JPH0963453A - Leakage trip device for earth leakage breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To output to the outside, by providing an auxiliary switch to be turned off only when a leakageis detected to turn off a main circuit switch. SOLUTION: A micro switch 9 is provided wherein a plate spring 8 is fitted to a leakage trip device 10 provided, as a unit, on an earth leakage breaker. The tip part 86 of the spring 8 is struck and pushed to the movable iron core of the movable part 42 of a leakage trip electromagnet 4 to push the operating part 91 of the switch 9, thereby changing the on/off of the switch 9. Consequently, the on/off of the switch 9 interlocks the movement of the part 42, including the movable iron core 45 of the magnet 4. Since, the movement of the part 42 interlocks the on/off of a main circuit switch, resultingly, the on-off of the switch 9 interlocks the on/off of the main circuit switch when the leakage is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth leakage breaker for detecting an earth leakage in a distribution system and preventing a ripple accident.
If a leakage is detected, it is also used as an earth leakage trip device to turn off the main circuit switch of the earth leakage breaker, especially as an overcurrent breaker that detects overcurrent and shuts off the main circuit switch in addition to leakage detection. The present invention relates to an earth leakage trip device for an earth leakage breaker.

[0002]

2. Description of the Related Art FIG. 8 is a circuit diagram of an earth leakage breaker. In this figure, an earth leakage breaker 100 comprises a zero-phase current transformer 1, an electronic circuit 2, a main circuit switch 5 and an earth leakage trip electromagnet 4, and the zero-phase current transformer 1 has two load side The electric wire 7 penetrates and is connected to the fixed contact 53 on the load side of the main circuit switch 5, and the electric wire 6 on the power supply side is the fixed contact 5 of the main circuit switch 5.
1 connected. Zero-phase current of main circuit is zero-phase current transformer 1
It is detected by the secondary coil 21 wound around and is amplified by the electronic circuit 2, and when the value of the detected current becomes equal to or more than a predetermined value, it is considered that the electric leakage occurs and the electric wire 23
An electric current is caused to flow through the drive coil 41 of the electric leakage trip electromagnet 4 via the to drive the movable portion 42. In the figure, the main circuit switch 5 is shown in an off state in which the movable contact 52 is separated from the fixed contacts 51, 53, but when the main circuit is in a normal state, these are in contact with each other and the main circuit switch 5 is turned on. Is actually the case. The power source of the electronic circuit 2 is taken from the electric wire 7 on the load side. Therefore, the main circuit switch 5
When is turned off, the electronic circuit 2 is turned off.

When a current flows through the drive coil 41, the movable portion 42 moves in the left direction in the figure to change from the on state to the off state shown in the figure to cut off the main circuit. This figure shows a circuit diagram in which the main circuit switch is turned off only when an electric leakage is detected, but it is assumed that the circuit functions purely as an earth leakage breaker. In an earth leakage circuit breaker that also serves as a device, an overcurrent trip device corresponding to the earth leakage trip device is provided. The main circuit shown in the figure is a single-phase circuit, but in the case of a three-phase circuit, three wires pass through the zero-phase current transformer 1, and a current transformer or overcurrent for detecting overcurrent is used. Three trip devices are provided for each phase.

FIG. 9 is a perspective view showing the outer shape of the earth leakage breaker. In this figure, the notch 60 on the left side of the drawing is provided with a connecting fitting (not shown) to which the electric wire on the power supply side is connected, and on the opposite side, a connecting wire (not shown) to which the electric wire on the load side is connected A notch 70 is provided in which a metal fitting is provided. The fact that there are three notches each indicates that it is an earth leakage breaker used in a three-phase circuit. Leakage trip device 1
0 is provided as a part of the earth leakage breaker 100 as illustrated. Illustrated on the upper surface in an oval shape are a display button, a light emitting diode, and the like, which will be described later, and a grip 150 for manually operating the main circuit switch 5 is provided on the earth leakage trip device 10 so as to project therefrom. Has been.

