JPH03233824A - earth leakage breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an earth leakage breaker, and more particularly to an earth leakage breaker that also serves as overload protection or short circuit protection.

[Conventional technology]

FIG. 8 shows a conventional three-pole type earth leakage breaker of this type, and the figure is a longitudinal sectional view of the central pole portion. In the figure, 1 is a case made of molded resin, 2 is a cover, 3 is a fixed contact integrated with the terminal plate 3a on the power supply side, 4 is a movable contact that opens and closes with respect to this, and 5 is a movable contact. 4 is an opening/closing mechanism that drives opening and closing, 6 is an overcurrent tripping mechanism that is activated by detecting an overload current or short circuit current, and 7 is a movable contact 4 and one end of the tripping coil 6a of the overcurrent tripping mechanism 6. Visible lead wire to connect, 8 is the terminal board on the load side,
9 is a flexible conductor made of stranded copper wire, one end of which is brazed to the tripping coil 6a and the other end is brazed to the terminal plate 8; 10 is a zero-phase current transformer with conductor 9 as the primary conductor; vessel, 11
12 is an amplification section that amplifies the secondary output of the zero-phase current transformer, and 12 is an earth leakage tripping mechanism that operates in response to the output of this amplification section 11. Figure 9 is an enlarged view of the portion from the overcurrent tripping mechanism 6 to the terminal plate 8 in Figure 8, with Figure 9 (A) being a plan view and Figure 9 (B) being a side view. be. As shown in the figure, various conductors 9 are bundled between the overcurrent release mechanism 6 and the terminal plate 8, and pass through the hollow part of the annular zero-phase current transformer 10. In such a configuration, current flows from the terminal plate 3a to the fixed contact 3, the movable contact 4, the lead wire 7, and the trip coil 6.
a, it flows through the conductor 9 to the terminal board 8, but if an overload current or short circuit current flows in this circuit, the overload release mechanism 6 attracts the armature 6b and releases the latch of the opening/closing mechanism 5,
The movable contact 4 is rapidly opened. Furthermore, when a current leak occurs in a device to which the illustrated earth leakage breaker is connected, the current flowing to the secondary side of the zero-phase current transformer 10 that has detected the ground fault current is transferred to the amplifier 11.
is amplified by the trip coil 12 of the earth leakage tripping mechanism 12.
added to a. As a result, the earth leakage tripping mechanism 12 attracts the armature 12b, hits the armature 6b of the overcurrent disconnection mechanism 6, and opens the movable contact 4.

[Problem to be solved by the invention]

However, in such a conventional earth leakage breaker, the earth leakage tripping mechanism 12 is connected to the overcurrent tripping mechanism 6 and the zero-phase current transformer 1.
0, and the amplifying section 11 is provided below the primary conductor 9 along the running direction. The dimension in the longitudinal direction (left-right direction in the figure) of the case l between the closing mechanism 6 and the terminal Fi8 is significantly large. Therefore, the case 1 and cover 2 of the earth leakage breaker and the above-mentioned molded circuit breaker have different configurations and are not structurally compatible.
Furthermore, earth leakage circuit breakers were larger than molded circuit breakers and required a large amount of space when installed on the board. Furthermore, in the illustrated earth leakage breaker, a flexible conductor is used for the primary conductor 9, and its length is quite long for the above reasons, so the earth leakage detection part partially assembled in the state shown in FIG. 9 has a shape as a whole. is not fixed, and in order to assemble it into case 1, it is necessary to support the overcurrent release mechanism 6 and terminal board 8 one pole at a time by hand and insert it into the specified location of case 1, which requires a lot of effort. Ta. This invention miniaturizes the earth leakage breaker so that it has the same dimensions as a molded case circuit breaker without the earth leakage protection function, making both structurally compatible and making it easy to incorporate the earth leakage detection part. The purpose is to provide an earth leakage breaker.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a zero-phase current transformer whose primary conductor is a conductor between an overcurrent disconnection mechanism and a terminal plate on the load side, and a secondary current of this zero-phase current transformer. In an earth leakage breaker equipped with an amplifying section that amplifies the current, and an earth leakage tripping mechanism that operates in response to the output of this amplifying section and opens a movable contact via an opening/closing mechanism, the primary A conductor is constructed, one end of which is connected to the overcurrent disconnection mechanism, and the other end is integrally provided with a load-side terminal plate, and an amplification is installed in a gate-shaped case placed perpendicularly to the primary conductor and placed over the zero-phase current transformer. These are integrated into a unit, and the earth leakage tripping mechanism is arranged side by side with the opening/closing mechanism.

