a high-pressure SF6 gas for securing the dielectric strength. As shown in FIG. 1, a stop valve 20 for exhausting and filling is installed in the moving passage 10 of the SF6 gas. Therefore, when the gas insulated switchgear 1 is inspected, extended, and the SF6 gas is inspected, the operator can manually operate the stop valve 20 to perform the SF6 gas exhausting and filling operation.

Typically, a plurality of such stop valves 20 are provided. Of the stop valves of the gas insulated switchgear, there are valves which must be normally closed and which must be normally open.

For example, the gas transfer passage of the gas insulated switchgear has a recovery section of gas and a charging section of gas. In a steady state, the stop valve of the gas recovery section should be opened and the stop valve of the gas filling section should be closed.

However, if the open / close state of the stop valve 20 can not be maintained due to some reason for the operation, it may cause breakdown of the insulation. Therefore, the operator is informed of the open / close state of the stop valve through the valve state display device. Keeping it constant is a very important issue.

In addition, when the use environment of the gas insulated switchgear is outdoors, there is a possibility of damage or breakage of the equipment due to the external environmental factors. Therefore, the problem of durability and weatherability of the facility should be additionally considered.

In addition, in the case of an operator constructing a gas-insulated switchgear or operating a stop valve, the convenience of installation of the valve state display device is also a very important issue, in addition to grasping the state of opening and closing of the stop valve.

KR 10-1996-0027116 A (July 22, 1996)

An object of the present invention is to confirm whether or not the valve is opened or closed, and the degree of opening or closing of the valve.

It is another object of the present invention to provide a valve state display device having improved durability, weather resistance, stability of driving, ease of use and installation, and a gas-insulated switchgear equipped therewith.

A valve state display device according to the present invention includes: a device body having a gear on an inner surface thereof and having a status display window communicating with the outside; a bridge shaft, which is accommodated in the device body and is connected to a rotary shaft of the valve, A planetary gear unit that rotates by rotation of the bridge shaft in engagement with the gear of the apparatus body and the gear of the bridge shaft; And a state display unit provided in the planetary gear unit and displaying a state of the valve by an area exposed to the outside of the apparatus body through the state display window, wherein the number of gear teeth of the planetary gear unit is greater than the number of gear teeth of the bridge shaft May be greater than the number of the gear teeth of the gears.

At this time, the apparatus body includes: a body base having the gear teeth in the circumferential direction and having a rear status display window communicating with the outside; And a body cover having a front state display window communicating with the outside and having a through hole through which the bridge shaft passes.

The planetary gear unit may further include a first planetary gear engaged with the gear of the body base and the gear of the bridge shaft so that the gear body faces the front state display window; And a second planetary gear that meshes with the gear of the body base and the gear of the bridge shaft so that the gear body faces the rear status display window.

The state display unit includes: a front display symbol provided on the gear body of the first planetary gear, the front display symbol having an entire surface or a part of the surface exposed by the rotation of the bridge shaft to the front surface display window; And a rear display symbol provided on the gear body of the second planetary gear, the rear display symbol having an entire surface or a partial surface exposed to the rear surface display window by rotation of the bridge shaft.

Preferably, the number of the gear teeth of the first planetary gear and the second planetary gear may be five or more and six or less times the number of the gear teeth of the bridge shaft.

Also, preferably, the front display symbol and the rear display symbol have at least the same area as the front state display window and the rear state display window, and may have different colors from the first and second planetary gears.

The valve state display device according to the present invention includes at least one fastening hole provided in at least one of the body base and the body cover. And a fastening member which is inserted into the fastening hole or detached from the fastening hole to couple or separate the body base and the body cover.

The apparatus may further include a valve handle coupled to the bridge shaft and disposed outside the apparatus body.

On the other hand, the present invention as another aspect provides a gas-insulated switchgear equipped with the above-described valve state display device.

The gas insulated switchgear according to the present invention includes a control valve provided in a gas flow path and completing an opening or closing setting of the gas flow path by completing rotation of a rotation axis in a clockwise or counterclockwise direction; And the valve state display device connected to the rotation shaft of the control valve having the opening or closing setting completed.

