Metal-enclosed switchgear
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KK TOSHIBA
- Filing Date
- 2023-02-28
- Publication Date
- 2026-08-03
Smart Images
Figure 0007899113000001 
Figure 0007899113000002 
Figure 0007899113000003
Abstract
Description
Technical Field
[0001] Embodiments of the present invention relate to a metal-enclosed switchgear.
Background Art
[0002] Conventionally, a metal-enclosed switchgear (metal-enclosed switchboard) having insulation performance has been known so that electrical equipment can be housed in a metal-enclosed casing and used safely for a long period of time.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] The basic configuration of a conventional two-tier metal-enclosed switchgear is, for example, a control room compartment for housing a control circuit and control equipment, and a circuit breaker for interrupting the current in the power circuit when an accident occurs in the power circuit or when the metal-enclosed switchgear is inspected. It is divided by partition plates into a circuit breaker compartment for housing, a busbar compartment for housing a busbar responsible for the main circuit connection between the power supply side of the circuit breaker and the adjacent panel, and a cable compartment for housing the main circuit cable drawn from the outside on the load side of the circuit breaker.
[0005] However, in a conventional two-tier metal-enclosed switchgear, the cable compartment is not divided by partition plates for each upper and lower circuit breaker. And when an operator wants to access the de-energized upper main circuit cable or the de-energized lower main circuit cable, there is a problem of further improving the safety in the cable compartment.
Means for Solving the Problems
[0006] To solve the above problems, the metal-enclosed switchgear of this embodiment comprises a housing, two circuit breakers arranged in upper and lower stages within the housing, a busbar compartment formed inside the housing, two circuit breaker compartments formed above and below the busbar compartment, a control compartment formed in front of each of the circuit breaker compartments, two cable compartments formed behind each of the circuit breaker compartments and corresponding to the load side of the circuit breakers, and a common compartment for housing a ground busbar. The boundaries of the busbar compartment, the two circuit breaker compartments, the control compartment, the two cable compartments, and the common compartment are separated by metal partition plates grounded to a predetermined level of protection. [Brief explanation of the drawing]
[0007] [Figure 1] Figure 1 is a side view illustrating the interior of the metal-closed switchgear of Embodiment 1. [Figure 2] Figure 2 is a perspective view illustrating the interior of the metal-closed switchgear of Embodiment 1. [Figure 3] Figure 3 is an explanatory diagram illustrating the positional relationship between the upper main circuit cable and the lower main circuit cable, the upper cable compartment and the lower cable compartment, and the duct-shaped partition plate when viewing the inside of the metal closed switchgear of Embodiment 1 from the rear side. [Figure 4] Figure 4 is a front view illustrating the front doors arranged vertically on the metal closed switchgear of Embodiment 1. [Figure 5] Figure 5 is an enlarged perspective view illustrating the common compartment. [Figure 6] Figure 6 is a rear view illustrating the upper and lower divided rear door of the opening / closing section that provides access to the two cable compartments of the metal-enclosed switchgear of Embodiment 1. [Figure 7]Figure 7 is a flowchart showing the operating procedure for the metal-closed switchgear of Embodiment 1, from a state where the upper cable compartment is charged to a state where the upper cable compartment is de-currented and accessible. [Figure 8] Figure 8 is a side view of the metal-closed switchgear of Embodiment 2. [Figure 9] Figure 9 is a rear view illustrating the rear door of the metal closed-type switchgear of Embodiment 2, which is positioned outside the housing beyond the rear partition plate. [Figure 10] Figure 10 is a rear view illustrating the upper and lower rear partition plate of the opening / closing section that allows access to the upper and lower cable compartments of the metal closed switchgear of Embodiment 2. [Figure 11] Figure 11 is a flowchart showing the operating procedure for the metal-closed switchgear of Embodiment 2, from a state where the lower cable compartment is charged to a state where the lower cable compartment is de-current and accessible. [Figure 12] Figure 12 is a side view illustrating the interior of the metal-closed switchgear of Embodiment 3. [Figure 13] Figure 13 is a perspective view illustrating the interior of the metal-closed switchgear of Embodiment 3. [Figure 14] Figure 14 is an explanatory diagram illustrating the positional relationship between the upper main circuit cable and the lower main circuit cable, the upper cable compartment and the lower cable compartment, and the duct-shaped partition plate when viewing the inside of the metal closed switchgear of Embodiment 3 from the rear side. [Figure 15] Figure 15 is a rear view illustrating the upper and lower divided rear door of the opening / closing section that provides access to the upper and lower cable compartments of the metal closed switchgear of Embodiment 3. [Figure 16] Figure 16 is a side view of the metal closed-type switchgear of Embodiment 4. [Figure 17]Figure 17 is a rear view illustrating the upper and lower rear partition plate of the opening / closing section that allows access to the cable compartment of the metal closed switchgear of Embodiment 4. [Modes for carrying out the invention]
[0008] (Switchgear of Embodiment 1) Referring to Figures 1 and 2, the structure of the metal-enclosed switchgear 1 (hereinafter referred to as switchgear 1) according to Embodiment 1 of the present invention will be described. In Figure 1, the switchgear 1, whose interior is shown in a side view, is housed in a metal enclosure 11, for example, where electrical equipment is enclosed, providing insulating properties. Furthermore, switchgear 1 is a so-called two-tiered metal-enclosed switchgear. Figure 2 is a perspective view illustrating the interior of the enclosure 11 of switchgear 1 according to Embodiment 1. Note that the structure of switchgear 1 according to Embodiment 1 is not limited to the examples shown in Figures 1 and 2.
[0009] The following explanation uses a Cartesian coordinate system with X, Y, and Z axes. The X-axis direction includes both the +X and -X directions. The Y-axis direction includes both the +Y and -Y directions. The Z-axis direction includes both the +Z direction (up) and the -Z direction (down). For example, the X-Y axis plane is the horizontal plane, and the Z-axis direction is the vertical direction.
[0010] The housing 11 shown in Figures 1 and 2 comprises, for example, a rectangular plate-shaped bottom plate 114, a pair of side walls 111 and 112 (see Figures 2 and 3) facing each other in the width direction (Y-axis direction) of the housing 11, front doors 113a and 113b located on the front side (-X direction side) of the housing 11, a flat plate-shaped ceiling 110, and an opening / closing section 6 located on the rear side (+X direction side) of the housing 11. The housing 11 is oriented such that the X-axis direction is the front-to-back direction, the Y-axis direction is the width direction, and the Z-axis direction is the up-and-down direction. Note that in Figure 2, the side wall 111 is partially cut out to illustrate the interior of the housing 11.
[0011] As shown in FIG. 1, in the space on the front side (-X direction side) within the housing 11, an upper breaker chamber compartment 131 and a lower breaker chamber compartment 132 are vertically partitioned and formed. That is, the breaker chamber compartment 131 is a space surrounded by a metal partition plate 133 which is a partition wall. Also, the breaker chamber compartment 132 is a space surrounded by a metal partition plate 134 which is a partition wall.
[0012] The space between the partition plate 133 and the partition plate 134 arranged at a predetermined interval in the vertical direction (Z-axis direction) is the busbar chamber compartment 120. That is, within the housing 11, the breaker chamber compartment 131 and the breaker chamber compartment 132 are formed above and below the busbar chamber compartment 120.
[0013] As shown in FIG. 1, the switchgear 1 includes a horizontal busbar 12, a breaker 13A, and a breaker 13B. The horizontal busbar 12 is housed within the busbar chamber compartment 120. The horizontal busbar is a main electric wire (conductor) in the power distribution equipment and connects the electric circuit with an adjacent panel.
[0014] The upper breaker 13A housed in the breaker chamber compartment 131 and the lower breaker 13B housed in the breaker chamber compartment 132 are each electrically connected to the horizontal busbar 12 via the main circuit conductor 20.
