WO2014103406A1

WO2014103406A1 - Current limiting device

Info

Publication number: WO2014103406A1
Application number: PCT/JP2013/066583
Authority: WO
Inventors: 林　和史
Original assignee: 三菱電機株式会社
Priority date: 2012-12-28
Filing date: 2013-06-17
Publication date: 2014-07-03
Also published as: EP2940822B1; EP2940822A4; EP2940822A1; JP5690031B2; JPWO2014103406A1

Abstract

An electrical circuit forming unit is constituted by forming a steady-state electrical circuit by arranging a plurality of mutually adjoining contact members (11) capable of contacting with and separating from each other between a first fixed electrode (4) and a movable electrode (10), and between a second fixed electrode (5) and the movable electrode (10), and by forming a current limiting electrical circuit by connecting a current limiting resistor (15) in parallel with the steady-state electrical circuit. Contact separation members (12) are arranged at both sides of the contact members (11), said contact separation members having engagement projections (12a) that can be fitted into recessed engagement portions (11a) provided on lateral sides of each contact member (11). The contact separation members (12) are driven by a contact-driving unit to move between an insertion position where the mutually adjoining contact members (11) are separated from each other, and a pull-out position which is the reverse of the insertion position. A current limiting device is constituted so that the engagement projections (12a) come in contact with all the recessed engagement portions (11a) of the contact members (11) which are separated when the contact separation members (12) move to the insertion position, even when the contact separation members (12) are in the pull-out position.

Description

Current limiting device

This invention relates to a current limiting device for suppressing an overcurrent (short-circuit current) generated when an accident occurs in a power system.

The conventional current limiting device, for example, is electrically connected between the power supply side circuit and the load side circuit of the power system, and the overcurrent flows through the power system and the low resistance steady circuit part that conducts the current at the steady state. A structure having a high-resistance current-limiting circuit for suppressing overcurrent is known.

As a current limiting device having such a structure, for example, a configuration as shown in FIG. 5 is disclosed. FIG. 5 shows only the main part of the current limiting device. The stationary electric circuit portion has a plurality of contact members 31 provided adjacent to each other, and a pair of contact separation members 32 are disposed on both side surfaces of the plurality of contact members 31. A current limiting resistor 33 is connected in parallel to each contact member 31 as a current limiting electric circuit portion.
The contact separating member 32 is retracted from the insertion position as shown in FIG. 5B where the adjacent contact members 31 are separated from each other to the opposite contact member side, and contacts the adjacent contact members 31. It is possible to displace between the extraction position as shown in FIG.
In order to engage the contact member 31 and the contact separating member 32, both side surfaces of each contact member 31 have concave engaging portions 31a, while the contact separating member 32 opposed thereto has a concave engagement. A plurality of engaging protrusions 32a that can be engaged with the joint portion 31a are provided.

When an overcurrent flows in the power system, the pair of contact separation members 32 are driven to the insertion position for separating the contact members 31, and the engagement protrusions 32a are completely fitted into the concave engagement portions 31a. As a result, the plurality of contact members 31 are separated from each other, and the overcurrent is commutated from the steady electric circuit portion to the current limiting resistor 33 that is the current limiting electric circuit portion.
In addition to opening the contact members 31 apart from each other, the contact opening member 32 is required to have a function of holding the contact members 31 adjacent to each other at a predetermined interval during the current limiting operation. From the above, the interval between the engagement protrusions 32a provided on the contact separation member 32 is designed to be the same as the interval after the separation of the concave engagement portions 31a of the contact members 31 adjacent to each other (for example, , See Patent Document 1).

JP 2010-25262 (page 6-7, FIG. 1)

In the conventional current limiting device as shown in Patent Document 1, the structure of the contact separating member 32 is such that, as described above, the distance between the engaging protrusions 32a provided on the contact separating member 32 is adjacent to each other. In the steady state as shown in FIG. 5 (a) in which the contact separating member 32 is in the extraction position, the A portion is designed to be the same as the interval after the opening of the concave engaging portion 31a. As shown in FIG. 4, there is a place where the contact opening member 32 and the contact member 31 cannot be brought into contact with each other.
In order to improve the current limiting performance, it is necessary to quickly perform the current limiting operation, that is, the contact member 31 is opened, but the contact breaking member 32 and the contact member 31 are not in contact with each other at the start of the current limiting. At the location, it takes time until the restraining force for opening the contact member 31 is applied, and a portion where the adjacent contact members 31 are separated quickly and a portion where the contact members 31 are separated slowly are generated. There was a problem that it became a factor to worsen.

