JP2009303416A - Current transformer for closed-type switchgear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a current transformer for a gas-insulated switchgear, capable of reducing the diameter of a closed vessel by considering the layout of a secondary-side lead wire. <P>SOLUTION: The secondary-side lead wires 31a to 33a and 31b to 33b of each phase in current transformer coils 23 and 24, arranged in the axial direction of main circuit conductors 9u, 9v and 9w are guided by using space formed by a plurality of spacing members 28u, 28v and 28w fitted to the end plates 26u, 26v and 26w of members 25u, 25v and 25w for inserting the lead wires, formed between the opposed sections of the adjacently arranged current transformer coils 23 and 24. The shape and position are held, while very much suppressing projections to the outer peripheral sections of the current transformer coils 23 and 24, insulations with the main circuit conductors 9u, 9v and 9w of each phase are also held in the desired state and guidance through the outer peripheral sections of the current transformer coils 23 and 24 is stopped, and the diameter of the closed vessel 6 for the current transformer is restrained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a current transformer for a hermetic switchgear constituted by arranging a main circuit conductor in a hermetically sealed container enclosing an insulating medium.

A closed type switchgear is composed of a circuit breaker, a disconnect switch, an installed switch, a main bus, a current transformer, etc., with the main circuit conductor insulated in a sealed container filled with an insulating medium. A gas insulated switchgear using an insulating gas is known. In this type of hermetic switchgear, each part that serves as a power application unit is neatly configured so as to prevent the hermetic container from becoming large, thereby reducing the insulation distance. For example, a current transformer has a current transformer coil arranged so as to surround the main circuit conductor, and a secondary lead wire connected to the end of the current transformer coil. The secondary side lead wire is connected to the insulated terminal that is attached to hold the signal and the signal is led out to the outside, but the diameter of the sealed container is increased depending on the arrangement of the secondary side lead wire. End up. In particular, when a current transformer is configured by arranging a plurality of current transformer coils in the axial direction of the main circuit conductor (see, for example, Patent Document 1), the secondary side lead wire of each current transformer coil Placement needs to be considered.
JP-A-8-294209

  However, since the secondary side lead wire in the general conventional current transformer for hermetic switchgear has been arranged and guided using the space existing between the outer periphery of the current transformer coil and the hermetic container, If it is supported while taking into consideration the insulation distance from the circuit conductor, the structure at the same part becomes complicated and the secondary lead wire may increase the diameter of the sealed container.

  An object of the present invention is to provide a current transformer for a hermetic switchgear that can simplify the structure and reduce the diameter of the hermetic container by considering the arrangement of the secondary lead wire.

  In order to achieve the above object, the present invention arranges a main circuit conductor in a current transformer sealed container enclosing an insulating medium in a state of being electrically insulated from the current transformer sealed container. Surrounding and arranging a plurality of current transformer coils in the axial direction of the main circuit conductor, attaching an insulating terminal plate to the airtight container for the current transformer to keep its airtightness, and secondary side of each current transformer coil In a current transformer for a closed type switchgear in which a lead wire is connected to each terminal of the insulated terminal plate, a lead wire insertion member is provided at a facing portion between two adjacent current transformer coils, and two adjacent The secondary lead wire of at least one of the current transformer coils is guided through a space portion formed within a diameter of the lead wire insertion member.

  Further, according to the present invention, a three-phase main circuit conductor is disposed in a current transformer sealed container filled with an insulating medium in a state of being electrically insulated from the current transformer sealed container. A plurality of current transformer coils are arranged in the axial direction of each main circuit conductor so as to surround the main circuit conductor, and an insulating terminal plate is attached to the current transformer hermetically sealed container to keep the hermetic seal. Each of the main circuit conductors arranged in the sealed container for the current transformer is U-shaped, respectively, in the current transformer for the closed switchgear in which the secondary lead wire of the coil is connected to each terminal of the insulated terminal plate. The lead wire insertion member is provided in the facing portion between the two adjacent current transformer coils of each phase, and the secondary lead wires of the two adjacent current transformer coils are , Empty formed within the diameter of each lead wire insertion member Characterized in that led through the parts.

