JP4736949B2 - Earth leakage breaker - Google Patents

Description

  The present invention relates to an earth leakage circuit breaker applied to a low voltage distribution system, and more particularly to a wiring structure of a main circuit conductor (primary conductor) for a zero-phase current transformer mounted on the circuit breaker.

  In addition to the overcurrent protection functional parts similar to the circuit breaker for wiring, the earth leakage breaker described above is equipped with a zero-phase current transformer that detects the leakage current of the main circuit using the main circuit as the primary conductor. For the zero-phase current transformer, the main circuit conductor connected to the load-side terminal of each pole arranged on the terminal block of the main body case is routed through the annular core of the zero-phase current transformer.

In addition, there are three-pole type earth leakage circuit breakers applicable to three-phase three-wire circuits and four-pole type earth leakage breakers applicable to three-phase four-wire circuits. Then, since the N-phase portion corresponding to the neutral wire is added, the number of main circuit conductors (primary conductors) passing through the annular core of the zero-phase current transformer is increased by one as compared with the three-pole circuit breaker.
In this case, the terminal conductor that penetrates the annular core as the primary conductor of the zero-phase current transformer is shared with the 3-pole earth leakage breaker and 4-pole earth leakage breaker to reduce the component cost, and the circuit breaker is compact. A wiring structure in which terminal conductors are standardized to two types of developed dimension parts is known (see, for example, Patent Document 1).

Next, FIG. 9 shows an assembly structure of a three-pole earth leakage breaker as an example, and FIG. 10 and FIG. 11 show wiring structures of terminal conductors corresponding to the three and four poles disclosed in Patent Document 1. Shown in
First, in FIG. 9, 1 is a main body case of a circuit breaker (a cover is omitted with a molded resin case), 2R, 2S, and 2T are cases in which terminal portions are arranged on the load side terminal block 1a of the main body case 1 on the left and right sides. Terminal conductors of R, S, and T phases that are routed inside, 3 is an opening / closing mechanism portion of a main circuit contact, 4 is an arc extinguishing device of a current interrupting portion, 5 is an operation handle, 6 is an overcurrent trip device, 7 Is a zero-phase current transformer, 8 is a leakage detection circuit, and 9 is a trip coil unit. As shown in FIG. 10, conductors 2R-1, 2S-1 connected to the terminal portions of the terminal conductors 2R, 2S, 2T of the respective phases. , 2T-1 is bent into a U-shape, and the annular core of the zero-phase current transformer 7 is passed through and routed inside the main body case 1 to provide the conductors 2R-1, 2S-1, 2T for each phase. -1 is connected to an overcurrent trip device (bimetal heater).

  Here, the terminal conductors 2R and 2S are U-shaped conductor parts having the same unfolded dimensions and opposite shapes, and the U-shaped conductors 2R-1 and 2S at the portion penetrating the annular core of the zero-phase current transformer 1. −1 is inserted and arranged so as to face each other in the opposite direction. Further, the terminal conductor 2T is set so that the length of the conductor 2T-1 is longer than that of the terminal conductors 2R and 2S, and is arranged so as to overlap the inside of the conductor 2S-1 from the same direction as the terminal conductor 2S. .

On the other hand, in the wiring structure applied to the four-pole earth leakage breaker shown in FIG. 11, an N-phase terminal conductor 2N corresponding to the neutral wire of the three-phase four-wire circuit is added to the right end side of the terminal block 1a. . Here, the terminal conductors 2R and 2N arranged at both ends of the terminal block 1a are provided with U-shaped conductor parts having the same unfolded dimensions as the terminal conductor 2T in FIG. 10 and the opposite shapes, and the terminal conductors 2S and 2T. Employs conductor parts having the same shape as the terminal conductors 2R and 2S in FIG. 10, and the conductors 2R-1 and 2N-1 of the terminal conductors 2R and 2N are arranged inside the conductors 2S-1 and 2T-1 of the terminal conductors 2S and 2T. Are placed side by side so as to overlap.
JP-A-6-215682 (FIGS. 1 and 2)

  Incidentally, the above-described terminal conductor wiring structure has the following problems. That is, in FIG. 10, the conductor 2S-1 of the terminal conductor 2S and the conductor 2T-1 of the terminal conductor 2T overlap inward and outward in the conductor thickness direction at the annular core penetration portion of the zero-phase current transformer 7, and in FIG. 2R / 2S and 2T / 2N conductors overlap each other in the conductor thickness direction. Therefore, the dimension d in the front-rear direction occupied by the terminal conductors of each phase including the zero-phase current transformer 7 is increased, and other parts (overcurrent trip device, opening / closing mechanism part) housed in the main body case 1 correspondingly. , Current interrupting part, etc.) are limited to secure a space for storing the circuit breaker, and the circuit breaker becomes larger.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a terminal conductor component in three and four poles for a load-side main circuit terminal conductor (primary conductor) to be inserted into a zero-phase current transformer. An object of the present invention is to provide an earth leakage circuit breaker which is improved so that it can be made compact while minimizing the depth dimension occupied by the assembly of terminal conductors including a zero-phase current transformer while minimizing the common use.

