JP3266213B2 - Earth leakage breaker - Google Patents

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 having an overcurrent protection function, and more particularly to an earth leakage circuit breaker which detects an overcurrent state with a current transformer and trips.

[0002]

2. Description of the Related Art An earth leakage breaker having an overcurrent protection function is:
When leakage is detected by the zero-phase current transformer provided in the main circuit, the trip coil is driven to trip the open / close mechanism, and the main circuit is opened, while the current flowing through each phase of the main circuit is constantly monitored.
When the current is in an overcurrent state, the switching mechanism is tripped and the main circuit is opened in the same manner as in the case of leakage. There are two types of tripping devices for overcurrent tripping: a mechanical type that trips the opening and closing mechanism with a bimetal or an electromagnet, and a tripping device that detects the current flowing through the main circuit with a current transformer. There is an electronic type that inputs to the trip coil and trips the opening / closing mechanism by the movement of the movable iron core, but recently it is easy to adjust the rated current and tripping characteristics according to the trend of intelligent devices. Electronic demand is growing.

[0003]

By the way, the earth leakage breaker is provided with an earth leakage display device for displaying the occurrence of the tripping operation due to the earth leakage. This earth leakage display device generally operates mechanically in conjunction with the interruption operation of the earth leakage breaker,
In an earth leakage breaker having an electronic overcurrent protection function, it is necessary to prevent the earth leakage display device from operating at the time of overcurrent trip so that the earth leakage trip and the overcurrent trip can be distinguished.

The present invention provides an electronic overcurrent trip device.
With the earth leakage breaker equipped only with the earth leakage trip operation
To display the ground fault and reset after trip operation.
It is an object of the present invention to provide an earth leakage breaker that has simplified operation .

[0005]

According to the present invention, a zero-phase current transformer and an overcurrent transformer detect the occurrence of a leakage current and an overcurrent state in a main circuit, respectively, to drive a trip coil, and to open and close a switching mechanism. in an earth leakage circuit breaker to open the main circuit tripping, the separately trip coil and for earth leakage tripping and for overcurrent tripping separately provided, and earth leakage trip in conjunction to the trip coil and the earth leakage trip the leakage display device for displaying the occurrence of operation provided Rutotomoni, said trip coil and earth leakage trip side by side and trip coil and overcurrent tripping side by side disposed next to the opening and closing mechanism, the closing mechanism Leakage after the trip operation on the side of the handle lever
Trip coil for trip and trip coil for overcurrent trip
And a reset pin for resetting the file in common. In claim 1, it is preferable that the two trip coils and the ground fault display device are integrated into a common base by being integrated (claim 2).

[0006]

According to the present invention, the present invention is applicable to earth leakage trip and overcurrent trip.
And a dedicated trip coil is separately provided for each of them, and a ground fault display device is provided so as to interlock with the ground fault trip coil. Thus, the leakage display device can be operated only at the time of the leakage trip regardless of the overcurrent trip.

The opening / closing mechanism of the main body of the earth leakage circuit breaker tripped by the trip coil usually moves the opening / closing handle, which has been moved between the on position and the off position along with the trip operation, beyond the off position to a point further therefrom. You can reset it by slightly pushing it down. Therefore, the two trip coils are arranged side by side and arranged beside the opening / closing mechanism, and the set pin common to the two trip coils is fixed to the side of the handle lever operated by the opening / closing handle, thereby resetting the earth leakage breaker body. The trip coil that tripped at the same time as the operation can be reset. In this case, by integrating the two trip coils and the leakage display device into a common mold base and integrating them as a trip coil unit , they can be collectively attached to and detached from the main case of the leakage breaker, and the assembly is simplified. In addition, when the specification is changed, the whole unit can be replaced, so that the response can be easily performed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Embodiment 1 FIGS. 1 to 5 show a basic embodiment of the present invention.
FIG. 1 is an exploded perspective view of a trip coil unit, FIG. 2A is a longitudinal sectional view of a set state of a trip coil part for earth leakage trip of FIG. 1, FIG. 1B is a view after the trip operation, and FIG. FIG. 4 is a plan view of the on-state in which a part of the earth leakage breaker having the trip coil unit of FIG. 1 is cut away, FIG. 4 is a longitudinal sectional view of FIG. 3, and FIG. It is an expanded perspective view shown. First, in FIG. 1 and FIG.
Is mounted in a recess of a box-shaped base 2 made of a mold resin having an open upper surface, and a trip coil 3 (hereinafter, referred to as a trip coil) for earth leakage trip.
An overcurrent trip coil (hereinafter, referred to as an overcurrent trip coil) 4 and an overcurrent trip coil 4 are housed side by side, and a resin molded product Z
The configuration is such that character-shaped sliders 5 and 6 are arranged, respectively.