According to the present invention, it is possible to confirm whether or not the valve is opened or closed, and the valve opening or closing degree of the valve.

Further, the durability, weather resistance, stability of driving, convenience of use and installation are improved.

In addition, there is an effect that the occurrence of a fatal error and related safety accidents due to an erroneous flow of the fluid can be prevented in advance.

Fig. 1 schematically shows a conventional gas insulated switchgear.
2 is a perspective view of a valve state display apparatus according to an embodiment of the present invention.
3 is a side view of a valve state display apparatus according to an embodiment of the present invention.
4 and 5 are exploded perspective views of a valve state display apparatus according to an embodiment of the present invention.
6 is a front view of a valve state display apparatus according to an embodiment of the present invention.
7 is an operational state diagram of a valve state display apparatus according to an embodiment of the present invention.
FIG. 8 is a rear operating state of the valve state indicating apparatus according to an embodiment of the present invention. FIG.
9 is a front view of a valve state display apparatus according to an embodiment of the present invention.
10 is a rear view of a valve state display apparatus according to an embodiment of the present invention.
11 is a front view of a valve state display apparatus according to another embodiment of the present invention.
12 schematically shows a gas insulated switchgear according to the present invention.

In order to facilitate an understanding of the description of the embodiments of the present invention, elements denoted by the same reference numerals in the accompanying drawings are the same element, and among the constituent elements that perform the same function in each embodiment, Respectively.

Further, in order to clarify the gist of the present invention, a description of elements and techniques well known in the prior art will be omitted, and the present invention will be described in detail with reference to the accompanying drawings.

It is to be understood, however, that the spirit and scope of the present invention are not limited to the embodiments shown, but may be suggested by those skilled in the art in other forms, additions, or alternatives, .

2, the valve state display device 100 according to the preferred embodiment of the present invention is provided with a rotation axis 30 of a valve provided in the fluid movement passage 10 to open or close the fluid movement passage 10, As shown in FIG.

For example, the fluid transfer passage 10 may be a passage through which SF6 gas used in the gas insulated switchgear may flow, and the valve provided in the fluid transfer passage 10 may be a relief valve or a butterfly valve .

Hereinafter, the valve status display apparatus according to the present invention will be described as an example of a gas insulated switchgear, but the present invention can be applied to other apparatuses other than the gas insulated switchgear.

The operator can control the flow inside the fluid transfer passage 10 through the valve provided in the fluid transfer passage 10 after finishing the setting and checking of the fluid transfer passage 10 through which the SF6 gas flows.

In the gas insulated switchgear, there are a plurality of fluid transfer passages 10 and valves, the valves of the fluid transfer passages in the gas recovery section are always set to open, and the valves of the fluid transfer passages in the gas filling section are set to be always closed The insulation can be maintained.

That is, if the fluid transfer passage 10 shown in FIG. 2 is the fluid transfer passage of the gas recovery section, the butterfly valve installed here must always be opened, and the rotary shaft 30 of the valve is to keep the valve always open Rotation must be completed in the direction in which it can be rotated.

However, since the butterfly valve can adjust the opening or closing degree of the fluid passage in accordance with the number of revolutions in addition to the rotational direction, if the valve can not completely maintain the open or closed state, the insulation breakdown of the gas insulated switchgear may occur. . Therefore, the present invention provides a valve state display device capable of grasping the degree of opening or closing of the fluid passage 10 according to the number of rotations of the rotary shaft 30 of the valve.

As described above, if the valve provided in the fluid transfer passage 10 shown in FIG. 2 is always open, the operator rotates the rotary shaft 30 of the valve clockwise or counterclockwise to move the fluid transfer passage 10 It can be kept open.

When the setting is completed, the apparatus body 110 of the present invention is positioned on the rotary shaft 30 and one side of the bridge shaft 120 passing through the apparatus body 110 can be connected to the rotary shaft 30 have. At this time, the valve handle 161 is connected to the other side of the bridge shaft 120 so that the rotation of the bridge shaft 120 can be easily controlled.

