WO2013073103A1

WO2013073103A1 - Earth-leakage circuit breaker

Info

Publication number: WO2013073103A1
Application number: PCT/JP2012/006583
Authority: WO
Inventors: 善明川嶋; 洋平細岡
Original assignee: 富士電機機器制御株式会社
Priority date: 2011-11-15
Filing date: 2012-10-15
Publication date: 2013-05-23
Also published as: CN103843101A; CN103843101B; JP2013105644A; JP5866993B2

Abstract

This earth-leakage circuit breaker is constructed by installing, inside a case (12), main circuit contacts, a contact opening/closing mechanism, a zero-phase current transformer (19) which is provided on the main circuit in an intervening manner, an earth-leakage tripping unit (21), an arc-extinguishing unit (18), a printed board (22) on which circuit components for an earth-leakage detection circuit and an earth-leakage test circuit are mounted, and a pushbutton-type test switch (25) which is connected to the earth-leakage test circuit. Additionally, an internal unit (29) that internally contains the printed board (22) is housed inside the case (12), and an arc gas generated by the arc-extinguishing unit (18) is prevented by the internal unit (29) from coming into contact with the printed board (22).

Description

Earth leakage breaker

The present invention relates to an earth leakage breaker provided with an earth leakage test circuit.

As an earth leakage breaker, for example, a device disclosed in Patent Document 1 is known.
The earth leakage breaker of Patent Document 1 includes a main circuit contact, a contact switching mechanism, a zero-phase current transformer interposed in the main circuit, an earth leakage trip device, an arc extinguishing device, an earth leakage detection circuit, and a case main body. It houses a printed circuit board on which circuit components of the leakage test circuit are mounted, a push button type test switch connected to the leakage test circuit, and the like.

FIG. 7 shows the structure around the pushbutton test switch of the earth leakage circuit breaker described in Patent Document 1, and a printed circuit board 2 is placed on the top of the zero-phase current transformer 1. A cover 3 of the case main body is arranged on the upper part of the case. An earth leakage trip device 4 is arranged in parallel to the zero-phase current transformer 1 while being located at the bottom of the printed circuit board 2.

Also, a pair of test pin terminals of the zero-phase current transformer 1 protrude from the upper surface of the printed circuit board 2, and these pair of test pin terminals are fixed

contacts

6 a and 6 b of the pair of test switches 5. The cover 3 is provided with a push button 8 of the test switch 5 that is movable downward and retracted upward by the return spring 7. A movable contact 9 that bridges the pair of

fixed contacts

6a and 6b by movement is fixed.

Japanese Patent Laid-Open No. 2000-3660 (FIGS. 1 to 5)

By the way, although the earth-leakage current of the patent document 1 mentioned above flows into the main circuit and the arc extinguishing device extinguishes an arc generated when the contact opening / closing mechanism performs a breaking operation, Between the printed circuit board 2 and the arc extinguishing apparatus, there is no shielding member that shields the arc gas generated by the arc extinguishing apparatus from moving toward the printed circuit board 2. For this reason, if the soot contained in the arc gas generated by the arc extinguishing device adheres to the circuit of the printed circuit board 2, the insulation performance of the printed circuit board 2 may be deteriorated.
Accordingly, an object of the present invention is to provide a leakage breaker capable of improving the insulating performance of a printed circuit board by preventing contact with arc gas.

In order to achieve the above object, an earth leakage breaker according to an embodiment of the present invention includes a main circuit contact, a contact opening / closing mechanism, a zero-phase current transformer interposed in the main circuit, an earth leakage A printed circuit board on which circuit components of a removal device, an arc extinguishing device, a leakage detection circuit and a leakage test circuit are mounted, and a push button type test switch connected to the leakage test circuit are incorporated, and the printed circuit board is arranged inside. The internal unit is configured to shield the contact between the arc gas generated in the arc extinguishing device and stored in the case with the printed circuit board.
According to the earth leakage breaker according to this embodiment, soot contained in the arc gas generated by the arc extinguishing device does not adhere to the circuit of the printed circuit board.