In order to achieve the above object, according to the present invention, there is provided a multi-pole earth leakage breaker having a main body case equipped with a contact switching part of a main circuit and a zero-phase current transformer having a main circuit as a primary conductor. In what is wired by routing the terminal conductor of each pole arranged on the side terminal block through the annular core of the zero-phase current transformer and inside the main body case,
With the exception of the N-phase terminal conductor corresponding to the neutral line of the main circuit, the R, S, and T-phase terminal conductors are bent into a U-shape at the core penetration portion, and then the annular core is connected to the zero-phase current transformer. The N-phase terminal conductor is divided into two conductor parts, and the divided conductor parts are divided into the front and rear sides of the annular core to provide other R, S, T-phase terminals. After shifting the position so that it does not overlap with the wiring path of the conductor and arranging them on the same surface, the connecting end portions are butted against each other from the front and rear at the center of the inner periphery of the annular core (Claim 1). Specifically, the wiring structure is configured in the following manner.
(1) About the said N phase terminal conductor, the connection end parts of the division | segmentation conductor components are screw-fastened on the annular core inner peripheral side of a zero phase current transformer, and are mutually connected (Claim 2).
(2) The terminal conductor for each phase of R, S, T is a common part for 3 poles and 4 poles, and for the circuit breaker for 4 poles, the terminal part of N phase conductor is the terminal for each of R, S, T phase conductors It is arranged side by side and arranged at either the left or right end of the main body case terminal block (claim 3).
(3) An insulating barrier member is provided for the annular core of the zero-phase current transformer, which is inserted into the core from the front and rear to hold the phase terminal conductors in a separated position (Claim 4). Is composed of a rectangular frame divided into two parts in the front and rear, and with each phase terminal conductor assembled to a zero-phase current transformer, the rectangular frame is fitted from the front and back to the inner periphery of the annular core to isolate the conductors of each phase. It is made to hold | maintain (Claim 5).

  According to said structure, it applies to a 4-pole earth-leakage circuit breaker by using the terminal conductor of R, S, T each phase fitted to the annular core of a zero-phase current transformer as a shared component, applying to a 3-pole earth-leakage circuit breaker In this case, the R, S, and T-phase wiring structure can be used as it is, and an N-phase terminal conductor can be simply added thereto. In addition, the N-phase terminal conductor is arranged so that the conductors of the respective phases are arranged on the same plane by shifting the wiring path so as not to overlap with the terminal conductors of the other phases in the conductor thickness direction, so that a zero-phase current transformer is included. By minimizing the depth dimension occupied by the wiring structure of the terminal conductor, it is possible to expand the storage space for other functional components mounted in the same main body case.

  In addition, the N-phase terminal conductor is divided into two conductor parts and arranged on both the front and rear sides of the annular core, and then the connection end is brought into contact with the inner peripheral center of the annular core of the zero-phase current transformer and screwed. As a result, the assembly workability of the terminal conductors is improved, and further, the annular core of the zero-phase current transformer is inserted into the inner peripheral hole of the core from the front and back to hold the terminal conductors of each phase in a separated position. By providing the insulating barrier member, the terminal conductor of each phase is stably held at a predetermined position without fear of contact, and the insulation creepage distance of each phase conductor terminal can be secured.

Hereinafter, embodiments of the present invention will be described based on the examples shown in FIGS. In addition, in the figure of an Example, the same code | symbol is attached | subjected to the member corresponding to FIGS. 9-11, and the description is abbreviate | omitted.
First, the wiring structure of the primary conductor applied to the zero-phase current transformer of the quadrupole earth leakage breaker is shown in FIGS. In this embodiment, with respect to the main body case 1 of the earth leakage circuit breaker shown in FIG. 2, the load-side terminal block 1a has terminal conductors 2N, 2R corresponding to the N-phase, R-phase, S-phase, and T-phase in order from the left side. , 2S, 2T are arranged, and conductors connected to the terminal portions thereof are routed through the annular core of the zero-phase current transformer 7 and wired inside the main body case.

