KR20150022628A - Earth leakage circuit breaker - Google Patents

Abstract

There is obtained an electric leakage circuit breaker provided with a test function capable of checking whether the electric leak detecting function is normal without interrupting the AC converter.
An electric leakage judgment part 5 connected to the secondary coil 3a of the video current transformer 3 inserted in the AC converter 1 to detect a leakage current flowing through the AC converter 1 and outputting a leakage detection signal, A trip circuit 8 for opening the open / close contact 2 inserted in the alternating current converter 1 by the output of the detection signal, a test circuit for supplying a test current to the test coil 12 of the video current transformer 3, A self-check test pulse generating circuit 15 for supplying a check test pulse signal to the test circuit and a test pulse discriminating section 17 for outputting a self-check test pulse signal, and the test pulse discriminating section 17 detects And the self-check abnormality display device 22 for displaying the test result without operating the trip mechanism 8 as described above is provided.

Description

{EARTH LEAKAGE CIRCUIT BREAKER}

TECHNICAL FIELD The present invention relates to an earth leakage circuit breaker that cuts off an electric path when a short circuit or a ground fault occurs in an alternating current converter. In particular, the present invention relates to a circuit breaker for testing a short circuit by flowing a pseudo short- To a circuit breaker equipped with a test circuit.

Examples of the earth leakage breaker equipped with a conventional test apparatus include an earth leakage detection circuit for detecting a unbalance due to a leakage current of a line current or the like by an image (zero-phase) current transformer and outputting a trip signal for shutting off the line, And a remote test switch connected in parallel through the relay to the leakage test switch so as to allow the leakage test switch to artificially output a trip signal to the electric leak detecting circuit by making a state of a false state of the line, During the electrical leak test, a leakage current test is made by operating a leak test switch or a remote test switch to output a trip signal to the electrical leak detecting circuit to shut off the AC circuit, (See, for example, Patent Document 1).

Patent Document 1: Japanese Patent Application Laid-Open No. 8-106844 (page 2, Fig. 1)

In the earth leakage breaker equipped with the conventional test apparatus as in Patent Document 1, when the leakage test operation is performed, the AC circuit to which the earth leakage breaker is connected is blocked, so that the power supply to the load connected to the AC converter It stops temporarily. It is preferable to conduct the leakage test periodically, but there has been a problem that it is not possible to perform an inspection of the earth leakage breaker for a user who can not stop the power supply.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to obtain an earth leakage breaker equipped with a test function capable of checking whether or not an electric leakage detecting function is normal without interrupting an AC converter.

The leakage circuit breaker according to the present invention comprises a phase transformer inserted in an AC converter and an electric leakage detection means connected to a secondary coil wound around the phase converter to output a leakage detection signal when a leakage current flowing in the AC converter exceeds a predetermined level A trip circuit that opens and closes the open / close contact inserted in the alternating current converter by the output of the electrical leak detection signal, a test circuit for passing a test current through the test coil wound around the video current transformer, Test pulse generating means for supplying a test pulse signal for checking to a test circuit and test pulse detecting means for detecting a test pulse signal so that the self-check test pulse signal is outputted at the time of the self- If it is not detected, it is regarded as abnormal (abnormal), and the test result Is provided with a display means for display.

According to the earth leakage breaker of the present invention, in addition to a normal test circuit, there are provided test pulse generating means for supplying a test pulse signal for self-check which is not detected as an electrical leak detection signal to the test circuit, And the test pulse signal is outputted and is not detected by the test pulse detecting means, the display means for displaying the test result without operating the trip means is provided. Thus, the test coil and the test coil It is possible to easily check whether or not a part of the electrical leak detecting function such as the car coil is normal.

1 is a block diagram showing a configuration of an earth leakage breaker according to Embodiment 1 of the present invention.
Fig. 2 is a time chart showing the operation of each circuit of the earth leakage breaker of Fig. 1; Fig.
3 is a block diagram showing a configuration of an earth leakage breaker according to Embodiment 2 of the present invention.
Fig. 4 is a time chart showing the operation of each circuit of the earth leakage breaker of Fig. 3; Fig.

Embodiment 1

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

First, the entire configuration will be described. 1, an earth leakage breaker 100 includes an open / close contact 2 for opening and closing an alternating current converter 1, a video current transformer (ZCT) 3 inserted in the middle of the alternating current transformer 1, a video current transformer 3, An A / D converter 4 connected to the secondary coil 3a of the A / D converter 4 for converting an output signal of the A / D converter 4 into a digital value, A trip coil 7 which is energized through the switching means 6 by an output signal of the earth leakage discrimination section 5 and a trip coil 7 which is energized by the output signal of the earth leakage discrimination section 5, And a trip mechanism (8) for driving the open / close contact (2) in a glowing manner at the time of activation. That is, the earth leakage breaker 100 is provided with a blocking function and a leakage detection function.