  According to the current transformer for hermetic switchgear according to the present invention, at least one of the two current transformer coils arranged in the axial direction using the lead wire insertion member arranged between the current transformer coils. Since the secondary lead wire is guided, most of the secondary lead wires can be arranged within the diameter of the lead wire insertion member except for the portion connected to each terminal of the insulated terminal plate. As a result, the diameter of the sealed container for the current transformer can be reduced as compared with the conventional case where the outer circumference of the current transformer coil is used for routing.

  Further, according to the current transformer for a closed type switchgear according to the second aspect of the present invention, the two lead wires are arranged in the axial direction using the lead wire insertion member arranged between the current transformer coils of each phase. Since the secondary side lead wires of the fluency coil are respectively guided, most of the secondary side lead wires are within the diameter of the lead wire insertion member except the portion connected to each terminal of the insulated terminal plate. It is possible to arrange the secondary side lead wire while maintaining a good insulation between the main circuit conductor having a folded structure and an orderly and simple configuration. Thus, compared with the case where it draws using the outer peripheral part of a current transformer coil, the diameter of the airtight container for current transformers can be suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 3 is a front view showing the external appearance of a hermetic switchgear that uses the current transformer for hermetic switchgear according to one embodiment of the present invention.
This hermetic switchgear has a circuit breaker, disconnector, grounding switch, current transformer, main bus, cable head, and each of these devices in a metal sealed container filled with insulating gas and other insulating media. It is an external view of a three-phase collective type closed type switchgear that is arranged and configured in a state where three phases such as conductors to be connected are electrically insulated from a sealed container. The configuration of each device configured in the sealed container will be described in detail later, but here, a schematic configuration is shown with a single-phase circuit diagram. A circuit breaker 2 is configured in the vertical type circuit breaker hermetic container 1. One side of the circuit breaker hermetic container 1 is connected to the horizontal main bus hermetic containers 3 and 4 side by side, and the circuit breaker is hermetically sealed. Similarly, horizontal type closed containers 5 and 6 for current transformers are connected to the other side of the container 1 side by side. A current transformer 8 is arranged in the lower current transformer sealed container 5 so as to surround the main circuit conductor 7 connected to one lower terminal side of the circuit breaker 2. The main circuit conductor 9 connected to the other upper terminal side of the circuit breaker 2 is folded in a U shape, and a current transformer 10 is disposed so as to surround the main circuit conductor 9.

  In addition, double main buses 11 and 12 are disposed in the main bus sealed containers 3 and 4 via disconnectors 13 and 14 respectively, and are connected to the upper terminal side of the circuit breaker 2 and turned back. The main buses 11 and 12 are connected to the other end side of each. A vertical cable head sealed container 15 is connected to the lower current transformer sealed container 5, and a disconnector 16, a ground switch 17, and a cable head 18 are configured in the cable head sealed container 15. It is electrically connected to the main circuit conductor 7 disposed in the current transformer sealed container 5.

FIG. 4 is an enlarged longitudinal sectional view showing a main part of the above-described hermetic switchgear.
The current transformer sealed container 5 connected to the lower portion of the vertical circuit breaker sealed container 1 forms the same space as the circuit breaker sealed container 1 and is filled with an insulating medium. The main circuit conductor 7 disposed in the current transformer sealed container 5 is electrically connected to one end of the main circuit conductor 7 that is mechanically supported on the blocking portion 2 side, and the other end is connected to the current transformer sealed container 5 and the cable head. It is supported in a state of being electrically insulated from the current transformer sealed container 5 by an insulating spacer 19 and an insulating support 20 that are arranged for partitioning the insulating medium at the connecting portion of the sealed container 15 for use. The current transformer coil 21 of the current transformer 8 disposed so as to surround the outer periphery of the main circuit conductor 7 is supported in a state of being electrically insulated from the current transformer sealed container 5.

  The current transformer sealed container 6 connected to the upper portion of the vertical circuit breaker sealed container 1 also forms the same space as the circuit breaker sealed container 1 and is filled with an insulating medium. The main circuit conductor 9 disposed in the current transformer sealed container 6 is folded in the vicinity of the end cover 36 that seals the end of the current transformer sealed container 6 while mechanically supporting one end of the main circuit conductor 9 on the blocking section 2 side. It is. A support member 37 is disposed on the inner surface side of the end lid 36, and an insulating support 35 is fixed to the support member 37, so that the folded portion of the main circuit conductor 9 is sealed by the insulating support 35. 6 is supported in an electrically insulated state from 6. The current transformer 10 disposed so as to surround the outer periphery of the main circuit conductor 9 is configured to include a plurality of current transformer coils 23 and 24 disposed in the axial direction of the main circuit conductor 9, and each current transformer coil is configured. 23 and 24 are supported in a state of being electrically insulated from the current transformer sealed container 5.