[0015] The breakers 13A and 13B are devices for interrupting the current in the power circuit when an accident occurs in the power circuit including the horizontal busbar 12 or when performing maintenance on the power circuit. An example of the breaker 13A and the breaker 13B is a high-voltage vacuum breaker (VCB). By setting the breaker 13A to the open state, the upper main circuit cable 4A shown in FIG. 1 can be de-energized. Also, by setting the breaker 13B to the open state, the lower main circuit cable 4B shown in FIG. 1 can be de-energized.
[0016] As shown in Figure 1, the upper control room compartment 141 is formed in front of the circuit breaker room compartment 131 (towards the -X direction), separated from the circuit breaker room compartment 131 by a partition plate 143a. Similarly, the lower control room compartment 142 is formed in front of the circuit breaker room compartment 132 (towards the -X direction), separated from the circuit breaker room compartment 132 by a partition plate 143b. In the example shown in Figure 1, the control room compartments 141 and 142 are separated into upper and lower sections by a partition plate 144, but the control room compartments 141 and 142 may be a single unit without being separated into upper and lower sections by a partition plate.
[0017] Control room compartments 141 and 142 house control equipment that controls the operation of circuit breakers 13A and 13B, etc. The control equipment is a conventional control terminal block, etc., which has a CPU, memory, and other storage media.
[0018] On the front side (-X direction side) of the housing 11, front doors 113a and 113b, as shown in Figures 1 and 4, are arranged vertically. The upper front door 113a is equipped with an opening / closing knob 113c that can be grasped by an operator, and when opened, it leads to the upper control room compartment 141 and the upper circuit breaker room compartment 131. The lower front door 113b is equipped with an opening / closing knob 113d that can be grasped by an operator, and when opened, it leads to the lower control room compartment 142 and the lower circuit breaker room compartment 132.
[0019] Operating units 149a and 149b are provided on the outer surfaces of the front doors 113a and 113b, respectively, allowing for individual operation of the opening and closing of circuit breakers 13A and 13B. The operating units 149a and 149b are equipped with touch panels or the like, and display the open / closed status of either circuit breaker 13A or circuit breaker 13B, as well as the value of the current flowing through the upper main circuit cable 4A or the lower main circuit cable 4B, respectively. They are also equipped with operating buttons that allow the operator to switch the open / closed status of either circuit breaker 13A or circuit breaker 13B.
[0020] To the rear (+X direction) of the circuit breaker compartment 131, the upper cable compartment 21 is formed, separated from the circuit breaker compartment 131 by a partition plate 133. Furthermore, to the rear (+X direction) of the circuit breaker compartment 132, the lower cable compartment 22 is formed, separated from the circuit breaker compartment 132 by a partition plate 134.
[0021] The busbar compartment 120, located between the circuit breaker compartment 131 and the circuit breaker compartment 132 in the Z-axis direction, is separated from the upper cable compartment 21 and the lower cable compartment 22 by a partition plate 25, which is located on the rear side (+X direction side) of the busbar compartment 120 and extends mainly in the Z-axis direction.
[0022] As shown in Figures 1 and 2, a metal duct-shaped partition plate 5 is installed behind the partition plate 25 (towards the +X direction), and the duct-shaped partition plate 5 separates the upper cable room compartment 21 from the lower cable room compartment 22.
[0023] As shown in Figure 1, a busbar-side circuit connection section 201, which includes a bushing or the like that penetrates the partition plate 133, is provided at the connection point between the main circuit conductor 20 electrically connected to the horizontal busbar 12 and the upper circuit breaker 13A. The circuit breaker 13A is also connected to the load-side conductor 32 via a load-side circuit connection section 31 that penetrates the partition plate 133.
[0024] For example, shutters 15a are provided between the busbar-side circuit connection 201 and the circuit breaker 13A, and between the load-side circuit connection 31 and the circuit breaker 13A. The shutters 15a have the function of keeping workers entering the panel away from the exposed live parts (not shown) that are normally housed inside when the circuit breaker 13A is pulled out in the X-axis direction from the circuit breaker room compartment 131 for inspection or the like.
[0025] A busbar-side circuit connection section 202, equipped with a bushing or the like that penetrates the partition plate 134, is provided at the connection point between the main circuit conductor 20, which is electrically connected to the horizontal busbar 12, and the lower circuit breaker 13B. The circuit breaker 13B is connected to the load-side conductor 34 via a load-side circuit connection section 33 that penetrates the partition plate 134. A shutter 15b is provided between the busbar-side circuit connection section 202 and the circuit breaker 13B, and between the load-side circuit connection section 33 and the circuit breaker 13B.
[0026] As shown in Figure 1, an upper-side current transformer 35A is connected to the load-side conductor 32 located in the upper cable compartment 21 within the housing 11. The upper-side current transformer 35A shown in Figures 1 and 2 comprises, for example, a main body 350, mounting feet 351 (shown only in Figure 1) connected to the main body 350, and two terminal plates 352 extending from the main body 350 along the X-axis. The mounting feet 351 of the upper-side current transformer 35A, located on the upper side, are bolted to, for example, the ceiling 110 of the housing 11. The upper-side current transformer 35A is constructed by, for example, winding the primary side, which has a low rated current, around an iron core (not shown) and connecting both ends of the winding to terminal plates 352, which are primary terminals, and winding the secondary side around another part of the iron core and connecting both ends to secondary terminals (not shown).
[0027] In the switchgear 1 of Embodiment 1, an upper-side current transformer 35A is mounted on the ceiling 110 of the housing 11 to connect the upper-side main circuit cable 4A to the load side of the circuit breaker 13A located on the upper side. Therefore, as shown in Figure 1, the radius of curvature of the bent portion of the upper-side main circuit cable 4A can be made larger. That is, since there is no need to bend the upper-side main circuit cable 4A sharply, the bend of the main circuit cable 4A can be made gentler, and bending stress can be reduced.
[0028] As shown in Figures 1 and 2, one end of a terminal conductor 36, which has a shape bent at a predetermined angle, is bolted to the upper current transformer 35A mounted on the ceiling 110 of the housing 11, and the other end of the terminal conductor 36 is connected to the upper main circuit cable 4A via a cable terminal conductor 40. The terminal conductor 36 has the function of alleviating bending stress on the upper main circuit cable 4A within the housing 11.
[0029] A lower-side current transformer 35B is connected to the load-side conductor 34, which is located in the lower cable compartment 22 within the housing 11 shown in Figures 1 and 2. The lower-side current transformer 35B has the same structure as the upper-side current transformer 35A. The lower-side current transformer 35B is attached, for example, to a partition plate 25. The partition plate 25 separates the busbar compartment 120 from the upper cable compartment 21 and the lower cable compartment 22.
[0030] As shown in Figure 1, the lower current transformer 35B is connected to the lower main circuit cable 4B via, for example, a terminal conductor 371 extending in approximately the Z-axis direction, a relay member 372 attached to the lower surface of the duct top plate 50 forming the duct-shaped partition plate 5, and a terminal conductor 373 connected to the relay member 372 and having a shape bent at a predetermined angle.
[0031] The relay member 372 has electrical insulation properties, for example, and is a strain insulator. The load side of the circuit breaker 13B located on the lower side within the housing 11 and the main circuit cable 4B extending within the lower cable room compartment 22 are connected via the relay member 372, which allows for a larger radius of curvature in the bent portion of the main circuit cable 4B on the lower side. In other words, since there is no need to bend the main circuit cable 4B on the lower side sharply, the bend in the main circuit cable 4B can be made gentler, thereby mitigating bending stress.
[0032] The upper main circuit cable 4A and the lower main circuit cable 4B are used to connect the upstream and downstream switchgears 1. Main circuit cables 4A and 4B are, for example, CV cables. As shown in Figures 1 and 3, the main circuit cables 4A and 4B are drawn into the switchgear 1 from the lower side (-Z direction side) of the housing 11. Figure 3 is an explanatory diagram illustrating the positional relationship between the upper main circuit cable 4A and the lower main circuit cable 4B, the upper cable compartment 21 and the lower cable compartment 22, and the duct-shaped partition plate 5, as viewed from the rear side (+X direction side) of the switchgear 1 of Embodiment 1, by cutting a part of the housing 11 along the line F1-F1 in Figure 1.