In the earth leakage circuit breaker having the function of the conventional overcurrent circuit breaker, in order to output the open / closed state of the main circuit switch 5 as a signal to the outside, the auxiliary circuit breaker is turned on / off in cooperation with the main circuit switch 5. It comes with a contact and an alarm contact that outputs the accident interruption status. Further, in order to visually confirm that the main circuit is turned off due to the detection of the electric leakage, a configuration in which the light emitting diode is turned on or the display button is mechanically projected is also adopted. In such a case, the auxiliary contact and alarm contact are interlocked with the on / off of the main circuit, so even if the main circuit switch is turned off due to the detection of overcurrent, the leakage is detected and turned off. The same output signal will be obtained. Therefore, in order to determine that the current is not due to the switch-off due to overcurrent but due to the electric leakage, it is possible only by visually observing the light emitting diode or the display button.

[0006]

As described above, it is visually determined to judge that the main circuit is interrupted due to the electric leakage, but the place where the earth leakage breaker is installed is to be visually inspected by both the display button and the light emitting diode. However, in the case of a light emitting diode, there is a problem that it is necessary to supply power from the outside in order to turn on the light even after the main circuit switch is cut off. This is because, as described above, the power supply for operating the earth leakage breaker is taken from the load side of the main circuit switch, so the power supply is cut off when the main circuit switch is turned off.

An object of the present invention is to solve such a problem, and to provide an auxiliary switch which is turned off only when the leakage is detected and the main circuit switch is turned off, so that the leakage of the earth leakage breaker can be output to the outside. To provide a trip device.

[0008]

In order to solve the above problems, according to the present invention, when a zero-phase current of the main circuit is detected, a current is passed through the coil of the earth leakage trip electromagnet provided in the earth leakage trip device. In the earth leakage breaker in which the movable contact of the main circuit switch that is interlocked with the movable portion moves to cut off the current in the main circuit, a leaf spring is attached to the earth leakage trip device. A micro switch is provided, and when a leakage is detected, the movable part of the leakage trip electromagnet presses the tip of the leaf spring, and the leaf spring operates the operation portion of the micro switch to turn on / off the micro switch. By changing, the on / off change of the micro switch is linked to the movement of the moving part of the earth leakage trip electromagnet,
Since the movement of the movable part is linked to the on / off change of the main circuit switch, the on / off change of the micro switch is eventually linked to the on / off change of the main circuit switch only when the leakage is detected. . Also, by coating the tip of the leaf spring that contacts the movable portion of the above-mentioned earth leakage trip electromagnet with polytetrafluoroethylene, generation of metal powder due to rubbing between the movable portion and the tip of the leaf spring is prevented. Prevents it and works smoothly.

Further, the above-mentioned leaf spring is provided with a first bent portion which is bent in a convex shape from the fixed portion with respect to the micro switch, and a concave portion which is separated from the first bent portion by a predetermined dimension in the direction of the tip. Forming a second bent portion bent to a second bent portion, and a third bent portion bent convexly with a predetermined dimension away from the second bent portion in the direction of the tip end. By providing the push-in portion 4 for pushing the operating portion of the micro switch in the portion between the bent portions, the pushing portion is operated by the operating portion of the micro switch when the leaf spring is pushed by the movable portion of the earth leakage trip electromagnet. Then, the third bent portion comes into contact with the container of the micro switch, and the second and first bent portions hardly change their positions. After that, the tip end side vibrates from the third bent portion. The state in which the operation part of the micro switch is pushed in does not change even if the user moves or moves. Et al., The operation state of the micro switch is stabilized.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. 1 is a plan view of a ground fault trip device for a ground fault circuit breaker showing an embodiment of the present invention, and FIG. 2 is a side view of FIG.
In each figure, the front container wall is notched to show the components inside. In these figures, the container 10
Reference numeral 1 is a box for integrating the respective constituent elements into a unit to form a unit, and all the respective constituent elements of the earth leakage trip device 10 are housed in this container 101 and covered with a cover 102 to form a part of the earth leakage breaker. As a result, it is protected so that the arc gas and the melted material do not enter when the contacts of the main circuit switch provided outside the container 101 are opened.

