JP2002008512A - Earth leakage breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the assembly, adjustment or wiring work simple in the two pole earth leakage breaker which is used as a safety breaker. SOLUTION: An opening 29 is provided at the backside of the mold case and a printed board mounted with an earth leakage detecting circuit is arranged facing this opening 29 and the adjustment of this leakage sensitive current is enabled to be made through the opening 29. By connecting the lead pin 32, which is joined with the terminal 4 of the load, with the power source terminal of the printed board 12, the lead cable which supplies power to the printed board is eliminated. A zero phase current transformer 10 is arranged in the vicinity of the power source terminal 3, and by connecting the output pin 33, which is penetrated through a fixed contact 5 and joined with the zero phase current transformer 10, with the printed board 12, the zero phase current transformer 10 and an overload detecting element (bimetal) 8 are separated. The zero phase current transformer 10 is made to be separately controlled in stock from the bimetal of different specifications in its rated current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-pole type earth leakage breaker used as a safety breaker.

[0002]

2. Description of the Related Art FIGS. 9 to 12 show conventional two poles (R and T poles).
FIG. 9 is a plan view showing the interior of the circuit breaker with the cover removed, FIG. 10 is a longitudinal sectional view, and FIG.
Is a connection diagram of lead wires, and FIG. 12 is an internal circuit diagram. In these figures, a power supply side terminal 3 and a load side terminal 4 are arranged at both ends of a molded case including a case 1 and a cover 2, and a fixed contact 5 is integrally formed with the power supply side terminal 3. A fixed contact 5, a movable contact 7 that is turned on / off with respect to the fixed contact 5 by an opening / closing mechanism 6, and a movable contact 7 between the power supply side terminal 3 and the load side terminal 4. An energization path is formed by a bimetal 8 serving as an overload detection element that is integrally tightened and connected to the case 1 and lead wires 9 whose both ends are respectively connected to the bimetal 8 and the load-side terminal 4.

A lead wire 9 is provided with a zero-phase current transformer 10 for detecting a leakage current, and the lead wire 9 passes through the zero-phase current transformer 10. The zero-phase current transformer 10 receives the leakage detection signal, is mounted on a printed board 12 equipped with a leakage detection circuit that outputs a trip signal to a leakage trip device 11, and the printed board 12 is mounted on a printed board case 13. It is stored and held upright in the case 1. As shown in FIG. 9, the leakage trip device 11 includes a coil 16 excited by a trip signal output from a leakage detection circuit, and a plunger 17 attracted by excitation of the coil 16. Is located near the power supply side terminal 3 and the tip of the plunger 17 has a yoke 27 (not shown in detail).
(FIG. 11) is engaged with one end of a lever arm 18 rotatably supported by the lever 6 and the other end of the lever arm 18 is connected to the opening / closing mechanism 6.
And one end of the trip crossbar 19 constituting the locking member of FIG. The other end of the trip cross bar 19 faces the upper end of the bimetal 8.

[0004] Here, in FIG.
Is supplied from the load side terminal 4 via the lead wires 20 and 21, and one ends of the lead wires 20 and 21 are spot-welded to the load side terminal 4 together with the lead wire 9 of the main circuit. Thus, the other end of the lead wire 20 is directly connected to one power supply terminal portion 12a of the printed board 12, while the lead wire 21 is connected to the other power supply terminal portion 12b via the auxiliary switch 22. I have. That is,
The other end of the lead wire 21 is connected to one terminal 22a of an auxiliary switch 22 composed of a micro switch, and the other end of the lead wire 23 having one end connected to the other terminal 22b is connected to the other power supply terminal of the printed circuit board 12. It is connected to the unit 12b. The output terminals 12c and 12d of the printed board 12 and the earth leakage trip device 11 are connected to the leads 24 and 2 respectively.
5 are connected. A test switch 14 for generating a pseudo leakage detection signal in the zero-phase current transformer 10 is held on the upper part of the printed board case 13, and a test button 15 (FIG. 10) of the test switch 14 is connected to the outside through the cover 2. I'm coming. When the test button 15 is pressed, the test switch 14 is turned on, the phases are short-circuited, and a pseudo leakage detection signal is output from the zero-phase current transformer 10.