[0033] As shown in Figure 3, for example, the upper main circuit cable 4A branches into three at its end. The three ends of the main circuit cable 4A are connected to the terminal conductor 36 via the cable terminal conductor 40.
[0034] As shown in Figure 1, the main circuit cable 4A extends from bottom to top within the upper cable room compartment 21, passing through, for example, a ring-shaped bracket 481 and bracket 483 (shown only in Figures 2 and 3). A monitor 481a is installed on bracket 481 to monitor, for example, the magnitude of the current flowing through the main circuit cable 4A that it supports. A zero-phase current transformer 482 for ground fault protection is attached to the main circuit cable 4A, which is installed below bracket 481.
[0035] As shown in Figure 3, for example, the lower main circuit cable 4B branches into three at its end. The three ends of the main circuit cable 4B are connected to terminal conductors 373 via cable terminal conductors 41. The main circuit cable 4B extends from bottom to top within the lower cable compartment 22, passing through, for example, a ring-shaped bracket 491. The bracket 491 is also equipped with, for example, a monitor 491a for monitoring the magnitude of the current flowing through the main circuit cable 4B it supports. Furthermore, a zero-phase current transformer 492 for ground fault protection is attached to the main circuit cable 4B.
[0036] Furthermore, for example, the measurement information from monitor 481a and monitor 491a can be transmitted to the respective operation units 149a and 149b shown in Figure 1 via a communication path not shown.
[0037] As shown in Figures 1 to 3, the bottom plate 114 of the housing 11 of the switchgear 1 of Embodiment 1 has a lower entry opening 115 for drawing in the main circuit cable 4A connected to the upper circuit breaker 13A from under the floor, which communicates with the upper cable room compartment 21. The bottom plate 114 also has a lower entry opening 116 for drawing in the main circuit cable 4B connected to the lower circuit breaker 13B from under the floor, which communicates with the lower cable room compartment 22. The lower entry openings 115 and 116 are formed at a predetermined distance apart in the Y-axis direction, but the lower entry openings 116 and 115 may be formed integrally. Furthermore, shutters (not shown) are provided at the lower entry openings 115 and 116, respectively.
[0038] As shown in Figures 1 and 2, the switchgear 1 of Embodiment 1 includes a common compartment 26 that houses the ground busbar 263 (shown only in Figure 1). As shown in Figure 1, the ground busbar 263 is connected to the grounding electrode 263b. The common compartment 26 is separated from the cable room compartment 21 and the cable room compartment 22 by a metal common compartment partition plate 27, as shown in Figures 1 and 5.
[0039] The common compartment partition plate 27 is erected almost vertically in an area further away from the lower entrance 116 and lower entrance 115 of the bottom plate 114 towards the rear (+X direction). As shown in Figure 1, in this embodiment, the common compartment 26 is formed as a separate space located at the lowest point on the rear (+X direction) side of the housing 11.
[0040] In the switchgear 1 of Embodiment 1, the upper cable compartment 21 and the lower cable compartment 22 are separated by a metal duct-shaped partition plate 5 shown in Figures 1 to 3. As shown in Figures 1 to 3, the duct-shaped partition plate 5 is positioned approximately midway in the Z-axis direction inside the housing 11.
[0041] The duct-shaped partition plate 5 comprises, for example, a duct top plate 50 that extends horizontally (in the X-axis and Y-axis plane direction) and has one end connected to the partition plate 25 shown in Figures 1 and 2, and a duct side plate 51 that hangs down from the duct top plate 50 and has its upper end integrally connected to the lower surface of the duct top plate 50. The lower end of the duct side plate 51 is connected to the bottom plate 114 of the housing 11.
[0042] The duct top plate 50 has, for example, a step in the Z-axis direction (vertical direction), and includes a high-step section 500 that is one step higher in the vertical direction, and a low-step section 501 that is one step lower than the high-step section 500 and is integrally connected to the high-step section 500 via a step section 502. The duct top plate 50 of the duct-shaped partition plate 5 divides the upper cable room compartment 21 and the lower cable room compartment 22 in the Z-axis direction.
[0043] The raised section 500 is formed in a roughly rectangular plate shape in plan view, extending substantially horizontally from the inner surface of the side wall 111 to the inner surface of the side wall 112, as shown in Figure 2, for example. A relay member 372 is attached to the lower surface of the raised section 500, as shown in Figure 1.
[0044] As shown in Figure 2, the flat lower section 501 has, for example, a roughly rectangular cutout hole 501a in the portion directly below the bracket 481 and zero-phase current transformer 482, which are located in the upper cable room compartment 21.
[0045] The duct side plate 51 includes, for example, a passage forming portion 511 that hangs down in the -Z direction from around the notched hole 501a on the lower surface of the lower step portion 501, and a thick portion 512 that is integrally formed on the lower end side of the passage forming portion 511, is thicker than the passage forming portion 511, and protrudes in the -Y direction.
[0046] The passage-forming portion 511 and the thickened portion 512 of the duct-shaped partition plate 5 separate the upper cable room compartment 21 and the lower cable room compartment 22 in the X-axis and Y-axis directions. The space enclosed by the passage-forming portion 511, the thickened portion 512, and the side wall 112 of the housing 11 becomes a passage 514 through which the main circuit cable 4A extends in the vertical direction. The passage 514 is an example of a passage formed by separating the main circuit cable 4A, which extends within the upper cable room compartment 21 and is connected to the upper circuit breaker 13A, from the lower cable room compartment 22, which is for the main circuit cable 4B connected to the lower circuit breaker 13B, using a metal duct-shaped partition plate 5 grounded to a predetermined protection level on the lower side. As shown in Figures 2 and 3, the passage 514 is formed in the bottom plate 114 of the housing 11 and is arranged to connect to the lower entry point 115 through which the main circuit cable 4A is brought in from under the floor, and is in communication with the lower entry point 115. The passage 514 also forms part of the upper cable room compartment 21.
[0047] For example, as shown in Figures 1, 2, and 5, the duct-shaped partition plate 5 has a notch 512b to avoid interference with the common compartment partition plate 27 in order to extend the passage 514 to the lower entrance 115. The notch 512b is formed, for example, by cutting out a groove-shaped section in approximately the lower half of the thick portion 512 of the duct side plate 51 on the +X side.
[0048] The partition plates 133, 134, 143, 144, 25, common compartment partition plate 27, and duct-shaped partition plate 5 shown in Figure 1 are, for example, made of metal and grounded with an IP2X protection rating.
[0049] The opening / closing section 6, located on the rear side (+X direction side) of the housing 11 shown in Figure 1, allows workers to independently access the cable room compartment 21 and the cable room compartment 22, respectively.
[0050] The opening / closing section 6 of the switchgear 1 in Embodiment 1 includes, for example, multiple rear doors that are divided vertically according to the partition between the upper cable compartment 21 and the lower cable compartment 22, and each of the cable compartment 21 and cable compartment 22 can be accessed independently by opening either of the corresponding rear doors.
[0051] As shown in Figures 1 and 6, the rear door of this embodiment consists of three doors: a first rear door 601 (hereinafter referred to as the first door 601) located on the upper side of the housing 11, a second rear door 602 (hereinafter referred to as the second door 602) located on the lower side in the +Y direction, and a third rear door 603 (hereinafter referred to as the third door 603) located on the lower side in the -Y direction. The first door 601 and the second door 602 may be integrally formed. The first door 601, the second door 602, and the third door 603 are made of metal. The switchgear 1 does not have a single rear door configuration like conventional switchgears, but rather has a configuration consisting of multiple rear doors as described above (a divided configuration).
[0052] The first door 601 and the second door 602 face the opening 21d on the +X side of the upper cable room compartment 21 and the passage 514 in the X-axis direction, as shown in Figures 1 and 2. The third door 603 faces the opening 22d on the +X side of the lower cable room compartment 22, as shown in Figures 1 and 2, in the X-axis direction.