The earth leakage trip coil 3 and the overcurrent trip coil 4 have the same configuration and dimensions of a magnetic holding type in this case, and are connected to the center of a U-shaped yoke 7 as shown in FIG. A demagnetizing coil 10 is wound around a fixed iron core 8 and a movable iron core 9 slidably opposed thereto, and a pair of permanent magnets 1 is shunted adjacent thereto via a shunt 11.
2 are arranged. The movable pin 13 fixed to the movable core 9 projects out of the yoke 7 through the fixed core 8, and a return spring 14 composed of a compression spring is inserted between the head 13 a and the yoke 7. The sliders 5 and 6 having the same shape and dimensions are inserted through two long holes 15 at upper and lower positions, and both ends are supported by upper and lower two iron pins 16 held by the base 2 so as to be slidable back and forth. The sliders 5 and 6 are urged toward the movable pins 13 of the trip coils 3 and 4 by a pair of left and right drive springs 17 formed of a tension spring hung between the sliders 5 and 6.

A display latch 18 and a leakage display piece 19 are arranged behind the leakage trip coil 3. The display latch 18 is rotatably supported by a fulcrum shaft 18a fitted in an arc groove on the upper surface of the base 2, and the tip thereof faces the movable iron core 9 of the earth leakage trip coil 3. On the other hand, the leakage display piece 19 is slidably guided by the bottom plate of the base 2 so that the cylindrical display portion 19a can be seen from the upper surface of the base 2. The leakage display piece 19 is urged upward in the figure by a display spring 20 (FIG. 2) composed of a compression spring inserted between the base 2 and the ground. Also,
As shown in FIG. 2, the leakage detecting piece 19 has a locking piece 19b extending toward the display latch 18, and the locking piece 19b is a columnar projection on the side surface of the display latch 18 in the set state of FIG. The display unit 19 is retained by being pushed into the base 2 by being locked by 18b. A cover plate 21 made of a transparent resin is attached to the base 2 by engagement, and holds the trip coils 3 and 4, the display latch 18, the leakage display piece 19, and the like. At this time, the display unit 19a of the leakage display piece 19
Project from a hole 22 (FIG. 1) of the cover plate 21.

The above-described trip coil unit 1
As shown in FIG. 3 and FIG. 4, the main body case 23 of the earth leakage breaker is mounted by fitting so as to be located above the right pole current path next to the opening / closing mechanism part 24, only a part of which is shown. It is held down by the cover 25. The key-shaped tips of the sliders 5 and 6 of the trip unit 1 are shown in FIG.
As shown in FIG. 2, the operation section faces the operation section of the trip crossbar 26 which constitutes a part of the opening / closing mechanism section 24. The display portion 19a of the leakage display piece 19 has a display hole 27 of the main body cover 25.
Is facing. A gate-shaped handle lever 29 having an operation handle 28 (FIG. 4) attached to its head is supported swingably in the front-rear direction (left-right direction in the figure) with its tip as a fulcrum. 6, a reset pin 30 is fixed by screwing. The reset pin 30 extends toward the trip coil unit 1 and faces the rear end surfaces of the sliders 5 and 6, as shown in FIG.

The earth leakage breaker is provided with a zero-phase current transformer 32 surrounding the three-phase main circuit conductor 31 (FIG. 4), and the main circuit conductor 31 of each phase is provided with an overcurrent transformer 33, respectively. Is provided. Then, the secondary output of the zero-phase current transformer 32 is input to the leakage trip coil 3 via the leakage detection circuit in the electronic circuit unit 34 (FIG. 3), and the secondary output of the overcurrent transformer 33 is also excessive. It is input to the overcurrent trip coil 4 via the current detection circuit. When the earth leakage breaker is turned on as shown in FIGS. 3 and 4, both the earth leakage trip coil 3 and the overcurrent trip coil 4 have the movable core 9 fixed by the magnetic flux of the permanent magnet 12 as shown in FIG. The sliders 5 and 6 are separated from the trip cross bar 26 by being pushed by the movable pins 13 against the drive spring 17.

When the occurrence of a ground fault is detected by the zero-phase current transformer 32, a trip signal is sent to the earth leakage trip coil 3 and the demagnetizing coil 10 is excited. As a result, the magnetic flux of the permanent magnet 12 is weakened, and the spring force of the drive spring 17 exceeds the attraction force.
As shown in (B), the slider 5 is pulled away from the fixed iron core 8 and at the same time, the slider 5 is driven to the trip coil 3 side to tilt the trip cross bar 26. As a result, the opening / closing mechanism 24 is pulled off, and the movable contact 35 (FIG. 4) is separated from the fixed contact 36 by the force of an opening / closing spring (not shown) to cut off the current. The movable iron core 9 that has been released after being released due to the above-described leakage leakage trip pushes the display latch 18 and rotates about the support shaft 18a as a fulcrum, as shown in FIG. 2B. As a result, the projection 18b faces the escape portion (not shown) cut out by the engagement piece 19b of the electrical leakage display piece 19, and the engagement of the engagement piece 19b is released. The display unit 19a is lifted up and protrudes from the display hole 27 to perform the leakage display.

