JP2004199881A - Ground fault breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To safely test a ground fault breaker by separating a ground fault detecting circuit from a main circuit with a simple operation when performing a voltage-withstanding test for the breaker having a main body case with a wiring breaker, components of a ground fault detecting/separating device mounted therein. <P>SOLUTION: The breaker with overcurrent and ground protection functions mounts a ground fault separating device including a main contact 2, an opening/closing mechanism 3, an operation handle, an overcurrent separating device 5 and a ground fault detecting circuit 7 for opening/closing a main circuit 1, and applies an interphase voltage of the main circuit 1 to the detecting circuit via a power supply line 9 wired between the detecting circuit. The breaker has a switch 21 for the voltage-withstanding test for switching on or off the circuit of the power supply line 9 connected to the detecting circuit in conjunction with opening/closing operations of the main contact 2, and, as the switch 21, an auxiliary switch of an attachment, for example, is used to separate the detecting circuit from the main circuit 1 in conjunction with the opening pole operation of the main contact 2 when performing the voltage-withstanding test. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth leakage circuit breaker having an overcurrent protection and a ground fault protection function applied to a low voltage distribution system, and more particularly to a protection means for separating an earth leakage detection circuit from a main circuit when performing a withstand voltage test of the earth leakage breaker. Related to
[0002]
[Prior art]
Wiring circuit breakers and earth leakage breakers are well-known as protection equipment for low-voltage distribution systems, and earth leakage circuit breakers that are widely used in Japan generally have overcurrent protection and ground fault protection functions. It is. In recent earth leakage breakers, wiring breakers and earth leakage breakers of the same frame have the same external dimensions and a main body case, and the main parts are shared as much as possible in order to improve the usability on the customer side. The mainstream of such a configuration is described in US Pat.
In order to flexibly cope with various protection systems for distribution equipment, various types of auxiliary devices such as auxiliary switches, alarm switches, voltage trip devices, undervoltage trip devices, etc. A combination of accessories has been generalized (for example, see Patent Document 2).
[0003]
Next, a circuit diagram of a conventional general earth leakage breaker (for a three-phase circuit) is shown in FIG. 7, and its structure is shown in FIG. First, in FIG. 7, 1 is a main circuit of R, S, and T phases, 2 is a main contact, 3 is an opening / closing mechanism of the main contact 2, 4 is an operation handle, 5 is an overload current and a short-circuit current flowing in the main circuit. This is a thermal or electromagnetic overcurrent trip device that trips the opening and closing mechanism by detecting the overcurrent.
Further, the earth leakage trip device that detects the occurrence of a ground fault in the distribution system and trips the switching mechanism includes a zero-phase current detection circuit that detects an unbalanced current in the main circuit 1 using the main circuit 1 of the R, S, and T phases as a primary conductor. A current transformer 6, a leakage detection circuit (electronic circuit including an IC) 7 for detecting occurrence of a ground fault from the secondary output level of the zero-phase current transformer 6, and an opening / closing mechanism which receives an output from the leakage detection circuit 7. And a trip coil unit 8 for tripping. Further, the leakage detection circuit 7 supplies an inter-phase voltage of the main circuit 1 as a control power supply through a power supply line 9 laid between the main circuit 1 and the rectifier circuit 10. In the illustrated example, the inter-phase voltage of the R-T phase of the main circuit 1 is supplied to the leakage detection circuit 7. However, the voltage of each of the R, S, and T phases may be converted to DC and supplied.
[0004]
On the other hand, in FIG. 8, reference numeral 11 denotes a main body case having a two-part structure including a lower case 11a and an upper cover 11b; 12, 13; main circuit terminals (screw terminals) on a power supply side and a load side; The fixed contact of the main contact, 15 is a movable contact, 16 is a rotary contact holder that supports the movable contact 15, and 17 is an arc extinguishing device. As is well known, the opening / closing mechanism 3 includes a toggle link 3a for connecting the contact holder 16 and the operation handle 4, a toggle link mechanism of the opening / closing spring 3b, a latch 18, and a latch receiver 19. , And a trip mechanism, which is a combination of a latch mechanism and a trip crossbar 20. The trip crossbar 20 is opposed to the operation ends of the overcurrent trip device 5 and the trip coil unit 8 (see FIG. 7). . The illustrated latch mechanism is an example, and other various latch mechanisms are known.