When the earth leakage breaker is turned on, the actuator 22c is pushed by the opening / closing mechanism 6 to turn on a contact (not shown) for opening and closing the terminals 22a and 22b. ). Since the earth leakage breaker usually has the power supply side terminal 3 connected to the main circuit power supply and the load side terminal 4 connected to the load, the power supply of the printed circuit board 12 supplied from the load side is performed when the earth leakage breaker is turned off. It is automatically cut off via the movable contact 7, but in rare cases, the load terminal 4 of the earth leakage breaker is connected to the main circuit power supply and used (reverse connection). Also, an auxiliary switch 22 is provided so that the power of the printed board 22 is automatically shut off when the earth leakage breaker is off. The auxiliary switch 22 is connected to the yoke 27 of the earth leakage trip device 11 through the base 26,
And is fixed to the case 1 by screws. As shown in FIGS. 9 and 10, the auxiliary switch 22 is provided on the opposite side of the earth leakage trip device 11 with the opening / closing mechanism 6 interposed therebetween.
It is arranged near the power supply terminal 3.

FIG. 9 shows an ON state of such an earth leakage breaker, in which a current flows from the power supply terminal 3 through the fixed contact 5, the movable contact 7, the bimetal 8, and the lead wire 9 to load. It flows to the side terminal 4. In this state, the auxiliary switch 22 is turned on by the opening / closing mechanism 6, and the printed circuit board 12 is turned on.
Is supplied with power. Here, when a leakage occurs, the current flowing through the zero-phase current transformer 10 becomes unbalanced, and
A leakage detection signal is input to the leakage detection circuit of the printed board 12 from the next side. The leakage detection circuit amplifies this signal, and when the level becomes higher than a certain level, outputs a trip signal to the leakage trip device 11. As a result, the plunger 17 is sucked, and the trip crossbar 19 is
As a result, the movable contact 7 is lifted up and separated from the fixed contact 5 as a result of the lock of the opening / closing mechanism 6 being released. At the same time, the auxiliary switch 22 is turned off, and the power supply to the printed board 12 is cut off.

In FIG. 10, the bimetal 8 generates heat in a current flowing state and is bent rightward at the upper end. When an overload current flows, the bimetal 8 trips after a time corresponding to the magnitude of the overload current. Press the cross bar 19 to turn off the earth leakage breaker. On the other hand, when the test button of the test switch 14 is pressed, a pseudo leakage detection signal is output as described above, and the leakage trip device 11 operates to turn off the leakage breaker. From the ON state of FIG.
When the opening / closing lever 28 is turned off to the position indicated by the broken line, the movable contact 7 is driven to open by the reversal of the toggle mechanism of the opening / closing mechanism 6. For details of the configuration of the conventional earth leakage trip device 11, auxiliary switch 22, opening / closing mechanism 6, etc. of the earth leakage breaker shown in the drawing, refer to JP-A-8-203412.

[0008]

