JPH08180792A - Earth leakage breaker - Google Patents

Abstract

PURPOSE: To prevent electric parts, e.g. coils of an electromagnetic apparatus, thyristors, etc., which compose an earth leakage test circuit, from being burned and damaged by continuous electricity application by continuous pressing of a remote control earth leakage test switch at the time when an earth leakage test is carried out in the case an electric power source of an earth leakage breaker and a load are reversely connected. CONSTITUTION: In the case an earth leakage test is carried out by remote control, when a remote control earth leakage testing switch 13 connected in parallel to an earth leakage test switch 10 is turned on, an amplifier 5 detects the current flowing in a coil 12 for a test and turns a thyristor 6 on and an electromagnetic apparatus 7 is excited and an electric line contact point 8 is turned off. Even if the remote control earth leakage test switch 13 is continuously pressed while a burning and damaging preventive switch 14 being turned off, current does not flow in the coil 12 for a test and coils and a thyristor 6 of the electromagnet apparatus 7 are prevented from being burned and damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth leakage circuit breaker, and more particularly to preventing a trip coil or the like from being burnt out by pressing a remote earth leakage test switch when a power source and a load of the earth leakage circuit breaker are reversely connected.

[0002]

2. Description of the Related Art FIG. 12 shows, for example, JP-A-58-4239.
It is a figure which shows the circuit structure of the conventional earth leakage breaker shown by the publication. In the figure, the part indicated by the alternate long and short dash line is the earth leakage breaker,
1 is a power supply terminal for connecting a power supply, 2 is a load terminal for connecting a load, 3 is an electric circuit for connecting the power supply terminal 1 and the load terminal 2, 4
Is a zero-phase current transformer provided in the electric path 3, 5 is an amplifier that amplifies the secondary output of the zero-phase current transformer 4 and determines its level, 6 is a thyristor that switches according to the determination signal of the amplifier 5,
Reference numeral 7 is an electromagnet device controlled by the thyristor 6, and 8 is an electric path contact, and an armature of the electromagnet device 7 disconnects the power supply terminal 1 and the load terminal 2 via the opening / closing mechanism (not numbered).

Reference numeral 9 is an earth leakage test circuit, which is a zero-phase AC generator 4
Leakage test switch 10 that artificially flows a pseudo-unbalanced current by pressing the switch, a test resistor 11 that suppresses and adjusts the pseudo-unbalanced current that flows by a leakage test, a test winding 12, and a leakage test switch 10 are connected in parallel. It is composed of a remote earth leakage test switch 13 which causes an unbalanced current to flow from the outside of the earth leakage breaker to the zero-phase current transformer 4. Further, the earth leakage test switch 10 is interlocked with the electromagnet device 7 and opens simultaneously with the earth leakage interruption operation.

Next, the operation will be described. When the power source terminal 1 is connected to a power source and the load terminal 2 is connected to a load to make a positive connection and the earth leakage test switch 10 or the remote switch 13 of the earth leakage test circuit 9 is continuously closed, the zero-phase current transformer 4 The secondary output is amplified by the amplifier 5, the thyristor 6 is operated, and the armature of the electromagnet device 7 opens the electric path contact 8 and the electric leakage test switch 10 through the opening / closing mechanism portion. No equilibrium current flows.

When a load is connected to the power supply terminal 1 and a power supply is connected to the load terminal 2, that is, when a so-called reverse connection is made,
When the leakage test switch 10 of the leakage test circuit 9 is continuously closed, the secondary output of the zero-phase current transformer 4 is amplified by the amplifier 5, the thyristor 6 is operated, and the opening / closing mechanism section is operated by the amateur of the electromagnet device 7. Since the electric circuit contact 8 and the leakage test switch 10 are opened through the leakage test circuit 9,
Even if power is applied from the load terminal 2, no unbalanced current flows in the leakage test circuit 9.

However, in the case of the reverse connection in which the load is connected to the power supply terminal 1 and the power supply is connected to the load terminal 2, if the remote earth leakage test switch 13 is continuously closed, the secondary output of the zero-phase current transformer 4 will be generated. Is amplified by the amplifier 5, the thyristor 6 is operated, and the armature of the electromagnet device 7 opens the electric path contact 8 and the earth leakage test switch 10 through the opening / closing mechanism, but the remote earth leakage test switch 13 remains closed. Since there is a reverse connection, power is applied from the load terminal 2 to the leakage test circuit 9. Therefore, the unbalanced current continues to flow in the leakage test circuit 9.