[For use]

The opening/closing mechanism that drives each type to open and close all at once is commonly provided on one of the poles (usually the center pole for a three-pole configuration, or either the left or right pole for a two-pole configuration), and there are There is plenty of space. Also, only one earth leakage tripping mechanism is provided corresponding to the zero-phase current transformer. Therefore, the earth leakage tripping mechanism is arranged side by side with the opening/closing mechanism to reduce the space required between the overcurrent tripping mechanism and the terminal board on the load side. Further, there is sufficient space above and on the left and right sides of the zero-phase current transformer through which the primary conductor passes. Therefore, by arranging the electronic components that make up the amplification section flat on a printed circuit board and housing them in a gate-shaped case that covers the zero-phase current transformer orthogonally to the primary conductor, it is possible to Keep the dimensions within the thickness range of the zero-phase current transformer. By these means, the longitudinal dimension required between the overcurrent release mechanism and the load-side terminal board to accommodate the zero-phase current transformer and amplifier can be reduced, and the distance between them without an earth leakage protection function can be reduced. It becomes possible to reduce the size to the same level as a molded case circuit breaker simply connected with a conductor. Furthermore, the primary conductor is made of a rigid strip material, one end of which is connected to the overcurrent release mechanism, and the other end is integrally provided with a terminal board on the load side. By attaching the shaped case to the zero-phase current transformer and making them into a unit, the part from the overcurrent release mechanism to the terminal plate can be assembled into the case in one operation as an assembled structure with a constant shape.