[0053] In the switchgear 1 of Embodiment 1, a common compartment opening / closing section 67 is provided on the rear side (+X direction side) of the housing 11 for the operator to access the common compartment 26. The common compartment opening / closing section 67 is equipped with a metal cover 671 that is grounded to a predetermined level of protection to match the partition shape of the common compartment 26. The cover 671 faces the opening 26d on the +X direction side of the common compartment 26 shown in Figures 1 and 2 in the X-axis direction. The cover 671 may be made of a non-metallic material such as engineering plastic.
[0054] As shown in Figures 1 and 6, for example, the rectangular cover 671 is a plate-shaped cover that can be removed from the housing 11 to allow the worker to access the common compartment 26. The cover 671 is fastened and secured at its four corners to a pair of side walls 111 and 112 of the housing 11 using bolts 671a, so that it cannot be easily removed by anyone other than a designated worker. Removing the cover 671 requires a specific tool, such as a wrench. That is, the common compartment opening / closing section 67 is fastened using a tool (not shown) and can only be opened with a tool.
[0055] As shown in Figure 6, for example, the largest of the doors, the first door 601, is rectangular in shape and has a handle portion 601a that can be gripped by an operator and rotated clockwise or counterclockwise when viewed from the X-axis side. Similarly, the second door 602 and the third door 603, which are located below the first door 601, also have handle portions 602a and 603a, respectively, that can be gripped by an operator.
[0056] The handle portion 601a of the first door 601, the handle portion 602a of the second door 602, and the handle portion 603a of the third door 603 are locked by, for example, a key (not shown), and can only be opened by unlocking with said key. For example, the handle portion 601a has a keyhole 601b, the handle portion 602a has a keyhole 602b, and the handle portion 603a has a keyhole 603b. The keys (not shown) that fit the keyholes 601b, 602b, and 603b may be different or the same. The first door 601, the second door 602, and the third door 603 cannot be easily opened by anyone other than a designated worker.
[0057] The switchgear 1 of Embodiment 1 is not limited to a configuration in which, for example, each door of the opening / closing section 6 is locked by a key (not shown) and can only be opened by unlocking with the key. That is, the first door 601, the second door 602, and the third door 603 of the opening / closing section 6 may be closed (for example, bolted and fixed) using a tool (for example, a bolt wrench or screwdriver, etc.) (for example, a bolt wrench or screwdriver, etc.) and can only be opened by the tool (not shown).
[0058] For example, metal mesh protective covers (not shown) are provided at positions that are on the inside side (-X direction side) of the housing 11, beyond the first door 601, the second door 602, the third door 603, and the cover 671, so as to cover the opening 21d, the passage 514, the opening 22d, and the opening 26d, respectively.
[0059] The following describes the operation procedure for the switchgear 1 of Embodiment 1, as explained using Figures 1 to 6, to bring the upper cable compartment 21 into a state where it is safe for an operator to access, for example, when the upper cable compartment 21 is charged, in conjunction with the flowchart in Figure 7. The state in which an operator can safely access the cable compartment 21 is when the main circuit cable 4A and the cable compartment 21 are de-voltageed and no current is flowing (a state of no current).
[0060] As shown in Figure 7, when the operation of the switchgear 1 is started (Step 0: Start), the operator recognizes the status of the circuit breaker 13A displayed on the operating unit 149a shown in Figure 1, for example, and determines whether or not operation of the circuit breaker 13A is necessary (Step 1). Here, if the circuit breaker 13A is in the open state (conductors separated), the operator proceeds to the next step 3. If the circuit breaker 13A is in the closed state (conductors in contact), the operator operates the circuit breaker 13A using the operating unit 149a to open it (Step 2). When the circuit breaker 13A is in the open state, or when the circuit breaker 13A is opened, no current flows through the upper main circuit cable 4A (current-free state), and the upper cable room compartment 21 and passage 514 shown in Figures 1 to 3 also become current-free.
[0061] After the main circuit cable 4A and the upper cable compartment 21 are de-energized, the lock on the first rear door 601 shown in Figures 1 and 6 is released (Step 3). In this embodiment, the operator unlocks the handle 601a with a key (not shown). Then, the first door 601 is opened by rotating the handle 601a and pulling it towards the operator (Step 4).
[0062] After the first door 601 is opened, the worker removes a protective cover (not shown) from the opening 21d of the housing 11 (step 5), thereby allowing the worker to access the upper cable room compartment 21.
[0063] As described above, the switchgear 1 of Embodiment 1 separates the upper cable compartment 21, to which the main circuit cable 4A connected to the upper circuit breaker 13A extends, and the lower cable compartment 22, to which the main circuit cable 4B connected to the lower circuit breaker 13B extends, using a metal duct-shaped partition plate 5 grounded to a predetermined protection level, so that they are independent of each other. Therefore, if a worker wants to access, for example, the upper main circuit cable 4A which has been de-energized, they will not come into contact with the main circuit cable 4B which extends into the lower cable compartment 22 which has not been de-energized, thereby preventing electric shock accidents and improving safety when working in the upper cable compartment 21.
[0064] In the switchgear 1, the common compartment 26 is separated from the upper cable room compartment 21 and the lower cable room compartment 22 by a metal common compartment partition plate 27. Therefore, when a worker accesses, for example, the upper cable room compartment 21, it is prevented from entering the common compartment 26 where the grounding busbar 263 and other components are housed, thus preventing electric shock accidents caused by contact with the grounding busbar 263 and other components.
[0065] In the switchgear 1, the housing 11 has an opening / closing section 6 on the rear side (+X direction side) for accessing the upper cable compartment 21 and the lower cable compartment 22. Therefore, the operator can access only the desired compartment from the cable compartments 21 and 22, which are separated independently of each other, via the opening / closing section 6.
[0066] For example, in the switchgear 1 of Embodiment 1, the opening / closing section 6 is locked by a key (not shown) and can only be opened by a key (not shown). Specifically, the opening / closing section 6 is divided vertically according to the partition between the upper cable room compartment 21 and the lower cable room compartment 22, and includes a first rear door 601, a second rear door 602, and a third rear door 603. The first rear door 601, the second rear door 602, and the third rear door 603 are each locked by a key (not shown) and can only be opened by a key (not shown). For example, the upper cable room compartment 21 can be accessed independently of the lower cable room compartment 22 by opening the corresponding first rear door 601. Similarly, the lower cable room compartment 22 can be accessed independently of the upper cable room compartment 21 by opening the corresponding second rear door 602. Therefore, if a worker wants to access, for example, the main circuit cable 4A on the upper side which has been de-energized, they will not come into contact with the main circuit cable 4B which extends into the lower side cable compartment 22 which has not been de-energized, thus preventing electric shock accidents. Consequently, the safety of work inside the upper side cable compartment 21 can be improved.
[0067] The switchgear 1 of Embodiment 1 has a common compartment opening / closing section 67 on the rear side (+X direction side) of the housing 11 for an operator to access the common compartment 26. The common compartment opening / closing section 67 is equipped with a metal cover 671 that is grounded to a predetermined level of protection, for example, to match the partition shape of the common compartment 26. The cover 671 is fastened with a tool and can only be opened with a tool. Therefore, the common compartment 26, which houses the ground busbar 263, etc., cannot be easily opened by anyone other than a designated operator, thus preventing accidents such as electric shock caused by someone other than an operator coming into contact with the ground busbar 263, etc.