[0007]

The conventional earth leakage breaker is constructed as described above, and since the remote earth leakage test switch 13 is installed at a place apart from the earth leakage breaker body, the remote earth leakage test switch 13 is depressed. Since it is not possible to confirm the leakage operation of the leakage breaker in the leakage test by, the remote leakage test switch 13 is often kept pressed. Therefore, in the case of reverse connection in which a load is connected to the power supply terminal 1 and a power supply is connected to the load terminal 2, if the remote earth leakage test switch 13 is kept closed, an unbalanced current due to the earth leakage test will continue to flow. The electromagnet device 7 remains in operation, and there is a problem that the coil of the electromagnet device 7 or an electric component such as the thyristor 6 burns out due to a current flowing therethrough.

The present invention has been made in order to solve the above-mentioned problems, and when the earth leakage test of the earth leakage breaker with the reverse connection is remotely operated, the remote earth leakage test switch 13 is closed. Even if it is continued, the purpose is to cut off the current to the electromagnet device 7 or the thyristor 6 of the earth leakage test circuit 9 to obtain an earth leakage breaker without damage.

[0009]

[Means for Solving the Problems]

(1) An earth leakage circuit breaker according to the present invention includes zero-phase current detecting means for detecting an earth leakage current in an electric circuit, and opening / closing means for opening the electric circuit in accordance with the zero-phase current detected by the zero-phase current detecting means. In an earth leakage circuit breaker having an earth leakage test circuit for inputting a test current to the zero-phase current detecting means when at least one switch of the earth leakage test switch and the remote earth leakage test switch is closed by being supplied with power from the electric path, A burnout prevention switch is provided which is connected in series to the earth leakage test switch and the remote earth leakage test switch and is opened / closed in accordance with the opening operation of the opening / closing means.

(2) Further, a zero-phase current transformer that detects a leakage current in an electric circuit, an electromagnet device that operates in accordance with the zero-phase current detected by the zero-phase current transformer, and an opening / closing operation of the electromagnet device. When the electric circuit contacts opened via the mechanism and at least one of the earth leakage test switch and the remote earth leakage test switch are closed by supplying power from the electric path, a test current is passed through the zero-phase current transformer. An earth leakage circuit breaker having an earth leakage test circuit is provided with a burnout prevention switch which is connected in series to the earth leakage test switch and the remote earth leakage test switch and is opened / closed in accordance with the operation of the electromagnet device or the opening / closing mechanism. .

(3) Further, a movable contact plate, which is made of an elastic conductive plate material and whose central portion is fixed and both ends thereof are integrally formed as a leakage test switch plate and a burnout prevention switch plate, respectively, faces the leakage test switch plate. The fixed contact of the earth leakage test switch provided with, the fixed contact of the burnout prevention switch provided facing the above burnout prevention switch plate, and move according to the operation of the opening / closing mechanism that turns the electric path contact on and off, A test-off lever for pressing the burnout prevention switch plate is provided, and the leakage test switch plate is normally separated from the fixed contact of the leakage test switch and is pressed and contacted during the test. It contacts the fixed contact of the burnout prevention switch, and is pressed through the test off lever according to the OFF operation of the opening / closing mechanism section to prevent the burnout. It is obtained as separates from the fixed contacts of the switch.

(4) The test-off lever is a test-off lever provided with a pressing portion for pressing the burnout prevention switch plate in the ON direction or in the OFF direction according to the ON / OFF operation of the opening / closing mechanism. The burnout prevention switch is turned on / off by the operation of the pressing portion.

(5) Further, a movable contact plate, which is made of an elastic conductive plate material and whose central portion is fixed and both ends thereof are integrally formed as a leakage test switch plate and a burnout prevention switch plate, respectively, faces the leakage test switch plate. The test-off in which the fixed contact of the earth leakage test switch provided on the above, the fixed contact of the burnout prevention switch provided facing the above burnout prevention switch plate, and the above fixed contact of the burnout prevention switch plate by pressing The lever and the armature of the electromagnet device are provided.The test-off lever is locked so that the burnout prevention switch is closed when the amateur is not operating, and the burnout prevention switch is opened when the amateur is operating. The test-off lever from the unlocked state and the locking means for releasing the lock of the test-off lever so that When the electromagnet device is in a non-excited state, the test-off lever is locked by the locking device to close the burnout prevention switch, and the electromagnet device is excited to operate the amateur. , The test-off lever is released from the locked state to open the burnout prevention switch, and when the electromagnet device is switched from the excited state to the non-excited state, the reset means can lock the test-off lever. It was done.