The earth leakage breaker according to one embodiment of the present invention includes a unit case in which the internal unit covers one surface side of the printed circuit board and opens on the other surface side of the printed circuit board. A unit cover that detachably engages with an opening edge of the unit case and closes the inside of the unit, and the push button type test switch is provided on the other surface of the printed circuit board disposed in the unit case. A fixed contact and a movable contact provided on a push button disposed on the unit cover and movable toward the fixed contact by a pressing operation of the push button are provided.
According to the earth leakage circuit breaker according to the one embodiment, since the button-type test switch is configured by the printed circuit board and the internal unit that accommodates the printed circuit board, the test switch can be downsized.

Further, in the earth leakage breaker according to one embodiment of the present invention, a pair of the fixed contacts are provided apart from each other on the other surface of the printed circuit board, and the movable contact of the push button A tip is provided so as to bridge between the pair of fixed contacts.
According to the earth leakage circuit breaker according to this embodiment, a large insulation distance can be ensured even for a small internal unit having a small facing distance between the printed circuit board and the unit cover.

Furthermore, in the earth leakage breaker according to one embodiment of the present invention, the movable contact that bridges between the pair of fixed contacts is a conductive plate that is elastically deformable.
According to the earth leakage breaker according to this embodiment, even if the push button is pushed in with a strong force, the movable contact that contacts the pair of fixed contacts bends while being elastically deformed, and excessive stress is applied to the pair of fixed contacts. Don't join.

According to the leakage breaker according to the present invention, the internal unit in which the printed circuit board is disposed is housed in the case, and the contact between the arc gas generated by the arc extinguishing device and the printed circuit board is shielded by the internal unit. Therefore, soot contained in the arc gas generated by the arc extinguishing apparatus does not adhere to the circuit of the printed circuit board, and the insulating performance of the printed circuit board can be improved.

It is principal part sectional drawing which shows the earth-leakage circuit breaker which concerns on this invention. It is a circuit diagram of an earth-leakage circuit breaker according to the present invention. It is a perspective view which shows the inside of the earth-leakage circuit breaker which removed a part of case of the earth-leakage circuit breaker concerning this invention. It is a figure which shows the state which removed the unit cover of the internal unit in the apparatus of FIG. It is a figure which shows the standby state of the pushbutton type test switch which concerns on this invention. It is a figure which shows the state which the fixed contact and movable contact of the pushbutton type test switch which concern on this invention are contacting. It is a figure which shows the structure of the pushbutton type test switch of the conventional earth-leakage circuit breaker.

DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of an essential part showing an earth leakage breaker according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the earth leakage breaker according to an embodiment, and FIG. The perspective view which shows the inside of the removed earth-leakage circuit breaker, FIG. 4 is a figure which shows the state which removed the unit cover of the unit accommodated in the main body case.

As shown in FIG. 1, the earth leakage breaker of the present embodiment includes a main circuit terminal 13 on the power source side, a main circuit terminal 14 on the load side, and a main circuit in a main body case 12 including a base 10 and a cover 11. A fixed contact 15 and a movable contact 16 constituting the contact, an operation handle 17 connected to an opening / closing mechanism (not shown), and a contact point between the fixed contact 15 and the movable contact 16 at the time of a blocking operation by the opening / closing mechanism. An arc extinguishing device 18 that extinguishes the generated arc, a zero-phase current transformer 19, an overcurrent tripping device 20 (see FIG. 2), and an earth leakage tripping device 21 are incorporated.

2 is a printed circuit board on which circuit components of the leakage detection circuit 23 and the leakage test circuit 24 are mounted. The leakage test circuit 24 mounted on the printed circuit board 22 includes a test switch 25 and a current limiting resistor 26. It has.
The test switch 25 of FIG. 2 includes a pair of

fixed contacts

27a and 27b and a movable contact 28 that bridges the pair of

contacts

27a and 27b by moving the push button 35.