The setting of the valve state indicating apparatus can be completed by indicating that the state indicating unit 140 provided in the apparatus body 110 fully opens the valve.

3, the apparatus body 110 according to the present invention is provided with a body base 115 and a body cover 116 covering a front surface of the body base 115, And can be coupled to each other by the fastening members 152. [

As described above, by separating the device body 110 into the body base 115 and the body cover 116 and allowing them to be combined or separated, an operator can more conveniently install the valve and valve state display device in the field.

If the material of the body base 115 and the body cover 116 is made of super engineering plastic of PEEK series, the strength and the weight can be reduced while improving the durability of the device and the convenience of the work.

At this time, the body base 115 may be provided with one surface facing the rotary shaft 30 of the valve so that the rotary shaft 30 of the valve may be drawn in. Inside the body base 115, And a planetary gear unit 130 engaged with the gear teeth 122 existing on the outer surface of the output shaft 120.

The planetary gear unit 130 may be provided with a first planetary gear 131 disposed on the bridge shaft 120 and a second planetary gear 132 disposed on the lower portion of the bridge shaft 120 .

The planetary gear unit 130 is driven to rotate by engaging with the gear 122 on the outer surface of the bridge shaft 120 so that the operator rotates the valve handle 161 to rotate the bridge shaft 120 more stably And the driving torque is reduced.

In addition, when the material of the bridge shaft 120 is SUS316 subjected to high temperature heat treatment and rapid cooling, sufficient weather resistance and mechanical strength can be ensured even when the installation position of the valve state display device is outdoors or repeatedly rotated. Therefore, abrasion and damage of the apparatus can be reduced, and the life of the apparatus can be prolonged.

The operator places the body base 115 on the rotary shaft 30 of the valve to draw the rotary shaft 30 into the body base 115 and then the bridge shaft 120 Can be connected to the rotary shaft (30).

4, the gear base 111 is provided on the inner surface of the body base 115 to engage with the gears of the planetary gear unit 130 in the circumferential direction.

The first planetary gear 13 is engaged with the upper portion of the gear 122 provided on the outer surface of one side of the shaft body 121 of the bridge shaft 120 and the second planetary gear 132 is engaged with the gears of the bridge shaft 120 And the planetary gear unit 130 can be fixed to the body base 115 by engaging with the lower portion of the body 122.

The planetary gear unit 130 thus set rotates in accordance with the rotation of the bridge shaft 120, thereby reducing the rotational load of the bridge shaft 120 and further enhancing the stability of driving the apparatus.

A state indicating unit 140 may be provided on the gear body of the planetary gear unit 130 to indicate the rotational state of the rotary shaft 30 of the valve.

The state indicating unit 140 has a function of displaying to the operator the rotational state of the rotary shaft 30 of the valve, whether the fluid passage is opened or closed, and the degree of opening or closing thereof. Preferably, have.

For example, if the state display unit 140 displays a state in which the valve is open, the state display unit can display green. If the state that the state display unit 140 should display is a closed state of the valve, The display unit can be reddish. However, such a color is not necessarily limited by the present invention but may be selected and applied in appropriate colors depending on the operator and the use environment.

The status indicating unit 140 may be provided on both the front surface and the rear surface of the apparatus body 110. Thus, the operator can know the state of the valve on both the front and back sides of the apparatus body 110, and the state of the valve can be checked at various angles, thereby reducing the occurrence of safety accidents.

Preferably, the status indicating unit 140 includes a front display symbol 141 installed at the front 12 o'clock direction of the first planetary gear 131, and the front display symbol 141 passes through the body cover 116 The entire area can be set to be exposed to the outside through the front surface state display window 114,

5, the status display unit 140 includes a rear display symbol 142 installed at a rear face 6 o'clock of the second planetary gear 132, and the rear display symbol 142 includes a body base The entire area can be set to be exposed to the outside through the rear surface display window 113,

4 and 5, when the planetary gear unit 130 is set, a front display symbol 141 provided on the first planetary gear 131 is inserted into the front state display window 114 provided on the body cover 116, So that the whole front display symbol 141 is exposed to the outside of the body cover 116 through the front state display window 114. [

5, the rear display symbol 142 provided on the second planetary gear 132 faces the rear surface display window 113 provided on the body base 115, and the entire rear display symbol 142 faces the rear surface state display window 113, So that it is exposed to the outside of the body base 115 through the display window 113.