  The main bus sealed containers 3 and 4 are connected to each other on the opposite side of the above-described vertical circuit breaker sealed container 1, and the insulating spacers 25 for insulating medium compartments are connected to the connecting portions, respectively. 26 is provided. An operating device 27 for opening and closing the circuit breaker 2 is disposed below the vertical closed circuit container 1 for circuit breakers.

  Since the cable head 18 is connected to the lower terminal side of the circuit breaker 2 as shown in FIG. 3 and is connected to a cable (not shown), the main bus hermetic container 3 of the circuit breaker hermetic container 1 is kept as it is. An unused space is formed in the upper part of the current transformer sealed container 5 as compared with the fourth side. However, the current transformer sealed container 6 is arranged here to constitute the current transformer 10, and the space is effectively utilized without increasing the installation area. In addition, a link mechanism or the like for connection with the operating device 27 exists in the lower part of the circuit breaker sealed container 1, whereas no such link mechanism exists in the upper part of the circuit breaker sealed container 1. . Therefore, the main circuit conductor 9 in the current transformer sealed container 6 is folded to be connected to the main bus bars 11 and 12 by utilizing the space above the circuit breaker sealed container 1.

  In this way, the main circuit conductor 9 having the folded structure can be arranged by effectively utilizing the space inside the current transformer sealed container 6 and the upper part of the circuit breaker sealed container 1, and the layout space of the current transformer 10 can be reduced. Secured. In particular, in this embodiment, the current transformer 10 has two current transformer coils 23 and 24 disposed so as to surround the main circuit conductor 9, and has a configuration in which each secondary lead wire is led out to the outside. Therefore, the axial arrangement space for the main circuit conductor 9 can be easily secured. For this reason, as will be understood from the description to be described later, the number of current transformer coils arranged in the axial direction of the main circuit conductor 9 is not limited to two and can be easily arranged even in the case of three.

Next, the secondary lead wire connected to the ends of the current transformer coils 23 and 24 in the current transformer 10 will be described.
FIG. 2 is an enlarged cross-sectional view showing only one phase of the current transformer 10 shown in FIG. The main circuit conductor 9w arranged in the current transformer sealed container 6 is U-shaped in the vicinity of the end cover 36 that seals the end of the current transformer sealed container 6 while mechanically supporting one end thereof on the side of the blocking portion 2. It is folded back into a shape. A support member 37 is disposed on the inner surface side of the end lid 36, and an insulating support 35 is fixed to the support member 37. The insulating support 35 changes the U-shaped folded portion 34w of the main circuit conductor 9w. It is supported in a state of being electrically insulated from the fluid container 6. As described above, the current transformer 10 disposed so as to surround the outer periphery of the main circuit conductor 9w is configured to include a plurality of current transformer coils 23w and 24w disposed in the axial direction of the main circuit conductor 9w. The current transformer coils 23w and 24w are supported while being electrically insulated from the current transformer sealed container 5. Each of the current transformer coils 23w and 24w is mechanically supported by interposing a lead wire insertion member 25 having a space portion between the opposing ends. The lead wire insertion member 25 includes an end plate 26 made of a disc-like or C-shaped non-magnetic material disposed at the opposite end of the current transformer coil 23w, and the opposite end of the current transformer coil 24w. An end plate 27 made of a disk-like or C-shaped non-magnetic material, and an interval between these end plates 26, 27 to form a space or hold a secondary lead wire to be described later Holding member 28.

1 is a cross-sectional view taken along line AA in FIG.
In the current transformer sealed container 6, three-phase main circuit conductors 9u, 9v, 9w on the side connected to the circuit breaker 2 are arranged at equal intervals, and each of these phase main circuit conductors 9u, 9v, 9w is arranged. The current transformer coils 23u, 23v, and 23w of each phase are arranged at substantially equal intervals. The folded portions 34u, 34v, 34w of the main circuit conductors 9u, 9v, 9w of each phase are arranged through a space formed between the current transformer sealed container 6 and the phase current transformer coils 23u, 23v, 23w. Yes. Each phase current transformer coil 23u, 23v, 23w is fixed to a predetermined position on the inner surface side of the current transformer sealed container 6 via insulators 22u, 22v, 22w, which are not shown in the figure. The same applies to the flow coil 24u, 24v, 24w, but may be supported and fixed by other known methods. Since the configuration of each phase is substantially the same, only the U phase will be described below.

