JP3890351B2 - Earth leakage breaker - Google Patents

Description

  The present invention relates to an earth leakage circuit breaker that improves the workability of a conductor passing through a zero-phase current transformer.

  The prior art of the earth leakage breaker is shown in FIG. 6 and FIG. 6 and 7, in the space formed by the case 1 and the cover 2, a fixed contact (not shown) connected to each of the power terminals 3a to 3c and a movable contact that opens and closes with respect to the fixed contact. (Not shown). A bimetal 5 as an overcurrent detection means is connected to the movable contact via a connection line 4, and the bimetal 5 and load terminals 6 a to 6 c are connected to each other by a conductor 7. The conductor 7 for each pole is plate-shaped and passes through the zero-phase current transformer 9 so that the portions penetrating the zero-phase current transformer 9 can be insulated from each other for each pole. Insulating tube 8 or insulating tape as shown is attached. When the ground fault current flowing through the circuit reaches a predetermined value, this leakage breaker is detected by the zero-phase current transformer 9 and is not shown via the leakage detection means 10 by the detection of the zero-phase current transformer 9. By driving the voltage trip device, the link mechanism (not shown) is operated in the same way as during the trip operation, so that the movable contact is separated from the fixed contact.

  By the way, the earth leakage circuit breaker of the prior art shown above is insulated by covering parts such as the insulating tube 8 or the insulating tape because the respective conductors 7 penetrating the zero-phase current transformer 9 are so thickened. There is a problem that the conductor 7 hardly penetrates the zero-phase current transformer 9 during wiring. In addition, when the insulating tube 8 is used, the insulating tube 8 itself may be damaged when the zero-phase current transformer 9 is penetrated, and when the insulating tape is used, the winding work may be defective. was there. Moreover, since the shape of the conductor 7 itself is large, it is difficult to accommodate in the limited space in the earth leakage breaker, and there is a problem that the entire breaker becomes large.

  In view of the above circumstances, an object of the present invention is to provide an earth leakage circuit breaker that can improve the workability for a zero-phase current transformer and can reduce the size of the circuit breaker itself even if it is a conductor having a plurality of poles. It is in.

[Means for solving problems]
In the present invention, in the earth leakage circuit breaker having the first conductor, the second conductor, and the third conductor that are electrically connected to the respective contacts and pass through the zero-phase current transformer and continue to the load terminal, The zero-phase current transformer is circular, the first conductor, the second conductor, and the third conductor are plate-shaped, and the first conductor plate and the second conductor plate have a U-shaped portion. The third conductor plate has a step-like bent portion, and an insulating barrier formed of an insulating resin and insulating each conductor is disposed inside the zero-phase current transformer. A concave holding part to be held on the three conductor plates, and the holding part have opposing projections facing the conductor plate on both sides, and further provided with wings protruding along the longitudinal direction of the opposing projections and then, the first conductive plate and second conductive plate is inserted into ZCT, the insulating bar the third conductive plate And is inserted between the first conductor plate and the second conductor plate, and the third conductor plate is disposed above the first conductor plate and the second conductor plate. To do.

  As described above, according to the present invention, the interpolar insulating barrier is disposed inside the zero-phase current transformer, and the conductors penetrating the zero-phase current transformer can be insulated from each other by the interpolar insulating barrier. Thus, it is not necessary to coat each conductor as in the prior art, and the conductor plate passes through the zero-phase current transformer as it is, so that the penetration work for the zero-phase current transformer is easy. As a result, the conductor can be formed in a small size so that it can be easily arranged in a limited space in the earth leakage circuit breaker. As a result, the workability for the zero-phase current transformer can be improved and the entire circuit breaker can be downsized. effective.

  Embodiments of the present invention will be described below with reference to the drawings using examples.