In the earth leakage trip electromagnet 4, the earth leakage current of the main circuit is detected by the zero-phase current transformer 1 shown in FIG. 8, the detected signal is amplified by the electronic circuit 2, and the earth leakage trip electromagnet 4 to be described later. A current is passed through the drive coil to release the magnetically held movable portion 42, the slider 104 is pulled by the force of the drive spring 103, and the main contact opening mechanism (not shown) is operated.

At the same time, a movable iron core, also called a plunger, which is connected to the movable portion 42 of the earth leakage tripping electromagnet 4, protrudes in the leftward direction in the drawing, and the display latch 10 is shown.
6 is actuated, the leakage indicator button 107, which has been restrained by the indicator latch 106, is released, and it projects upward due to the force of a spring (not shown) to mechanically indicate the main contact opening state due to the leakage. The part protruding to the lower part of FIG. 2 is a transmission mechanism that is connected to the leakage display button 107 and transmits the position of the leakage display button 107 to other members.

Further, when the movable iron core, which is a part of the movable portion 42 of the earth leakage trip electromagnet 4, projects to the left in the drawing, the leaf spring 8
Since the tip of the leaf spring 8 is moved in the leftward direction in FIG. 1 by pressing, the on / off of the microswitch 9 is changed by pushing the operation portion 91 of the microswitch 9 in the middle of the leaf spring 8. To work. The operation of the micro switch 9 can output the contact signal only when the leakage breaker operates by being drawn out of the main body of the leakage breaker by the lead wire connected to the terminal 92.

The spacer 109 is a component for fixing the leaf spring 8 and the micro switch 9 to the base 101. 3 and 4 are plan views showing the microswitch and the leakage tripping electromagnet of FIG. 1 in an extracted manner. The leakage tripping electromagnet is partially shown in a sectional view, and FIG. 3 shows the same leakage as in FIG. When the movable iron core of the tripping electromagnet does not protrude to the left side, FIG. 4 is a diagram when the electric leakage is detected and the movable iron core protrudes to the left side. In these drawings, the earth leakage trip electromagnet 4 is a case 4 which also functions as a movable portion 42 and a yoke.
3, fixed iron core 44, movable iron core 4 which is a part of movable part 42
The magnetic flux generated by the permanent magnet 46 passes through the yoke 47, the movable iron core 45, the fixed iron core 44, and the case 43, and is again a permanent magnet. A magnetic circuit returning to 46 is formed. In the state of FIG. 3, the drive spring spring 1 of FIG.
The force of 03 is smaller than the sum of the force of the spring 48 and the magnetic force acting between the movable iron core 45 and the fixed iron core 44 due to the magnetic flux generated by the permanent magnet 46, so that the state shown in the drawing is maintained. On the other hand, in the case of FIG. 4, the movable iron core 45 is the fixed iron core 4.
Since the magnetic force is small because it is away from No. 4, and the force of the drive spring 103 is greater than the sum of this magnetic force and the force of the spring 48, the state of FIG. 2 is maintained. Then, in order to change from the state of FIG. 3 to the state of FIG. 4, a current is passed through the drive coil 41 in a direction in which the magnetic flux generated by the permanent magnet 46 is canceled, and the magnetic force between the movable iron core 45 and the fixed iron core 44 is increased. Make it smaller. Then, the force of the drive spring 103 in FIG. 2 becomes larger, and the movable portion 42 including the movable iron core 45 moves to the state of FIGS. 3 to 4.

When the movable iron core 45 is in the state shown in FIG. 3, the tip portion 86 of the leaf spring 8 is separated from the movable iron core 45 and no force is exerted, and therefore the operating portion 91 of the microswitch 9 is used.
The operating portion 91 is in a protruding state without contacting with. As shown in FIG. 4, when the movable iron core 45 moves to the left side of the figure, the left end surface of the movable iron core 45 pushes the tip portion 86 of the leaf spring 8 in the left direction, and the leaf spring 8 pushes the operating portion 91 inward. The on / off state of the contact in the micro switch 9 which is interlocked with the operation unit 91 changes.

Since the earth leakage trip electromagnet 4 operates only after it is determined by the zero-phase current transformer 1 and the electronic circuit 2 that there is an earth leakage, the on / off state of the microswitch 9 changes after the earth leakage occurs. To do. Therefore, if a voltage is applied from the outside between the reciprocating leads drawn from the microswitch 9 via the terminal 92, the current changes when a leakage occurs, and the occurrence of the leakage can be known outside. .