[0014]

[Action]

(1) In the earth leakage breaker of the present invention, even if the earth leakage breaker is reversely connected and the remote earth leakage test switch continues to be closed, the burnout prevention switch is opened according to the opening operation of the opening / closing means.

(2) Further, even if the earth leakage breaker is reversely connected and the remote earth leakage test switch continues to be closed, the burnout prevention switch is opened according to the operation of the electromagnet device or the opening / closing mechanism.

(3) Further, the test switch plate and the burnout prevention switch plate are integrally formed as a movable contact plate, and the earth leakage test switch plate is normally separated from the fixed contact of the earth leakage test switch and is pressed and contacted during the test. The burnout prevention switch plate normally contacts the fixed contact of the burnout prevention switch, and is pressed by the test off lever in accordance with the OFF operation of the opening / closing mechanism to be separated from the fixed contact of the burnout prevention switch.

(4) Also, the pressing portion of the test-off lever presses the burnout prevention switch plate in the ON direction or in the OFF direction to perform the ON / OFF operation of the burnout prevention switch.

(5) Further, the test switch plate and the burnout prevention switch plate are integrally formed as a movable contact plate, and when the electromagnet device is in the non-excited state, the test-off lever is locked by the locking means to close the burnout prevention switch. Then, when the electromagnet device is excited and the armature operates, the test-off lever is released from the locked state and the burnout prevention switch is opened, and when the electromagnet device is changed from the excited state to the non-excited state, the reset means is operated. Lock the test off lever.

[0019]

【Example】

Example 1. 1 and 2 are diagrams showing a circuit configuration of an earth leakage breaker according to the present invention. In the figure, 1 to 13 are the same as those described in the above conventional example. Reference numeral 14 is a burnout prevention switch. In the earth leakage test circuit 9, an earth leakage test switch 10 and a remote earth 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 interlocked with the opening / closing mechanism portion or the electromagnet device 7, and is normally in a closed state, but is configured to open the electrode at the same time as the leakage interruption operation.

The operation of the earth leakage breaker having the above configuration will be described. When the remote earth leakage test switch 13 is pressed 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 source terminal 1, a pseudo unbalanced current flows in the earth leakage test circuit 9 and the amplifier 5 The electric leakage interruption operation is performed via the electromagnet device 7. Due to this 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 electrical parts such as the thyristor 6 can be prevented from being burnt out.

A power supply is connected to the power supply terminal 1, and a load terminal 2 is connected.
In the normal connection with the load connected to, the electric circuit contact 8 is opened due to the earth leakage interruption operation, so that no voltage is applied to the earth leakage test circuit 9 and the burnout prevention switch 14 is also opened, which naturally damages the electric parts. There is no.

Example 2. 3 is a perspective view of a main part of a damage prevention switch according to a second embodiment of the present invention, FIG. 4 is a cross-sectional view of a main part of the damage prevention switch in a closed state, and FIG. 5 is a main part 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,
The test switch plate 16a and the 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 its central portion 16c fixed to the wiring board 19, and has test switch plates 16a at both ends.
And a burnout prevention switch plate 16b are formed, and the test switch plate 16a is always urged to separate from the test switch fixed contact 17 to prevent the burnout prevention switch plate 16b.
Is urged to contact the fixed contact 18 of the burnout prevention switch.

Reference numeral 20 denotes a lead wire end from the remote earth leakage test switch 13, one of which is the connector 21 and the wiring board 1.
9 is connected to the central portion 16c of the movable contact plate 16 via 9,
The other is connected to the test winding 12 shown in FIG. The central portion 16c of the movable contact plate 16 has an earth leakage test switch 1
0, remote leakage test switch 13, and burnout prevention switch 1
4 common electrical connections.

Reference numeral 22 is an earth leakage display button, and 23 is an electric circuit contact 8.
It is a crossbar attached to the movable side contact of
When the electric path contact 8 is turned on and off by the opening / closing mechanism, the electric path contact 8 rotates as shown by an arrow A. A test-off lever 24 is provided between the arm portion 23a of the crossbar 23 and the burnout prevention switch plate 16b so as to be vertically movable.

As for the positional relationship, when the electric circuit contact 8 is in the ON state, the test-off lever 24 separates from the burnout prevention switch plate 16b, and the burnout prevention switch plate 16b and the burnout prevention switch fixed contact 18 come into contact with each other. Arm 2
The test-off lever 24 is pushed up by 3a to push up the burnout prevention switch plate 16b, and the contact conduction between the burnout prevention switch plate 16b and the burnout prevention switch fixed contact 18 is cut off.