The above-mentioned conventional earth leakage breaker has the following problems. That is, the zero-phase current transformer 10 is mounted on a printed board 12, and both ends of the zero-phase current transformer 10 are connected to the load-side terminal 4 and the bimetal 8.
The lead wire 9 spot-welded through the wire forms a unit. However, since the bimetal 8 has different specifications depending on the rated current of the earth leakage breaker, conventionally, the bimetal 8 also includes a leakage detecting unit (the printed board 12 and the zero-phase current transformer 10) that is not related to the rated current. It is necessary to build the above unit,
Parts inventory increases. Conventionally, if the above unit is incorporated in the case 1, the leakage sensitivity of the printed board 12 cannot be adjusted.
Although the sensitivity adjustment is performed for the printed board 12 alone, after the case is assembled, readjustment may be required due to variations in the characteristics of the zero-phase current transformer 10 and the printed board IC. Must be removed and unit assembly started again. Since the zero-phase current transformer 10 is mounted on the printed board 12, its size is limited, and there are many design restrictions. Since the earth leakage trip device 11 and the trip cross bar 19 are separated from each other, a relay member (lever arm) 18 is required for transmitting the motion, and it takes time to adjust the accuracy after the case is assembled. The wiring process of the lead wires 24 and 25 connecting between the printed board 12 and the earth leakage trip device 11 is troublesome. The power of the printed circuit board 12 is supplied via the lead wires 20 and 21, but the wiring process is troublesome, and the lead wires 20 and 21 are spotted together with the lead wire 9 of the main circuit to the load terminal 4. The work of welding has poor workability and takes time. Since the auxiliary switch 22 uses a micro switch, the cost is high, and the wiring process of the lead wire 23 connected to the printed board 12 is troublesome. SUMMARY OF THE INVENTION It is an object of the present invention to address the above problems, simplify wiring processing and assembling work, and reduce costs by reducing the number of components.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a power supply side terminal and a load side terminal arranged at both ends of a mold case, which are formed integrally with the power supply side terminal. A fixed contact, a movable contact that is turned on / off with respect to the fixed contact by an opening / closing mechanism, an overload detection element that connects the movable contact to the load-side terminal, and a lead wire. An electric current path is formed, and in the current path, a two-pole type earth leakage breaker equipped with a zero-phase current transformer for detecting an earth leakage current, wherein an opening is provided on a back surface of the mold case; Input the leakage detection signal of
A printed circuit board equipped with a leakage detection circuit for outputting a trip signal to the leakage trip device is arranged facing the opening, and the leakage sensitivity current can be adjusted through this opening. . In the earth leakage breaker according to the present invention, it is preferable that a lead pin is connected to the load side terminal, and the lead pin is connected to a power terminal of the printed board (claim 2). 2. The earth leakage breaker according to claim 1, wherein the zero-phase current transformer is disposed near the power supply side terminal and penetrates the fixed contact, and an output pin coupled to the zero-phase current transformer is printed on the printed circuit board. It is preferable to connect to a plate (claim 3).

[0010] In the earth leakage breaker according to the first aspect, it is preferable that the inner diameter of the zero-phase current transformer is larger than the width of the power supply side terminal and the fixed contact. Further, it is preferable that the earth leakage trip device is disposed between the switching mechanism and the load-side terminal so as to face a trip portion of the switching mechanism (claim 5). In the earth leakage circuit breaker according to the fifth aspect, it is preferable that a lead pin is connected to the earth leakage trip device, and the earth leakage trip device is supported upright on the printed board via the lead pin. In the earth leakage circuit breaker according to the sixth aspect, an earth leakage test contact can be held on the upper part of the earth leakage trip device. Further, in the earth leakage circuit breaker according to claim 1, the movable contact is turned on / off by the movable contact and a fixed contact body that is fixed to the printed board and that comes into contact with and separates from the movable contact that performs on / off operation. It is preferable that an auxiliary switch for detecting a state is formed, and the auxiliary switch is inserted into a power supply circuit of the printed board.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that the same reference numerals are used for the portions corresponding to the conventional example. Well, FIG.
FIG. 2 is a vertical sectional view of a two-pole earth leakage circuit breaker showing an embodiment of the present invention in an ON state, FIG. 2 is a rear view of the state with a bottom cover removed in FIG. 1, and FIG. It is a top view of the load side terminal part of a container. In FIG. 1 and FIG.
A rectangular opening 29 is provided on the back surface of the printed circuit board 12 on which the leakage detection circuit is mounted.
Are arranged along the back surface of. Various electronic components on the printed board 12, in particular, an adjustment resistor 30 for the earth leakage sensitivity current
(FIG. 2) is mounted on the back side of the case 1 and is accessible from the opening 29. The opening 29 is normally closed by a detachable back cover 31, but when the back cover 31 is removed, the adjustment resistor 30 approaches the adjustment resistor 30 through the opening 29 and, for example, is laser-trimmed to thereby adjust the printed board 1.
The leakage current can be adjusted while the case 2 is incorporated in the case 1.