[0005]
Although not illustrated in the drawing of FIG. 8, a phase space wall is formed in the lower case 11 a and the upper cover 11 b in the main body case 11, and each of the phases assembled in the main body case by the phase space wall is formed. Parts are isolated from each other. Further, the leakage detection circuit 7 shown in FIG. 7 is mounted on a printed board, assembled inside the main body case 11, and then soldered (or screwed) with the power supply line 9 wired between the main circuit 1 and the main circuit 1. Connected. Similarly, a lead wire corresponding to the overcurrent trip device 5 interposed in series with each phase of the main circuit 1, between the secondary output side of the zero-phase current transformer 6 and the leakage detection circuit 7, and between the leakage detection circuit 7 A lead wire connecting between the main body case 11 and the trip coil unit 8 is also wired.
[0006]
In the above configuration, when the operation handle 4 is moved to the ON / OFF position, the toggle link mechanism of the opening / closing mechanism 3 is reversed in conjunction with the operation handle 4, and the movable contact 15 is opened / closed. When the main contact is closed (ON), the latch 18 is locked by the latch receiver 19, and the latch receiver 19 is supported by the trip crossbar 20 at this position. In this state, when an overload current and a short-circuit current flow in the main circuit and the overcurrent trip device 5 operates, the trip crossbar 20 rotates counterclockwise to release the engagement between the latch receiver 19 and the latch 18. I do. As a result, the opening / closing mechanism 3 trips, and the movable contact 15 is separated from the fixed contact 14 to cut off the current in the main circuit. Similarly, when a ground fault current flows through the main circuit 1 of FIG. 7 and the trip coil unit 8 of the earth leakage trip device operates, the trip crossbar 20 is driven to the release position. As a result, the opening / closing mechanism 3 trips, the movable contact 15 opens, and the main circuit 1 is disconnected. In order to reclose the circuit breaker after the trip operation, the operation handle 4 stopped at the trip position is returned from the trip position to the RESET position (a position slightly beyond the OFF position) to reset the latch mechanism. Then, by further moving the operation handle 4 from the OFF position to the ON position, the movable contact 15 is closed.
[0007]
By the way, regarding the above-mentioned earth leakage circuit breaker products, it is stipulated in the standards that they have a predetermined dielectric strength from the viewpoint of safety, and therefore, a breakdown voltage test is performed for each product so that insulation breakdown does not occur. Make sure that you are. This withstand voltage test is performed by applying a specified test voltage between the phases of the main circuit terminals in accordance with the test method specified in the standard, and the test voltage is specified for each rated voltage of the earth leakage breaker. For example, the test voltage at the earth leakage breaker having a rated voltage of 300 to 600 V is 2500 V.
In Japan, manufacturers are currently conducting tests on this withstand voltage test before shipping the leakage breaker on the manufacturer side. In this case, if a high test voltage is applied between the phases while the leakage detection circuit (IC) is connected to the main circuit in a product assembled state of the leakage breaker, the leakage detection circuit is broken by the high voltage. For this reason, the withstand voltage test has been performed with the power supply line of the leakage detection circuit removed.
[0008]
On the other hand, in overseas countries such as Europe and the United States, unlike the earth leakage breaker in Japan, the circuit breaker for wiring is combined with a leakage detection unit of another structure (unitized with a zero-phase current transformer, leakage detection circuit, etc.). It is common to use. For this reason, the above-mentioned withstand voltage test is performed by a user of the distribution equipment installation facility on the user side in a state where the leakage detecting unit is assembled to the circuit breaker for wiring. In order to cope with this withstand voltage test, for example, a switch for a withstand voltage test of a push button type is provided in the leakage detection unit, and when performing the withstand voltage test, the switch for the withstand voltage test is operated to configure the leakage detection circuit. There is known a device in which a leakage circuit is connected to a main circuit by operating a withstand voltage test switch after completion of a withstand voltage test and returning to a normal use state after a withstand voltage test is completed (for example, Patent Document 3). reference.).
[0009]
[Patent Document 1]
Patent No. 3246562
[0010]
[Patent Document 2]
Patent No. 3097368
[0011]
[Patent Document 3]
US Patent Application Publication No. 2001/0022713 A1
[0012]
[Problems to be solved by the invention]
By the way, the above-mentioned conventional earth leakage breaker has the following problems in correspondence with the withstand voltage test.
(1) As shown in Fig. 8, the products of the earth leakage breaker, in which the components of the circuit breaker for wiring and the earth leakage trip device including the earth leakage detection circuit are assembled in a single main unit case, are exported from the manufacturer overseas. If the user intends to conduct a withstand voltage test after shipment, remove the cover of the main unit case, and then solder the power supply wires that are wired between the leakage detection circuit and the main circuit. It is necessary to disconnect the leakage detecting circuit from the main circuit by temporarily removing the portion or the screwed portion, which requires a great deal of time for the test preparation work.