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

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

The operating handle is provided in the opening / closing mechanism, and when operated in a state where the electromagnet device 7 is not excited, the crossbar 23 of the opening / closing mechanism rotates to turn on / off the electric path contact 8. After the electromagnet device 7 operates, the opening / closing mechanism is reset by the operation handle to turn on the electric path contact 8.

As described above, even if the earth leakage breaker is in the reverse connection state and the earth leakage test switch 10 or the burnout prevention switch 14 is continuously pressed, the earth leakage test circuit 9 is connected to the electromagnet device 7 or the thyristor 6. Energization is blocked. Since the opening / closing mechanism for resetting the earth leakage breaker to turn on the electric circuit contact 8 again turns the crossbar 23 in the ON direction of the electric circuit contact 8, the test-off lever 24 is pushed down by the elastic biasing force of the burnout prevention switch plate 16b. The
The burnout prevention switch 14 is closed.

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

Example 3. 6 is a perspective view of a main part of a burnout prevention switch unit according to a third embodiment 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. 8 is a main part showing an open state of the burnout prevention switch. FIG. 9 is a cross-sectional view, and FIG. 9 is a main-portion cross-sectional view showing an open state of the burnout prevention switch whose cross-sectional direction is changed.

In the figure, 10, 13, 15-18, 2
3 to 25 are the same as those described in the second embodiment. In the third embodiment, the burnout prevention switch plate 16b is urged in a direction to be always separated from the burnout prevention switch fixed contact 18. Reference numeral 23b denotes an engagement hole provided on the side surface of the arm portion 23a of the crossbar 23, and the test-off lever 24
The engagement protrusion 24c is engaged in the hole, and the cross-bar 23 is turned on and off to forcibly move the test-off lever 24 up and down.

Reference numerals 24a and 24b denote push arms which are provided in parallel on the upper portion of the test-off lever 24, and a burnout prevention switch plate 16b is inserted between the push arms. Therefore, since the burnout prevention switch plate 16b is closed and opened with the fixed contact 18 of the burnout prevention switch in conjunction with the turning on and off of the crossbar 23, the elastic force of the burnout prevention switch plate 16b is controlled by the number of times of opening and closing. Even if it becomes weaker due to the increase, the contact can be closed and opened surely, and the reliability of the burnout prevention switch 13 is improved.

In this embodiment, the push arms 24a and 24b are formed in parallel with each other, but the burnout prevention switch plate 16b is provided.
May be a square-shaped hole into which is inserted, or a square-shaped hole into which only the tip of the burnout prevention switch plate 16b is inserted and which does not penetrate. That is, the test-off lever 2
The burnout prevention switch plate 16b may be configured to be pressed up and down when the 4 moves up and down.

Example 4. 10 is a sectional view of a main portion of a burnout prevention switch unit in an open state according to Embodiment 4 of the present invention, and FIG. 11 is a sectional view of a main portion of the burnout prevention switch in a closed state. In the figure, reference numerals 13, 15 to 19 and 22 are the same as those described in the third embodiment. 7 is an electromagnet device, 7
a is a coil of the electromagnet device 7, 26 is an amateur,
It is biased in the direction opposite to 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. 27 is a display button 2
2 is a test-off lever formed integrally with 2. 27a
Is a push arm, 27b is a stopper that comes into contact with the sliding protrusion 26b, 27c is a reset arm provided on the test-off lever 27, and 28 is a reset lever. The burnout prevention switch 13 is provided with a push arm 27a to prevent the burnout prevention switch plate 16b.
Is in contact with the fixed contact 18 of the burnout prevention switch.

Next, the operation will be described. With the burnout prevention switch of FIG. 10 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 depressing the earth leakage test switch 10 or by earth leakage interruption operation. This action causes the hook 26c
The trip bar of the opening / closing mechanism (not shown), which is hooked on, is pulled to open the electric path contact 8 of FIG. 2 via the opening / closing mechanism. At the same time, the stopper 27b comes out of contact with the sliding projection 26b, and the test-off lever 27 is damaged by the burnout prevention switch plate 1.
The urging force of 6b causes the display button 22 to move in the direction of the arrow B, and the burnout prevention switch 13 of FIG.