4 and 5, when the shape and the width of the front display symbol 141 and the rear display symbol 142 are made equal to the shape and the width of the front state display window 114 and the rear state display window 113, It is possible to further increase the sensitivity of the sensor.

That is, as the shapes and the widths of the front display symbol 141 and the rear display symbol 142 are smaller than the shapes and the widths of the front state display window 114 and the rear state display window 113, The front display symbol 141 and the rear display symbol 142 can not fill the front display window 114 and the rear display window 113 when the user moves the display screen.

Therefore, the greater the difference between the shape and the width of the front display symbol 141 and the rear display symbol 142 than the shape and width of the front display window 114 and the rear display window 113, The smaller the difference, the higher the sensitivity of the display becomes, and the operator can express the sensitivity more sensitively. Therefore, the operator can select the sensitivity of the indication of the valve display device appropriately and apply it.

5, a valve connection hole 125 through which a rotary shaft (30 in FIG. 3) of the valve can be inserted may be provided at a front portion of the bridge shaft 120. [ Preferably, the valve connection hole 125 is provided to have an interference fit or an intermediate fitting tolerance with the rotation axis of the valve (30 in FIG. 3) so that the valve rotation axis (30 in FIG. 3) So that they can rotate together.

4 and 5, a thread 123 may be provided on the other part of the shaft body 121 of the bridge shaft 120, and the thread 123 may pass through the through hole 117 of the body cover 116 And can engage with the valve handle 161 outside the device body 110. To this end, a screw groove (not shown) may be provided on the inner surface of the valve handle 161 to engage with the thread 123 of the bridge shaft 120, and a nut may be additionally provided to further secure the coupling. . However, the present invention is not necessarily limited to the present invention, but may be modified and applied by a person skilled in the art to an appropriate coupling means.

6 (a) shows the body base 115 of the valve state display apparatus that has been set up in the above manner, and FIG. 6 (b) shows the set body cover 116. The body base 115 and the body cover 116 that have been set up in principle are mutually coupled by the fastening member 152 and the fastening hole 151 into which the fastening member 152 is inserted, The body base 115 and the body cover 116 are shown in a separated state.

After the rotary shaft 30 of the valve completes the rotation in the direction corresponding thereto by whether or not the predetermined fluid flow passage is opened or closed, the shaft body 121 of the bridge shaft is connected to the rotary shaft 30, And can be inserted and coupled to the rotary shaft 30 in a method. At this time, thread, screw groove, or the like may be applied to make the coupling more robust, or bolts, nuts, or other fastening means may be additionally applied.

In this state, the front display symbol 141 of the first planetary gear 131 can be installed at the 12 o'clock position of the first planetary gear 131, As can be seen, the entire area can be exposed to the outside through the body cover 116. That is, the front display symbol (141) fills the entire front surface state display window (114 of FIG. 4) of the body cover.

7 (a) and 7 (b), the shaft body 121 of the bridge shaft is rotated due to an unexpected factor so that the valve partially rotates and the fluid movement The front display symbol 141 can not fill a part of the front status display window 114 when the passage is partially opened or partially closed so that the operator can not fully fill the front status display window 114 with the front display symbol 141 The degree of rotation of the valve can be confirmed.

Similarly, as shown in FIGS. 8A and 8B, the rear state display window 113 provided on the rear surface of the body base 115 also displays the state of the valve by the same principle, The state of the valve can be recognized in both the direction of the valve body 115 and the direction of the body cover 116.

