JP4013959B2 - Earth leakage breaker - Google Patents

Description

  The present invention relates to an earth leakage breaker, and in particular, to prevent burning of a trip coil or the like due to pressing of a remote earth leakage test switch when a power source and a load of the earth leakage breaker are reversely connected.

  Connect the power supply to the power supply terminal, connect the load to the load terminal, connect the load to the load terminal, and continue to close the leakage test switch of the leakage test circuit, the secondary output of the zero-phase current transformer is amplified by the amplifier. Since the thyristor is operated and the electric circuit contacts and the leakage test switch are opened through the switching mechanism by the armature of the electromagnet device, no unbalanced current flows in the leakage test circuit.

  In addition, when a load is connected to the power supply terminal and a power supply is connected to the load terminal, so-called reverse connection, if the leakage test switch of the leakage test circuit is kept closed, the secondary output of the zero-phase current transformer is output. Amplifying with an amplifier, operating the thyristor, and opening the circuit contact and the leakage test switch through the switching mechanism by the armature of the electromagnet device, even if power is applied to the leakage test circuit from the load terminal, There is no unbalanced current in the leakage test circuit.

JP 58-4239 A (second page, lower right column, line 11 to page 3, upper left column, line 7)

  Since the conventional earth leakage breaker is configured as described above, in the case of providing a remote earth leakage test switch that is connected in parallel with the earth leakage test switch and flows an unbalanced current from the outside of the earth leakage breaker to the zero-phase current transformer, In the case of reverse connection in which a load is connected to the power supply terminal and a power supply is connected to the load terminal, if the remote leakage test switch is kept closed, the secondary output of the zero-phase current transformer is amplified by an amplifier and the thyristor is turned on. The circuit contacts and leakage test switch are opened through the switching mechanism by the armature of the electromagnetic device, but the remote leakage test switch remains closed, and the leakage test circuit has a load terminal for reverse connection. Power is applied from For this reason, an unbalanced current continues to flow in the leakage test circuit.

  In general, the remote earth leakage test switch is installed in a location away from the main body of the earth leakage breaker. Therefore, since the earth leakage operation of the earth leakage breaker in the earth leakage test by pressing the remote earth leakage test switch cannot be confirmed, the remote earth leakage test switch is kept pressed. There is often. Therefore, in the case of reverse connection in which a load is connected to the power supply terminal and the power supply is connected to the load terminal, if the remote leakage test switch is kept closed, an unbalanced current due to the leakage test will continue to flow, so the thyristor and the electromagnetic device will operate. As a result, there is a problem that the coil of the electromagnet device or an electric component such as a thyristor is burned by a current flowing therethrough.

  The present invention has been made to solve the above-described problems. When the leakage test of the leakage breaker in reverse connection is operated remotely, the remote leakage test switch may be kept closed. An object of the present invention is to cut off the current to the electromagnet device or thyristor of the earth leakage test circuit and obtain an earth leakage breaker without damage.

  An earth leakage breaker according to the present invention is opened via an open / close mechanism by an electromagnet device that operates according to a zero-phase current detected by a zero-phase current transformer that detects a leakage current of an electric circuit. A leakage test circuit for supplying a test current to the zero-phase current transformer when power is supplied from the circuit and at least one of the leakage test switch and the remote leakage test switch is closed; and the leakage An earth leakage circuit breaker having a burnout prevention switch connected in series to the test switch and the remote earth leakage test switch and opened and closed according to the operation of the switching mechanism, wherein the earth leakage test switch and the burnout prevention switch are elastic conductive plate materials The center part is fixed, and both ends are movable contacts that are integrally formed as an earth leakage test switch board and a burnout prevention switch board. And an earth leakage test switch fixed contact provided opposite to the earth leakage test switch plate, and a burnout prevention switch fixed contact provided opposite to the burnout prevention switch plate, and the remote earth leakage test switch A pair of lead wires that are electrically connected to the movable contact plate and the earth leakage test switch fixed contact, and a test-off lever that moves as the switching mechanism is turned off presses the burnout prevention switch plate. By doing so, the burnout prevention switch plate and the burnout prevention switch fixed contact which are normally closed are separated.

  When operating the earth leakage test of the earth leakage breaker in reverse connection remotely, even if the remote earth leakage test switch is kept pressed, the burnout prevention switch connected in series to the earth leakage test switch and earth leakage test circuit Since the opening and closing means are opened according to the opening operation, the circuit components are prevented from being burned out.