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 where the burnout prevention switch 13 of FIG. 11 is opened, the tip of the reset lever 28 moves the reset arm 27c. Push down. As a result, the test-off lever 27 moves in the direction of the arrow B, and the protrusion of the display button 22 is returned to its original state, 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 becomes the sliding protrusion 26.
The stopper 27b is pulled down from the
It is lowered from the contact surface of b and moves in the direction of arrow D by the urging force of the amateur 26. When the pressing force of the reset lever 28 disappears, the sliding protrusion 26b contacts the stopper 27b and the burnout prevention switch 13 is maintained in the closed state.

In the second and third embodiments, the burnout prevention switch 13 is opened / closed every time the leak is cut off and the operating handle is manually turned on / off.
Although 6b may be broken due to fatigue, in the configuration of the fourth embodiment, the burnout prevention switch 13 opens and closes only when the earth leakage test switch is pressed or the earth leakage cutoff operation is performed. The life of the plate 16 can be extended. Also, the test-off lever 27
Since the display button 22 and the display button 22 are integrally formed, a special projecting device for the display button 22 can be eliminated.

Example 5. In the above embodiment, the zero-phase current transformer is used to detect the zero-phase current, but other zero-phase current detecting means may be used. For example, a line current is detected by a current detector using a current transformer or a hall element, a zero-phase current is calculated by using this detected current by a microprocessor, and an electromagnet device is operated according to the calculation result. You may make it operate.

In the leakage test in this case, an unbalanced excess current is made to flow and detected by the operation of the leakage test switch, or a pseudo test signal input is applied to the microprocessor by the operation of the leakage test switch. hand,
The operation of circuits after the microprocessor may be tested.

Example 6. Although the burnout prevention switch 14 is turned on / off in accordance with the operation of the electromagnet device or the opening / closing mechanism in the above-mentioned Embodiments 2 to 4, since this contact may have a small current capacity, the output of the amplifier 5 shown in FIGS. It is also possible to provide another relay that operates in accordance with 1. and use the contact of the dust relay as the contact 14 of the burnout prevention switch.

Further, another relay (which may have a small ampere turn) which operates by using the output of the thyristor 6 is connected in parallel or in series with the coil of the electromagnet device, and the contact of the dust relay is used as the contact 14 of the burnout prevention switch. Good. That is, the amplifier 5, the thyristor 6, the electromagnet device 7, which forms the opening / closing means, the opening / closing mechanism (not shown), and the electric path contact 8
The burnout prevention switch 14 may be operated according to any one of the above operations.

[0046]

Since the present invention is configured as described above, it has the following effects.

(1) When remotely operating the earth leakage test of the earth leakage breaker with the reverse connection, even if the remote earth leakage test switch is continuously pressed, the earth leakage test switch and the earth leakage test circuit are connected in series. Since the burnout prevention switch is opened according to the opening operation of the opening / closing means, the burnout of the circuit components is prevented.

(2) Further, even if the remote earth leakage test switch for remotely operating the earth leakage tester of the earth leakage breaker with the reverse connection is kept pressed, the remote earth leakage test switch and the earth leakage test circuit are connected in series. Since the burnout prevention switch is opened according to the operation of the electromagnet device or the opening / closing mechanism, the circuit components are prevented from being burnt out.

(3) Further, since the test switch plate and the burnout prevention switch plate are integrally formed as the movable contact plate, the number of constituent parts of the switch is reduced.

(4) Further, since the test-off lever is provided with a pressing portion for pressing the burnout prevention switch plate in the ON direction or the OFF direction, the burnout prevention switch plate is operated by this pressing portion. The burnout prevention switch can be opened and closed without being affected by the elastic fatigue of the burnout prevention switch plate.

(5) Further, since the test-off lever is moved by the operation of the amateur of the electromagnet device to open the burnout prevention switch, the operation of the burnout prevention switch is performed when the leakage test switch is pressed or the leakage cutoff operation is performed. Only by reducing the frequency of opening and closing the burnout prevention switch plate, its life is extended.

[Brief description of drawings]

FIG. 1 is a diagram showing a circuit configuration of an earth leakage breaker according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a circuit configuration of an earth leakage breaker according to Embodiment 1 of the present invention.

FIG. 3 is a perspective view of a main part of a burnout prevention switch unit according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of an essential part of a burnout prevention switch according to a second embodiment of the present invention in a closed state.

FIG. 5 is a sectional view of relevant parts showing an open state of a burnout prevention switch according to a second embodiment of the present invention.

FIG. 6 is a perspective view of a main part of a burnout prevention unit according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of a main part of a burnout prevention switch according to a third embodiment of the present invention in a closed state.

