JPH03152822A - Wiring breaker with leakage alarming function - Google Patents

Abstract

PURPOSE:To enhance the miniaturization of a wiring breaker and the labor saving in the installation work to a board, and prevent the shock and vibration at the time of switching operation of the switching mechanism part in a case and the chattering of an internal contact by building a zero phase current transformer and a leakage relay in the breaker case of the wiring breaker. CONSTITUTION:A heavy-weighted zero phase current transformer 7 consisting of an iron core and a coil is held in a sealed vessel 27. The vessel 27 is inserted into a hole 2c formed on a base 2a and fixed to the base 2a. A leakage relay 8 is firmly mounted onto the side surface of the vessel 27. As the relay 8 is firmly fixed to the sealed vessel 27 of the heavy-weighted current transformer 7 through a mounting plate 21, the shock and vibration received by a cover 2b is not transmitted to the relay 8 as a large shock and vibration. Therefore, the shock and vibration caused at the time of switching operation of a switching mechanism part 20 is extremely attenuated, and hardly transmitted to the internal contact 50 of the leakage relay 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a molded case circuit breaker with an earth leakage alarm function that has a function of detecting earth leakage in a power distribution line.

[Prior Art] Molded case circuit breakers are used to protect power distribution lines from overloads and short circuits, but when constantly monitoring current leakage in power distribution lines equipped with this type of molded case circuit breaker, it is necessary to An earth leakage alarm system that combines a phase current transformer and earth leakage relay was installed on this distribution line. For this reason, two devices, a molded circuit breaker and an earth leakage alarm device, were installed in the power distribution line. When a leakage occurs in this distribution line, a zero-phase current transformer installed in the distribution line detects the leakage current, and this detection signal is amplified to drive the earth leakage relay and issue an alarm. .

[Problems to be Solved by the Invention] As mentioned above, conventionally, the earth leakage alarm device and the molded circuit breaker must be placed separately, and wiring between them is also required, so it is difficult to provide these devices. There was a problem in that the board space was large and the installation to the board was time-consuming.

This invention was made to solve this problem, and by incorporating a zero-phase current transformer and an earth leakage relay into the circuit breaker case of a molded circuit breaker, the space of the panel can be saved and the circuit breaker can be made smaller and smaller. Installation on the panel saves labor, and
Wiring with an earth leakage alarm function that prevents chattering at the internal contacts of the earth leakage relay due to shocks and vibrations generated by the opening/closing mechanism inside the circuit breaker case during opening/closing operations, and electromagnetic rusting caused by changes in current when the main circuit connects and disconnects. The purpose is to obtain a circuit breaker for use.

[Means for Solving the Problems] In order to achieve the above object, the circuit breaker with an earth leakage alarm function according to the present invention includes a circuit breaker on the base side of the circuit breaker case at a position away from the opening/closing mechanism inside the circuit breaker case. a shielding container made of a magnetic material fixed between the inner surface thereof, a zero-phase current transformer surrounded and fixed to the shielding container, a mounting means made of a magnetic material fixed to the shielding container, and the mounting means and an earth leakage relay fixed to the shield frame and enclosed in the shield frame.

[Function] In this invention, since the zero-phase current transformer and earth leakage relay are built into the circuit breaker case, only the panel space required for the molded circuit breaker is required, and only the circuit breaker is required to be installed on the panel. Furthermore, the earth leakage relay, which is wrapped in a shield frame made of magnetic material, is fixed to the shield container for the zero-phase current transformer by an attachment means, and this shield container is fixed to the inner surface of the base of the circuit breaker case without any gaps. Therefore, the impact vibrations generated during the opening/closing operation of the opening/closing mechanism located at a position away from the earth leakage relay are difficult to be transmitted to the earth leakage relay. In addition, since the earth leakage relay is enclosed in a shield frame and mounting means made of magnetic materials and is always in electrical contact with the shield container, the magnetic flux generated when the main circuit connects and disconnects causes an abnormal voltage in the internal coil of the earth leakage relay. do not induce

[Example] An example of a molded circuit breaker with an earth leakage alarm function (hereinafter abbreviated as circuit breaker) of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view including a partial cross section showing the earth leakage relay 8 and zero-phase current transformer 7 of this embodiment attached to the circuit breaker case 2, and FIG. 2 is a perspective view showing the external appearance of this embodiment. 3 is a schematic front view of the circuit breaker 1 shown in FIG. 2 with the cover 2b removed, and FIG. 4 is a schematic circuit diagram of the circuit breaker 1 shown in FIG. 2. Second
In the figure, the appearance of circuit breaker l is a base 2a and a cover 2b.
The circuit breaker case 2 has a window frame 3 formed approximately at the center of the front surface of the cover 2b. A manual handle 4 is provided which projects outward from the opening 3a of the window frame 3. Further, the window frame 3 is provided with an electric leakage indicator 11, such as an electric indicator that lights up a lamp in the event of an electric leak, or a mechanical indicator that has a protruding button. Further, the window frame 3 is provided with a reset button 12 for resetting the earth leakage display section 11, and a test button 13 used when confirming a simulated earth leakage operation.

A load side terminal section 5 and a power supply side terminal section 6 are provided at both ends of the circuit breaker case 2, respectively, and a leakage alarm lead wire 14 is led out from the side surface.