The trip coil 7 and the trip mechanism 8 constitute tripping means.

The earth leakage breaker 100 further includes a test button 9 for testing a leak current function by a user and a test pulse generating circuit 10 for generating a drive signal for generating a test current when the test button 9 is turned on And switching means 13 which is driven by the test pulse generating circuit 10 and which supplies a test current adjusted to a predetermined current value to the test coil 12 through the resistor 11, A test circuit is constructed.

The electric leakage circuit breaker 100 includes a self-check test signal generator 14 for generating a signal for performing a self-check test operation, and an electric leak checker 5 A self-check test pulse generating circuit 15 which is a test pulse generating means for generating a drive signal having a pulse width that can not be detected by the self-check test pulse generating circuit 15, And a switching means (16) for flowing a self check test pulse current to the coil (12).

That is, in the present embodiment, a self-check test pulse generating circuit 15 is provided as a test pulse generating means for the self-check test, in addition to the test pulse generating circuit 10 that generates a pseudo leakage current to operate the tripping means.

It also has a test pulse discriminating section 17 as test pulse detecting means for detecting the self-check test pulse current based on the digital signal from the A / D converting section 4. [

A NOT circuit 18 for inverting the output signal of the test pulse discriminating section 17 and an AND circuit 19 for outputting the AND of the output signals of the NOT circuit 18 and the self- A switching means 20 which is driven by an output signal of the AND circuit 19 and a self-check abnormality display means 20 which is driven via a resistor 21 to display an abnormality when the switching means 20 is turned on, (22).

As a power supply circuit for supplying excitation current to the trip coil 7, a test current to be supplied to the test coil 12, and a DC power supply to an internal circuit such as the test pulse generating circuit 10, And an AC / DC power supply circuit 23.

Next, each operation of the earth leakage breaker 100 will be described with reference to the time chart of Fig.

First, the operation of the leakage current will be described.

When a short circuit occurs in the AC converter 1, the ZCT output signal D is outputted from the image transformer 3 and is input to the leakage current judgment section 5 through the A / D conversion section 4. The leakage current detection output signal E is outputted and the switching means 6 is driven so that the excitation current J is supplied to the trip coil 7. The excitation current J is supplied to the trip coil 7 through the trip mechanism 8, (2) drives.

At this time, in order to prevent unnecessary operation due to instantaneous surge or noise, the leakage detecting section 5 judges that only an input signal having a certain width is detected as a short circuit.

Next, the test operation will be described.

When the test button 9 is closed, the power source (point A voltage) is supplied to the test pulse generating circuit 10, and the test current C is supplied to the test coil 12 through the switching means 13. At this time, since the pulse width of the test current C caused by the drive signal generated by the test pulse generating circuit 10 is a duty ratio simulating a short circuit, The operation of the tripping circuit is discriminated in the same manner as the operation, and the leakage detection output signal E is outputted. As in the case of the occurrence of the leakage, the tripping means is driven and the leakage circuit breaker 100 trips.

Next, the self check test operation will be described.

If a signal is output from the self-check test signal generating source 14 and the self-check test pulse generating circuit 15 has the self-check test input B, the switching means 16 is driven so that the self- The test current C flows. Since the self-check test pulse at this time is a self-check test pulse signal of a narrow pulse that is less than the width detected by the electrical leak detecting section 5 as described in the previous section, The leakage current detection output signal E is not output.

The output signal from the self-check test signal generating source 14 is also input to the AND circuit 19.

On the other hand, the test pulse discriminating section 17 detects this self check test current and outputs a test pulse detection output signal G. Since the output signal G is inverted in the NOT circuit 18, the output to the switching means 20 is canceled by the AND circuit 19. Therefore, while the self-check test signal B is outputted, the output from the test pulse judging unit 17 is not outputted to the switching means 20. [ This is a normal self-check test operation.

In the self-check test operation, if there is an abnormality such as a break in the test coil 12 or the like and the test pulse judging unit 17 has failed to detect the self-check test current, Check abnormality output signal H is output by the NOT circuit 18 and the AND circuit 19 and the switching means 20 is driven so that the self-check abnormality display operation current K flows and the self-check abnormality display device 22 (for example, a light emitting diode or the like).