For example, if the front display symbol 114 is filled up, it means that the valve is in a perfectly normal state. If the front display symbol 141 does not fill the front display window 114 In addition to being able to recognize that the valve is in an abnormal state, it is also possible to predict how much the valve is open or how close it is depending on the degree of failure. Therefore, the operator can judge whether or not the state of the valve needs to be checked immediately, thereby increasing the efficiency of the operation.

In addition, the direction in which the front display symbol (141 of FIG. 7 (a)) and the rear display symbol move is different in accordance with the rotation direction of the planetary gear unit 130 so that the direction in which the front display symbol and the rear display symbol move, It is possible to grasp in which direction the rotation is performed.

7 and 8, the number of gear teeth of the planetary gear unit 130 is larger than the number of gear teeth 122 provided on the outer surface of the shaft body 121 of the bridge shaft (120 of FIG. 5) More preferably, the number of gear teeth of the planetary gear unit 130 may be five or more and six or less times the number of gear teeth 122 of the bridge shaft (120 of FIG. 5).

This is because the rotation of the planetary gear unit 130 makes one revolution only when the bridge shaft (120 in FIG. 5) is rotated five to six times, and the rotation error of the valve must be found within one to four times, Rotation errors within a range of one to three times are usually the most sensitive and important problems.

Therefore, when the number of gears of the planetary gear unit 130 is made to be five times or more and six times or less the number of the gears 122 of the bridge shaft (120 of FIG. 5) The front display symbol 141 remains in the front state display window 114 until the error is detected, so that the rotation error of the valve can be recognized at an early stage.

In addition, when the valve is reached just before five or six or more rotation errors, the front display symbol 141 is displayed on the front status display window 114 since it is just before the rotation of the planetary gear unit 130 almost once It is not exposed to the outside. In this case, the operator can see that the valve that is initially set to open is just before the valve is completely closed, and that the valve that is initially closed set is just before the valve is fully opened. The same applies to the rear display symbol 142 and the rear status display window 113 shown in FIG.

In addition, the gear ratio of the gear teeth 122 and the planetary gear unit 130 on the outer surface of the shaft body 121 may be modified in consideration of the specification of the valve, the working environment, the sensitivity of error display, etc. For example, If the gear ratio of the gear 122 on the outer surface of the shaft body 121 and the gear ratio of the planetary gear unit 130 is 1: 5.17, the opening degree or closing degree of the valve is more than simply indicating the opening or closing state of the valve It is possible to easily grasp the wrong number of revolutions of the valve.

At this time, the gear ratio is not necessarily limited to the present invention but may be appropriately changed depending on the specifications of the valve, the maximum number of revolutions of the valve rotation shaft, and the like.

9 and 10 show the valve state display device 100 provided in the fluid movement passage 10 which must be open at all times.

Since the fluid transfer passage 10 is always open, the device body 110 is indicated in green, and a front display symbol 141 provided on the front surface of the device body 110 and a rear display symbol 142 ) Was also made green which is the same as that of the device body 110.

On the contrary, FIG. 11 shows the valve state display device 100 provided in the fluid movement passage 10, which must be always closed.

Since the fluid transfer passage 10 is always closed, the device body 110 is indicated in red, and the hue of the front display symbol 141 provided on the front surface of the device body 110 is also the same as the device body 110 Red, which can be equally applied to the rear surface.

The state shown in FIGS. 9 to 11 is a state in which the entire area of the state indicating unit 140 is exposed to the outside of the apparatus body 110, and the state in which the rotation axis of the valve (20 in FIG. 3) There is no rotation and the fluid passage 10 is also maintained as initially set.

The colors of the apparatus body 110 and the state indicating unit 140 are appropriately selected and the state of the present valve is visually displayed by writing a phrase such as 'normally open' or 'normally closed' Can be easily expressed.

12, the present invention as another aspect provides a gas insulated switchgear 200 having a valve state display device 100 constructed as described above.

The gas insulated switchgear 200 according to the present invention includes a gas valve 210 and a control valve 200. The gas insulated switchgear 200 is installed in the gas passage 210 to complete rotation or counterclockwise rotation of the rotary shaft 220, Or the valve state display device 100 connected to the rotation shaft 220 of the control valve in which the closing operation is completed.

