Limit switch operation check device

Abstract

To provide a limit switch operation confirming device capable of safely and easily confirming the state of a limit switch in a state where a breaker is in a "connection position".SOLUTION: A drawer type breaker includes a limit switch 20 which is for confirming a connection position and which is positioned and fixed to a drawer frame 2 so as to be closed when a breaker main body 1 is in a "connection position", and a control relay 21 that is interlocked with the limit switch 20 and allows an input command to be applied from a control circuit to the breaker. In the drawer type breaker, a terminal base 27 that are provided with terminals 27a, 27b electrically connected to a terminal of the control relay 21 is disposed on the front surface of a board. The terminal base 27 may be disposed to be adjacent to a power source switch 25 disposed on the front surface of the board.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a limit switch operation checking device capable of checking the operation of a limit switch that detects the connection position of a circuit breaker body of a draw-out type circuit breaker. [Background technology]

[0002] A field circuit breaker is used to break the field circuit of a generator, an electric motor, etc. As shown in Fig. 4, this field circuit breaker has a breaker body 1 housed in a draw-out frame 2, and is equipped with a main circuit disconnecting unit 100 and a control circuit disconnecting unit 200, main electrode contacts PL, PU, ​​NL, NU that open and close the field circuit, and discharge electrode contacts DL, DU that reverse the opening and closing action, and has the function of breaking the field circuit when an accident occurs in the field circuit or when a short circuit occurs in the main machine circuit.

[0003] In addition, to facilitate inspection and part replacement, the field breaker is designed so that the breaker body 1 can be pulled out, removed and inserted, and the pull-out position of the breaker body 1 can be switched between a "connected position" (FIG. 5(a)) in which the main circuit disconnection unit 100 and the control circuit disconnection unit 200 are both connected, a "test position" (FIG. 5(b)) in which the main circuit disconnection unit 100 is disconnected and the control circuit disconnection unit 200 is connected, and a "disconnected position" (FIG. 5(c)) in which both the main circuit disconnection unit 100 and the control circuit disconnection unit 200 are disconnected, as shown in FIG. 5.

[0004] In order to confirm the pull-out position of the circuit breaker body 1, a pull-out position indicator 3 is provided on the front cover 1a of the circuit breaker body 1 as shown in FIG. 6. The pull-out position indicator 3 switches between "connected," "test," and "disconnected" in conjunction with the movement position of the circuit breaker body 1. In addition, there is a spring charge indicator 4 which displays "energized" when the closing spring is charged and "released" when it is released, an on / off indicator 5 which displays "on" when the circuit is closed and "off" when the circuit is open, a handle insertion port 7 which allows the insertion of an operating handle 6 which changes the moving position of the circuit breaker main body 1, a circuit opening push button 8 which is pressed to manually open (cut) the circuit breaker, and a closing push button 9 which is pressed to manually close (open) the circuit breaker.

[0005] Between the pull-out position indicator 3 and the spring charge indicator 4, a pull-out operation release lever 10 is provided which can be tilted downward when pulling out the circuit breaker body 1 to enable the pull-out operation (inserting the operating handle 6 and turning it). A shutter 11 that moves in conjunction with the movement of a pull-out operation release lever 10 is attached to the inside of the handle insertion port 7, and when the pull-out operation release lever 10 is lowered with the circuit breaker in the "off" state, the shutter 11 opens.

[0006] Therefore, in the "connected position" where the circuit breaker body 1 has been moved to the innermost part of the draw-out frame 2, the pull-out position indicator 3 displays "connected," and from this state, the pull-out operation release lever 10 is tilted downward to open the shutter 11 of the handle insertion port 7, and the operating handle 6 is inserted into the handle insertion port 7 and turned, making it possible to pull out the circuit breaker body 1. Then, when the circuit breaker body 1 is moved to the "test position," the pull-out position indicator 3 switches to "test," the main circuit is disconnected, and the control circuit is connected, making it possible to perform opening and closing operations, operation tests of the control circuit, and electrical operation tests. Furthermore, when the operating handle 6 is further turned to move the circuit breaker body 1 to the “disconnected position”, the pull-out position indicator 3 switches to “disconnected”, both the main circuit and the control circuit are disconnected, and the circuit breaker body is completely separated from the line.

[0007] In addition to the display of the pull-out position indicator 3 according to the pull-out position of the circuit breaker body 1, in order to electrically detect the pull-out state of the circuit breaker, as shown in FIG. 5, a limit switch 20 is attached to the pull-out frame 2. The limit switch 20 is pressed by the circuit breaker body 1 and turns ON when the circuit breaker body 1 moves to the "connected position".