[0013]
(2) In the configuration of the leakage detection device disclosed in Patent Document 3, when a withstand voltage test switch (dielectric test switch) provided in the leakage detection unit is turned off at the time of performing the withstand voltage test, the leakage is detected. As soon as the detection circuit is disconnected from the main circuit, a circuit breaker trips and the main contact is opened. As a result, the leakage detection circuit can be separated from the main circuit to safely perform the withstand voltage test.
However, the withstand voltage test switch is not linked with the opening / closing operation of the circuit breaker, and the ON return is performed independently by operating the button of the switch. Even when the switch is not turned back on, the main contact can be turned on by operating the handle of the wiring breaker. For this reason, there is a risk of forgetting to return the withstand voltage test switch to the ON state after the withstand voltage test and turning on the main contact with the operation handle of the wiring breaker to return the wiring breaker to the use state. In addition, if the user forgets to turn on the withstand voltage test switch after the end of the withstand voltage test, the leakage detection circuit will remain disconnected from the main circuit. A situation occurs in which the protection function does not work.
[0014]
The present invention has been made in view of the above points, and has a configuration in which the components of the circuit breaker for wiring and the components of the leakage detection and trip device are collectively incorporated in a single main body case as shown in FIG. Even if a withstand voltage test is performed on the user side after the product is shipped to a leakage breaker, the leakage detection circuit has been modified so that the leakage detection circuit can be separated from the main circuit with a simple operation and the withstand voltage test can be performed safely. The purpose is to provide a vessel.
[0015]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, there is provided an earth leakage circuit breaker having overcurrent protection and ground fault protection functions, comprising a main contact, a switching mechanism, an operation handle, an overcurrent trip device, and an earth leakage detection. An earth leakage trip device including a circuit is collectively provided in the main body case, and as a power supply of the earth leakage detection circuit, the inter-phase voltage of the main circuit is supplied via a power line wired between the earth leakage detection circuit and the main circuit. In things
In the first invention, there is provided a withstand voltage test switch for turning on and off the power supply circuit of the power supply line connected to the leakage detection circuit in conjunction with the ON / OFF operation of the main contact (claim 1). As an embodiment thereof, an auxiliary switch which is an accessory of the earth leakage circuit breaker can be used as the withstand voltage test switch (claim 2).
[0016]
In the above configuration, when the main contact is opened with the operation handle at the time of performing the withstand voltage test, the withstand voltage test switch is automatically turned off at the same time, and the power supply circuit of the power supply line from the main circuit to the leakage detection circuit is disconnected. I do. Therefore, there is no need for troublesome preparation work such as removing the circuit breaker cover and removing the soldered part of the internal wiring of the leakage detection circuit during the withstand voltage test, and the leakage detection circuit is started from the high test voltage applied between the main circuits. The withstand voltage test can be performed safely by safely disconnecting. When the main contact is closed by operating the handle after the end of the withstand voltage test, at the same time, the withstand voltage test switch returns to ON and the power supply circuit of the leakage detection circuit returns to the energized state.
[0017]
Also, in this case, as the above-mentioned withstand voltage test switch, an auxiliary switch which is an accessory of the earth leakage breaker (the original function of the auxiliary switch is to extract the open / closed state of the main contact of the breaker to the outside by an electric signal. If the auxiliary switch is connected to the power supply line between the main circuit and the leakage detection circuit using the switch of (1), the withstand voltage test can be performed without making a large change to the leakage breaker.
On the other hand, in the second invention, a manually operated withstand voltage test switch for turning on and off the power supply circuit of the power supply line connected to the earth leakage detection circuit is provided in the main body case, and the switch is opened and closed by the main contact. The mechanism is interlocked, and the opening / closing mechanism is tripped in conjunction with the OFF operation of the withstand voltage test switch to open the main contact (claim 3). It can be configured as follows.
[0018]
(1) An actuator that follows the ON / OFF operation of the withstand voltage test switch is provided in the withstand voltage test switch, and the actuator is linked to the trip crossbar of the opening / closing mechanism. The crossbar is driven to the latch release position to trip the opening / closing mechanism, and the trip crossbar is restrained to the latch release position to prevent the main contacts from being turned on. It is configured to release the constraint (claim 4).
(2) After providing an actuator that follows the ON / OFF operation of the switch for the withstand voltage test, the actuator is linked to the trip crossbar of the opening / closing mechanism, and the trip crossbar is turned off by the OFF operation of the withstand voltage test switch. Is driven to the latch release position to trip the opening / closing mechanism, and the reset operation of the handle drives the trip crossbar to the latch locked position to reset the latch mechanism. At the same time, turns on the withstand voltage test switch via the trip crossbar. (Claim 5).
[0019]
(3) In the preceding paragraphs (1) and (2), a slide switch or a toggle switch is used as a withstand voltage test switch, and an actuator is provided on an operation member connected to the operation knob to link the trip crossbar (claim) 6).