At this time, the SF6 gas may flow into the gas channel 210, and the gas channel 210 may be present in the gas recovery section or the gas filling section. Depending on whether the gas passage 210 exists in the gas recovery section or in the gas charging section, the control valve may open or close the gas passage 210 at all times.

Specifically, the rotary shaft 220 of the control valve is inserted into the valve connection hole 125 of the bridge shaft, thereby connecting the rotary shaft 220 of the control valve 220 ) And the valve state display device can be interlocked.

In addition, the setting of the valve state display apparatus can be completed by the above-described method, so that the state of the rotation shaft 220 of the control valve, that is, whether the gas passage 210 is opened or closed, and the degree of opening or closing can be transmitted to the operator.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be apparent to those of ordinary skill in the art.

1, 200: gas insulated switchgear 10: moving passage
20: Stop valve 30, 220:
100: valve state display device 110: device body
112: Status display window 115: Body base
116: body cover 117: through hole
120: bridge shaft 121: shaft body
130: planetary gear unit 131: first planetary gear
132: second planetary gear 140: state indicating unit
141: front display symbol 142: rear display symbol
151: fastening hole 152: fastening member
161: valve handle 210: gas flow path

Claims (9)

A device body having gears on its inner surface and having a status display window communicating with the outside;
A bridge shaft received in the apparatus body and connected to a rotation axis of the valve, the bridge shaft having a gear on an outer surface thereof;
A planetary gear unit that rotates by the rotation of the bridge shaft in engagement with the gear of the apparatus body and the gear of the bridge shaft; And
And a status display unit provided in the planetary gear unit and displaying the state of the valve by an area exposed to the outside of the apparatus body through the status display window,
Wherein the number of gear teeth of the planetary gear unit is larger than the number of gear teeth of the bridge shaft.
The method according to claim 1,
The apparatus body includes:
A body base having the gear teeth in a circumferential direction and having a rear status display window communicating with the outside; And
A body cover having a front state display window communicating with the outside and having a through hole through which the bridge shaft passes;
Wherein the valve state display device comprises:
3. The method of claim 2,
Wherein the planetary gear unit includes:
A first planetary gear engaged with the gear of the body base and the gear of the bridge shaft so that the gear body faces the front surface state display window; And
A second planetary gear meshing with the gear of the body base and the gear of the bridge shaft so that the gear body faces the rear status display window;
Wherein the valve state display device comprises:
The method of claim 3,
Wherein the status display unit comprises:
A front display symbol provided on the gear body of the first planetary gear and having an entire surface or a partial surface exposed to the front surface state display window by rotation of the bridge shaft; And
A rear display symbol provided on the gear body of the second planetary gear, the rear display symbol having an entire surface or a partial surface exposed to the rear surface display window by rotation of the bridge shaft;
Wherein the valve state display device comprises:
5. The method of claim 4,
Wherein the number of the gear teeth of the first planetary gear and the second planetary gear is not less than 5 times and not more than 6 times the number of the gear teeth of the bridge shaft.
6. The method of claim 5,
Wherein the front display symbol and the rear display symbol are arranged in a matrix,
Wherein the first and second planetary gears have at least the same width as the front surface display window and the rear surface display window, and are provided in different colors from the first and second planetary gears.
3. The method of claim 2,
At least one fastening hole provided on at least one of the body base and the body cover; And
A fastening member inserted into the fastening hole or separated from the fastening hole to couple or separate the body base and the body cover;
Further comprising: a pressure sensor for detecting the valve state of the valve.
The method according to claim 1,
A valve handle coupled to the bridge shaft and disposed outside the device body;
Further comprising: a valve-state display unit for displaying the valve state of the valve.
A control valve provided in the gas flow passage and completing the opening or closing of the gas flow passage by completing rotation of the rotation axis in a clockwise or counterclockwise direction; And
The valve state display device according to any one of claims 1 to 8, which is connected to the rotation axis of the control valve in which the opening or closing setting is completed.
And a gas insulated switchgear.

Images