The present invention has been made to solve the above-described problems. When an overcurrent flows in the power system, the current limiting performance can be improved by performing a quick current limiting operation. The purpose is to obtain a current limiting device.

A current limiting device according to the present invention is a current limiting device that is electrically connected between a power supply side circuit and a load side circuit of a power system, and that limits an overcurrent flowing through the power system, and has a pair of parallel surfaces. A plurality of contact members having a concave engagement portion formed on a side surface, arranged parallel to each other so as to be able to contact and separate, and a current limiting resistor electrically connected to the plurality of contact members in parallel. Forming a steady circuit for flowing a steady current through a plurality of contact members between the power supply side circuit and the load side circuit, and limiting the overcurrent flowing between the power supply side circuit and the load side circuit. An electric circuit forming portion that forms an electric current circuit, and a plurality of engaging projections that can be fitted to the concave engaging portions of the plurality of contact members, and the adjacent contacts by inserting the engaging protruding portions into the concave engaging portions The insertion position that separates the members, and the contact position member away from the insertion position Is electrically connected between the power supply side circuit and the load side circuit, and a steady current is supplied from the power system. When the contact is received, the contact breaking member is held at the extraction position to form a steady circuit in the circuit forming part, and when receiving an overcurrent from the power system, the contact breaking member is displaced to the insertion position to form the circuit. A contact driving part that forms a current-limiting electric circuit in the part, and the engagement protrusion of the contact release member is disengaged by opening the contact release member to the insertion position even when the contact release member is in the extraction position. It is comprised so that the concave engaging part of a member may be contacted.

According to the current limiting device of the present invention, the contact opening member having the plurality of engaging protrusions that can be fitted to the concave engaging portions formed on the respective side surfaces of the plurality of contact members is provided. The joint protrusion is configured to contact the concave engaging portions of all the contact members that are displaced to the insertion position and opened even when the contact separation member is in the extraction position. When the contact driving unit receives current and the contact driving member is displaced from the extraction position to the insertion position by the contact driving unit to open the contact members adjacent to each other, the contact members are opened. Is transmitted simultaneously with the start of the displacement from the extraction position of the contact separating member to the insertion position, so that the current limiting operation can be accelerated and the current limiting performance can be improved.

It is sectional drawing which shows the state which has the contact breaking member in the extraction position of the current limiting device by Embodiment 1 of this invention. It is sectional drawing which shows the state which has the contact breaking member in an insertion position of the current limiting device by Embodiment 1 of this invention. It is principal part sectional drawing of the current limiting device by Embodiment 2 of this invention. It is an expanded sectional view of the A section in FIG. It is explanatory drawing explaining the principal part structure of the conventional current limiting device.

Embodiment 1 FIG.
Hereinafter, a current limiting device according to Embodiment 1 of the present invention will be described with reference to the drawings. 1 and 2 are sectional views showing a current limiting device according to the first embodiment. FIG. 1 shows a state where the contact breaking member is in the extraction position, and FIG. 2 shows a state where the contact breaking member is in the insertion position.
In FIG. 1, an upper frame 1 and a lower frame 2 are provided so as to face each other with a space therebetween. The upper frame 1 and the lower frame 2 are connected to each other by a plurality of connecting frames 3. A first fixed electrode 4 and a second fixed electrode 5 are provided on the lower surface of the upper frame 1 at intervals in the length direction. The first fixed electrode 4 is connected to either the load side electric circuit or the power source side electric circuit of the AC power system.

A fixed iron core 6 is fixed to the upper surface of the lower frame 2. An electromagnetic coil 7 as a contact drive unit and a plurality of contact pressure springs 8 are provided at the center of the upper surface of the fixed core 6. One end of the conductor of the electromagnetic coil 7 is connected to the second fixed electrode 5, and the other end is connected to the other of the load side electric circuit and the power source side electric circuit of the power system. Thereby, the electromagnetic coil 7 generates the electromagnetic force according to the magnitude | size of the electric current which flows into an electric power grid | system. The spring force of the contact pressure spring 8 is set to be larger than the electromagnetic force of the electromagnetic coil 7 when a steady current flows through the electromagnetic coil 7.