FIG. 5 is an enlarged side view showing the leaf springs of FIGS. 3 and 4, and FIG. 6 is a plan view of the same. In these drawings, the leaf spring 8 has a fixed portion 81 fixed to the micro switch 9, and a tip portion opposite to the fixed portion 81 is a tip portion 86, and the tip portion 86 abuts the movable iron core 45. Fixed part 8
1 and the tip portion 86, three bent portions, that is, the first bent portion 82 and the second bent portion 8 from the fixed portion 81 side.
3 and a third bent portion 85, each of which is bent as shown in the drawing to form the leaf spring 8. A pushing portion 84 for pushing the operating portion 91 of the micro switch 9 shown in FIGS. 3 and 4 is provided between the second and third bent portions 83 and 85.

The protruding portion of the fixing portion 81 in FIG. 6 to the bottom of the drawing is adopted as a shape suitable for fixing the leaf spring 8 and is not essential to the present invention. Further, in this figure, the second bent portion 83 and the bent portion 85 are bent at a right angle, but this is for the purpose of proper positional relationship between the fixed portion 81, the pushing portion 84 and the tip portion 86. However, the shape bent in such a plane is not essential to the present invention.

The tip portion 86 is coated with polytetrafluoroethylene known as Teflon (trade name) to form a polytetrafluoroethylene coating 87. The polytetrafluoroethylene coating 87 is provided to reduce friction at the contact portion between the leaf spring 8 and the movable iron core 45 so as to allow smooth sliding and to prevent generation of metal powder due to sliding. If metal powder is generated, it may get stuck in the driving part and increase frictional resistance, causing equipment failure, or sticking to conductors and causing insulation failure. The ethylene coating 86 is provided to prevent such a problem.

FIG. 7 is an explanatory view for explaining the operation of the leaf spring 8. In this figure, the leaf spring 8 shown by the solid line shows a state in which the movable iron core 45 is in the first position where the movable iron core 45 is not in contact with the tip portion 86, and the leaf spring 8 at the position shown by the chain double-dashed line moved by A from this position. Is the operation unit 9 of the micro switch 9.
The third position is the state of the second position in which 1 is pushed in, and the third position further moved by B from this second state is the state in which the movable iron core 45 further presses the tip portion, or the second and third positions. 2 shows a state when the leaf spring 8 vibrates. As shown in the figure, the leaf spring 8 is rotationally moved with the first bent portion 82 as a fulcrum until it moves from the first position by A to the second state. The second position is a position in which the pushing portion 84 pushes the operating portion 91 and the third bent portion 85 contacts the surface of the microswitch 9, and when the leaf spring 8 moves further downward from this position. The third bent portion 85 serves as a fulcrum, and the portion up to the tip portion 86 from this fulcrum rotates, and the portion closer to the fixed portion 81 than the third bent portion does not move. Therefore, for example, even if there is a movement from the second position to the third position due to vibration or the like due to chattering or the like, the pushing portion 84 of the leaf spring 8 causes the operating portion 91 to move.
Keep pressed in. Therefore, even if the movable iron core 45 or the tip end portion 85 of the leaf spring vibrates due to chattering or the like, the state in which the operation portion 91 is pushed in is maintained as it is and a stable operation state does not occur at the contact portion of the microswitch 9 without causing chattering. Becomes

[0021]

As described above, according to the present invention, a micro switch having a leaf spring is attached to an earth leakage trip device provided in the form of a unit in an earth leakage breaker, and the tip of the leaf spring is provided with an earth leakage trip electromagnet. By pressing the movable part against the movable part and pressing the operating part of the microswitch to change the on / off state of the microswitch, the on / off state of the microswitch is linked to the movement of the movable part of the earth leakage trip electromagnet. Of the main circuit switch is linked with the on / off state of the main circuit switch, so that the on / off state of the micro switch is linked with the on / off state of the main circuit switch when a leakage is detected. Therefore, when the overcurrent trip electromagnet is activated and the main circuit switch is turned off, the on / off state of the microswitch does not change, so if the on / off state of the microswitch changes, it is easy to judge that it is due to electric leakage. be able to. Since the on / off change of the micro switch can be detected by the reciprocating lead drawn out from the terminal of the micro switch, it is possible to know the presence or absence of the leakage at a position sufficiently distant from the earth leakage breaker.