FIG. 3 is a schematic front view of the circuit breaker l shown in FIG. It passes through and is connected to the opening/closing mechanism section 20. This opening/closing mechanism section 20
is arranged substantially on the back side of the manual handle 4, and has a mechanism for connecting and separating the power supply side and load side contacts. As described above, in the circuit breaker l of this embodiment, the zero-phase current transformer 7, which is penetrated by the three-phase electrical path of the main circuit, is disposed at a position away from the switching mechanism section 20. The earth leakage signal detected by the zero-phase current transformer 7 is amplified by the □ amplifier 9 and is configured to drive the earth leakage relay 8. An externally provided alarm unit receives this leakage signal via the earth leakage alarm lead wire 14 and issues an alarm. Note that since the alarm is electrically latched inside the circuit, the alarm state is maintained until the reset button 12 is pressed or the main circuit power is turned off.

FIG. 4 shows a schematic circuit diagram of the circuit breaker of this embodiment.

The main parts of this embodiment configured as described above will be explained below. FIG. 1 shows a zero-phase current transformer 7 fixed to the base 2a of the circuit breaker case 2, and an earth leakage relay 8 attached to the zero-phase current transformer 7.

As shown in the figure, the I-1 consists of an iron core and a winding, and has a large diameter of 6 m.
The zero-phase current transformer 7 having a single current is encased and held in a shield container 27 that is firmly formed of a magnetic material, for example, an iron plate. This shield container 27 is fitted into a hole 2c formed in the base 2a and is firmly fixed to the base 2a with screws 29. And this shield container 27
An earth leakage relay 8 is firmly attached to the side surface. A part of the earth leakage relay 8 is a cylindrical shield frame 26 made of magnetic material.
The shield frame 26 and the earth leakage relay 8 are fitted inside the mounting plate 2I, which is the mounting means 21 made of magnetic material.
Fixed inside. The shield frame 26 and the earth leakage relay 8 are fixed to the inside of the mounting plate 21 by fixing the board 8a of the earth leakage relay 8 with a fixing claw formed on the mounting plate 21. This mounting plate 21 is fixed to the shield container 27 by screws or caulking. In FIG. 1, the known three-phase electrical circuit conductor that is disposed through the through hole 7' of the zero-phase current transformer 7 is omitted for the sake of simplicity, but in reality, the three-phase electrical circuit conductor is This zero-phase current transformer 7 detects the presence or absence of electrical leakage in the power distribution line connected to. In this way, the earth leakage relay 8
is firmly fixed to the base 2a of the circuit breaker 1 via a shield container 27 and a mounting plate 21 at a position away from the opening/closing mechanism 2°. It should be noted that the shock and vibration generated in the opening/closing mechanism section 20 during the opening/closing operation are mainly caused by the collision of the manual operation handle 4 with the cover 2b.
These shocks and vibrations are transmitted to the base 2a through means for fixing the cover 2b and the base 2a, such as screws, and then to the earth leakage relay 8. However, in the configuration of this embodiment, the earth leakage relay 8 is not directly attached to the cover 2b or the base 2a, but is firmly fixed to the shield container 27 of the heavy zero-phase current transformer 7 via the mounting plate 21. Therefore, the shock and vibration received by the cover 2b are absorbed by the earth leakage relay 8.
It is not transmitted as a large shock or vibration. Therefore, shocks and vibrations generated during the opening/closing operation of the opening/closing mechanism section 2o are transmitted to the internal contacts 5.degree.l of the earth leakage relay 8 only as greatly damped vibrations.

In addition, since the earth leakage relay 8 is housed in the shield frame 26, fixed inside the mounting plate 21, and attached to the shield container 27, the magnetic flux generated by the change in current when the conductor of the main circuit is opened/closed is Abnormal voltage due to this magnetic flux is absorbed by the shield frame 26, mounting plate 21, and shield container 27 made of magnetic materials, and the abnormal voltage due to this magnetic flux is not induced in the internal coil 502 of the earth leakage relay 8, and chattering occurs at the internal contacts 501 of the earth leakage relay 8. Does not occur. Therefore, during the opening/closing operation of the opening/closing mechanism section 2°, no vibration or chattering due to electromagnetic corrosion occurs at the internal contact 501 of the leakage 7u relay 8.

[Effects of the Invention] As described above, according to the present invention, a zero-phase current transformer and an earth leakage relay are built into the circuit breaker case of a molded circuit breaker, thereby reducing the size of the panel by saving space and reducing the installation work to the panel. In addition to saving labor, the earth leakage relay is separated from the opening/closing mechanism and is firmly fixed to the circuit breaker case using a mounting member made of magnetic material (R), which prevents shocks and vibrations caused by opening/closing operations. This makes it possible to obtain a molded circuit breaker with an earth leakage alarm function in which chattering does not occur in the internal contacts of the earth leakage relay, and chattering does not occur in the earth leakage relay due to electromagnetic corrosion caused by changes in current when the main circuit connects and disconnects. be.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts including a partial cross section showing one embodiment of the present invention, Fig. 2 is an external perspective view of the embodiment of Fig. 1, and Fig. 3 is the device shown in Fig. 2 with the cover removed. FIG. 4 is a schematic front view and a schematic circuit diagram of the apparatus of FIG. 2. In the figure, 2 is a circuit breaker case, 7 is a zero-phase current transformer, 8 is an earth leakage relay, 21 is a mounting means, 26 is a shield frame, and 27
is a shielded container. In addition, in the figure, the same reference numerals are the same.
or a corresponding portion.

Claims (1)

[Claims] (1) A shield container made of a magnetic material that is fixed between the inner surface of the base side of the circuit breaker case at a position away from the opening/closing mechanism inside the circuit breaker case, and a zero phase that is surrounded and fixed to the shield container. A molded circuit breaker with an earth leakage alarm function, comprising: a current transformer; a mounting means made of a magnetic material fixed to the shield container; and an earth leakage relay fixed to the mounting means and enclosed in a shield frame. .