  Embodiments of the present invention will be described below with reference to FIGS. 1 to 4 show a first embodiment of a leakage breaker according to the present invention. As shown in FIG. 1, the earth leakage breaker of the embodiment has a space formed by the case 11 and the cover 12, and a contact for opening and closing a circuit is built in the space. The contact is composed of a fixed contact 14 provided at one end of the fixed contact base 13 and a movable contact 15 provided at one end of the movable contact base 16. The movable contact 15 contacts the fixed contact 14 to form a circuit. It is possible to energize. The fixed contact base 13 is fixed to the case 11, and the other end is disposed on the outer side of the case 11 to constitute a power terminal 13a. The movable contact base 16 is pivotally supported on the case 11 by a shaft 17 and is urged by a spring 18 so as to be pivotable counterclockwise in FIG. 1. The spring force of the spring 18 makes the movable contact 15 constant with respect to the fixed contact 14. The contact is made with the power of. Further, a bimetal 20 as an overcurrent detection means is connected to the other end of the movable contact base 16 via a lead wire 19, the bimetal 20 has an adjusting screw 20 a at the tip, and a connecting portion with the lead wire 19. Has a heater 21. Further, a load terminal 23 is connected to the bimetal 20 via a conductor 22. In that case, the conductor 22 is provided for each pole (three wires corresponding to three phases in this example), and each of them penetrates the zero-phase current transformer 35. The zero-phase current transformer 35 has a leakage detection means and electronic voltage tripping means (both not shown in FIG. 1) on which electronic components such as ICs are mounted at a position away from this.

  On the other hand, a hook 25 is pivotally supported by a shaft 24 at a position above the movable contact base 16, and the hook 25 is biased counterclockwise by a drive spring 26. A link mechanism portion 40 composed of a plurality of link members is connected between the hook 25 and the lower portion of the movable contact base 16, and the link mechanism 40 is connected to the hook 25 counterclockwise from the position shown in FIG. The movable contact base 16 is rotated clockwise against the urging force of the spring 18 by tripping in conjunction with the operation of the hook 25, and the movable contact 15 is opened from the fixed contact 14. I try to let them. On the other hand, the trip fitting 27 that engages with the hook 25 is pivotally supported by a pin 28 and is urged clockwise by a spring, and one end thereof is locked to a tripping lever 29. The tripping lever 29 has an operating rod 30 at the lower portion thereof, and a central portion is pivotally supported by a pin 31. The tripping lever 29 is biased counterclockwise by a spring, and the end near the pin 31 abuts on the upper end of the trip fitting 27 to lock the trip fitting 27. A common relay shaft 32 is disposed on the opposite side of the trip lever 27 of the trip lever 29. The relay shaft 32 is rotatably supported by the case 11 and is urged clockwise by a spring. Has been. Then, when the corresponding bimetal 20 is bent due to an overcurrent flowing in the circuit of one of the poles, the pressed plate 32a is pressed by the bimetal 20 via the adjustment screw 20a, so that it operates counterclockwise. It has become. Further, when the relay shaft 32 is actuated by the bending operation of the bimetal 32, the operating rod 30 of the tripping lever 29 is pressed and the tripping lever 29 is operated clockwise to engage the tripping lever 29 with the trip fitting 27. I am trying to release the match.

  As shown in FIG. 1, when the circuit is in an energized state due to the contact between the fixed contact 14 and the movable contact 15, when the overcurrent flows, the heater 21 is heated, and the bimetal 20 is bent to the left side by the heating. The relay shaft 32 is actuated counterclockwise, and the relay shaft 32 presses the operating rod 30 of the tripping lever 29 to cause the tripping lever 29 to move in the clockwise direction around the pin 31, and pulls it by the response. The release lever 29 releases the lock on the trip fitting 27, and the trip fitting 27 is rotated clockwise by the spring force by this release, whereby the engagement between the trip fitting 27 and the hook 25 is released, and the hook 25 is driven. It is possible to operate counterclockwise by the spring force of the spring 26, and further, the link mechanism 40 is tripped and the movable contact point 16 is rotated clockwise. The moving contact 15 opens from the fixed contact 14. When the ground fault current flowing through the circuit reaches a predetermined value, the zero-phase current transformer 35 detects it, amplifies the detection signal by a leakage detection means (not shown), and drives the voltage trip device. The voltage trip device presses the operating rod of the trip lever 29, and the trip lever 29 responds clockwise in the same manner as when an overcurrent is detected, and the link mechanism section 40 trips, whereby the movable contact 15 To break apart.

  For this reason, the relay shaft 32, the trip lever 29, the trip fitting 27, and the hook 25 form an overcurrent trip mechanism. Therefore, this circuit breaker includes a contact made up of the fixed contact 14 and the movable contact 15, a link mechanism unit 40 for opening and closing the movable contact 15 with respect to the fixed contact 14, and an overcurrent for causing the link mechanism unit 40 to perform a trip operation. A tripping mechanism and a bimetal 20 are provided. In FIG. 1, reference numeral 41 denotes a handle for opening and closing the contacts.