  Here, the terminal conductors 2R, 2S, and 2T corresponding to the R, S, and T phases are common parts that can also be applied to the three-pole leakage breaker, and each terminal conductor penetrates the annular core of the zero-phase current transformer 7. The part to be bent is formed in a U shape. That is, the U-phase terminal conductor 2R and the T-phase terminal conductor 2T have the conductors 2R-1 and 2T-1 extending in the lateral direction from the terminal portion toward the zero-phase current transformer 7, and the intermediate portion thereof is It is bent and formed in a U shape in opposite directions. In contrast, the S-phase terminal conductor 2S extends vertically from the conductor 2S-1 or the terminal portion, and its intermediate portion is bent into a U-shape. FIG. In the assembled state, the conductors 2R-1, 2S-1, 2T-1 of each phase are arranged on the same plane.

  On the other hand, the conductor of the N-phase terminal conductor 2N is divided into a front-side conductor 2N-1a and a rear-side conductor 2N-1b connected to the terminal portion, and the wiring path is R as shown in FIG. , S and T are formed so as to bypass the upper and lower sides of the terminal conductors 2R and 2S so as not to overlap with the terminal conductors of the respective phases and to be arranged on the same plane as the terminal conductors of the other phases in the assembled state (see FIG. 1 (b)). Further, tab-shaped connection ends 2N-2 are formed at the tips of the divided conductors 2N-1a and 2N-1b from the front and rear to fit into the inner periphery of the core of the zero-phase current transformer 7. A screw hole for passing the fastening screw 10 is opened in the plate surface of the connection end.

In addition, in the illustrated embodiment, a phase change conductor is used as an insulating barrier member that separates and holds the terminal conductor of each phase inserted into the annular core of the zero phase current transformer 7 at a predetermined position separately from the terminal conductor components. Square frames 11 and 12 which are fitted into the annular core from the front and rear of the flow device 7 are prepared.
Next, an assembling procedure for assembling the above-described components to the zero-phase current transformer 7 will be described with reference to FIGS. 1 (a), 5 and 6. FIG. First, the U-shaped conductors 2R-1 and 2T-1 of the terminal conductors 2R and 2T are inserted into the annular core of the zero-phase current transformer 7 from the left and right from the exploded state of FIG. Next, the rear-side divided conductor 2N-1b of the N-phase terminal conductor 2N is overlapped on the rear side of the annular core, and the connection end 2N-2 is fitted into the center of the inner periphery of the annular core. Subsequently, the rectangular frame 12 of the insulating barrier member is fitted into the inner periphery of the annular core from the back side of the divided conductor 2N-1b, and surrounds the connection end 2N-2 of the divided conductor 2N-1b. The state of this assembly stage is shown in FIG.

  Next, the split conductor 2N-1a of the terminal conductor 2N is overlapped on the annular core from the front side of the zero-phase current transformer 7, and the tab-shaped connection end 2N-2 is fitted into the inner periphery of the core. The parts 2N-2 are butted against each other. Subsequently, the fastening screw 10 is screwed into the abutting portion of the connection end 2N-2 from the front to interconnect the divided conductor 2N-1a on the front side and the divided conductor 2N-1b on the rear side. FIG. 6 shows the state of this assembly stage.

From this assembly stage, the U-shaped conductor 2S-1 of the S-phase terminal conductor 2S is then inserted into the gap remaining between the inner peripheral edge of the annular core and the connection end 2N-2, and finally the front 3 is inserted into the inner periphery of the annular core to complete the assembled state of FIG.
Next, FIG. 4 shows the arrangement of the terminal conductors of each phase and the insulating barrier members inserted into the annular core of the zero-phase current transformer 7. As can be seen from this figure, the connection end 2N-2 of the N-phase terminal conductor is located in the center of the inner periphery of the annular core, and the conductors 2R of the R, S, T phases are disposed so as to surround the connection end 2N-2. −1, 2S-1 and 2T-1 are arranged on the left and right sides and the lower side along the inner circumference of the core, and are separated by an insulating barrier member so that the conductors do not contact each other.