On the upper surface side of the fixed iron core 6 between each

fixed electrode

4, 5 and the fixed iron core 6, a plate-like movable iron core 9 connected to the upper end portion of the contact pressure spring 8 and the upper surface of the movable iron core 9 are fixed. The movable electrode 10 is provided.
The movable iron core 9 and the movable electrode 10 are in a state where the first fixed electrode 4 and the second fixed electrode 5 are electrically short-circuited as shown in FIG. They can be displaced integrally with each other between “current-limiting positions” as shown in FIG. 2 that are sometimes attracted by the electromagnetic force of the electromagnetic coil 7. In the short-circuit position, the spring force of the contact pressure spring 8 is biased toward the

fixed electrodes

4 and 5 from the fixed iron core 6 side. When an overcurrent flows through the electromagnetic coil 7, the spring of the contact pressure spring 8. The electromagnetic force resists the force and moves to the current limiting position.
The fixed iron core 6, the electromagnetic coil 7, the contact pressure spring 8, and the movable iron core 9 constitute a contact drive unit that drives the contact part.

A plurality of contact members 11 are arranged adjacent to each other between the first fixed electrode 4 and the movable electrode 10 and between the second fixed electrode 5 and the movable electrode 10 so as to be continuous. The contact member 11 is made of a metal including at least one of copper, silver, or aluminum, for example.
A plurality of contact members 11, each of which is arranged between the first fixed electrode 4 and the movable electrode 10 and each of the contact member rows arranged between the second fixed electrode 5 and the movable electrode 10, respectively. A pair of contact separating members 12 made of an insulator are arranged opposite to each other on both sides of the contact member row. Detailed shapes of the contact member 11 and the contact separating member 12 will be described later.

Further, an outer pressing spring 13 and an inner pressing spring 14 that serve to press the contact separating member 12 toward the contact member 11 are provided. One end of the outer contact pressure spring 13 is fixed to the connection frame 3 side, and the other end is fixed to the back surface of the contact separating member 12. The inner pressing spring 14 is fixed to the back surface of each contact separating member 12 inside the two contact member rows. The contact breaking member 12 is always biased toward the contact member 11 by the pressing force of the

pressing springs

13 and 14.
Further, the first fixed electrode 4 and the second fixed electrode 5 are connected, and a high resistance current limiting resistor 15 is provided in parallel with the plurality of contact members 11, whereby the

electrodes

4 and 5 are electrically connected. It is connected to the.

For each of the fixed

electrodes

4, 5 and the movable electrode 10, the adjacent contact member 11 adjacent to them, that is, the nearest contact member 11, is joined to each electrode and is always electrically connected. Further, the contact members 11 adjacent to each other in the vertical direction can be brought into contact with and separated from each other on one lower surface and the other upper surface.
The shape of the contact member 11 includes a pair of parallel surfaces 11b that are in contact with / separate from other contact members 11 or joined to the

electrodes

4, 5, 10, and a concave engaging portion 11a formed on the side surface. have. The concave engaging portion 11a is constituted by, for example, a V-shaped concave engaging portion 11a that is recessed in the lengthwise direction from the ends of the pair of parallel surfaces 11b in the longitudinal direction.

Next, the shape of the contact separating member 12 will be described.
The contact separating member 12 has a serrated continuous inclined surface formed on the side surface of the contact member 11 facing the concave engaging portion 11a. The continuous inclined surface has a plurality of engagement protrusions 12a that are tapered toward the V-shaped concave engagement portion 11a of the contact member 11 facing each other. It can be fitted into the concave engaging portion 11a. Details of the pitch of the engaging protrusions 12a will be described later.

Further, one end side of the contact separating member 12, in the case of FIGS. 1 and 2, is rotatably supported by a rotating shaft 16 fixed to the connecting frame 3 side.
Thereby, the contact separation member 12 is inserted into the V-shaped concave engagement portion 11a of the adjacent contact member 11 with the engagement protrusion 12a and the insertion position which is a position for separating the contact members 11 from each other. The contact member 11 is retracted from the insertion position to the side opposite to the contact member 11, and can be displaced between an extraction position where the engagement protrusion 12 a is extracted from the concave engagement portion 11 a of the contact member 11.

Here, the relationship of the shape of the engaging protrusion 12a of the contact separating member 12 with respect to the concave engaging portion 11a of the contact member 11 is as follows.
In the state where the contact separating member 12 is in the extraction position as shown in FIG. 1 and the contact members 11 are in close contact with each other, the upper inclined surface of the outer wall of the uppermost engaging protrusion 12a and the V-shaped concave engagement The upper slopes of the inner wall of the portion 11a are in contact with each other, and the lower slope of the outer wall of the second and subsequent engagement protrusions 12a and the lower slope of the inner wall of the concave engagement portion 11a are , All the facing parts are in contact with each other.