【Example】

Hereinafter, the present invention will be explained in detail based on FIGS. 1 to 7. In the following embodiments, the same reference numerals are used for parts corresponding to those in the conventional example shown in FIG. First, Figure 2 is a plan view showing the inside of the earth leakage breaker, and Figure 3 is a cross-sectional view (however, the part from the earth leakage tripping mechanism and the overcurrent disconnection mechanism to the terminal board on the load side is a side view. ). In the figure, 1 is a case made of molded resin, 2 is a cover, and 3 is a terminal board 3 on the power supply side.
4 is a movable contact that opens and closes the movable contact 4, and 5 is an opening/closing mechanism that opens and closes the movable contact 4 (in Fig. 3, only a portion is shown because it overlaps with the earth leakage tripping mechanism described later). (shown by a two-dot chain line), 6 is an overcurrent release mechanism that operates by detecting overload current and short circuit current, 7 is the movable contact 4 and one end of the heater conductor 6a of the overcurrent release mechanism 6. The fixed conductor 9 connects with the tripping coil 6 at one end.
10 is a zero-phase current transformer whose primary conductor is the conductor 9, and 13 is an amplifier section that amplifies the secondary output of the zero-phase current transformer. 11 (Figure 1)
12 is an earth leakage tripping mechanism that operates in response to the output of the amplifier section 11. Current flows from the terminal plate 3a to the terminal plate 8 via the fixed contact 3, movable contact 4, fixed conductor 7, heater conductor 6a, and conductor 9, but the fixed conductor 7 replaces the lead wire 7 of the conventional example. One end is in sliding contact with the movable contact 4 that moves to open and close, and the other end is overlapped with the heater conductor 6a.
is tightened. In the illustrated embodiment, the overcurrent release mechanism 6 is of a so-called thermal-electromagnetic type, and when an overload current flows, the bimetal 6c is bent due to the heat generated by the heater conductor 6a, and When a large current flows, the latch of the opening/closing mechanism 5 is tripped by instantaneous adsorption of the armature 6b by the fixed iron core 6d. The earth leakage tripping mechanism 12 is arranged side by side on the right side of the opening/closing mechanism 5. To briefly explain this with the enlarged side view of FIG. 4, the earth leakage tripping mechanism 12 includes an electromagnet W15,
A slider 17 that is guided by rollers 16 and slides to the left and right in the figure, an operation display bar 18, and a base 19 that holds these.
, a trip spring 20 mounted between the base 19 and the slider 17, and the like. ! It consists of a magnet device 15b, a yoke 15a, a permanent magnet 15b, a fixed iron core 15c, a plunger 15d, a trip coil 15e, etc.
The plunger 15d is normally attracted to the fixed iron core 15c by the magnetic flux of the permanent magnet 15b acting through the yoke 15a. The slider 17 is subjected to a force to the left in the figure due to the tensile force of the tripping spring 20, but is blocked by the plunger 15d that comes into contact with it via the push rod 21, and is always maintained in the state shown in the figure. In this state, when the trip coil 15c is energized, its magnetic flux cancels the magnetic flux of the permanent magnet 15b, so the attraction of the plunger 15d is released and the slider 17 slides to the left in the figure by the spring force of the tripping spring 20. do. Returning to FIG. 3, the slider 17 that has slid to the left uses the hook-shaped operating portion 17a to engage the trip crossbar 22.
is rotated counterclockwise in the figure to unlatch the opening/closing mechanism 5 and separate the movable contact 4. As shown in FIG. 5, the earth leakage tripping mechanism 12 is attached to the case 1 in a fitting manner. That is, in FIG. 5, the case 1 is provided with a mounting groove 23 in the side wall 1a and a mounting groove 24 in the partition wall 1b between the right pole and the center pole, and the base 19 of the earth leakage tripping mechanism 12 has these grooves. Corresponding mounting legs 19a and 19b are provided. Therefore, mounting groove 2
By aligning the mounting legs 19a and 19b with 3 and 24 and inserting them from above, the earth leakage tripping mechanism 12 is attached to the case 1.
It can be attached to. This earth leakage tripping mechanism 12 is fixed by a cover 2 placed over the case 1 so as not to come out. FIG. 1 is an enlarged perspective view showing in detail the portion from the overcurrent release mechanism 6 to the terminal plate 8 of the earth leakage breaker shown in FIGS. 2 and 3. FIG. In the figure, the primary conductor 9 is formed by punching and bending a copper strip into the shapes shown for each phase of R, S, and T (9R and 9T are symmetrical).
, and the heater conductor 6a of the overcurrent release mechanism 6 are integrally joined by brazing. Heater conductor 6a and fixed core 6d
is caulked with the pin 6e. Armature 6
b is rotatably supported by the case 1 via arms protruding left and right, but a return spring 6f is hooked between the armature 6b and the fixed core 6d, and the armature 6b
It is constantly biased in the clockwise direction in the figure. The gate-shaped case 13 connects the zero-phase current transformer 1 orthogonally to the primary conductor 9.
0, and its thickness in the front-rear direction is almost the same as that of the zero-phase current transformer 10. One side of the gate-shaped case 13 (the front right side side in the figure) is open, and electronic components such as ICs and thyristors that make up the amplifying section 11 are mounted on the printed board attached to the bottom of the case. It is arranged in a plane so that it fits within 13. Zero phase current transformer 10
The lead wire 25 and the lead wire 26 on the input side of the amplifier section 110 are connected by a connector 27, and the output side lead wire 28 of the amplifier section 11 and the earth leakage tripping mechanism 12 are connected through a connector 29. Power of the amplifying section (1) is supplied from a lead wire 30 connected to the primary conductors 9R, 9T to a power terminal 31 of the amplifying section via a connector (not shown). In order to incorporate these into case 1, the primary conductor 9 and heater conductor 6a are joined together, and the gate-shaped case 13 is placed over the zero-phase current transformer 10 to form a unit. insert. Then, as shown in FIG. 3, screws 14 and 34 are used to tighten the case 1 from below using the screw holes 32 of the heater conductor 6a and the screw holes 33 of the terminal board 8. At this time, the lower part of the zero-phase current transformer 10 is supported and positioned by an arcuate receiving groove (not shown) at the bottom of the case 1. Further, both shoulders 13a of the gate-shaped case 13 are pressed and fixed by the cover 2. In such a configuration, when an overload current or short circuit current passes through the earth leakage breaker, the bimetal 6c bends to the left in FIG. 3, or the armature 6b is attracted to the fixed iron core 6d and the It rotates counterclockwise in FIG. 1 and hits the trip cross spar 22 with its upper end to separate the movable contact 4. Furthermore, when a ground fault current flows due to an earth leakage, the output of the zero-phase current transformer 10 that detects this is amplified by the amplifying section 11 and applied to the trip coil 14e of the earth leakage tripping mechanism 12. 17 slides to the left in FIG. 1 and hits the trip cross spar 22, causing it to separate like the movable contact 4. According to the illustrated configuration, the earth leakage tripping mechanism 12 is disposed on the side of the opening/closing mechanism 5, and the amplifying section 11 is housed in a flat case 13 placed over the zero-phase current transformer 10 so as to be perpendicular to the primary conductor 9. Therefore, the longitudinal dimension from the current-carrying disconnection mechanism 6 to the terminal plate 8 on the load side is significantly reduced compared to the conventional example, and the leakage detection section (zero-phase current transformer 10 and amplifier section 11)
It is as compact as a molded case circuit breaker without one. In addition, the primary conductor 9 is made of a rigid copper strip and is integrally joined to the overcurrent release mechanism 6, and the gate-shaped case 13 is placed over the zero-phase current transformer IO to reduce the overall shape. Since they are formed into a uniform unit, they can be inserted into the case 1 in one motion, making assembly work easy. Figure 6 shows the overcurrent detection part when constructing a molded case circuit breaker excluding only the earth leakage detection function by using the circuit breaker main body of the earth leakage breaker shown in Figures 2 and 3 as is. 7
The figure shows a molded circuit breaker incorporating this. In FIG. 6, a conductor 35 of the same shape made of a copper strip is brazed to the multi-pole overcurrent release mechanism 6, and a terminal plate 8 is integrally formed at the end thereof. The positional relationship between the screw hole 32 of the heater conductor 6a and the screw hole 33 of the terminal plate 8 with respect to the case 1 is exactly the same as in the earth leakage circuit breaker shown in FIGS. 2 and 3, and the unit shown in FIG. , the unit consisting of the overcurrent tripping mechanism 6 and the main circuit conductor 35 shown in FIG. 6 can be incorporated as is. That is, according to the illustrated configuration, the longitudinal dimension of the portion of the earth leakage breaker from the overcurrent tripping mechanism 6 to the terminal board 8 can be kept to the same level as that of a molded case circuit breaker with the same rating and without an earth leakage protection function. By using the same circuit breaker body for the earth leakage breaker and the molded case circuit breaker, and selecting the unit shown in Figure 1 or Figure 6 to be incorporated into it, you can freely use either the earth leakage breaker or the molded case circuit breaker. It will be possible to configure. This allows for rationalization in the factory, such as simplified parts management and common assembly lines, as well as various advantages in use, such as increased freedom of placement on the panel since the external dimensions of both are the same. Force Z is generated.