  A lead wire insertion member 25u is disposed at the opposite end of the current transformer coil 23u constituting the current transformer 10u. The lead wire insertion member 25u may be integrally formed, and various configurations can be adopted. Here, as described above, a C-shaped or ring-shaped member disposed at the opposite end of the current transformer coil 23u. A non-magnetic end plate 26u, a similar end plate disposed at the opposite end of the current transformer coil 24u (not shown), and a plurality of spacing members 28u disposed between the end plates. The spacing member 28u is constituted by two cylindrical members that are concentric on the end plate 26u and provided discretely on the circumference of the virtual circle. Various configurations such as a position to be arranged can be adopted. Various configurations can be adopted for supporting and fixing the lead wire insertion member 25u, and the lead wire insertion member 25u can be supported and fixed together with each phase current transformer coil 24u. 1 is a cross-sectional view taken along the line AA in FIG. 2, the current transformer coil 24u and the end plate 27u are removed, and only the opposite end face of the current transformer coil 23u is shown.

  The current transformer sealed container 6 is provided with insulating terminal plates 29 and 30 having terminals that are connected to secondary lead wires, which will be described later, of the current transformer coils 23u, 23v, and 23w and are led out to the outside. The positions of the insulating terminal plates 29 and 30 substantially correspond to the lead wire insertion members 25u, 25v and 25w in the axial direction of the current transformer sealed container 6, and in the circumferential direction of the current transformer sealed container 6 It is in the vicinity of the lead wire insertion members 25u and 25v.

  The insulated terminal plate 29 disposed at a position corresponding to the current transformer coil 23 u is attached to the cylindrical portion 6 a branched in the radial direction of the current transformer sealed container 6 while maintaining airtightness. Are connected to the secondary lead wires of the current transformer coils 23u, 23v, 23w. The insulated terminal plate 30 arranged at a position corresponding to the current transformer coil 23v is attached to the cylindrical terminal 6b branched in the radial direction of the current transformer sealed container 6 while maintaining airtightness, and is provided on the insulated terminal plate 30. The secondary lead wires of the current transformer coils 24u, 24v, 24w are connected to a plurality of terminals.

  The secondary lead wires 31a and 31b connected to both ends of the current transformer coil 23u are first regulated in position while passing between the spacing members 28u of the end plate 26u provided in the current transformer coil 23u, and the shape thereof is maintained. The end plate 26v of the current transformer coil 23v is guided onto the end plate 26v, and the end plate 26v is also regulated in position while passing between the interval holding members 28v, and finally the terminal of the insulating terminal plate 30 is retained. Connected to. On the other hand, the secondary side lead wires 33a and 33b connected to both ends of the current transformer coil 23w regulate the position while passing between the interval holding members 28w of the end plate 26w provided in the current transformer coil 23w and the shape thereof. The end plate 26v of the current transformer coil 23v is guided to the end plate 26v, the position of the end plate 26v is regulated while passing between the interval holding members 28v, and the shape of the end plate 26v is finally held. Connected to the terminal. The secondary lead wires 32a and 32b of the current transformer coil 23v are directly connected to the terminals without using the end plate 26w of the lead wire insertion member 25w because the insulating terminal plate 30 is located in the vicinity thereof. Connected.

  In this way, the secondary side lead wires 31a to 33a and 31b to 33b are inserted between the opposing portions of the current transformer coils 23 and 24 arranged in the axial direction of the three-phase main circuit conductors 9u, 9v, and 9w. Since the passing members 25u, 25v, and 25w are arranged and guided by using the empty portions formed by the lead wire inserting members 25u, 25v, and 25w, they are accommodated within the diameter of the current transformer coils 23 and 24. Can be placed. The distance between the current transformer coils 23 and 24 is a level necessary for the arrangement of the lead wire insertion member 25 and is not so large. In the assembled state, most of the secondary side lead wires 31a to 33a and 31b to 33b are arranged on the outer peripheral portions of the current transformer coils 23 and 24 as in the prior art. The secondary lead wires 31a to 33a and 31b to 33b are processed so as to be hardly noticeable. For this reason, it is not necessary to guide through the outer peripheral portions of the current transformer coils 23 and 24 as in the prior art, and the configuration is simplified by that much, and the secondary current can be obtained without increasing the diameter of the current transformer sealed container 6. The lead-out processing of the side lead wires 31a to 33a and 31b to 33b becomes possible.