1 and 3, an L-shaped lead pin 32 is connected to the load terminal 4 at one end by caulking, and the other end is connected to a power supply terminal at one end of the printed board 12 by soldering. Have been. As a result, the lead wires 20 and 21 (FIG. 11) for supplying power to the printed board 12 are replaced by the lead pins 32, and the lead wires 20 and 21 are routed in the case 1 and the load side together with the lead wire 9. The troublesome work of spot welding to the terminal 4 becomes unnecessary. In this case, as will be described later, since one of the power supplies of the printed board 12 is supplied via the auxiliary switch 22, the lead pin 32 of the R pole in FIG. Although the soldering is performed, the lead pin 32 of the T pole is soldered to the outside of the circuit pattern of the printed board 12 merely for mechanical support of the printed board 12.

On the other hand, the zero-phase current transformer 10 is disposed in the vicinity of the power supply terminal 3, and has the fixed contact 5 penetrated as a primary conductor. The zero-phase current transformer 10 has an L
One end of the output pin 33 is connected, and the other end is soldered to the input terminal of the printed circuit board 12. Since the zero-phase current transformer 10 is combined with the overload detecting element (bimetal) 8 having different specifications depending on the rated current at the time of assembling, it may be stocked in common for the bimetal 8 of each rated current.

In FIG. 1, the zero-phase current transformer 10 is arranged near the power supply terminal 3 separately from the printed circuit board 12, so that its size is not restricted by the printed circuit board 12. Therefore, the dimensions can be appropriately increased within the range allowed by the space in the mold case, and the degree of freedom in design is large. Here, the power supply side terminal 3 and the fixed contact 5
Fig. 4 (cross-sectional view along the line IV-IV in Fig. 1)
5 (a plan view of the power-supply-side terminal portion in FIG. 1), the fixed contact 5 having the maximum width.
Is larger than the width w of the zero-phase current transformer 10 (d> w). Therefore, the fixed contact 5 is the zero-phase current transformer 1
After assembling 0 into the case 1, it can be inserted into the zero-phase current transformer 10 from the power supply side and combined as shown in FIG.

Next, referring to FIG.
Is disposed between the opening / closing mechanism 6 and the load-side terminal 4 so as to face a trip portion (trip crossbar) 19 of the opening / closing mechanism 6. Thus, a pair of lead pins 34 leading to the lead wire of the coil 16 is provided to the earth leakage trip device 11.
Are connected in a leg shape, and the earth leakage trip device 11 is connected to the lead pin 3.
4 and is supported upright on the output terminal portion of the printed board 12. FIG. 6 shows a front view in which the earth leakage trip device 11 is extracted. As shown in FIG. 1, the plunger 17 attracted by the excitation of the coil 16 is directly connected to the trip crossbar 19, and does not require a relay member such as the lever arm 18 (FIG. 9), so that assembling accuracy can be easily ensured. is there. In addition, since the earth leakage trip device 11 is electrically connected to the printed board 12 by the rigid lead pins 34 and is mechanically supported, the lead wires 24 and 25 (FIG. 11) are unnecessary, and There is no need for processing and no separate support member is required. As shown in FIG. 7, the lead pins 34 are accommodated in grooves 35 formed in the case 1 and the cover 2 and are insulated from the surroundings. As shown in FIGS. 1 and 6, a test switch 14 including a fixed contact 14a and a movable contact 14b is held on the upper part of the earth leakage trip device 11, and the test switch 14 is a lead pin 36 (FIG. 1).
Is connected to the printed circuit board 12 via the.