Here, as shown in FIG. 3, an internal unit 29 formed of an insulating material such as a synthetic resin material is accommodated in the upper portion of the zero-phase current transformer 19 inside the main body case 12.
The internal unit 29 includes a unit case 30 that holds the printed circuit board 22 and a unit cover 31 that is detachably engaged with the opening edge of the unit case 30 while facing the upper surface of the printed circuit board 22. Has been.

As shown in FIG. 4, the unit case 30 includes side partition walls 30a to 30e formed around the periphery of the printed circuit board 22, and a side partition wall 30c so that only the upper part is opened as shown in FIG. The bottom partition walls 30f to 30h are formed integrally with the lower part of 30 to 30e, and the printed circuit board 22 is in contact with and supported by the upper part of the bottom partition wall 30f.
As shown in FIG. 5, on the upper surface of the printed circuit board 22, a pair of pin terminals drawn out from the zero-phase current transformer 19 protrude toward the unit cover 31 with a predetermined interval. The pair of pin terminals are a pair of

fixed contacts

27a and 27b that constitute the test switch 25 described above.

As shown in FIG. 5, the button cover 31 a is formed at a position corresponding to the button insertion hole 11 a formed in the cover 11 in the unit cover 31 engaged with the opening edge of the unit case 30. The button holding portion 31a is a cylindrical portion that communicates vertically, and the push button 35 constituting the test switch 25 is directed toward the printed circuit board 22 in the button insertion hole 11a of the button holding portion 31a and the cover 11. It is mounted so that it can move.
An elastically deformable conductive plate facing the pair of

fixed contacts

27a and 27b of the printed circuit board 22 is fixed to the end of the push button 35 protruding from the lower opening of the button holding portion 31a. The plate is the movable contact 28 constituting the test switch 25 described above.

The push button 35 attached to the button holding portion 31a and the button insertion hole 11a includes the first coil spring 32 disposed between the movable contact 28 and the unit cover 31 having the same coil axis direction, and the unit cover 31. And the second coil spring 33 disposed between the push buttons 35 is urged in a direction away from the pair of

fixed contacts

27a and 27b by the spring force of the second coil spring 33. It is held in contact with the lower surface of 31.
The distance (insulation distance) between the movable contact 28 in the standby state and the pair of

fixed contacts

27a and 27b is set to H1 and H2.
The case according to the present invention corresponds to the main body case 12.

Next, operation | movement of the earth-leakage circuit breaker of this embodiment is demonstrated.
When the push button 35 is pushed against the spring force of the first coil spring 32 and the second coil spring 33 during the leakage test, the movable contact 28 moves downward together with the push button 35 as shown in FIG. Then, the leakage test circuit 24 shown in FIG. 2 is brought into an energized state by bridging between the pair of fixed

contacts

27a and 27b.

As a result, an earth leakage simulation current flows through the zero-phase current transformer 19, the earth leakage trip device 21 is activated by the secondary output of the zero-phase current transformer 19, and the earth leakage breaker is tripped to operate the main circuit contactor. The stationary contact 15 and the movable contact 16 are opened.
Here, even if the push button 35 is pushed in with a strong force, the movable contact 28 that contacts the pair of fixed

contacts

27a and 27b bends while being elastically deformed, so that excessive stress is applied to the pair of fixed

contacts

27a and 27b. Don't join.

Also, when a short circuit current or an overload current flows between the main circuit terminal 13 on the power source side and the main circuit terminal 14 on the load side, the fixed contact 15 and the movable contact 16 are opened simultaneously and fixed. An arc is generated between the contact points of the contact 15 and the movable contact 16. This arc comes into contact with the grid of the arc extinguishing device 18 and is divided and cooled, so that the arc is extinguished early.
Here, since the printed circuit board 22 arranged inside the main body case 12 is stored in a sealed state in an internal unit 29 including a unit case 30 and a unit cover 31, arc gas generated by the arc extinguishing device 18 is stored. Do not touch.