Embodiment 1 FIG.
1 and 2 are diagrams showing a circuit configuration of an earth leakage circuit breaker according to the present invention. In the figure, a one-dot chain line is an earth leakage breaker, 1 is a power terminal for connecting a power source, 2 is a load terminal for connecting a load, 3 is an electric circuit for connecting the power terminal 1 and the load terminal 2, and 4 is an electric circuit 3 The provided zero-phase current transformer 5 is an amplifier that amplifies the secondary output of the zero-phase current transformer 4 and discriminates its level, 6 is a thyristor that is switched by the discrimination signal of the amplifier 5, and 7 is controlled by the thyristor 6. An electromagnet device 8 is an electric circuit contact, and the armature of the electromagnet device 7 cuts off the power supply terminal 1 and the load terminal 2 via an opening / closing mechanism unit (not shown).

  Reference numeral 9 denotes an earth leakage test circuit, an earth leakage test switch 10 for artificially passing a pseudo unbalanced current by pressing the switch to the zero-phase current transformer 4, and a test resistor 11 for suppressing and adjusting the pseudo unbalanced current flowing by the earth leakage test. The test coil 12 and the earth leakage test switch 10 are connected in parallel to each other, and are composed of a remote earth leakage test switch 13 for flowing an unbalanced current from the outside of the earth leakage breaker to the zero-phase current transformer 4. The earth leakage test switch 10 is interlocked with the electromagnet device 7 and opens simultaneously with the earth leakage interrupting operation.

  Reference numeral 14 denotes a burnout prevention switch. In the leakage test circuit 9, a leakage test switch 10 and a remote leakage test switch 13 are connected in parallel, and a burnout prevention switch 14 is connected in series thereto. The burnout prevention switch 14 is linked to the opening / closing mechanism section or the electromagnet device 7 and is normally in a closed state, but is configured to open at the same time as the opening operation of the electric circuit contact 8 or the leakage interrupting operation.

  The operation of the ground fault circuit breaker having the above configuration will be described. In a so-called reverse connection state in which a power source is connected to the load terminal 2 and a load is connected to the power terminal 1, when the remote leakage test switch 13 is pressed, a pseudo unbalanced current flows through the leakage test circuit 9, and the amplifier 5 The leakage current is cut off via the electromagnet device 7. By this earth leakage interruption operation, the burnout prevention switch 14 is opened and the pseudo-unbalanced current is interrupted, so that the coil of the electromagnet device 7 or the electric parts such as the thyristor 6 can be prevented from being burned out.

  In a normal connection in which a power source is connected to the power terminal 1 and a load is connected to the load terminal 2, the circuit contact 8 is disconnected by the leakage interrupting operation, so that no voltage is applied to the leakage test circuit 9, and the burnout prevention switch 14 Of course, there is no damage to the electrical components.

Embodiment 2. FIG.
3 is a perspective view of a main part of a burnout prevention switch according to a second embodiment of the present invention, FIG. 4 is a cross-sectional view of a main part of the burnout prevention switch in a closed state, and FIG. 5 is a diagram showing an open state of the burnout prevention switch. FIG. In the figure, 10, 13, and 14 are the same as those described in the first embodiment.

  15 is a test button, 16 is a movable contact plate made of an elastic conductive plate material, and a test switch plate 16a and a burnout prevention switch plate 16b are integrally provided. Reference numeral 17 is a test switch fixed contact, 18 is a burnout prevention switch fixed contact, and 19 is a wiring board. The movable contact plate 16 has a central portion 16c fixed to the wiring board 19, and a test switch plate 16a and a burnout prevention switch plate 16b are formed at both ends. The test switch plate 16a is always connected to the test switch fixed contact 17. Is urged to open, and the burnout prevention switch plate 16b is urged to contact the burnout prevention switch fixed contact 18.

  Reference numeral 20 denotes a lead wire end from the remote earth leakage test switch 13. One is connected to the central portion 16 c of the movable contact plate 16 through the connector 21 and the wiring board 19, and the other is connected to the test winding 12 shown in FIG. 1. It is connected. The central portion 16 c of the movable contact plate 16 serves as a common electrical connection for the leakage test switch 10, the remote leakage test switch 13, and the burnout prevention switch 14.

  22 is a leakage indicator button, and 23 is a cross bar attached to the movable contact of the electric circuit contact 8, which rotates as indicated by an arrow A when the electric circuit contact 8 is turned on and off by an opening / closing mechanism. A test off lever 24 is provided between the arm portion 23a of the cross bar 23 and the burnout prevention switch plate 16b so as to be movable up and down.