In the above assembly structure, as shown in FIG. 1B, the terminal conductors of the respective phases that are inserted into the zero-phase current transformer 7 and are routed to the front and rear surfaces thereof are arranged on the same surface without overlapping in the front and rear. It is out. Thereby, compared with the wiring structure shown in FIG. 11, the depth dimension d of the conductor containing a zero phase current transformer can be reduced.
In the illustrated example, the N-phase terminal conductor 2N is disposed on the left end side of the main body case terminal block 1a shown in FIG. 2, but conversely, the N-phase terminal conductor 2N is disposed on the right end of the terminal block 1a. It is also possible to arrange the load side terminals in the order of R, S, T, N phase. In this case, the terminal conductor 2N is shaped symmetrical to the illustrated example.

  Next, FIGS. 7 and 8 show the primary conductor wiring structure of the zero-phase current transformer 7 in which the R, S, and T phase terminal conductors 2R, 2S, and 2T are applied to the three-pole earth leakage circuit breaker as a common part. . Even in this assembly structure, the depth dimension of the terminal conductor assembly is the same as the dimension d shown in FIG.

It is a wiring structure diagram of the embodiment of the present invention applied to a four-pole earth leakage breaker, (a) is an exploded perspective view showing a state before the main circuit terminal conductor of each phase is assembled to the zero-phase current transformer, (b) is Plan view of the assembled state Configuration perspective view of a quadrupole earth leakage breaker in which the assembly of FIG. A perspective view of FIG. Sectional drawing showing arrangement | positioning of the terminal conductor of each phase and insulation barrier which were inserted by the annular core of the zero phase current transformer in FIG. The perspective view showing the assembly stage which assembled | attached the R side, T phase terminal conductor, and the rear side division | segmentation conductor of the N phase terminal conductor from the state of Fig.1 (a) to the annular core of a zero phase current transformer. FIG. 5 is a perspective view showing an assembly stage in which the front side divided conductor of the N-phase terminal conductor is assembled and screwed together. The perspective view showing the wiring structure of the main circuit terminal conductor which applied the R, S, T phase terminal conductor in FIG. Plan view of FIG. Configuration perspective view showing assembly structure of 3-pole earth leakage breaker The top view showing the conventional assembly structure of the main circuit terminal conductor assembled | attached to the zero phase current transformer of 3 pole earth-leakage circuit breaker The top view showing the assembly structure of the main circuit terminal conductor which applied the terminal conductor of FIG.

Explanation of symbols

1 Breaker body case 2R, 2S, 2TR, S, T-phase terminal conductor 2R-1, 2S-1, 2T-1 U-shaped conductor 2N N-phase terminal conductor 2N-1a, 2N-1b Split conductor 2N-2 Connection end 7 Zero-phase current transformer 10 Fastening screw 11, 12 Square frame (insulation barrier)

Claims (5)

This is a multi-pole earth leakage circuit breaker equipped with a main circuit contact opening / closing part and a zero-phase current transformer with the main circuit as the primary conductor. Zero terminal conductors are arranged on the load side terminal block of the main body case. In what is wired through the body case through the annular core of the phase current transformer,
With the exception of the N-phase terminal conductor corresponding to the neutral line of the main circuit, the R, S, and T-phase terminal conductors are bent into a U-shape at the core penetration portion, and then the annular core is connected to the zero-phase current transformer. The N-phase terminal conductor is divided into two conductor parts, and the divided conductor parts are divided into the front and rear sides of the annular core to provide other R, S, T-phase terminals. An earth leakage circuit breaker characterized in that it is arranged on the same surface while being shifted in position so as not to overlap with the wiring path of the conductor, and its connection end portions are butted against each other from the front and back at the center of the inner periphery of the annular core. . 2. The earth leakage circuit breaker according to claim 1, wherein the connection end of the divided conductor part of the N-phase terminal conductor is screwed and interconnected on the inner peripheral side of the annular core of the zero-phase current transformer. vessel. The earth leakage circuit breaker according to claim 1, wherein the terminal conductors of each of the R, S, and T phases are shared parts of the three-pole and four-pole specifications, and the terminal portion of the N-phase conductor is defined as R, An earth-leakage circuit breaker, wherein the circuit breaker is arranged at one of the left and right ends of the main body case terminal block alongside the terminal portions of the S and T phase conductors. The earth leakage circuit breaker according to claim 1, further comprising an insulating barrier member that is inserted into the core from the front and rear sides of the annular core of the zero-phase current transformer to hold the phase terminal conductors in a separated position. An earth leakage circuit breaker. 5. The earth leakage circuit breaker according to claim 4, wherein the insulating barrier member is constituted by a rectangular frame divided into front and rear, and the rectangular frame is disposed in an annular core in a state where each phase terminal conductor is assembled to a zero-phase current transformer. An earth leakage circuit breaker characterized by being fitted to the circumference from the front and rear.

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