[0068] In the switchgear 1 of Embodiment 1, the housing 11 is provided with a lower entry port 115 for drawing in the upper main circuit cable 4A from under the floor, and a lower entry port 116 for drawing in the lower main circuit cable 4B from under the floor. To separate the main circuit cable 4A, which extends within the upper cable compartment 21 and is connected to the load side of the circuit breaker 13A located on the upper side, from the lower cable compartment 22 for extending the main circuit cable 4B, which is connected to the load side of the circuit breaker 13B located on the lower side, a passage 514 formed by separating the lower side of the housing 11 with a metal duct-shaped partition plate 5 grounded with a predetermined protection rating is arranged to connect to the lower entry port 115. Therefore, when a worker wants to access the main circuit cable 4A, which is currently de-energized and extends into the upper cable room compartment 21, for example, by passing through the passage 514, it is prevented from coming into contact with the main circuit cable 4B, which is currently de-energized and extends into the lower cable room compartment 22. As a result, electric shock accidents can be prevented, and the safety of work inside the upper cable room compartment 21 can be improved.
[0069] (Switchgear of Embodiment 2) Referring to Figures 8 to 10, the structure of the metal closed-type switchgear 1A (hereinafter referred to as switchgear 1A) according to Embodiment 2 of the present invention will be described. Figure 8 is a side view showing the inside of the switchgear 1A of Embodiment 2. Switchgear 1A is a modified version of the switchgear 1 of Embodiment 1 shown in Figures 1 to 2, and components similar to those in switchgear 1 are denoted by the same reference numerals and their description is omitted.
[0070] The configuration of the switchgear 1A in Embodiment 2 shown in Figure 8 differs from that of the switchgear 1 in Embodiment 1, mainly in the configuration on the rear side (+X direction side). The opening / closing section 6 of the switchgear 1 includes a first rear door 601, a second rear door 602, and a third rear door 603, which are divided vertically to match the partition between the upper cable compartment 21 and the lower cable compartment 22. In contrast, the switchgear 1A has an opening / closing section 6A on the rear side (+X direction side) of the housing 11 for accessing the upper cable compartment 21 and the lower cable compartment 22. The opening / closing section 6A shown in Figure 8 includes a rear door 68 (see Figure 9) that allows workers to access the common compartment 28, and a rear partition plate that is installed on the inside side (-X direction side) of the housing 11 from the rear door 68 and is divided vertically to match the partition between the upper cable compartment 21 and the lower cable compartment 22.
[0071] In this embodiment, the rear partition plates consist of three plates, as shown in Figure 10: a first rear partition plate 605 (hereinafter referred to as the first rear plate 605) located on the upper side of the housing 11; a second rear partition plate 606 (hereinafter referred to as the second rear plate 606) located on the lower side in the +Y direction; and a third rear partition plate 607 (hereinafter referred to as the third rear plate 607) located on the lower side in the -Y direction. The first rear plate 605 and the second rear plate 606 may be integrally formed. The rear door 68 shown in Figure 9, and the first rear plate 605, second rear plate 606, and third rear plate 607 shown in Figure 10 are made of metal.
[0072] In the switchgear 1A of Embodiment 2, the common compartment 28 is formed by the space provided between the first rear panel 605, the second rear panel 606, and the third rear panel 607 shown in Figures 8 and 10 and the rear door 68 in the X-axis direction, as well as the lowest space on the rear side (+Y direction side) of the housing 11.
[0073] The rear door 68 shown in Figures 8 and 9 is a single door large enough to cover the first rear panel 605, the second rear panel 606, the third rear panel 607, and the entire common compartment 28 shown in Figure 10. The rear door 68 is equipped with a handle portion 681 that can be grasped by an operator and rotated, for example, clockwise or counterclockwise when viewed from the X-axis side. The rear door 68 is attached to the +X side end of the housing 11 via a hinge (not shown) and can be opened, for example, to the left.
[0074] The first rear panel 605 and the second rear panel 606, which are positioned to extend into the interior of the housing 11, face the opening 21d on the +X side of the upper cable compartment 21 and the passage 514 in the X-axis direction, respectively, as shown in Figures 2 and 8. The third rear panel 607 faces the opening 22d on the +X side of the lower cable compartment 22, as shown in Figures 2 and 8, in the X-axis direction.
[0075] As shown in Figure 10, for example, the largest of the back panels, the first back panel 605, is rectangular in shape and has a handle 605a for the worker to grip. Similarly, the second back panel 606 and the third back panel 607, located below the first back panel 605, also have handles 606a and 607a, respectively, for the worker to grip.
[0076] The first back panel 605, the second back panel 606, and the third back panel 607 are fastened and secured to the pair of side walls 111 and 112 of the housing 11 using bolts 605b, 606b, or 607b, for example, at their four corners, so that they cannot be easily removed by anyone other than a designated worker. In other words, removing the first back panel 605, the second back panel 606, and the third back panel 607 requires a specific tool, such as a wrench. Alternatively, a protruding pin may be provided on the housing 11 side, and keyholes may be provided at the four corners of the first back panel 605, the second back panel 606, and the third back panel 607. The keyholes can then be inserted through the protruding pins to secure the first back panel 605, the second back panel 606, and the third back panel 607 to the housing 11 side. In this case, the first back panel 605, the second back panel 606, and the third back panel 607 can be removed without using a specific tool. In addition, in the switchgear 1A, for example, each back plate of the opening / closing section 6A may be locked by a key (not shown), and can only be opened by unlocking with said key.
[0077] The following describes the operating procedure for the switchgear 1A of Embodiment 2, for example, when the lower cable compartment 22 is in a charged state and then de-energized to a safe state where an operator can access the cable compartment 22, along with the flowchart in Figure 11.
[0078] As shown in Figure 11, when the operation of the switchgear 1A shown in Figure 8 is started (Step 0: Start), the operator recognizes the status of the circuit breaker 13B displayed on the operating unit 149b shown in Figure 8, for example, and determines whether or not operation of the circuit breaker 13B is necessary (Step 1). Here, if the circuit breaker 13B is in the open state, the operator proceeds to the next step 3. If the circuit breaker 13B is in the closed state, the operator operates the circuit breaker 13B using the operating unit 149b to open it (Step 2). When the circuit breaker 13B is in the open state, or when the circuit breaker 13B is opened, no current flows to the lower main circuit cable 4B, and the lower cable room compartment 22 becomes current-free.
[0079] After the main circuit cable 4B and the lower cable compartment 22 are de-energized, the rear door 68 shown in Figures 8 and 9 is opened (Step 3). In other words, in this embodiment, the operator opens the rear door 68 by rotating the handle 681 and pulling it towards them.
[0080] After opening the rear door 68, the worker releases the fastening of the third rear panel 607 that closes the opening 22d of the housing 11 using a tool (not shown) (step 4), and removes the third rear panel 607 from the opening 22d (step 5), thereby allowing the worker to access the lower cable room compartment 22.
[0081] As described above, the switchgear 1A of Embodiment 2 has an opening / closing section 6A on the rear side (+X direction side) of the housing 11 for accessing the upper cable room compartment 21 and the lower cable room compartment 22. The opening / closing section 6A includes a rear door 68 that allows access to the common compartment 28, and a first rear partition plate 605, a second rear partition plate 606, and a third rear partition plate 607, which are installed on the interior side of the housing 11 from the rear door 68 and are divided vertically according to the partition between the cable room compartment 21 and the cable room compartment 22. The first rear partition plate 605 and the second rear partition plate 606 allow workers to access the corresponding cable room compartment 21 independently of the cable room compartment 22 via the common compartment 28. The third rear partition plate 607 also allows workers to access the corresponding cable room compartment 22 independently of the cable room compartment 21 via the common compartment 28. Therefore, if a worker wants to access, for example, the main circuit cable 4B on the lower side that has been de-energized, they will not come into contact with the main circuit cable 4B that extends into the passage 514 and the cable room compartment 21 on the upper side, which have not been de-energized, thus preventing electric shock accidents. Thus, the safety of work inside the cable room compartment 22 on the lower side can be improved.