  When the electric circuit contact 8 is in the on state, the test off lever 24 is separated from the burnout prevention switch plate 16b, the burnout prevention switch plate 16b and the burnout prevention switch fixing contact 18 are in contact, and when the electric circuit contact 8 is in the off state, the arm portion 23a. As a result, the test-off lever 24 is pushed up, the burnout prevention switch plate 16b is pushed up, and the contact conduction between the burnout prevention switch plate 16b and the burnout prevention switch fixed contact 18 is cut off.

  The test button 15, the test switch plate 16 a, and the test switch fixed contact 17 constitute the earth leakage test switch 10, and the burnout prevention switch plate 16 b, the burnout prevention switch fixed contact 18, and the test off lever 24 constitute the burnout prevention switch 14. is doing. A base 25 supports the wiring board 19 and constitutes a guide rail for the test-off lever 24.

  Next, the operation will be described. The open / close mechanism is operated to rotate the crossbar 23 by turning off the operation handle (not shown) of the earth leakage breaker by manual operation, detecting earth leakage, or operating the earth leakage test switch 10 and the remote earth leakage test switch 13 by operating a pseudo earth leakage. The electric circuit contact 8 is opened. At this time, the arm portion 23 a of the cross bar 23 pushes up the burnout prevention switch plate 16 b via the test-off lever 24 and opens the burnout prevention switch 14.

  The operation handle is provided in the opening / closing mechanism, and when the electromagnet device 7 is operated without being excited, the crossbar 23 of the opening / closing mechanism rotates to turn the electric circuit contact 8 on and off. After the electromagnet device 7 operates, the opening / closing mechanism is reset with the operation handle to turn on the electric circuit contact 8.

  As described above, even when the earth leakage breaker is in the reverse connection state and the earth leakage test switch 10 or the remote earth leakage test switch 13 is continuously pressed, the electromagnet device 7 or the thyristor 6 of the earth leakage test circuit 9 is energized. Be blocked. An open / close mechanism that resets the earth leakage circuit breaker to turn on the electric circuit contact 8 again rotates the crossbar 23 in the ON direction of the electric circuit contact 8, so that the test-off lever 24 is pushed down by the elastic biasing force of the burnout prevention switch plate 16b. Thus, the burnout prevention switch 14 is closed.

  Further, the test switch plate 16a and the burnout prevention switch plate 16b are integrally formed on the movable contact plate 16, and the central portion 16c is a common electrical connection of the earth leakage test switch 10, the remote earth leakage test switch 13, and the burnout prevention switch 14. Therefore, the number of switch components can be reduced.

Embodiment 3 FIG.
FIG. 6 is a perspective view of a main part of a burnout prevention switch according to Embodiment 3 of the present invention, FIG. 7 is a cross-sectional view of a main part of the burnout prevention switch in a closed state, and FIG. FIG. 9 is a fragmentary cross-sectional view, and FIG. 9 is a fragmentary cross-sectional view showing the open state of the burnout prevention switch with the cross-sectional direction changed. In the figure, numerals 10, 14 to 19, and 22 to 25 are the same as those described in the second embodiment.

  In the third embodiment, the burnout prevention switch plate 16b is biased in a direction in which the burnout prevention switch fixed contact 18 is always in contact. Reference numeral 23b denotes an engagement hole provided on the side surface of the arm portion 23a of the crossbar 23. By engaging the engagement protrusion 24c of the test-off lever 24 in the hole and turning the crossbar 23 on and off, the test is performed. The off lever 24 is forcibly moved up and down.

  Reference numerals 24a and 24b denote push arms protruding in parallel with the upper portion of the test-off lever 24, and a burnout prevention switch plate 16b is inserted between the push arms. Accordingly, the burnout prevention switch plate 16b is closed and opened with the burnout prevention switch fixed contact 18 in conjunction with the turning on and off of the crossbar 23, so that the elastic force of the burnout prevention switch plate 16b is the number of times of opening and closing. Even if it becomes weaker due to the increase, it can be surely closed and opened, and the reliability of the burnout prevention switch 14 is improved.

  In the third embodiment, the push arms 24a and 24b are formed in a projecting manner in parallel. However, the push-arms 24a and 24b may be formed in a square-shaped hole into which the burnout prevention switch plate 16b is inserted. It is good also as a hole which does not penetrate by the square shape where only is inserted. That is, the burnout prevention switch plate 16b may be configured to be pressed up and down when the test-off lever 24 moves up and down.