Next, referring to FIG.
An inverted J-shaped fixed contact body 37 is soldered upright to the power supply terminal of the pole, and the fixed contact body 37 comes into contact with the movable contact 7 in a closed state as shown in the figure, and is indicated by a chain line. As described above, the movable contact 7 is separated from the movable contact 7 in the separated state. The fixed contact body 37, together with the movable contact 7, constitutes the auxiliary switch 22 for detecting the on / off state of the earth leakage breaker. As shown in the connection diagram of FIG. 8, in the ON state of the earth leakage breaker,
Power is supplied to the printed circuit board 12 via the auxiliary switch 22, and when the earth leakage breaker is turned off, the power is cut off. The auxiliary switch 22 has few parts and is inexpensive, and does not require the conventional lead wires 20 and 23 between the load terminal 4 and the printed board 12.

[0017]

As described above, according to the present invention, the number of components and the number of lead wires are reduced, so that assembling work and component management are facilitated, and a highly reliable earth leakage breaker can be manufactured at low cost. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an earth leakage breaker showing an embodiment of the present invention.

FIG. 2 is a bottom view of FIG.

FIG. 3 is a plan view of a load-side terminal portion in a state where a cover of the earth leakage breaker of FIG. 1 is removed.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a plan view of a zero-phase current transformer in a state where a cover of the earth leakage breaker of FIG. 1 is removed.

FIG. 6 is a partial front view taken along the line VI-VI of FIG. 1;

FIG. 7 is a perspective view of a groove portion of a mold case for accommodating a support pin in FIG. 6;

FIG. 8 is an internal circuit diagram of the earth leakage breaker of FIG. 1;

FIG. 9 is a plan view of a conventional earth leakage breaker with a cover removed.

FIG. 10 is a longitudinal sectional view of the earth leakage breaker of FIG. 9;

FIG. 11 is a lead connection diagram of the earth leakage breaker of FIG. 9.

FIG. 12 is an internal circuit diagram of the earth leakage breaker of FIG. 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 Power supply terminal 4 Load side terminal 5 Fixed contact 6 Opening / closing mechanism 7 Movable contact 8 Bimetal 9 Lead wire 10 Zero-phase current transformer 11 Earth leakage trip device 12 Printed board 14 Test switch 15 Test button 22 Auxiliary switch 32 Lead pin 33 Output pin 34 Lead pin 37 Fixed contact body

Claims (8)

[Claims] A fixed contact formed integrally with the power-supply-side terminal between a power-supply-side terminal and a load-side terminal disposed at both ends of a mold case; An energizing path formed by a movable contact that is driven to open and close, an overload detection element that connects the movable contact to the load-side terminal, and a lead wire is formed. In a two-pole type earth leakage breaker equipped with a current transformer, an opening is provided on the back surface of the mold case, a leakage detection signal of the zero-phase current transformer is input, and a trip signal is output to an earth leakage trip device. A printed circuit board having a leakage detection circuit mounted thereon is disposed facing the opening, and the leakage current can be adjusted through the opening. 2. The circuit breaker according to claim 1, wherein a lead pin is connected to the load-side terminal, and the lead pin is connected to a power terminal of the printed board. 3. The method according to claim 1, wherein the zero-phase current transformer is disposed near the power supply side terminal and penetrates the fixed contact, and an output pin connected to the zero-phase current transformer is connected to the printed board. The earth leakage breaker according to claim 1, wherein: 4. The earth leakage breaker according to claim 1, wherein the inner diameter of the zero-phase current transformer is larger than the width of the power supply terminal and the fixed contact. 5. An earth leakage circuit breaker according to claim 1, wherein said earth leakage trip device is arranged between said opening / closing mechanism and said load terminal so as to face a trip portion of said opening / closing mechanism. . 6. The electric leakage device according to claim 5, wherein a lead pin is connected to the electric leakage trip device, and the electric leakage trip device is connected to the printed board via the lead pin and supported upright. Circuit breaker. 7. An earth leakage circuit breaker according to claim 6, wherein an earth leakage test switch is held above said earth leakage trip device. 8. An auxiliary switch comprising the movable contact and a fixed contact body which is fixed to the printed board and which comes into contact with and separates from the movable contact which opens and closes. The auxiliary switch is connected to a power supply circuit of the printed board. The earth leakage breaker according to claim 1, wherein the earth leakage breaker is inserted.