The test pulse detection output signal G is also outputted from the test pulse judging unit 17 in the case of the leakage current operation or the test operation which was described in the preceding paragraph. If the self-check test signal B is not outputted, the AND circuit 19 switches The output to the means 20 is canceled, so that the self-check abnormality display device 22 (for example, a light emitting diode or the like) does not operate.

The self-check abnormality display device 22 displays abnormality. However, when the self-check abnormality output signal H is not output in conjunction with the output information of the self-check test signal, May be displayed. That is, it may be made to function as display means for displaying the result of the self-check test.

The signal B outputted from the self-check test signal generating source 14 may be output based on a self-check test button (not shown) or a self-check test command from the outside, but may be generated automatically by a microcomputer or the like It is preferable to provide an automatic generation function for outputting the image data periodically.

The present invention is not limited to the A / D conversion unit 4, the leakage determination unit 5, the test pulse determination unit 17, the test pulse generation circuit 10, The pulse generating circuit 15, the self-check test signal generating source 14, the NOT circuit 18, and the AND circuit 19 may be configured as software by a microcomputer.

As described above, according to the earth leakage breaker of the first embodiment, when a leakage current is detected when the leakage current flowing through the AC converter is exceeded by being connected to a secondary side secondary winding wound around the secondary side transformer A test circuit for passing a test current through a test coil wound around the video current transformer; and a test circuit for detecting a current flowing through the test current flowing through the current transformer Test pulse generating means for supplying a self-check test pulse signal to a test circuit, and test pulse detecting means for detecting a test pulse signal, wherein during a self-check test, a self-check test pulse signal is outputted, It is judged that there is an abnormality, and the tester Hayeoteumeuro the display means to display the result, it is possible to easily check whether the part of the short-circuit detection function of, and test coils and the secondary coils without the top blocking AC converter.

Embodiment 2 Fig.

3 is a block diagram showing a configuration of an earth leakage breaker according to Embodiment 2 of the present invention. 4 is a time chart showing the operation of the earth leakage breaker shown in Fig.

In the first embodiment, since the self-check and the drive circuit (switching means 6, 20, etc.) of the electrical leak detecting (including the test operation) are divided, I could not check the above.

Thus, in the present embodiment, the drive circuit of the self-check and the electrical leak detecting (including the test operation) are made common so that anomalous check such as disconnection of the trip coil 7 can be performed also in the self-check.

The same components as those in Fig. 1 of the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted. In the following, mainly the differences will be mainly described.

3, the test pulse generating circuit 10 of the present embodiment also has the function of the self-check test pulse generating circuit 15 of the first embodiment. That is, this portion serves as a test pulse generating means for self-checking.

The switching means 6 for driving the trip coil 7 is driven by the leakage current judgment section 5 through the diode 31 and also by the test pulse judgment section 17 via the diode 32 . The anode of the diode 32 is connected to the connection point of the test pulse judging unit 17 and the NOT circuit 18. [ Switching means 33 driven by the electrical leak discrimination section 5 is connected between the connection point of the test pulse discrimination section 17 and the NOT circuit 18 and the ground.

Switching means 34 driven by an output signal of the NOT circuit 18 (which is closed) is connected between the switching means 6 and the trip coil 7. [

A resistor 35 is connected in parallel to the switching means 34. [ One end of the test operation display device 37 is connected to the connection point between the switching means 34 and the trip coil 7 via the resistor 36 and the other end of the test operation display device 37 is connected to the switching means 38 And is connected to the connection point of the switching means 34 and the switching means 6 through the switching means.

Next, the leakage operation of the earth leakage breaker 101 at the time of leakage and the test operation for performing the self-check will be described with reference to the time chart of Fig.

First, the operation of the leakage current will be described.

When a short circuit occurs in the alternating current converter 1, a detection signal is output from the image transformer 3, and when the short circuit is judged to be a short circuit by the leakage judging unit 5, the switching means 6 is activated. At this time, the test pulse detection output G is also outputted from the test pulse discrimination unit 17. However, since the switching unit 33 is activated by the output E of the leakage current judgment unit 5, the test circuit 18 outputs the test operation signal H Is not inputted, and the switching means 34 is closed. Thus, the excitation current J is supplied to the trip coil 7 through the switching means 34 by the activation of the switching means 6 and the opening / closing contact 2 is driven by the trip mechanism 8 through the trip mechanism 8.