  As described above, the test-off lever 24 is provided with a pressing portion for pressing the burnout prevention switch plate 16b in the ON direction or pressing in the OFF direction, and the operation of the burnout prevention switch plate 16b is performed by this pressing portion. The burnout prevention switch 14 can be reliably opened and closed without being affected by the elastic fatigue of the burnout prevention switch plate 16b.

  Further, in the case of remotely operating the leakage test of the leakage circuit breaker in reverse connection including the second embodiment, even if the remote leakage test switch 13 is kept pressed, the remote leakage test switch 13 and the leakage test circuit 9 Since the burnout prevention switch 14 connected in series to the switch is opened in accordance with the opening operation of the opening / closing means, the circuit component is prevented from being burned, and in either case of normal connection or reverse connection, When the electric circuit contact 8 is in an off state other than the earth leakage breaking operation and the pseudo earth leakage breaking operation, the earth leakage display button 22 does not protrude even if the pseudo earth leakage breaking operation is performed, so that the performance of the earth leakage breaker depends on the connection state. Can be unified.

Embodiment 4 FIG.
FIG. 10 is a cross-sectional view of the main part of the burnout prevention switch according to Embodiment 4 of the present invention in the closed state, and FIG. 11 is a cross-sectional view of the main part of the burnout prevention switch in the open state. In the figure, reference numerals 14 to 16, 18, 19, and 22 are the same as those described in the third embodiment. 7 is an electromagnet device, 7a is a coil of the electromagnet device 7, and 26 is an amateur, and is biased in the direction opposite to the arrow C by a spring (not shown).

  26a is an iron core of the amateur 26, 26b is a sliding protrusion, and 26c is a hook. Reference numeral 27 denotes a test off lever formed integrally with the electric leakage display button 22. Reference numeral 27a denotes a push arm, 27b denotes a stopper that contacts the sliding protrusion 26b, 27c denotes a reset arm provided on the test-off lever 27, and 28 denotes a reset lever. In the burnout prevention switch 14, the burnout prevention switch plate 16b is in contact with the burnout prevention switch fixed contact 18 by the push arm 27a.

  Next, the operation will be described. When the burnout prevention switch of FIG. 10 is closed, the armature 26 is attracted and moved in the direction of arrow C by energizing the coil 7a of the electromagnet device 7 by pressing the leakage test switch 10 or by interrupting the leakage. By this operation, a trip bar of an opening / closing mechanism (not shown) that is hooked on the hook 26c is pulled, and the electric circuit contact 8 of FIG. 2 is opened through the opening / closing mechanism. At the same time, the contact of the stopper 27b with the sliding projection 26b is released, and the test-off lever 27 is moved in the direction of arrow B with the electric leakage display button 22 by the urging force of the burnout prevention switch plate 16b. 14 is opened.

  When the reset lever 28 is rotated in the direction of arrow E by the reset operation of the operation handle connected to the opening / closing mechanism from the state in which the burnout prevention switch 14 of FIG. 11 is open, the tip of the reset lever 28 pushes down the reset arm 27c. As a result, the test-off lever 27 moves in the direction of the arrow B, and the protrusion of the electric leakage display button 22 is restored, and the push arm 27a brings the burnout prevention switch plate 16b into contact with the burnout prevention switch fixed contact 18.

  At this time, the stopper 27b is pulled down from the sliding projection 26b, and the stopper 27b is moved down from the contact surface of the sliding projection 26b and moves in the direction of arrow D by the biasing force of the armature 26. When the pressing force of the reset lever 28 disappears, the sliding projection 26b comes into contact with the stopper 27b and the burnout prevention switch 14 is maintained in a closed state.

  In the second and third embodiments, since the burnout prevention switch 14 is opened and closed every time the on / off operation is performed by the earth leakage interrupting operation and the manual operation of the operation handle, the burnout prevention switch plate 16b may break down due to fatigue. In the configuration of the fourth embodiment, since the burnout prevention switch 14 opens and closes only when the earth leakage test switch is pressed or the earth leakage interruption operation is performed, the frequency of opening and closing is reduced, and the life of the burnout prevention switch plate 16b can be extended. In addition, since the test-off lever 27 and the earth leakage display button 22 are integrally formed, a special protruding device for the earth leakage display button 22 can be dispensed with.

Embodiment 5 FIG.
In each of the above embodiments, the zero-phase current transformer is used for detecting the zero-phase current, but other zero-phase current detecting means may be used. For example, the current of a route is detected with a current transformer using a current transformer or a Hall element, and a zero-phase current is calculated using the detected current using a microprocessor, and an electromagnet device is installed according to the calculation result. You may make it operate | move.