[0082] (Switchgear of Embodiment 3) Referring to Figures 12 to 14, the structure of the metal closed-type switchgear 1B (hereinafter referred to as switchgear 1B) according to Embodiment 3 of the present invention will be described. Figure 12 is a side view showing the interior of the switchgear 1B of Embodiment 3. Figure 13 is a perspective view illustrating the interior of the housing 11 of the switchgear 1B of Embodiment 3. Figure 14 is an explanatory diagram showing the positional relationship between the upper main circuit cable 4A and the lower main circuit cable 4B, the upper cable compartment 21B and the lower cable compartment 22B, and the duct-shaped partition plate 5B, as viewed from the rear side (+X direction side) of the switchgear 1B by cutting a part of the housing 11 along the line F2-F2 in Figure 12. Switchgear 1B is a modified version of the switchgear 1 of Embodiment 1 shown in Figures 1 to 2, and components similar to those in switchgear 1 are denoted by the same reference numerals and their description is omitted.
[0083] In the switchgear 1 of Embodiment 1, the housing 11 is equipped with lower entry ports 115 and 116 for drawing in the upper main circuit cable 4A and the lower main circuit cable 4B from under the floor. In contrast, in the switchgear 1B of Embodiment 3, the housing 11 is equipped with an upper entry port 117 for drawing in the upper main circuit cable 4A from the ceiling 110, and an upper entry port 118 for drawing in the lower main circuit cable 4B from the ceiling 110. This is the main difference between the switchgear 1 of Embodiment 1 and the switchgear 1B of Embodiment 3. In addition, in accordance with this difference, the locations of the upper current transformer 35A and the lower current transformer 35B, as well as the positions of the upper cable room compartment 21B and the lower cable room compartment 22B within the housing 11, also differ.
[0084] As shown in Figure 12, the upper circuit breaker 13A is connected to the load-side conductor 323 via a load-side circuit connection part 31 that penetrates the partition plate 133. The upper current transformer 35A is connected to the load-side conductor 323. In the switchgear 1B, the upper current transformer 35A is attached to a partition plate 25 that separates the busbar compartment 120 from the upper cable compartment 21B and the lower cable compartment 22B.
[0085] The lower circuit breaker 13B is connected to the load-side conductor 343 via a load-side circuit connection part 33 that penetrates the partition plate 134. The lower current transformer 35B is connected to the load-side conductor 343. In the switchgear 1B of Embodiment 3, the lower current transformer 35B is mounted on the bottom plate 114 of the housing 11.
[0086] As shown in Figures 12 to 14, an upper entry opening 117 for drawing in the main circuit cable 4A connected to the upper circuit breaker 13A is formed in the ceiling 110 of the housing 11 of the switchgear 1B, and communicates with the upper cable room compartment 21B. In addition, an upper entry opening 118 for drawing in the main circuit cable 4B connected to the lower circuit breaker 13B from the ceiling is formed in the ceiling 110 of the housing 11, and communicates with the lower cable room compartment 22B. The upper entry openings 117 and 118 are formed at a predetermined distance apart in the Y-axis direction, but they may also be formed integrally. Furthermore, shutters 117a and 118a are provided at the upper entry openings 117 and 118, respectively.
[0087] As shown in Figure 14, the main circuit cable 4A, which is drawn from the upper entry port 117 into the upper cable room compartment 21B inside the housing 11, branches into three at its end. The three ends of the main circuit cable 4A are connected to the upper current transformer 35A via the cable terminal conductor 42 and the terminal conductor 38 shown in Figure 12.
[0088] The main circuit cable 4A extends from top to bottom within the upper cable compartment 21, passing through, for example, a ring-shaped bracket 484. A monitor 484a is also installed on the bracket 484, for example, to monitor the magnitude of the current flowing through the main circuit cable 4A that it supports. A zero-phase current transformer 485 for ground fault protection is also attached to the main circuit cable 4A.
[0089] As shown in Figure 14, the main circuit cable 4B, which is drawn from the upper entry port 118 into the lower cable compartment 22B inside the housing 11, branches into three at its end. The three ends of the main circuit cable 4B are connected to the lower current transformer 35B via the cable terminal conductor 44 and the terminal conductor 39 shown in Figure 12.
[0090] As shown in Figure 14, the main circuit cable 4B extends from bottom to top within the lower cable compartment 22, passing through, for example, ring-shaped brackets 496 and 495. A monitor 495a is installed on bracket 495 to monitor the magnitude of the current flowing through the main circuit cable 4B that it supports. A zero-phase current transformer 497 for ground fault protection is attached to the main circuit cable 4B.
[0091] For example, the measurement information from monitor 484a and monitor 495a can be transmitted to the respective operating units 149a and 149b shown in Figure 12 via a communication path not shown.
[0092] As shown in Figures 12 to 14, a metal duct-shaped partition plate 5B is installed behind the partition plate 25 (towards the +X direction), and the duct-shaped partition plate 5B separates the upper cable room compartment 21B from the lower cable room compartment 22B.
[0093] The duct-shaped partition plate 5B includes, for example, a duct bottom plate 55 that extends horizontally (in the X-axis and Y-axis plane direction) and has one end connected to the partition plate 25 shown in Figures 12 and 13, and a duct side plate 56 that is erected with its lower end integrally connected to the upper surface of the duct bottom plate 55 and has its upper end connected to the ceiling 110 of the housing 11.
[0094] The duct bottom plate 55 has, for example, a step in the Z-axis direction, and includes a high-step section 550 that is one step higher in the Z-axis direction, and a low-step section 551 that is one step lower than the high-step section 550 and is integrally connected to the high-step section 550 via a step section 552. The duct bottom plate 55 of the duct-shaped partition plate 5B divides the upper cable room compartment 21B and the lower cable room compartment 22B in the Z-axis direction.
[0095] As shown in Figure 13, the flat, elevated section 550 has, for example, a roughly rectangular cutout hole 550a in the portion directly above the bracket 495 and zero-phase current transformer 497, which are located in the lower cable room compartment 22b.
[0096] The duct side plate 56 includes, for example, a passage forming portion 561 erected in the +Z direction from around the notched hole 550a on the upper surface of the raised portion 550, and a thickened portion 562 integrally formed on the upper end side of the passage forming portion 561, which is thicker than the passage forming portion 561 and protrudes in the -Y direction.
[0097] The passage-forming portion 561 and the thickened portion 562 of the duct-shaped partition plate 5B separate the upper cable room compartment 21B and the lower cable room compartment 22B in the X-axis and Y-axis directions. The space enclosed by the passage-forming portion 561, the thickened portion 562, and the side wall 112 of the housing 11 becomes a passage 565 through which the main circuit cable 4B extends in the vertical direction. As shown in Figure 14, passage 565 is an example of a passage formed by separating the main circuit cable 4B, which extends within the lower cable room compartment 22B and is connected to the lower circuit breaker 13B, from the cable room compartment 21B through which the main circuit cable 4A, connected to the upper circuit breaker 13A, extends, using a metal duct-shaped partition plate 5B grounded to a predetermined protection level on the upper side of the housing 11.
[0098] As shown in Figure 13, the passage 565 is positioned to connect to the upper entry point 118 formed in the ceiling 110 of the housing 11, through which the main circuit cable 4B is brought in, and is in communication with the upper entry point 118. The passage 565 also forms part of the lower cable room compartment 22B.
[0099] The opening / closing section 6B, located on the rear side (+X direction side) of the housing 11 as shown in Figure 12, allows workers to independently access the cable room compartment 21B and the cable room compartment 22B.
[0100] The opening and closing section 6B of the switchgear 1B in Embodiment 3 includes, for example, a plurality of rear doors that are divided vertically to match the partition between the upper cable compartment 21B and the lower cable compartment 22B, and each of the cable compartments 21B and 22B can be accessed independently by opening either of the corresponding rear doors.
[0101] As shown in Figures 12 and 15, the rear door of this embodiment consists of three doors: a first rear door 651 (hereinafter referred to as the first door 651) located on the +Y side of the upper section, a second rear door 652 (hereinafter referred to as the second rear door 652) located on the -Y side of the upper section, and a third rear door 653 (hereinafter referred to as the third door 653) located on the lower section of the housing 11. The third door 653 and the first door 651 may be integrally formed. The third door 653, the first door 651, and the second rear door 652 are made of metal. Unlike conventional switchgears, the switchgear 1B does not have a single rear door, but rather a configuration consisting of multiple rear doors as described above (a divided configuration).