  Further, in the earth leakage breaker of the embodiment, each of the conductors 22 penetrating the zero-phase current transformer 35 is insulated from each other by the inter-electrode insulation barrier 42. Here, before describing the inter-electrode insulation barrier 42 in detail, the conductor 22 will be described first. As shown in FIG. 2, the conductor 22 corresponds to three phases from the first to third conductor plates 221 to 223. It has become. Of these, the first conductor plate 221 is formed by bending, one end 221 a connected to the heater 21, the other end 221 b constituting the load terminal 23, and an intermediate portion 221 c forming a U-shape. It is a plate body which has. The second conductor plate 222 is symmetrical with the first conductor plate 221. The third conductor plate 223 is bent linearly and substantially stepwise, and an intermediate portion 223c between the one end 223a and the other end 223b forms a horizontal direction. The inter-electrode insulating barrier 42 is formed of an insulating synthetic resin, and is disposed inside the zero-phase current transformer 35 as shown in FIGS. A main body 42a having a shape, wings 42b and 42c that protrude from both sides of the main body 42a and hold the intermediate portion 221c of the first conductor plate 221 and the intermediate portion 222c of the second conductor plate 222, respectively, and an upper portion of the main body 42a Are formed with opposing projections 42d and 42d for holding the intermediate portion 223c of the third conductor plate 223, and leg portions 42e hanging from the bottom of the main body 42a so as to insulate the first to third conductor plates 221 to 223 from each other. ing. When the interpolar insulating barrier 42 is inserted into the zero-phase current transformer 35, the tip of the leg portion 42e is formed in the lower part inside the zero-phase current transformer 35 as shown in FIG. And the wings 42 b and 42 c are disposed inside the zero-phase current transformer 35 by fitting to the support protrusions 35 c projecting from the inside of the zero-phase current transformer 35.

  Next, the case where the conductor 22 and the interelectrode insulating barrier 42 are incorporated in the zero-phase current transformer 35 will be described. First, among the conductors 22, as shown in FIG. 2, the first conductor plate 221 and the second conductor plate 222 are passed through the zero-phase current transformer 35, and the respective intermediate portions 221c and 222c become the zero-phase current transformer 35. Keep it positioned. Next, the intermediate portion 223 c of the third conductor plate 223 is held between the opposing protrusions 42 d and 42 d of the interpolar insulating barrier 42, and this is held, and the first conductor plate 221 and the second conductor plate 222 in the zero-phase current transformer 35. As shown in FIG. 3, the leg portion 42 e of the interpolar insulating barrier 42 is fitted into the recessed portion 35 b of the zero-phase current transformer 35, and the opposing protrusion 42 d is inserted into the zero-phase current transformer 35. Fit to the support protrusion 35c. As a result, the central portion 221c of the first conductor plate 221 is supported by one end of the interpolar insulating barrier main body 42a by the wing portion 42b, and the central portion 222c of the second conductive plate 222 is supported on the other side of the main body 42a. Since the central portion 223c of the third conductor plate 223 is supported by the opposing protrusions 42d, the inter-electrode insulation barrier 42 insulates the first to third conductor plates 221 to 223 from each other. Can be held by.

  As described above, the interpolar insulating barrier 42 is disposed inside the zero-phase current transformer 35, and the conductor plates 221 to 223 that penetrate the zero-phase current transformer 35 can be insulated from each other by the interpolar insulating barrier 42. Therefore, compared with the prior art, it is not necessary to cover each of the conductor plates 221 to 223 one by one. For this reason, it is possible to prevent the conductor plate from becoming thick, and the conductor plate as it is passes through the zero-phase current transformer 35, so that the penetration work to the zero-phase current transformer 35 can be easily performed. Moreover, since the inter-electrode insulating barrier 42 relatively determines the positions of the first to third conductor plates 221 to 223, the performance of the zero-phase current transformer 35 itself is stabilized. In addition, as described above, the conductor plates 221 to 223 do not have insulating parts attached thereto, and they can be formed in a small size as a whole by being appropriately bent. It can be easily placed in a limited space in the vessel.