2, the contact member 11 adjacent to each other is opened when the engagement protrusion 12a of the contact separation member 12 and the concave engagement portion 11a of the contact member 11 are fitted to each other. The intervals are set to be substantially equal at any location.
That is, the pitch and shape of the engaging protrusions 12a of the contact opening member 12 are determined so as to achieve such a state.
Further, as described above, since the nearest contact member 11 adjacent to each of the

electrodes

4, 5, 10 is fixed to each contact side, the contact member 11 adjacent to the movable electrode 10 is connected to the movable electrode 10. It moves with the movement to the current limiting position. Therefore, the engagement protrusion 12a of the contact separating member 12 is not opposed to the contact member 11.

As can be seen from FIGS. 1 and 2, the first fixed electrode 4, the movable electrode 10, and the portion made up of the plurality of contact members 11 arranged therebetween, the second fixed electrode 5, the movable electrode 10, and the arrangement between them. In addition, a part of the plurality of contact members 11 is formed with a series of electric circuits via the movable electrode 10, and further, a current limiting resistor 15 is connected in parallel to this electric circuit, so that the power supply side electric circuit and the load side electric circuit as a whole An electric circuit forming unit that connects the two is configured.
When the movable electrode 10 is in the short-circuited position as shown in FIG. 1, the electric circuit forming unit forms a steady electric circuit for allowing a steady current to flow between the power supply side electric circuit and the load side electric circuit. Further, as shown in FIG. 2, when the movable electrode 10 is in the current limiting position, the contact members 11 adjacent to each other are separated, current flows to the current limiting resistor 15 side, and between the power supply side electric circuit and the load side electric circuit. A current-limiting circuit for limiting the flowing overcurrent is formed.

Next, the operation will be described. First, as shown in FIG. 1, when a steady current flows through the power system, the spring force of the contact pressure spring 8 is larger than the electromagnetic force generated by the electromagnetic coil 7, so that the movable electrode 10 is at the short-circuit position. While being held, the contact separating member 12 is held at the extraction position, the contact members 11 adjacent to each other are pressed against each other, and a stationary electric circuit is formed between the

fixed electrodes

4, 5 and the movable electrode 10. At this time, the current flows from the first fixed electrode 4 to the first fixed electrode 4 side of the contact member 11, the movable electrode 10, the second fixed electrode 5 side of the contact member 11, the second fixed electrode 5, and the electromagnetic coil 7. It flows in order, and then flows in the reverse direction due to the inversion of the AC phase.

On the other hand, when an overcurrent occurs in the power system, the overcurrent flows in the electromagnetic coil 7, so that the electromagnetic force generated by the electromagnetic coil 7 becomes larger than the spring force of the contact pressure spring 8, and this electromagnetic force The movable iron core 9 and the movable electrode 10 are displaced from the short-circuit position to the current-limiting position. By this displacement, the contact state of each contact member 11 is released, and the contact breaking member 12 is rotated from the extraction position to the insertion position while rotating about the rotation shaft 16 by the spring force of each

pressing spring

13, 14. The engaging protrusions 12a of the contact separating member 12 are pushed into the concave engaging portions 11a of the opposing contact member 11 and are fitted to each other. As a result, the contact members 11 adjacent to each other are separated from each other, the steady electric circuit of the electric circuit forming part is cut off to form a current limiting circuit, and the overcurrent is limited between the

fixed electrodes

4 and 5 by the current limiting resistor 15. .

When the abnormality of the power system is resolved and the overcurrent changes to a steady current, the spring force of the contact pressure spring 8 becomes larger than the electromagnetic force generated by the electromagnetic coil 7, and the movable electrode 10 is moved from the current limiting position. It is displaced to the short-circuit position, and due to this displacement, the contact members 11 adjacent to each other are displaced to contact each other. Along with the displacement of the contact member 11, the engagement protrusion 12a of the contact separation member 12 is pushed back to the side opposite to the contact member 11, and the contact separation member 12 is displaced from the insertion position to the extraction position.
Thereby, the fitting state of the engaging protrusion 12a of the contact separating member 12 and the concave engaging portion 11a of the contact member 11 is canceled, the displacement of the contact member 11 advances, and the contact member 11 returns to the initial position. As a result, the contact members 11 adjacent to each other are pressed together again, and a stationary electric circuit is formed between the

fixed electrodes

4 and 5 and the movable electrode 10.