Next, the effect of the earth leakage breaker of this embodiment is demonstrated.
In the earth leakage breaker of this embodiment, the printed circuit board 22 is housed in the main body case 12 in a state of being sealed in the internal unit 29, so that the soot contained in the arc gas generated by the arc extinguishing device 18 is printed. It does not adhere to the circuit of the substrate 22. Therefore, the insulation performance of the printed circuit board can be improved.
In addition, the test switch 25 of the leakage test circuit 24 is provided with a pair of fixed

contacts

27 a and 27 b on the printed circuit board 22, and the movable contact 28 is provided on the unit cover 31 side of the internal unit 29 that accommodates the printed circuit board 22. Since the structure is provided, the test switch 25 can be downsized.

Since the pair of fixed

contacts

27a and 27b of the printed circuit board 22 are provided with the insulating distances H1 and H2 between the movable contact 28 provided on the unit cover 31 side, the printed circuit board 22 and Even a small internal unit 29 having a small facing distance to the unit cover 31 can ensure a large insulation distance of H1 + H2.
Furthermore, even if the push button 35 is pushed in with a strong force, the movable contact 28 that contacts the pair of fixed

contacts

27a and 27b bends while being elastically deformed, and an excessive stress is not applied to the pair of fixed

contacts

27a and 27b. The durability of the test switch 25 can be improved.

As described above, the leakage breaker according to the present invention is useful for improving the insulation performance of the printed circuit board by preventing contact with the arc gas.

DESCRIPTION OF SYMBOLS 10 ... Base, 11 ... Cover, 11a ... Button insertion hole, 12 ... Main body case, 13 ... Main circuit terminal on power supply side, 14 ... Main circuit terminal on load side, 15 ... Fixed contact, 16 ... Movable contact, 17 DESCRIPTION OF SYMBOLS ... Operation handle, 18 ... Arc extinguishing device, 19 ... Zero phase current transformer, 20 ... Overcurrent tripping device, 21 ... Leakage tripping device, 22 ... Printed circuit board, 23 ... Leakage detection circuit, 24 ... Leakage test circuit, 25 ... Test switch, 26 ... Current limiting resistor, 27a, 27b ... Fixed contact, 28 ... Movable contact, 29 ... Internal unit, 30 ... Unit case, 30a-30e ... Side partition, 30f-30h ... Bottom partition, 31 ... Unit cover, 31a ... Button holding part, 32 ... First coil spring, 33 ... Second coil spring, 35 ... Push button

Claims

Printed circuit board with main circuit contacts, contact opening / closing mechanism, zero-phase current transformer, leakage trip device, arc extinguishing device, leakage detection circuit and leakage test circuit in the case And a push button type test switch connected to the leakage test circuit,
The internal circuit unit in which the printed circuit board is disposed is housed in the case and shields the contact between the arc gas generated by the arc extinguishing device and the printed circuit board by the internal unit.
The internal unit covers one surface side of the printed circuit board and opens in the other surface side of the printed circuit board. And a unit cover for closing
The push button type test switch is provided on a fixed contact provided on the other surface of the printed circuit board provided on the unit case and on a push button provided on the unit cover. The earth leakage circuit breaker according to claim 1, further comprising a movable contact that is movable toward the fixed contact.
A pair of the fixed contacts are provided apart from each other on the other surface of the printed circuit board,
The earth leakage circuit breaker according to claim 2, wherein the movable contact is provided at a tip of the push button so as to bridge between the pair of fixed contacts.
The earth leakage circuit breaker according to claim 3, wherein the movable contact that bridges the pair of fixed contacts is an elastically deformable conductive plate.