[0008] This limit switch 20 is located at the back of the draw-out frame 2, at the bottom of the draw-out frame 2, and when the circuit breaker body 1 is inserted, it is inaccessible from the front by the circuit breaker body 1. As shown in Figure 7, when this limit switch 20 is turned ON, a control relay 21 located on the back of the panel which operates in conjunction with this is operated (terminals α and β become conductive), and the closing relay (41C) 22 for closing the circuit breaker can be placed in a state where it can be excited by a closing command from the control circuit 23.

[0009] Therefore, when the operator turns the operating handle to move the circuit breaker body, which is in the "test position" or "disconnected position", to the "connected position", the pull-out position indicator switches to the "connected position". By visually checking this display, the operator can confirm the current position of the circuit breaker and recognize that the field circuit breaker is in a state where it can be closed without any problems in response to the closing command from the control circuit 23. [Prior art documents] [Non-patent literature]

[0010] [Non-Patent Document 1] "Field Breaker Instruction Manual" Terasaki Electric Industries Co., Ltd. KRB-0149k Revised March 2017 Summary of the Invention [Problem to be solved by the invention]

[0011] However, the information displayed on the pulled-out position indicator 3 is dependent on the position of the circuit breaker body 1 as a result of rotating the operating handle 6, and is premised on the limit switch accurately operating at the operation timing of Fig. 5(d) above, but if this operation timing is deviated for some reason, for example, if there is a deviation in the mounting position of the limit switch 20, or if the limit switch 20 is not closed due to the degree to which it is pressed by the circuit breaker body 1, the display of the pulled-out position indicator 3 will not match the operation of the limit switch 20. In this way, since the display state of the pulled-out position indicator 3 and the state of the limit switch 20 are not necessarily linked, an event may occur in which the field circuit breaker does not close in response to a closing command from the control circuit 23, even if the circuit breaker body is in the "connected position".

[0012] Therefore, it is desirable to check the state of the limit switch after moving the circuit breaker body to the "connected position", but when the field circuit breaker is in the "closed position" (when the circuit breaker body 1 is pushed into the pull-out frame 2), the limit switch 20 is hidden behind the circuit breaker body 1 and cannot be seen, and since there are charging points nearby, it is virtually impossible to access the limit switch 20 and check the voltage or resistance value.

[0013] It was also possible to access the control relay 21 linked to the limit switch 20, but since the control relay 21 was arranged on the back side of the panel along with many other relays, it would not be easy to get to the back of the panel, and since many relays were arranged there, it would be difficult to identify the control relay 21 linked to the limit switch 20. Furthermore, since the charging part was also nearby, it was nearly impossible to access the control relay 21 and check the voltage value or resistance value.

[0014] The present invention has been made in consideration of the above circumstances, and its main objective is to provide a limit switch operation confirmation device that can safely and easily check the state of a limit switch when the circuit breaker is in the "connected position." [Means for solving the problem]

[0015] In order to achieve the above object, a limit switch operation confirmation device according to the present invention comprises: This is used in a draw-out type circuit breaker in which a circuit breaker body accommodated in a draw-out frame can be inserted and removed between a connection position and a disconnection position, a limit switch for confirming a connection position, the limit switch being positioned and fixed to the draw-out frame so as to close when the circuit breaker body is in the connection position; A control relay that is linked with the limit switch and enables a closing command to be applied from a control circuit to the circuit breaker; A limit switch operation confirmation device comprising: A terminal block having terminals electrically connected to the terminals of the control relay is disposed on the front surface of the board. Therefore, when the circuit breaker body is housed in the pull-out frame, and particularly when the connection position indicator shows that the circuit breaker body is in the connection position, it is possible to confirm whether the limit switch has operated (whether it has turned ON) by measuring the electrical quantity (resistance value, etc.) on the terminal block located on the front of the panel.

[0016] Here, the terminal of the control relay and the terminal of the terminal block may be electrically connected by a lead wire drawn from the terminal of the control relay. Also, a lamp indicating the operating state of the control relay may be provided together with the terminal of the terminal block. It is possible to check the operation of a limit switch (control relay) using only the lamp, but if you are checking for rare phenomena by the presence or absence of the lamp display, you need to ensure that the lamp is reliable, and in the unlikely event that the lamp is burned out, you will not be able to accurately check the operation of the limit switch (control relay).In contrast, if you use a connection terminal, there is no reliability issue, so it is suitable for checking the operation of the limit switch (control relay).