In the above operation, when moving from the steady circuit to the current-limiting circuit, the faster current-commutation speed toward the current-limiting resistor 15 can suppress the increase in the current-limiting current and improve the current-limiting performance.
The contact members 11 that are adjacent to each other are separated by the restraining force that the engagement protrusions 12 a of the contact separation member 12 exert on the concave engagement portions 11 a of the contact member 11.
In the present embodiment, even when the engagement protrusion 12a of the contact opening member 12 is in the extraction position, it contacts the concave engagement portions 11a of all the contact members 11 that are displaced to the insertion position and separated. Therefore, since the contact separation member 12 can apply a restraining force to the contact member 11 from the initial stage of displacement from the extraction position of the contact separation member 12 to the insertion position, the contact members 11 adjacent to each other can be opened. The separation speed is increased, and the current limiting performance can be improved.

As described above, according to the current limiting device of the first embodiment, the contact breaking member having the plurality of engaging protrusions that can be fitted to the concave engaging portions formed on the respective side surfaces of the plurality of contact members is provided. The engagement protrusions of the contact release member are configured to contact the concave engagement portions of all contact members that are displaced to the insertion position and opened even when the contact release member is in the extraction position. Therefore, when the contact drive unit receives an overcurrent from the power system, and the contact release member is displaced from the extraction position to the insertion position by the contact drive unit, the contact members are separated from each other. Since the force for opening the contact is transmitted simultaneously with the start of displacement from the extraction position of the contact opening member to the insertion position, the current limiting operation can be accelerated, and the current limiting performance can be improved.

In addition, the contact separating member is supported at one end by a rotating shaft and is configured to be displaceable between an extraction position and an inserting position by rotating around the rotating shaft. The separation member can be displaced between the extraction position and the insertion position, and the above effect can be obtained.

Embodiment 2. FIG.
A current limiting device according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 3 is a cross-sectional view of an essential part showing a steady electric circuit portion composed of an electrode and a contact member of the current limiting device, and FIG. 4 is an enlarged view of a portion B in FIG. Since the entire configuration of the current limiting device excluding the steady circuit portion is the same as that of FIG. 1 of the first embodiment, illustration and description thereof are omitted. Further, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

In the first embodiment, the contact separation member 12 is configured to rotate about the rotation shaft 16. However, in the second embodiment, as illustrated in FIGS. 3 and 4, the contact separation member 12 is configured to rotate. A pair of contacts are separated from each other so that each of the two adjacent contact members 11 is opposed to the V-shaped concave engagement portion 11a and sandwiched from both sides in order from the fixed

electrodes

4 and 5 side. A member 17 is provided.
Referring to FIG. 3, for the five contact members 11 arranged between the first fixed electrode 4 and the movable electrode 10, a pair of contacts on both sides of the first and second contact members 11 from the top. A separating member 17 is provided, and a pair of contact separating members 17 are provided on both sides of the third and fourth contact members 11. The same applies to the five contact members 11 arranged between the second fixed electrode 5 and the movable electrode 10.
Since the contact member 11 adjacent to the movable electrode 10 is fixed to the movable electrode and moves together with the movable electrode 10, the contact opening member is not opposed.

Further, an upper and lower pressing spring 18 is inserted between the contact opening and closing members 17 which are upper and lower. As a result, the upper and lower contact separating members 17 are connected by the upper and lower pressing springs 18 and are urged in a direction in which they are separated from each other.
Further, an outer pressing spring 19 and an inner pressing spring 20 are connected to the back side of each contact separating member 17, that is, the opposite surface to the surface facing the contact member 11, and the contact separating member 17 is connected by these springs. It is biased toward the contact member 11 side.

The relationship between the shape of the contact separating member 17 and the contact member 11 will be described with reference to FIG.
The contact release member 17 is provided with

engagement protrusions

17a and 17c on the side facing the contact member 11, and the two

engagement protrusions

17a and 17c are adjacent two contact members. The eleven concave engaging portions 11a face each other. Of these, the upper slope 17b of the engagement protrusion 17a is an upper slope of the inner wall of the V-shaped concave engagement portion 11a of the contact member 11 disposed on the upper side when the two contact members 11 are in close contact. Further, the lower inclined surface 17d of the engaging protrusion 17c is in contact with the lower inclined surface of the inner wall of the concave engaging portion 11a of the contact member 11 disposed on the lower side. Otherwise, substantially the same gap is formed.