Further, by covering the tip end portion of the leaf spring which comes into contact with the movable portion of the earth leakage trip electromagnet with polytetrafluoroethylene, generation of metal powder due to rubbing between the movable portion and the tip portion of the leaf spring is prevented. In addition, since the frictional resistance is reduced and the micro switch moves smoothly, there is no fear that the micro switch malfunctions. In addition, the leaf spring
A first bent portion bent in a convex shape from the fixed position to the micro switch, a second bent portion bent in a concave shape with a predetermined distance from the first bent portion toward the tip, It has a third bent portion that is bent convexly with a predetermined dimension away from the second bent portion in the direction of the tip portion, and the operation part of the microswitch is provided between the second bent portion and the third bent portion. When the leaf spring is pressed against the movable part of the earth leakage trip electromagnet, the operation part of the microswitch is pressed so that the third bent part comes into contact with the container of the microswitch. Most of the second and first bent parts do not change their positions,
After that, even if the tip side is vibrated from the third bent portion, the state in which the operating portion of the microswitch is pressed does not change, so that a stable operating state of the microswitch can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view of an earth leakage trip device for an earth leakage breaker showing an embodiment of the present invention.

FIG. 2 is a side view of the earth leakage trip device of FIG.

FIG. 3 is a relational diagram with a trip electromagnet when the microswitch of FIG. 1 is off.

FIG. 4 is a relational diagram with a trip electromagnet when the micro switch of FIG. 3 is on.

5 is a side view of the leaf spring of FIG.

6 is a plan view of the leaf spring of FIG.

FIG. 7 is an operation diagram of the leaf springs of FIGS.

FIG. 8 is a circuit diagram of an earth leakage breaker.

FIG. 9 is a perspective view of an earth leakage breaker.

[Explanation of symbols]

100 ... Leakage breaker, 1 ... Zero-phase current transformer, 2 ... Electronic circuit,
10 ... Leakage trip device, 4 ... Leakage trip electromagnet, 41
... drive coil, 42 ... movable part, 5 ... main circuit switch, 8
... leaf spring, 81 ... fixed part, 82 ... first bent part, 83 ...
2nd bending part, 84 ... pushing part, 85 ... 3rd bending part, 8
6 ... Tip, 87 ... Polytetrafluoroethylene coating, 9
… Micro switch, 91… Operating part, 92… Terminal

Claims (3)

[Claims] 1. When a zero-phase current of the main circuit is detected, an electric current is passed through a coil of an earth leakage trip electromagnet provided in an earth leakage trip device to drive a movable portion, and a main circuit switch interlocked with the movable portion. In an earth leakage circuit breaker in which a movable contact moves to interrupt the current in a main circuit, a micro switch having a leaf spring attached to the earth leakage trip device is provided, and the earth leakage trip electromagnet is provided when earth leakage is detected. The movable part of the electric spring presses the tip of the leaf spring, and the leaf spring operates the operating portion of the microswitch to turn ON / OFF the microswitch. 2. A ground fault trip device for a ground fault circuit breaker according to claim 1, wherein the tip of the leaf spring contacting the movable portion of the earth leakage trip electromagnet is covered with polytetrafluoroethylene, and the movable portion and the leaf spring are separated. An earth leakage trip device for an earth leakage breaker, characterized in that it prevents generation of metal powder due to rubbing with a tip portion and enables smooth movement. 3. The earth leakage trip device for earth leakage circuit breaker according to claim 1, wherein the leaf spring is bent from the fixing portion to the micro switch in a convex shape.
A second bent portion that is bent concavely at a predetermined distance from the bent portion in the direction of the tip, and is bent convexly at a predetermined distance away from the second bent portion in the direction of the tip. An electric leakage trip device for an earth leakage breaker, which has a third bent portion, and has a push-in portion for pushing the operation portion of the microswitch in a portion between the second and third bent portions.