【Effect of the invention】

According to this invention, the earth leakage breaker can be made as small as a molded circuit breaker without the earth leakage protection function, making it possible to share the main body of the circuit breaker, and making it easy to incorporate the earth leakage detection section. .

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing an earth leakage detection unit in an embodiment of the present invention, Fig. 2 is a plan view showing the inside of an earth leakage breaker equipped with the earth leakage detection unit of Fig. 1, and Fig. 3 is a longitudinal section thereof. Figure, 4th
The figure is an enlarged side view of the earth leakage tripping mechanism in Figures 2 and 3, Figure 5 is an exploded perspective view showing the configuration for incorporating the earth leakage tripping mechanism in Figure 4 into a case, and Figure 6 is an exploded side view of the earth leakage tripping mechanism shown in Figure 4. Figure 3 is an exploded perspective view showing an overcurrent detection section of a molded circuit breaker that is incorporated into the circuit breaker body in place of the earth leakage detection section shown in Figure 1, and Figure 7 is an exploded perspective view showing the overcurrent detection section of the molded circuit breaker that is incorporated into the circuit breaker body in place of the earth leakage detection section shown in Figure 6. FIG. 8 is a vertical cross-sectional view of a conventional example, FIG. 9 (A) is a plan view of the earth leakage detection section in FIG. 8,
FIG. 9(B) is a side view thereof. 5... Opening/closing mechanism, 6... Overcurrent tripping mechanism, 9...
・-Illustrated illustration of Yoshihide Komada, a side patent attorney

Claims (1)

[Claims] 1) A zero-phase current transformer whose primary conductor is the conductor between the overcurrent tripping mechanism and the terminal board on the load side, an amplifier section that amplifies the secondary current of this zero-phase current transformer, and this amplifier section. In an earth leakage breaker equipped with an earth leakage tripping mechanism that operates in response to the output of A terminal plate on the load side is connected to the tripping mechanism and is integrally provided at the other end, and an amplifying section is housed in a gate-shaped case placed perpendicularly to the primary conductor and placed over the zero-phase current transformer to form a unit. The earth leakage breaker is further characterized in that an earth leakage tripping mechanism is arranged side by side with the opening/closing mechanism.