[0017] The terminal block is provided on the front surface of the board. A switch that turns on and off the power supplied from a DC control power supply to the control circuit.It is desirable to place it in parallel with the DC power switch. This is because when measuring resistance by applying a measuring instrument to the terminals of the terminal block, it is desirable to turn the power off to prevent relay malfunctions, etc. By placing the terminal block in parallel with the power switch, it is possible to perform a series of operations, such as turning the power on and off and measuring the electrical quantity with the terminal block, without changing the working position. Effect of the Invention

[0018] As described above, according to the present invention, a terminal block having terminals electrically connected to the terminals of a control relay that works in conjunction with the limit switch is arranged on the front side of the panel. Therefore, when the circuit breaker main body is in the "connected position" (when the connection position indicator displays "connected position"), it is possible to check the operation of the limit switch using the terminal block on the front side of the panel, making it possible to safely and easily check the status of the limit switch. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing a limit switch operation checking device according to the present invention, and is a schematic diagram showing a state in which a circuit breaker body is accommodated in a draw-out frame, where (a) is a side cross-sectional view and (b) is a front view. [Diagram 2] FIG. 2 is a perspective view showing the appearance of a limit switch attached to a drawer frame. [Diagram 3] FIG. 3 is a circuit diagram of the limit switch operation checking device according to the present invention. [Figure 4] FIG. 4 shows the configuration of a draw-out type field circuit breaker, where (a) is a side view, (b) is a rear view of the circuit breaker body, and (c) is a diagram showing the field circuit to be broken by the circuit breaker. [Diagram 5] FIG. 5 is a diagram explaining the state of each pull-out position of the field breaker, where (a) is a diagram showing the “connected position”, (b) is a diagram showing the “test position”, (c) is a diagram showing the “disconnected position”, and (d) is a diagram explaining the operation timing of the limit switch. [Figure 6]FIG. 6(a) is a perspective view showing the front cover and the operating handle on the front surface of the circuit breaker body, and FIG. 6(b) is a front view of the front cover of (a). [Figure 7] FIG. 7 is an exploded connection diagram for explaining the operation accompanying the closing of a limit switch of a conventional circuit breaker. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] As shown in FIG. 1, the draw-out type field circuit breaker has a circuit breaker body 1 housed in a draw-out frame 2 that can be moved in and out between a connected position and a disconnected position. Since the circuit breaker body 1 is similar to the conventional circuit breaker body shown in FIGS. 4 to 6, the same reference numerals are used to refer to the same parts and their explanations will be omitted.

[0022] As shown in Figure 2, the pull-out frame 2 is located behind the pushed-in circuit breaker body 1 and is fitted with a limit switch 20 for confirming the connection position. The limit switch 20 is pressed by the circuit breaker body 1 to close (ON) when the circuit breaker body 1 is in the "connection position".

[0023] This limit switch 20 is located at the back of the draw-out frame 2, at the bottom of the draw-out frame 2, and when the circuit breaker body 1 is inserted, it is inaccessible from the front by the circuit breaker body 1, and is attached with its movable rod 20a protruding forward so as to be able to abut against the circuit breaker body 1.

[0024] As shown in FIG. 3, the limit switch 20 is connected in series with a control relay (LT1) 21 between the power supply line (CBP) and the ground line (CBN). When the limit switch 20 is turned on, the control relay (LT1) 21 operates (energizes).

[0025] When the control relay (LT1) 21 operates to close terminals α and β inside the relay, the closing relay (41C) 22 for closing the circuit breaker can be placed in an excitable state, and a closing command from the control circuit 23 excites the closing relay 22 to close the circuit breaker. Reference numeral 24 denotes a DC control power supply that supplies power to the control circuit 23, and 25 denotes a power switch that turns the supply of power from the DC control power supply 24 on and off.

[0026] Therefore, normally, when the circuit breaker body 1 moves from the "disconnected position" or "test position" of the draw-out frame 2 to the "connected position", the limit switch 20 is pressed by the circuit breaker body 1 and turns ON, the control relay 21 operates, and the circuit breaker becomes capable of sequence control by the control circuit 23 (it will be closed in response to a closing command from the control circuit 23).

[0027] This control relay 21 is arranged on the back side of the board together with many other relays, and the terminals (α, β) of this control relay are connected to lead wires 26. The lead wires 26 drawn from the terminals α, β of the control relay 21 are routed inside the wall surface of the board, led to the front surface of the board, and connected to terminals 27a, 27b of a terminal block 27 attached to the front surface of the board.