FIG. 8 is a sectional view of a key portion showing an open state of a burnout prevention switch according to a third embodiment of the present invention.

FIG. 9 is a cross-sectional view of essential parts showing an open state of a burnout prevention switch with a changed cross-sectional direction according to a third embodiment of the present invention.

FIG. 10 is a cross-sectional view of essential parts of a burnout prevention switch according to a fourth embodiment of the present invention in a closed state.

FIG. 11 is a cross-sectional view of a main part of a burnout prevention switch according to a fourth embodiment of the present invention in an open state.

FIG. 12 is a diagram showing a circuit configuration of a conventional earth leakage breaker.

[Explanation of symbols]

1 power supply terminal, 2 load terminal, 3 electric circuit, 4 zero-phase current transformer, 5 amplifier, 7 magnet device, 7a coil, 8 electric circuit 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, 1
6 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, 2
2 leakage indicator 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 (5)

[Claims] 1. A zero-phase current detecting means for detecting a leakage current of an electric path, an opening / closing means for opening the electric path according to a zero-phase current detected by the zero-phase current detecting means, and a power supply from the electric path. An earth leakage circuit breaker having an earth leakage test circuit for inputting a test current to the zero-phase current detecting means when at least one of the earth leakage test switch and the remote earth leakage test switch is closed. An earth leakage circuit breaker comprising a burnout prevention switch connected in series to a test switch and opened / closed in accordance with an opening operation of the opening / closing means. 2. A zero-phase current transformer that detects a leakage current in an electric circuit, an electromagnet device that operates according to a zero-phase current detected by the zero-phase current transformer, and an operation of the electromagnet device through an opening / closing mechanism. Circuit, which is opened and closed, and a circuit for supplying a test current to the zero-phase current transformer when at least one of the earth leakage test switch and the remote earth leakage test switch is closed when power is supplied from the above electricity path. And a burnout prevention switch that is connected in series to the earth leakage test switch and the remote earth leakage test switch and is opened / closed according to the operation of the electromagnet device or the opening / closing mechanism. Circuit breaker. 3. The movable contact plate made of an elastic conductive plate material, the central portion of which is fixed, and both end portions of which are integrally formed as a leakage test switch plate and a burnout prevention switch plate, and the leakage test switch plate according to claim 2. The fixed contact of the earth leakage test switch provided opposite to the fixed contact, the fixed contact of the burnout prevention switch provided opposite to the above-mentioned burnout prevention switch plate, and the movement depending on the operation of the opening / closing mechanism that turns the electric path contact on and off However, it is equipped with a test-off lever that presses the burnout prevention switch plate.The leakage test switch plate is normally separated from the fixed contact of the leakage test switch, and is pressed and contacted during the test. At the time, the fixed contact of the burnout prevention switch is contacted, and is pressed through the test off lever according to the off operation of the opening / closing mechanism section, and the burnout is performed. An earth leakage breaker characterized by being opened from a fixed contact of the loss prevention switch. 4. The test-off lever according to claim 3, wherein the test-off lever is provided with a pressing portion for pressing the burnout prevention switch plate in an ON direction or an OFF direction in accordance with an ON / OFF operation of the opening / closing mechanism section. An earth leakage circuit breaker, which is a lever, and a burnout prevention switch is turned on / off by the operation of the pressing portion. 5. The movable contact plate made of an elastic conductive plate material, the central portion of which is fixed, and both end portions of which are integrally formed as an earth leakage test switch plate and a burnout prevention switch plate, respectively, and the earth leakage test switch plate. The fixed contact of the earth leakage test switch provided facing each other, the fixed contact of the burnout prevention switch installed opposite to the burnout prevention switch plate, and the fixed contact of the burnout prevention switch plate pressed against each other The test-off lever is provided on the armature of the electromagnet device, and the test-off lever is locked so that the burnout prevention switch is in a closed state when the amateur is not operating, and the burnout prevention switch is operated when the amateur is operating. The locking means for releasing the lock of the test-off lever and the test-off lever are unlocked so that the test-off lever is unlocked. When the electromagnet device is in a non-excited state, the test-off lever is locked by the locking device to close the burnout prevention switch, and the electromagnet device is excited and the armature is excited. Is operated, the test-off lever is released from the locked state and the burnout prevention switch is opened, and when the electromagnet device is changed from the excited state to the non-excited state, the reset means locks the test-off lever. An earth leakage circuit breaker, which is characterized in that