  FIG. 5 shows another example of the leakage breaker of the present invention. In this case, the first to third conductor plates 221 to 223 that penetrate the zero-phase current transformer 35 are held in an insulated state by the inter-electrode insulating barrier 42. Since the configuration of the interelectrode insulating barrier 42 is the same as that of the first embodiment, the description thereof is omitted here. This embodiment differs from the previous embodiment in that the leakage detecting means of the zero-phase current transformer 35 is accommodated in the insulating case 36 and the insulating case 36 is incorporated in the zero-phase current transformer 35. That is, the insulating case 36 is formed in an approximately U-shape by an insulating synthetic resin, and has a shape that can accommodate a leakage detecting means in which the central body 36a is connected to the zero-phase current transformer 35. In addition, the main body 36 a has a space portion 36 b that can accommodate the upper portion of the zero-phase current transformer 35 itself, and the leg portions 36 c and 36 d on both sides penetrate the zero-phase current transformer 35. The central part 221c and the central part 222c of the second conductor plate 222 are inserted respectively. Then, one leg portion 36c of the insulating case 36 is inserted into the central portion 221c of the first conductor plate 221 protruding outside the zero-phase current transformer 35, and the other leg portion 36d is inserted into the zero-phase current transformer. The main body 36a is inserted into the zero-phase current transformer 35 so that the upper portion of the zero-phase current transformer 35 is accommodated in the space portion 36b of the main body 36a. When covered, the insulating case 36 surrounds the zero-phase current transformer 35. According to this embodiment, when the insulating case 36 houses the leakage detecting means and is assembled, the insulating case 36 surrounds the zero-phase current transformer 35, so that a large current flows through the circuit. Can be prevented from adhering to the zero-phase current transformer 35 and the leakage detection means, and thus the zero-phase current transformer 35 and the leakage detection means can be protected. In this example, the leakage detection means is stored in the main body 36a of the insulating case 36. However, the leakage detecting means may be an outer portion of the main body 36a and is insulated from the surroundings by the insulating case 36 anyway. It may be arranged as follows.

It is a whole sectional view showing the 1st example of the earth-leakage circuit breaker of the present invention. It is a disassembled perspective view which shows the relationship between each conductor plate, an insulation barrier, and a zero phase current transformer. It is a front view which shows the state which integrated the conductor plate and the insulation barrier into the zero phase current transformer. It is sectional drawing which follows the AA line of FIG. It is explanatory drawing which shows the other Example of the earth-leakage circuit breaker of this invention. It is a partially broken front view which shows one structural example of the conventional earth-leakage circuit breaker. Similarly, it is a partially broken side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Case, 12 ... Cover, 14 ... Fixed contact, 15 ... Movable contact, 22 ... Conductor, 221 ... First conductor plate, 222 ... Second conductor plate, 223 ... Third conductor plate, 25 ... Hook, 27 ... Trip Metal fitting, 29 ... Trip lever, 30 ... Operation rod, 32 ... Relay shaft common to all poles, 35 ... Zero phase current transformer, 36 ... Insulating case, 40 ... Link mechanism part, 42 ... Insulation barrier between poles.

Claims (1)

In an earth leakage circuit breaker having a first conductor, a second conductor, and a third conductor, each electrically connected to a contact, penetrating a zero-phase current transformer and continuing to a load terminal,
The zero-phase current transformer is circular, and the first conductor, the second conductor, and the third conductor are plate-shaped,
The first conductor plate and the second conductor plate have a U-shaped shape portion, and the third conductor plate has a stepped bent portion,
Inside the zero-phase current transformer, an insulating barrier that is formed of an insulating resin and insulates each conductor is disposed,
The insulating barrier has a concave-shaped holding portion for holding a third conductor plate,
The holding part has opposing protrusions facing the conductor plate on both sides, and further has a shape provided with wings protruding along the longitudinal direction of the opposing protrusions,
The first conductor plate and the second conductor plate are inserted through a zero-phase current transformer, the third conductor plate is held by the insulation barrier, and is inserted between the first conductor plate and the second conductor plate. And the said 3rd conductor board has been arrange | positioned above the said 1st conductor board and the 2nd conductor board, The earth-leakage circuit breaker characterized by the above-mentioned.

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