[0028] The terminal block 27 is a known type, which is mounted at a height that is easily accessible to workers and is fixed with bolts or the like so that the terminals are exposed on the front surface of the panel.

[0029] In addition, a power switch 25 for turning on and off the DC control power supply 24 that operates the control circuit 23 is also provided on the front surface of the board, and the terminal block 27 is disposed near the power switch 25, in this example, parallel to the power switch 25.

[0030] In the above configuration, when the circuit breaker body 1 is moved to the "connected position", the limit switch 20 should be pressed and turned ON, and in conjunction with this, the control relay (LT1) 21 should operate, allowing the circuit breaker to be operated by a control signal from the control circuit 23. However, depending on the misalignment of the limit switch 20 installation position or the manner in which the circuit breaker body 1 presses the limit switch, it is anticipated that the limit switch 20 will not be closed, and by extension the control relay 21 will not operate, even though the circuit breaker body 1 is normal. In order to deal with such inconveniences, it is desirable to check the operating state of the limit switch 20 (control relay 21) after moving the circuit breaker body 1 to the "connected position".

[0031] In the present invention, lead wires 26 are drawn from terminals α and β of control relay 21, and terminal block 27 having terminals 27a, 27b electrically connected to terminals α, β of control relay 21 via lead wires 26 is disposed on the front side of the panel (draw-out frame 2). Therefore, when the field breaker power supply lock is released, an operator can check whether or not the breaker main body 1 has been pushed into the connection position and the limit switch 20 is closed (whether the control relay 21 is operating) by placing a measuring device (tester) against terminals 27a, 27b of terminal block 27.

[0032] As a method of checking using a measuring device (tester), for example, a resistance value between the terminals (α, β) of the control relay 21 may be measured by the terminals 27 a , 27 b of the terminal block 27 . If the measured resistance value is 0Ω, it can be confirmed that terminals α and β of the control relay 21 are in a conductive state (the control relay is in a closed (ON) state). Conversely, if the resistance value is infinite, it can be determined that the relay is not operating and is in an open (OFF) state, which means that the circuit breaker body 1 may not have been pushed all the way into the connection position.

[0033] When measuring resistance, it is desirable to turn the power switch "off" to avoid relay malfunctions, etc. Therefore, to ensure that power switch 25 is turned off when measuring resistance using terminal block 27, it is advisable to display a note next to terminal block 27 on the surface of the board indicating that the power should be turned off during measurement. Alternatively, a mechanism may be provided that prevents access to terminals 27a and 27b of terminal block 27 unless the power is turned off.

[0034] Therefore, with the above configuration, when the connection position indicator is in the "connection position", the operation of the control relay 21 linked to the limit switch 20 can be checked using the terminal block 27 on the front side of the panel, thereby making it possible to reliably check the operating state of the limit switch 20, thereby making it possible to safely and easily check the state of the limit switch 20.

[0035] In addition, in the above-mentioned configuration, a light-emitting element 28 such as an LED may be connected in parallel to the terminals α and β or the lead wire 26 of the control relay 21, and the light-emitting state of the light-emitting element 28 may be checked at the same time. In such a configuration, the light-emitting element 28 can be used as an auxiliary checking means for checking the operation of the limit switch, and the operating state of the limit switch 20 can be double-checked. [Explanation of symbols]

[0036] 1 Circuit breaker body 2 Drawer Frame 20 Limit Switch 21 Control Relay 23 Control circuit 25 Power Switch 26 Lead Wire 27 Terminal block 27a, 27b terminal α, β terminal

Claims

1. This is used in a draw-out type circuit breaker in which a circuit breaker body accommodated in a draw-out frame can be inserted and removed between a connection position and a disconnection position, a limit switch for confirming a connection position, the limit switch being positioned and fixed to the draw-out frame so as to close when the circuit breaker body is in the connection position; A control relay that is linked with the limit switch and enables a closing command to be applied from a control circuit to the circuit breaker; A limit switch operation confirmation device comprising: A limit switch operation confirmation device characterized in that a terminal block having terminals electrically connected to the terminals of the control relay is disposed on the front surface of the board.

2. 2. The limit switch operation confirmation device according to claim 1, wherein the terminal of the control relay and the terminal of the terminal block are electrically connected by a lead wire drawn from the terminal of the control relay.

3. The terminal block is a switch provided on the front surface of the panel, and is arranged in parallel with a DC power supply switch that turns on and off the power supplied from the DC control power supply to the control circuit. The limit switch operation confirmation device according to claim 1 or 2.

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