  Further, the above-described end plate 26u is provided with a plurality of interval holding members 28u, and is guided while holding the shapes of the secondary side lead wires 31a to 33a and 31b to 33b while passing between these interval holding members 28u. Thereafter, the secondary lead wires 31a to 33a and 31b to 33b do not protrude outward from the lead wire insertion members 25u, 25v, and 25w. That is, the secondary lead wires 31a to 33a and 31b to 33b are configured to be covered with insulation, but can be formed into a desired shape among the plurality of spacing members 28u and easily held. For this reason, it is possible to prevent the lead wire insertion members 25u, 25v, and 25w from projecting outward and to adopt a positional relationship that makes the electric field between the main circuit conductors 9u, 9v, and 9w located nearby desirable. And the insulation distance can be maintained well.

  The explanation of the secondary side lead wires 31a to 33a and 31b to 33b described above is for the current transformer coil 23 among the current transformer coils arranged in the axial direction of the main circuit conductors 9u, 9v and 9w of each phase. It is. In the other current transformer coils 24, the secondary lead wires are similarly led using the same lead wire insertion member 25 and connected to the terminals of the insulating terminal plate 29. At this time, the secondary lead wires of the two current transformer coils 23 and 24 may be arranged at the same position of the lead wire insertion member 25, but one of the secondary lead wires is not arranged. If it is considered that the other secondary side lead wire is arranged as much as possible in the place, the axial length of the lead wire insertion member 25 can be shortened.

  According to such a gas-insulated switchgear current transformer, two current transformer coils 23 arranged in the axial direction using a common lead wire insertion member 25 arranged between the current transformer coils 23 and 24. When the secondary lead wires of 24 are respectively guided, most of the secondary lead wires except for the portions connected to the respective terminals of the insulating terminal plates 29 and 30 have the diameter of the lead wire insertion member 25. Can be arranged in a well-organized and simplified configuration, and maintains good insulation between the main circuit conductors 9u, 9v, 9w of each phase without increasing the diameter of the current transformer sealed container 6 be able to. Therefore, it becomes easy to arrange the current transformer 10 by disposing the folded main circuit conductors 9u, 9v, 9w inside the current transformer sealed container 6, and the diameter of the current transformer sealed container 6 is increased. It can be assembled as a hermetic switch as shown in FIG.

  However, since the juxtaposed current transformer coil 24 has a space with some margin at the opposite end rather than the facing portion of the current transformer coil 23, the secondary lead wire of the current transformer coil 24 is A dedicated lead wire insertion member arranged in the opposite side space is used for guidance, and the insulating terminal plate 29 is shifted in the axial direction of the current transformer sealed container 6 so as to correspond to the opposite side space. Also good. In such a configuration, when three current transformer coils are arranged in the axial direction, the two current transformer coils are configured in the same manner as in FIG. 1, but applied to the remaining one current transformer coil. You can also. Moreover, it is possible to obtain substantially the same effect even if a single current transformer coil has an integral structure having the lead wire insertion member 25 and the necessary number of the members are arranged in the axial direction.

  In any case, the lead wire insertion member 25 is arranged in the facing part of two current transformer coils among the plurality of current transformer coils positioned in the axial direction, and the lead wire insertion member 25 is arranged at least one of the current transformer coils. The effect mentioned above can be acquired by using for the arrangement | positioning and shape maintenance of the secondary side lead wire of a current transformer coil. Further, the configuration in which the lead wire insertion member 25 is used to guide the secondary lead wire of the current transformer coil is also applicable to a gas insulated switchgear having a configuration without the main circuit conductors 9u, 9v, 9w having a folded structure. Even in this case, since the secondary side lead wire is not arranged on the outer peripheral portion of the current transformer coil as in the prior art, the orderly and simplified configuration and the current transformer sealed container 6 Does not increase the diameter.