[0102] The third door 653 and the first door 651 are opposite the opening 22e and passage 565 on the +X side of the lower cable room compartment 22B shown in Figures 12 to 14, respectively, in the X-axis direction. The second door 652 is opposite the opening 21e on the +X side of the upper cable room compartment 21B shown in Figures 12 to 14, in the X-axis direction.
[0103] As shown in Figure 12, the switchgear 1B of Embodiment 3 includes a common compartment 26 and a common compartment opening / closing section 67, similar to the switchgear 1 of Embodiment 1.
[0104] As shown in Figure 15, the third door 653, the largest of the three doors, is rectangular in shape and has a handle portion 653a that can be rotated by the worker. Similarly, the first door 651 and the second door 652, located above the third door 653, also have handle portions 651a and 652a, respectively, that the worker can grip. For example, the handle portion 653a has a keyhole 653b, the handle portion 651a has a keyhole 651b, and the handle portion 652a has a keyhole 652b. The keys (not shown) that fit the keyholes 653b, 651b, and 652b may be different or the same. The third door 653, the first door 651, and the second door 652 cannot be easily opened by anyone other than the designated worker.
[0105] In the switchgear 1B of Embodiment 3, for example, the third door 653, the first door 651, and the second door 652 of the opening / closing section 6B may be closed (for example, by bolting them in place) using a tool (for example, a bolt wrench or screwdriver, etc.) and may be configured to be open only by the same tool (for example, not shown).
[0106] For example, on the interior side (-X direction side) of the housing 11, beyond the third door 653, the first door 651, the second door 652, and the cover 671 of the common compartment opening / closing section 67, protective covers made of metal, for example, mesh are provided to cover the opening 22e, the passage 565, the opening 21e, and the opening 26d of the common compartment 26, respectively.
[0107] The following describes the operation procedure for the switchgear 1B of Embodiment 3, specifically for a case where the upper cable compartment 21B is in a charged state and then de-energized to a safe state where an operator can access it, along with the flowchart in Figure 7.
[0108] As shown in Figure 7, when the operation of the switchgear 1B shown in Figure 12 is started (Step 0: Start), the operator recognizes the status of the circuit breaker 13A displayed on the operating unit 149a shown in Figure 12, for example, and determines whether or not operation of the circuit breaker 13A is necessary (Step 1). If the circuit breaker 13A is in the open state (conductors separated), the operator proceeds to the next step 3. If the circuit breaker 13A is in the closed state (conductors in contact), the operator operates the circuit breaker 13A using the operating unit 149a to open it (Step 2). When the circuit breaker 13A is in the open state, or when the circuit breaker 13A is opened, no current flows through the upper main circuit cable 4A, and the upper cable room compartment 21B becomes current-free.
[0109] After the main circuit cable 4A and the upper cable compartment 21B are de-energized, the lock on the second door 652 shown in Figures 12 and 15 is released (Step 3). Then, the handle 652a is rotated and pulled forward to open the second door 652 (Step 4). After the second door 652 is opened, the worker removes a protective cover (not shown) from the opening 21e of the housing 11 (Step 5), allowing the worker to access the upper cable compartment 21B.
[0110] As described above, in the switchgear 1B of Embodiment 3, the housing 11 is provided with an upper entry port 117 for drawing in the upper main circuit cable 4A from the ceiling 110, and an upper entry port 118 for drawing in the lower main circuit cable 4B from the ceiling 110. In order to separate the main circuit cable 4B, which extends within the lower cable room compartment 22B and is connected to the load side of the circuit breaker 13B located on the lower side, from the upper cable room compartment 21B for extending the main circuit cable 4A connected to the upper circuit breaker 13A, a passage 565 formed by separating the upper side of the housing 11 with a metal duct-shaped partition plate 5B grounded with a predetermined protection class is arranged to connect to the upper entry port 118. Therefore, if a worker wants to access, for example, the main circuit cable 4A on the upper side that extends within the upper cable room compartment 21B and has been de-energized, they will not come into contact with the main circuit cable 4B that extends within the lower cable room compartment 22B, which has not been de-energized, thus preventing electric shock accidents. This improves the safety of work within the upper cable room compartment 21B.
[0111] (Switchgear of Embodiment 4) The structure of the metal closed-type switchgear 1C (hereinafter referred to as switchgear 1C) according to Embodiment 4 of the present invention will be described below with reference to Figure 16. Figure 16 is a side view showing the inside of the switchgear 1C of Embodiment 4. Switchgear 1C is a modified version of the switchgear 1B of Embodiment 3 shown in Figures 12 to 15, and components similar to those of switchgear 1B are denoted by the same reference numerals and their description is omitted.
[0112] The main difference between the switchgear 1C of Embodiment 4 and the switchgear 1B of Embodiment 3 lies in the configuration of the rear side (+X direction side). The opening / closing section 6B of the switchgear 1B includes a first rear door 651, a second rear door 652, and a third rear door 653, which are divided vertically to match the partition between the upper cable compartment 21B and the lower cable compartment 22B. In contrast, the switchgear 1C has an opening / closing section 6C on the rear side (+X direction side) of the housing 11 for accessing the upper cable compartment 21B and the lower cable compartment 22B. The opening / closing section 6C shown in Figures 16 and 17 includes a rear door 68 that allows a worker to access the common compartment 28, and a rear partition plate that is installed on the inside side (-X direction side) of the housing 11 from the rear door 68 and is divided vertically to match the partition between the upper cable compartment 21B and the lower cable compartment 22B. The rear door 68 shown in Figure 16 is identical to the one shown in Figure 9.
[0113] In this embodiment, the rear partition plates consist of three plates, as shown in Figure 17, for example: a first rear partition plate 661 (hereinafter referred to as the first rear plate 661) located on the +Y side of the upper section; a second rear partition plate 662 (hereinafter referred to as the second rear plate 662) located on the -Y side of the upper section; and a third rear partition plate 663 (hereinafter referred to as the third rear plate 663) located on the lower section of the housing 11. The third rear plate 663 and the first rear plate 661 may be formed integrally. The rear door 68, the third rear plate 663, the first rear plate 661, and the second rear plate 662 are made of metal.
[0114] In the switchgear 1C of Embodiment 4, the common compartment 28 is formed by the space provided between the third rear plate 663, the first rear plate 661, the second rear plate 662 and the rear door 68 in the X-axis direction, and the lowest space on the rear side (+Y direction side) of the housing 11.
[0115] The third rear panel 663 and the first rear panel 661, which are positioned to extend into the interior of the housing 11, face the opening 22e on the +X side of the lower cable compartment 22B and the passage 565 in the X-axis direction, respectively, as shown in Figures 13 and 16. The second rear panel 662 faces the opening 21e on the +X side of the upper cable compartment 21B, as shown in Figures 13 and 16, in the X-axis direction.
[0116] As shown in Figure 17, for example, the third back panel 663, which is the largest of the back panels, is formed in a rectangular shape and is equipped with a handle 663a for the worker to grip. Similarly, the first back panel 661 and the second back panel 662, which are located above the third back panel 663, are also equipped with handles 661a and 662a, respectively, for the worker to grip.
[0117] The third back panel 663, the first back panel 661, and the second back panel 662 are fastened and secured to a pair of side walls 111 and 112 of the housing 11, for example, at their four corners, using bolts 663b, 661b, or 662bb, respectively, so that they cannot be easily removed by anyone other than a designated worker. In other words, removing the third back panel 663, the first back panel 661, and the second back panel 662 requires a specific tool, such as a wrench. The switchgear 1C may also be designed so that each back panel of the opening / closing section 6C is locked with a key (not shown), and can only be opened by unlocking with the key.
[0118] The following describes the operating procedure for the switchgear 1C of Embodiment 4, for example, when the lower cable compartment 22B is in a charged state and then de-energized to a safe state where an operator can access the cable compartment 22B, along with the flowchart shown in Figure 11.
