JP3954342B2 - Earth leakage breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an earth leakage breaker, and more particularly to an improvement in a switch portion of an earth leakage breaker that can be reversely connected.
[0002]
[Prior art]
The earth leakage breaker is provided with a test circuit for confirming whether or not the breaking operation is surely performed when the earth leakage occurs. This test circuit is configured so that by pressing the test button provided on the circuit breaker operation surface, the switch part of the test circuit is turned on to generate a pseudo leakage current, and the circuit breaker actually trips. Yes. Since this test circuit may cause a fault if a leakage current occurs due to the pressing operation of the test button in the main circuit open state with the circuit breaker turned off or after the circuit breaker is turned off, By providing the circuit, the leakage current does not flow even when the test button is operated when the main circuit is open.
[0003]
However, in the case of an earth leakage circuit breaker that can be connected in reverse without limiting the load side terminal and the power source side terminal, the main circuit provided with the test circuit remains charged even in the above configuration even if the main circuit is opened. Therefore, even when the operation handle for opening and closing the main circuit is turned off or in the open state in which the circuit breaker is tripped, a pseudo-leakage current is generated by operating the test button.
Therefore, in the earth leakage circuit breaker that can be connected reversely, a micro switch is provided so that the test circuit itself does not become a closed circuit even if the test button is operated with the main circuit open, or the test button is disabled. It was.
[0004]
FIG. 4 shows a circuit diagram of an earth leakage circuit breaker provided with a micro switch so that the test circuit does not operate when the main circuit is opened. 21 is a main circuit, 22 is a test circuit, and 23 is a micro switch. The micro switch 23 is opened by the operation of the trip coil 25 together with the provided contact portion 24.
Thus, by interposing the micro switch in the test circuit, the test circuit is not operated when the main electric circuit is opened. Reference numeral 26 denotes a zero-phase current transformer for detecting electric leakage, 27 denotes a circuit board, and 28 denotes a switch unit that is operated by pressing a test button (not shown).
[0005]
FIG. 5 and FIG. 6 show the configuration in which the operation of the test button is disabled, and both are explanatory views of the main part of the leakage breaker with the cover removed. FIG. 5 shows a case where the main electric circuit is in a conductive state, FIG. 6 shows a case where the main electric circuit is opened, and in both cases, (a) is a state where the test button is not operated, and (b) is a state where the test button is pressed. Is shown.
In the figure, 31 is a test button, 32 is a movable piece constituting the switch section, 33 is a fixed piece corresponding to the movable piece 32, 34 is a separator for operating a movable contact (not shown), and one end of the movable piece 32 is a circuit. The contact is fixed to the substrate 35 and contacts the fixed piece 33 with the other end as a free end.
[0006]
When the main electric circuit is in a conducting state, the approximate center of the movable piece 32 is pressed downward as shown in FIG. 5B by the pressing operation of the test button 31, and the contact provided at the tip contacts the fixed piece 33. Then the test circuit operates. However, in the state where the main electric circuit is open, as shown in FIG. 6B, the tip is locked to the separator 34 in the raised position, so that the movable piece 32 is pressed and deformed by pressing the test button 31. Does not contact the fixed piece 33, and the test circuit does not close. In this way, the operation of the test button was disabled.
[0007]
[Problems to be solved by the invention]
However, the configuration using the microswitch 23 is not a preferable configuration because it operates reliably, but the microswitch itself is expensive and a space for installation must be secured. Moreover, although the structure which makes operation | movement of the test button 31 impossible cannot be formed cheaply without providing an element like a microswitch separately, since the movable piece 32 is the structure which the front-end | tip locks to the separator 34, a test button Depending on the amount of pushing 31 and the amount of deformation of the movable piece 32, the separator 34 is unlocked, causing the test circuit to malfunction, or the movable piece 32 contacts the fixed piece 33 and the test circuit is turned on. there were. Further, since the structure is such that the operation is prevented by locking the tip, the movable piece 23 is fixed at both ends and is deformed by the test button, causing plastic deformation and unstable operation.
[0008]
Therefore, in view of the above problems, the present invention operates the test button in a state where the switch part of the test circuit does not close even when the test button is operated in the state where the main circuit is opened, in the state where the switch part does not close. However, it is an object of the present invention to provide an earth leakage circuit breaker in which excessive stress is not applied to the movable piece of the switch unit.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention of claim 1 is characterized in that a contact portion composed of a movable contact operated by a separator and a fixed contact that moves toward and away from the movable contact is interposed in the main electric circuit so that an electric leakage occurs. The separator has a test circuit that operates the movable contact to open the contact portion to open the main electric circuit and generate a pseudo-leakage current. By operating a test button provided on a circuit breaker operation surface In the earth leakage circuit breaker capable of conducting an earth leakage interruption test by closing the switch part of the test circuit, the switch part has a movable piece elastically deformed by a pressing force of a test button and a contact point facing a part of the movable piece. The movable piece has one end fixed to the separator and the other end as a free end.
[0010]
The invention of claim 2 is characterized in that, in the invention of claim 1, the portion where the pressed test button abuts is the free end of the movable piece.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. 1 to 3 show an example of an earth leakage circuit breaker according to the present invention. FIGS. 1 and 2 are side views of main parts with a cover removed, and FIG. 1 is a diagram when the main circuit is in a conductive state. 2 shows a case where the main electric circuit is opened. Further, (a) shows a state where the test button is not operated, and (b) shows a state where the test button is pressed. FIG. 3 shows a side view of the movable piece forming a part of the switch portion.