  In this case, the leakage test is performed by detecting and testing an unbalanced excess current caused by the operation of the leakage test switch, or by adding a pseudo test signal input to the microprocessor by the operation of the leakage test switch. You may test the operation | movement of the circuit after a processor.

Embodiment 6 FIG.
In the second to fourth embodiments, the burnout prevention switch 14 is turned on / off according to the operation of the electromagnet device or the opening / closing mechanism. However, since this contact may have a small current capacity, the amplifier 5 shown in FIGS. Another relay that operates by output may be provided, and the contact of this relay may be used as the burnout prevention switch 14.

  Further, another relay that operates using the output of the thyristor 6 (the ampere turn may be small) may be connected in parallel or in series with the coil of the electromagnet device, and the contact of this relay may be used as the burnout prevention switch 14. That is, the burnout prevention switch 14 may be operated in accordance with any of the operations of the amplifier 5, the thyristor 6, the electromagnet device 7, the switching mechanism (not shown), and the electric circuit contact 8 that form the switching means.

It is a figure which shows the circuit structure of the earth-leakage circuit breaker by Embodiment 1 of this invention. It is a figure which shows the circuit structure of the earth-leakage circuit breaker by Embodiment 1 of this invention. It is a principal part perspective view of the burning prevention switch part by Embodiment 2 of this invention. It is principal part sectional drawing of the closing state of the burnout prevention switch by Embodiment 2 of this invention. It is principal part sectional drawing which shows the opening state of the burnout prevention switch by Embodiment 2 of this invention. It is a principal part perspective view of the burning prevention switch part by Embodiment 3 of this invention. It is principal part sectional drawing of the closing state of the burning prevention switch by Embodiment 3 of this invention. It is principal part sectional drawing which shows the opening state of the burnout prevention switch by Embodiment 3 of this invention. It is principal part sectional drawing which shows the opening state of the burning prevention switch which changed the cross-sectional direction by Embodiment 3 of this invention. It is principal part sectional drawing of the closing state of the burnout prevention switch by Embodiment 4 of this invention. It is principal part sectional drawing of the opening state of the burning prevention switch by Embodiment 4 of this invention.

Explanation of symbols

1 power supply terminal, 2 load terminal, 3 electric circuit, 4 zero-phase current transformer, 5 amplifier,
7 Electromagnet device, 7a Coil, 8 Electrical contact, 9 Earth leakage test circuit,
10 earth leakage test switch, 12 test winding,
13 Remote earth leakage test switch, 14 Burnout prevention switch,
15 test button, 16 movable contact plate, 16a test switch plate,
16b Burnout prevention switch plate, 17 Test switch fixed contact,
18 burnout prevention switch fixed contact, 19 wiring board, 22 earth leakage display button,
23 Crossbar, 23a Arm, 24 Test-off lever,
25 base, 26 amateur, 26b sliding protrusion,
27 Test off lever, 27a Push arm, 28 Reset lever.

Claims (2)

An electromagnet device that operates in accordance with a zero-phase current detected by a zero-phase current transformer that detects a leakage current of an electric circuit;
An electric circuit contact that is separated through an opening / closing mechanism by the operation of the electromagnet device;
A leakage test circuit for supplying a test current to the zero-phase current transformer when power is supplied from the circuit and at least one of a leakage test switch and a remote leakage test switch is closed;
In the earth leakage circuit breaker provided with the burnout prevention switch connected in series to the earth leakage test switch and the remote earth leakage test switch and opened / closed according to the operation of the opening / closing mechanism,
The earth leakage test switch and the burnout prevention switch are made of an elastic conductive plate material, the center portion is fixed, and both ends are integrally formed as an earth leakage test switch plate and a burnout prevention switch plate, respectively, and the earth leakage test switch plate And a grounding test switch fixed contact provided opposite to the burnout prevention switch fixed contact provided opposite to the burnout prevention switch plate,
A pair of lead wires constituting the remote earth leakage test switch are electrically connected to the movable contact plate and the earth leakage test switch fixed contact, and a test off lever that moves in accordance with an off operation of the opening / closing mechanism is burned out. An earth leakage circuit breaker characterized in that the burnout prevention switch plate and the burnout prevention switch fixed contact, which are normally closed, are separated by pressing the prevention switch plate. In claim 1,
Two push arm portions are provided on the test-off lever, and a burnout prevention switch plate is inserted between the push arm portions, and the burnout prevention switch plate is closed and opened in a direction to be closed and opened. An earth leakage circuit breaker characterized in that the burnout prevention switch is opened and closed by pressing.

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