When the occurrence of an overcurrent state is detected by the overcurrent transformer 33, a trip signal is output from the overcurrent detection circuit to the overcurrent trip coil 4 with a delay time corresponding to the magnitude of the current. The current is interrupted by the same action as in the case of the earth leakage trip. However, in the case of this overcurrent trip, the overcurrent trip coil 4 that operates is connected to the display latch 1.
8 and no leakage display is performed. When the earth leakage breaker trips, the handle lever 29 moves from the ON position in FIG. 4 to the trip position slightly rotated clockwise in the drawing, while the driven slider 5 or 6 moves leftward in the drawing. And the reset pin 30 approaches the end face of the slider 5 or 6 as shown in FIG.

When the handle lever 29 is further rotated clockwise in FIG. 4 from the trip position to the reset position in order to reset the opening / closing mechanism 24 which has been pulled out of the trip state, the slider 5 or 6 is reset. The movable pin 13 is released by being pushed back by the pin 30 against the drive spring 17. Therefore, the movable pin 13 follows the slider 5 or 6 by the force of the return spring 14, and causes the movable iron core 9 to approach the fixed iron core 8. Thereby, the movable iron core 9 is attracted to the fixed iron core 8 again, and the driven earth leakage trip coil 3 or the overcurrent trip coil 4 is driven as shown in FIG.
Is reset to the state shown in As described above, in the illustrated embodiment, the earth leakage trip coil 3 and the overcurrent trip coil 4 are provided separately, and the earth leakage display piece 19 is provided so as to operate only with the earth leakage trip coil 3 accordingly. Thus, the earth leakage trip and the overcurrent trip can be clearly distinguished. The opening / closing mechanism 24
At the same time as resetting the earth leakage trip coil 3 or overcurrent
Since the trip coil 4 is reset, the trip
The reset operation of the coils 3 and 4 is simple. Two more
Trip coils 3 and 4 and leakage display devices 18 and 19
Is a trip coil unit on the common mold base 2.
These are integrated as 1
Can be attached to and detached from the breaker body case 23 for easy assembly
At the same time as changing the specifications
It is easy to deal with.

Embodiment 2 Next, an embodiment in which the sliders 5 and 6 have a buffer function will be described with reference to FIGS. Here, FIG. 6 is a longitudinal sectional view of the trip coil unit having substantially the same configuration as that in the first embodiment when the earth leakage breaker is off, and FIG. FIG. 8 is an enlarged view of a cushion material portion in FIG. 7, and FIG. 8 is a diagram showing another embodiment of the cushion material portion. The trip coil unit shown in FIG. 6 or FIG. 7 is slightly different in the shape of the details from that in the first embodiment. 2 has substantially the same configuration.

FIG. 6 shows that the operation handle of the earth leakage breaker after the trip operation is moved to the reset position to reset the opening / closing mechanism of the earth leakage breaker body and the trip coil unit 1 as already described in the first embodiment. Thereafter, a state is shown in which the hand is released from the operation handle, and this is automatically returned to the off position by the action of an opening / closing spring (not shown) of the main body. In this case, a small gap indicated by dimension A is provided between the movable pins 13 and the sliders 5 and 6 whose positions are regulated by the reset pins 30 in order to surely reset the trip coil unit 1. . However, in this state, when a trip test of only the opening / closing mechanism is mechanically performed by pressing a test button (not shown) of the earth leakage breaker main body, the operation handle is moved to the trip position, and accordingly, the reset pin 30 is also indicated by an arrow. At this time, the sliders 5, 6 released from the reset pins 30 move forward by the gap A instantaneously and hit the movable pins 13, and the impact of the impacts on the attracting force of the movable core 9 There is a danger that the trip coil unit 1 will be operated by overcoming it.

Therefore, in order to cope with such a mistrip, in this embodiment, as shown in FIGS. 7 and 8, a contact portion 5a of a slider 5 for pushing the movable pin 13 (similarly, the slider 6) is provided. A cylindrical concave portion 37 is provided, into which a columnar cushion rubber 38 is inserted so that the tip slightly protrudes. Thereby, the shock between the slider 5 and the movable pin 13 is absorbed by the cushion rubber 38,
There is no need to worry about the trip coil unit 1 operating.
In this case, if the cushion rubber 38 is fixed by bonding, the rubber is hardened and deteriorates, and the cushioning property is impaired. Therefore, it is advisable to press-fit the cushion rubber 38 with a slightly larger outer diameter than the inner diameter of the recess 37. However, if there is still a danger of falling off, the recess 37 of the cushion rubber 38 may be used.
Set a longer insertion length in consideration of the following.