[0119] As shown in Figure 11, when the operation of the switchgear 1C shown in Figure 16 is started (Step 0: Start), the operator recognizes the status of the circuit breaker 13B displayed on, for example, the operating unit 149b and determines whether or not operation of the circuit breaker 13B is necessary (Step 1). If the circuit breaker 13B is open, the operator proceeds to the next step 3. If the circuit breaker 13B is closed, the operator operates the circuit breaker 13B using the operating unit 149b to open it (Step 2). When the circuit breaker 13B is open, no current flows through the lower main circuit cable 4B, and the lower cable room compartment 22B, along with the passage 565, becomes current-free.
[0120] After the main circuit cable 4B and the lower cable compartment 22B are de-energized, the worker opens the rear door 68 shown in Figure 16 by rotating the handle 681 and pulling it towards them (Step 3).
[0121] After opening the rear door 68, the worker uses a tool (not shown) to release the fastening of the third rear plate 663 that closes the opening 22e of the housing 11 (step 4), and removes the third rear plate 663 from the opening 22e (step 5), thereby allowing the worker to access the lower cable room compartment 22B.
[0122] As described above, the switchgear 1C of Embodiment 4 has an opening / closing section 6C on the rear side (+X direction side) of the housing 11 for accessing the upper cable room compartment 21B and the lower cable room compartment 22B. The opening / closing section 6C includes a rear door 68 that allows access to the common compartment 28, and a third rear partition plate 663, a first rear partition plate 661, and a second rear partition plate 662, which are installed on the interior side of the housing 11 from the rear door 68 and are divided vertically to match the partition between the cable room compartment 21B and the cable room compartment 22B. The third rear partition plate 663 and the first rear partition plate 661 allow a worker to access the cable room compartment 22B independently of the cable room compartment 21B via the common compartment 28. Furthermore, the second rear partition plate 662 allows workers to access the cable room compartment 21B independently of the cable room compartment 22B via the common compartment 28. Therefore, if a worker wants to access, for example, the main circuit cable 4B on the lower side which has been de-energized, they will not come into contact with the main circuit cable 4A extending into the upper cable room compartment 21B which has not been de-energized, thus preventing electric shock accidents. Consequently, the safety of work inside the lower cable room compartment 22B can be improved.
[0123] Although several embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]
[0124] 1: Metal-closed switchgear of Embodiment 1 11: Enclosure 110: Ceiling 111, 112: Side walls 113a, 113b: Front door 114: Base plate 115, 116: Bottom entry opening 12: Horizontal busbar 120: Busbar compartment 13A: Upper circuit breaker 13B: Lower circuit breaker 131: Upper circuit breaker compartment 132: Lower circuit breaker compartment 133, 134: Partition plate 141: Upper control room compartment 142: Lower control room compartment 20: Main circuit conductor 21: Upper cable room compartment 22: Lower cable room compartment 25: Partition plate 26: Common compartment 263: Grounding busbar 27: Common compartment divider 35A: Upper current transformer 35B: Lower current transformer 372: Intermediate component 4A: Main circuit cable on the upper side 4B: Main circuit cable on the lower side 5: Duct-shaped partition plate 50: Duct top plate 51: Duct side plate 512b: Notch 514: Passageway 6: Opening / Closing Section 601: First rear door 602: Second rear door 603: Third rear door 67: Common compartment opening / closing section 671: Cover 1A: Metal-closed switchgear of Embodiment 2 28: Common compartment 6A: Opening / closing section 605: First rear partition plate 606: Second rear partition plate 607: Third rear partition plate 68: Rear door 1B: Metal-closed switchgear of Embodiment 3 117, 118: Upper entry point 21B: Upper cable room compartment 22B: Lower cable room compartment 5B: Duct-shaped partition plate 55: Duct bottom plate 56: Duct side plate 565: Passageway 6B: Opening / Closing Section 651: First rear door 652: Second rear door 653: Third rear door 1C: Metal-closed switchgear of Embodiment 4 6C: Opening / Closing Section 661: First rear partition plate 662: Second rear partition plate 663: Third rear partition plate
Claims
1. The casing and Two circuit breakers are arranged in an upper and lower position within the enclosure, A busbar compartment formed inside the housing, Two circuit breaker compartments are formed above and below the busbar compartment, A control room compartment is formed in front of each of the circuit breaker compartments, Two cable compartments are formed separately behind each of the circuit breaker compartments and correspond to the load side of the circuit breaker, It includes a common compartment for housing the grounding busbar, A metal-enclosed switchgear in which the boundaries of the busbar compartment, the two circuit breaker compartments, the control compartment, the two cable compartments, and the common compartment are separated by metal partition plates grounded to a predetermined level of protection.
2. The metal-enclosed switchgear according to claim 1, wherein the common compartment is separated from the two cable room compartments by a metal common compartment partition plate.
3. The metal closed switchgear according to claim 2, having an opening and closing section on the rear side of the housing for accessing two cable compartments.
4. The metal closed switchgear according to claim 3, wherein the opening and closing portion is closed using a tool and can only be opened using said tool.
5. The metal closed switchgear according to claim 3, wherein the opening and closing section is locked by a key and can only be opened by unlocking with the key.
6. The enclosure is equipped with a bottom entry point for drawing in the main circuit cable from under the floor, A metal closed switchgear according to claim 2, 3, 4, or 5, wherein the upper main circuit cable, which extends within the upper cable compartment and is connected to the load side of the circuit breaker located on the upper side, is separated from the lower cable compartment for which the lower main circuit cable, which is connected to the load side of the circuit breaker located on the lower side, extends, and a passage formed by separating it with a metal duct-shaped partition plate grounded with a predetermined protection class is arranged on the lower side of the housing so as to connect to the lower inlet.
7. The metal closed-type switchgear according to claim 6, wherein the metal duct-shaped partition plate has a notch to avoid interference with the common compartment partition plate in order to extend the passage to the lower inlet.
8. The enclosure is equipped with an upper entry point for drawing in the main circuit cable from the ceiling, A metal closed switchgear according to claim 2, 3, 4, or 5, wherein the lower main circuit cable, which extends within the lower cable compartment and is connected to the load side of the circuit breaker located on the lower side, is separated from the upper cable compartment for which the upper main circuit cable, which is connected to the load side of the circuit breaker located on the upper side, extends, and a passage formed by separating it with a metal duct-shaped partition plate grounded to a predetermined protection class is arranged on the upper side of the housing so as to connect to the upper inlet.
9. The opening and closing section comprises multiple rear doors that are divided vertically to match the partition between the two cable room compartments. The metal-closed switchgear according to claim 3, 4, or 5, wherein the upper cable compartment and the lower cable compartment are independently accessible by opening either of the corresponding rear doors.
10. The housing has a common compartment opening / closing section on the rear side for accessing the common compartment, The metal-closed switchgear according to claim 2, wherein the common compartment opening / closing section is provided with a non-metallic or metal cover grounded to a predetermined level of protection to match the partition shape of the common compartment, the cover being fastened with a tool and openable only by the tool.
11. The opening and closing section includes a rear door that allows access to the common compartment, It comprises a rear partition plate installed on the interior side of the housing beyond the rear door, and divided vertically to match the partition between the two cable compartments, The metal-closed switchgear according to claim 3, 4, or 5, wherein the upper cable compartment and the lower cable compartment are independently accessible via the common compartment by opening either of the corresponding rear partition plates.
12. The enclosure is equipped with an upper-stage current transformer mounted on the ceiling, The metal-closed switchgear according to claim 6, wherein the load side of the circuit breaker located on the upper side within the housing and the upper side main circuit cable are connected via the upper side current transformer.
13. The aforementioned metal duct-shaped partition plate is equipped with a relay member attached to its lower surface, The metal closed-type switchgear according to claim 6, wherein the load side of the circuit breaker located on the lower side within the housing and the lower side main circuit cable are connected via the relay member.