[0012]
In the figure, reference numeral 1 is a base of an earth leakage breaker, a circuit board 2 on which an earth leakage detection circuit and a test circuit are formed is arranged upright, 3 is a test button that exposes an upper part from a cover (not shown), A movable piece 5 constituting one side is a fixed piece arranged opposite to the movable piece 4 and constituting the other side of the switch unit, and 6 represents a resistor constituting a part of the test circuit.
Reference numeral 8 denotes a separator, which is a member for opening / closing a movable contact that forms one of contact points for opening / closing a main electric circuit (not shown), and trips when the main electric circuit is opened or when leakage occurs. At the same time, it moves upward in the figure and performs an operation of lifting the movable contact.
[0013]
The movable piece 4 is formed of a metal plate having elasticity, and as shown in the enlarged view of FIG. 3, a contact 4a that makes contact with and separates from the fixed piece 5 is formed to protrude substantially at the center. Two places are bent in opposite directions and fixed to the separator 8. In addition, the other end on the left side of the figure is bent upward and the tip end portion is formed to be horizontal to form a free end and form a contact portion of the test button 3.
[0014]
The operation of the movable piece 4 will be described. When the circuit breaker is in the on state, that is, the main electric circuit conduction state, the separator 8 is lowered to push down the movable contact (not shown) as shown in FIG. The fixed movable piece 4 is also lowered in conjunction. Therefore, the contact point 4a of the movable piece 4 approaches the fixed piece 5 that is opposed to the movable piece 4. When the test button 3 is pressed in this state, the tip of the movable piece 4 is pushed in, and the contact portion 4a of the movable piece 4 and the fixed piece 5 come into contact with each other as shown in FIG. Thus, the test circuit forms a closed circuit and generates a pseudo leakage current.
[0015]
When the circuit breaker is off, that is, when the main electric circuit is open, the separator 8 is raised to lift the movable contact as shown in FIG. 2, and the movable piece 4 fixed to the separator 8 is also raised. Therefore, the contact 4 a of the movable piece 4 is greatly separated from the fixed piece 5. When the test button 3 is pressed in this state, the tip of the movable piece 4 is pushed in and the whole is bent downward, but the contact point 4a contacts the fixed piece 5 as shown in FIG. Absent. As a result, no pseudo-leakage current is generated even if the circuit breaker is reversely connected to the main circuit.
[0016]
As described above, the movable piece of the switch portion is not blocked by the movable side end being locked by the locking member or the like, so that a stable operation is obtained without causing a problem of unlocking. be able to. In addition, since the free end of the movable piece is pressed by the test button, stress is not concentrated on the local area, and the movable piece is not deformed beyond the range of elasticity, allowing stable button operation. It can last.
[0017]
【The invention's effect】
As described above in detail, according to the first aspect of the present invention, since there is no locking member or the like for locking the movable piece, there is no problem such as release of locking. Therefore, the test circuit does not operate when the circuit breaker is opened.
[0018]
According to the invention of claim 2, in addition to the effect of claim 1, the movable piece is pressed at the free end by the test button, so that stress is not concentrated on the local portion, and the movable piece has an elastic range. Stable button operation can be continued without being deformed beyond.
[Brief description of the drawings]
FIG. 1 shows an example of an embodiment of a leakage breaker according to the present invention, and is an explanatory side view of a main part of a leakage breaker with a cover removed when a main circuit is conducted. FIG. , (B) shows a state where the test button is pressed.
2 is an explanatory side view of a main part of the earth leakage circuit breaker of FIG. 1 when the main circuit is opened, where (a) shows a state where the test button is not operated, and (b) shows a state where the test button is pressed. .
3 is an enlarged side view showing a movable piece of the earth leakage circuit breaker switch part of FIG. 1; FIG.
FIG. 4 is a circuit diagram of a conventional earth leakage breaker, showing a configuration in which a microswitch is provided in a test circuit.
FIGS. 5A and 5B are side view for explaining a main part of the earth leakage circuit breaker with the cover removed when the main circuit is connected, wherein FIG. 5A is a state in which the test button is not operated, and FIG. 5B is a test button; The state which pushed is operated is shown.
6 is an explanatory side view of a main part of the leakage breaker of FIG. 5 when the main circuit is opened, in which (a) shows a state where the test button is not operated, and (b) shows a state where the test button is pressed. .
[Explanation of symbols]
3 .... Test button, 4 .... Movable piece, 4a ... Contact, 5 .... Fixed piece, 8 .... Separator.

Claims (2)

A contact portion composed of a movable contact operated by a separator and a fixed contact that moves toward and away from the movable contact is interposed in the main electric circuit, and the separator operates the movable contact when an electric leakage occurs, so that the contact portion A test circuit that opens the main circuit to open the main circuit and generates a pseudo-leakage current, and operates the test button provided on the circuit breaker operation surface to close the switch part of the test circuit, thereby causing a leakage break test. In the earth leakage breaker that can
The switch portion includes a movable piece that is elastically deformed by a pressing force of a test button and a fixed piece that constitutes a contact point facing a part of the movable piece, and the movable piece has one end fixed to the separator and the other end An earth leakage circuit breaker characterized by having a free end. 2. The earth leakage circuit breaker according to claim 1, wherein a portion where the pressed test button comes into contact is a free end of the movable piece.

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