That is, when the trip coil unit 1 is reset, the slider 5 is further pushed rightward from the position shown in FIG. 2, but does not move any further when it hits the pin 16 at the left end in the figure. Therefore, the gap between the movable pin 13 and the slider 5 at the point where the slider 5 abuts on the pin is maximized. If the length of insertion of the cushion rubber 38 into the concave portion 37 is made larger than this maximum gap amount, The cushion rubber 38 never falls off. Further, when the cushion rubber 38 hits the movable pin 13, the cushioning effect is weakened if there is no escape area in the lateral direction at the tip end.
A relief space 13a (FIG. 8) is formed at the front of the vehicle by counterbore.

In the structure shown in FIG. 8, there is no fear that the cushion rubber 38 will fall off after the slider 5 is assembled to the base 2, but there is a concern that the slider 5 alone will fall off.
The embodiment of FIG. 9 takes this point into consideration. In FIG. 9, an annular groove 39 is formed in the end face of the contact portion 5a, and an O-ring 40 is fitted into the groove 39 as a cushion material. The inner diameter of the O-ring 40 is smaller than the inner diameter of the groove 39, and the O-ring 40 is held by the tension. The outer shape of the groove 39 is larger than the outer shape of the O-ring 40 so that the O-ring 40 can escape to the outside when deformed by an impact.

[0021]

According to the present invention, the earth leakage trip coil and the overcurrent trip coil are separately provided, and the earth leakage display device is linked only to the earth leakage trip coil, so that it is not affected by overcurrent tripping. An electric leakage display can be performed. In addition, since the leakage detection circuit and the overcurrent detection circuit are completely electrically separated, the insulation performance between these circuits is enhanced. Furthermore, two trip coils are arranged side by side and arranged beside the opening / closing mechanism of the earth leakage breaker main body, and a reset pin for commonly resetting the trip coil after the trip operation is provided on the side of the handle lever of the opening / closing mechanism. Fixed
By the, Runode can reset the reset and trip coil simultaneously fault interrupter body, reset operation is simple. In such a case, by incorporating the two trip coils and the leakage display device into a common base and integrating them as a trip coil unit, it is easy to respond to attachment / detachment to / from the leakage breaker main body and a change in the specification of the trip coil. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a trip coil unit according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the trip coil unit of FIG. 1,
(A) shows the set state, and (B) shows the state after the trip operation.

FIG. 3 is a plan view of an earth leakage breaker including the trip coil unit of FIG. 1;

FIG. 4 is a longitudinal sectional view of FIG.

FIG. 5 is an enlarged perspective view of a part of FIG. 4;

FIG. 6 is a longitudinal sectional view of the trip coil unit according to the present invention in a state where an earth leakage breaker is off.

FIG. 7 is a longitudinal sectional view of a trip coil unit showing another embodiment of the present invention.

FIG. 8 is an enlarged view of a part of FIG. 7;

FIG. 9 is a longitudinal sectional view of a main part when an O-ring is mounted on the slider in FIG. 6;

[Explanation of symbols]

 Reference Signs List 1 trip coil unit 2 base 3 trip coil for earth leakage trip 4 trip coil for overcurrent trip 5 slider 6 slider 7 yoke 8 fixed iron core 9 movable iron core 10 demagnetizing coil 12 permanent magnet 13 movable pin 17 drive spring 18 display latch 19 Leakage display piece 24 Open / close mechanism 26 Trip crossbar 28 Operating handle 29 Handle lever 30 Reset pin 31 Main circuit conductor 32 Zero-phase current transformer 33 Overcurrent transformer 34 Electronic circuit unit 38 Cushion rubber 40 O-ring

Claims (2)

(57) [Claims] 1. A zero-phase current transformer and an overcurrent transformer detect the occurrence of a leakage current and an overcurrent condition in a main circuit, respectively, to drive a trip coil, trip an opening / closing mechanism, and open the main circuit. in an earth leakage circuit breaker to the separately trip coil and for earth leakage tripping and for overcurrent tripping separately provided, leakage display for displaying the occurrence of earth leakage trip operation in conjunction with the trip coil and the earth leakage trip Rutotomoni provided apparatus, wherein arranged the earth leakage trip trip coil and said trip coil by overcurrent tripping next to the opening and closing mechanism arranged next to each other, tripping the side surface of the opening and closing mechanism portion of the handle lever operation The earth leakage trip
An earth leakage breaker characterized by fixing a reset pin for resetting a lip coil and an overcurrent trip coil in common. Wherein earth leakage breaker according to claim 1, wherein the integrated incorporates the two trip coils and leak display device on a common base.