  Moreover, the current transformer for a closed type switchgear according to the present invention is applied to a current transformer for a three-phase package type hermetic type switchgear in which three-phase main circuit conductors 9u, 9v, 9w are arranged in a current transformer sealed container 6. In particular, in the three-phase collective type, the main circuit conductors 9u, 9v, 9w for three phases are arranged so as to be positioned at the vertices of the triangle, and the main circuit conductors 9u, 9v, 9w are respectively surrounded by Since a plurality of current transformer coils 23u to 23w and 24u to 24w are respectively arranged in the axial direction, there is not enough tolerance in the current transformer sealed container 6 having a limited diameter in consideration of insulation of each part. In addition, since the secondary lead wire is led out to the same portion, the diameter of the current transformer sealed container 6 is increased. However, the lead wire insertion members 25u, 25v, 25w are respectively provided in the facing portions of the adjacent current transformer coils 23u-23w, 24u-24w of each phase, and the diameters of the respective lead wire insertion members 25u, 25v, 25w are provided. Since the secondary lead wire is guided through the space formed in the inner terminal plate 29, 30, most of the secondary side lead wire except for the portion connected to each terminal of the insulating terminal plates 29, 30 is the lead wire insertion member 25u, 25v. 25w, and the main circuit conductors 9u, 9v, 9w arranged in the current transformer sealed container 6 are folded in a U-shape. The diameter of the closed vessel 6 for the current transformer can be made to be an orderly and simple structure while maintaining good insulation of each part, and compared with the case where the outer periphery of the current transformer coil is used as in the prior art. To suppress various It is possible to adapt the enclosed type switchgear take location configuration.

  The current transformer for the closed type switchgear according to the present invention can be applied not only to the closed type switchgear having the configuration shown in FIG. 4. For example, the current transformer 8 in the current transformer sealed container 5 includes a plurality of current transformers 8. In the case of a current transformer coil, the present invention can be applied in the same manner, and can be applied not only to a three-phase package type closed type switchgear but also to a phase separation type sealed edge switchgear.

It is a cross-sectional view showing a current transformer for a closed switchgear according to an embodiment of the present invention. It is a longitudinal cross-sectional view which shows only the part for one phase of the current transformer for closed type switchgear shown in FIG. It is a front view of the closed type switchgear using the current transformer for closed type switchgear shown in FIG. It is a principal part expanded sectional view of the sealing type switchgear shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit breaker sealed container 2 Circuit breaker 3, 4 Main bus sealed container 5, 6 Current transformer sealed container 7, 9 Main circuit conductor 8, 10 Current transformer 22 End cover 23, 24 Current transformer coil 25, 25u, 25v, 25w Lead wire insertion member 26, 26u, 26v, 26w End plate 27 End plate 28, 28u, 28v, 28w Spacing member 29, 30 Insulating terminal plate 31a, 31b Secondary lead wire 32a, 32b Secondary side Lead wire 33a, 33b Secondary lead wire

Claims (2)

  A main circuit conductor is disposed in a current transformer sealed container enclosing an insulating medium in a state of being electrically insulated from the current transformer sealed container, and surrounds the main circuit conductor in the axial direction of the main circuit conductor. A plurality of current transformer coils are arranged, and an insulated terminal plate is attached to the airtight container for current transformer while keeping its airtightness, and a secondary lead wire of each current transformer coil is attached to each terminal of the insulated terminal plate. In each of the connected current transformers for closed switchgear, a lead wire insertion member is provided at a facing portion between two adjacent current transformer coils, and at least one of the two adjacent current transformer coils The secondary side lead wire is led through a space portion formed within the diameter of the lead wire insertion member.   A three-phase main circuit conductor is placed in a current transformer sealed container enclosing an insulating medium in a state of being electrically insulated from the current transformer sealed container, and each main circuit is surrounded by each main circuit conductor. A plurality of current transformer coils are arranged in the axial direction of the conductor, and an insulating terminal plate is attached to the current transformer sealed container while keeping its airtightness, and the secondary lead wires of the current transformer coils are insulated. In the current transformer for a closed type switchgear connected to each terminal of the terminal plate, each main circuit conductor disposed in the current transformer sealed container is configured to be folded in a U-shape and adjacent to each phase. Lead wire insertion members are respectively provided at the opposing portions between the two current transformer coils, and the secondary lead wires of the two adjacent current transformer coils are within the diameter of each of the lead wire insertion members. Characterized by being guided through the space formed in Current transformer for that sealed switchgear.

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