With such a configuration, even when the contact separating member 17 is pulled out as shown in FIG. 3, some of the engaging

protrusions

17 a and 17 c of the contact separating member 17 are recessed engaging portions 11 a of the contact member 11. In contact with.
When an overcurrent is generated in the power system, the movable electrode 10 is driven downward by electromagnetic force, so that the contact opening member 17 is pressed by the outer pressing spring 19 and the inner pressing spring 20 and the side surface of the contact member 11. The contact separating member 17 is displaced to the insertion position, and the engaging

protrusions

17a and 17c are fitted into the opposing concave engaging portions 11a to separate the adjacent contact members 11 from each other.
Here, since the separation between the second and third from the top of the contact member 11 in FIG. 4 may become unstable, the upper and lower contact release members 17 are opened by the upper and lower pressing springs 18. In this way, the opening operation of the contact member 11 is stabilized.
As described above, since the contact separation member 17 can apply a restraining force to the contact member 11 from the initial stage of the displacement from the extraction position to the insertion position, the separation speed of the contact members 11 adjacent to each other can be increased. And current limiting performance can be improved.

As described above, according to the current limiting device of the second embodiment, the contact separation member is divided and arranged corresponding to each of two adjacent contact members, and the divided contact separation members are separated from each other. Since it is connected by a spring and is configured to be movable in the contact / separation direction of the contact member, the contact separation member can apply a restraining force to the contact member from the initial stage of displacement from the extraction position to the insertion position. The opening speed of adjacent contact members can be increased, and the current limiting performance can be improved.
Further, even when the number of contact members arranged is large, it can be easily handled.

In the present invention, within the scope of the invention, the embodiments can be freely combined, or the embodiments can be appropriately changed or omitted.

1 upper frame, 2 lower frame, 3 connecting frame,
4 first fixed electrode, 5 second fixed electrode, 6 fixed iron core, 7 electromagnetic coil,
8 Pressure spring, 9 Movable iron core, 10 Movable electrode, 11 Contact member,
11a concave engagement part, 11b parallel surface, 12 contact opening member,
12a engagement protrusion, 13 outer pressing spring, 14 inner pressing spring,
15 current limiting resistor, 16 rotating shaft, 17 contact opening member,
17a, 17c engaging protrusion, 17b upper slope, 17d lower slope,
18 upper and lower pressure springs, 19 outer pressure springs, and 20 inner pressure springs.

Claims

A current-limiting device that is electrically connected between a power-side electric circuit and a load-side electric circuit of an electric power system, and that limits an overcurrent flowing through the electric power system,
A plurality of contact members having a pair of parallel surfaces and having a concave engagement portion formed on a side surface, arranged parallel to each other so that the parallel surfaces are adjacent to each other, and electrically connected in parallel to the plurality of contact members A stationary current path for flowing a steady current between the power supply side circuit and the load side circuit via the plurality of contact members, and the power supply side circuit and the load side An electric circuit forming section for forming a current limiting circuit for limiting an overcurrent flowing between the electric circuits;
A plurality of engaging protrusions that can be fitted to the concave engaging portions of the plurality of contact members; and the adjacent contact members are separated by inserting the engaging protruding portions into the concave engaging portions. A contact release member provided to be displaceable between an insertion position to be moved, and an extraction position for retreating from the insertion position to a side away from the contact member and bringing the adjacent contact members into contact with each other;
It is electrically connected between the power supply side electric circuit and the load side electric circuit, and when the steady current is received from the power system, the contact opening member is held at the extraction position and the steady state is provided in the electric circuit forming unit. A contact driving unit that forms an electric circuit and displaces the contact breaking member to the insertion position when the overcurrent is received from the electric power system to form the current limiting electric circuit in the electric circuit forming unit. ,
The engagement protrusions of the contact release member contact the concave engagement portions of all the contact members that are displaced and opened to the insertion position even when the contact release member is in the extraction position. It is comprised so that the current limiting device characterized by the above-mentioned.
The current limiting device according to claim 1,
One end side of the contact opening member is supported by a rotation shaft, and is configured to be rotatable about the rotation shaft so as to be displaceable between the extraction position and the insertion position. Current limiting device to do.
The current limiting device according to claim 1,
The contact opening member is divided and arranged corresponding to each of the two adjacent contact members, and the divided contact opening members are connected by a spring and moved in the contact / separation direction of the contact member. A current limiting device characterized by being configured.