At this time, the switching means 38 is not activated because the switching means 34 is closed, and the test operation display device 37 does not operate because no current flows.

Next, the self-check test operation of the second embodiment will be described.

When the test button 9 is closed, power is supplied to the test pulse generating circuit 10, and a test current C flows to the test coil 12 through the switching means 13. The test pulse at this time is a signal that is less than the width of the electrical leak determination as in the self-check test pulse described in the first embodiment, and the electrical leak determining section 5 does not determine that the electrical leak is short-circuited. On the other hand, the test pulse discriminating section 17 detects and outputs the test pulse. The switching means 6 is activated by the test pulse detection output signal G of the test pulse discrimination section 17. [ At this time, since the test operation output H is inputted to the NOT circuit 18, the switching means 34 is opened so that the switching means 38 is activated and the exciting current of the trip coil 7 is supplied to the resistors 36, And flows as a test operation display drive current K through the test operation display device 37, so that the test operation display device 37 operates. This is normal operation.

In the abnormal state of the self-check test operation, the test pulse detection output signal G is not detected and the test operation display device 37 does not operate.

The test operation display device 37 is configured such that when the test button 9 is closed, the test pulse detection output signal G is not output and the test operation display drive current K does not flow, So that an abnormal display may be made. That is, it may be made to function as a display means of a test result.

As described above, it is possible to confirm whether or not the circuit including the trip coil 7 is normal by this test operation.

The value of the resistor 36 is set so as to be sufficient to operate the test operation display device 37 but to be suppressed to an insufficient current for activating the trip mechanism 8. [ That is, in the case of the self-check test operation, the earth leakage breaker 101 is not tripped, and only the test operation display device 37 is operated.

When the pulse width of the test pulse generated by the test pulse generating circuit 10 is set to a duty ratio simulating a short circuit, a test operation for tripping the earth leakage breaker 101 by driving the tripping means, Can also be performed.

As described in the first embodiment, it is preferable that the self-check test pulse is provided with an automatic generation function automatically generated by a microcomputer or the like so as to be output periodically. Then, it is possible to regularly check that the electrical leak detecting function is normal without interrupting the alternating current converter.

As described above, according to the earth leakage breaker of the second embodiment, in addition to the configuration having the electrical leak detecting device, the test circuit, the test pulse generating device, and the test pulse detecting device similar to those of the first embodiment, It is possible to easily check whether or not a part of the electrical leak detecting function such as the test coil and the secondary coil is normal without shutting off the AC converter as in the first embodiment And it is possible to confirm whether or not the drive circuit of the trip means is normal during the test operation.

In addition, since the automatic generation function for automatically generating the self-check test pulse signal is provided, it is possible to regularly check whether or not the electrical leak detecting function of the electrical leak detecting circuit breaker is normal.

The present invention can be freely combined with each embodiment within the scope of the invention, and each embodiment can be suitably modified, or omitted.

1: AC converter, 2: open / close contact,
3: Video current transformer, 3a: Secondary coil,
4: A / D conversion section, 5: leak detection section,
6: switching means, 7: trip coil,
8: trip mechanism, 9: test button,
10: a test pulse generating circuit, 11: a resistor,
12: test coil, 13: switching means,
14: Self-check test signal source,
15: Self-check test pulse generating circuit,
16: switching means, 17: test pulse discrimination unit,
18: NOT circuit, 19: AND circuit,
20: switching means, 21: resistance,
22: Self-check abnormality display device, 23: AC / DC power supply circuit,
31, 32: diode, 33, 34: switching means,
35, 36: resistance, 37: test operation display device,
38: Switching means, 100, 101: Earth leakage breaker.

Claims (3)

An electric leakage detecting means for outputting a electric leakage detecting signal when a leakage current flowing through the alternating current converter exceeds a predetermined level, the leakage current detecting means being connected to a secondary coil wound around the alternating current transformer, A test circuit for passing a test current through a test coil wound around the image current transformer; and a self-checking circuit for detecting a leakage current from the AC current sensor, Test pulse generating means for supplying a test pulse signal to the test circuit; and test pulse detecting means for detecting the test pulse signal,
And a display means for displaying the test result without operating the trip means when the self-check test pulse signal is outputted and not detected by the test pulse detecting means at the time of the self-check test Features an earth leakage breaker. The method of claim 1,
Wherein a part of the drive circuit for driving the trip means and a part of the drive circuit for driving the display means are made common. The method according to claim 1 or 2,
And an automatic generation function for automatically generating the self-check test pulse signal.

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