In the above configuration, if the withstand voltage test switch is turned off during the withstand voltage test, the leakage detection circuit is disconnected from the main circuit, and the opening and closing mechanism trips in conjunction with the operation of the switch to open the main contact. Pole. Thereby, the preparation for the withstand voltage test is completed, and the withstand voltage test can be safely performed in a state where the leakage detection circuit is disconnected from the main circuit.
[0020]
In addition, when the withstand voltage test switch is in the OFF state, the trip crossbar is restrained and held at the latch release position. As a result, even if the operation handle is moved to the ON position and the main contact is to be turned on again without returning the withstand voltage test switch to the ON state, the main contact can be closed because the latch mechanism is reset. Thus, it is possible to avoid closing the main contact and returning the earth leakage breaker to the use state while leaving the earth leakage detection circuit disconnected from the main circuit due to forgetting to turn on the withstand voltage test switch after the end of the test.
Also, by resetting the trip crossbar by resetting the operation handle and resetting the latch mechanism, at the same time, by interlocking so as to return the withstand voltage test switch to ON via the trip crossbar, the configuration is the same as described above. In addition, it is possible to prevent the user from forgetting to turn on the withstand voltage test switch after the test is completed.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the examples shown in FIGS. In the drawings of the embodiment, members corresponding to those in FIGS. 7 and 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[Example 1]
1 to 3 are configuration diagrams of an embodiment corresponding to claims 1 and 2 of the present invention. The earth leakage breaker of this embodiment is basically the same as the conventional structure shown in FIGS. 7 and 8, but a power supply line 9 is wired between the main circuit 1 and the circuit as shown in the circuit diagram of FIG. A withstand voltage test switch 21 is newly provided in the power supply circuit of the leakage detection circuit 7. The withstand voltage test switch 21 is a switch that operates so as to turn on and off the power supply circuit in conjunction with the opening and closing operation of the main contact 2. An auxiliary switch mounted on the main body case 11 is employed as a product. In the illustrated embodiment, three power lines 9 corresponding to the R, S, and T phases are connected between the main circuit 1 and the leakage detection circuit 7, and the three-phase power is converted to DC (three-phase power). The power supply circuit 9 is used to supply power to the leakage detection circuit 7, and the withstand voltage test switch 21 has three contacts (three micro switches) in accordance with the wiring of the power supply line 9. ing.
[0022]
In FIG. 1, the withstand voltage test switch 21 has three contacts corresponding to the respective power lines 9 of the R, S and T phases, but two contacts corresponding to two of the three phases. Can also be implemented. As shown in FIG. 7, in the case of a two-phase power supply in which two power supply lines 9 are wired between the main circuit 1 and the leakage detection circuit 7 to supply an inter-RT-phase voltage, It is assumed that the test switch 21 has two contacts or one contact in either R or T phase.
FIG. 2 is a configuration diagram of an earth leakage breaker adopting an auxiliary switch as an accessory of the earth leakage breaker as the withstand voltage test switch 21 (an upper cover is removed), and the auxiliary switch 22 is an operation handle. 4 and are incorporated in the accessory storage section of the main body case so as to be insertable and removable from the outside (see Patent Document 2). Here, the auxiliary switch 22 includes three microswitches corresponding to the withstand voltage test switch 21 in FIG. 1, and the microswitches are turned ON and OFF according to the opening and closing operations of the main contact as described below. OFF operation.
[0023]
Next, the opening / closing mechanism and operation of the auxiliary switch 22 (withstand voltage test switch 21) will be described with reference to FIGS. 3 (a) and 3 (b). In FIG. 3, the auxiliary switch 22 includes a lever-type actuator 23 having a support shaft 23a as a swing fulcrum so as to interlock between an operation end of the auxiliary switch 22 and the contact holder 16 of the movable contact 15. The tip of the actuator 23 faces the contact holder 16.
Here, FIG. 3A shows a closed state of the main contact 1 (see FIG. 1) in which the contact 15a of the movable contact 15 is in contact with the contact 14a of the fixed contact 14. In this state, the actuator 23 is separated from the contact holder 16 and each microswitch of the auxiliary switch 22 is turned on to keep the power supply circuit of the leakage detection circuit 7 shown in FIG. 1 conductive.
[0024]
In this state, when the operating handle 4 is moved from the ON position to the OFF position in order to open the main contact when the withstand voltage test is performed, the toggle link mechanism of the opening / closing mechanism 3 is turned over as described with reference to FIG. As a result, the movable contact 15 is opened, and the rear end of the contact holder 16 pushes the actuator 23 in conjunction with this operation. As a result, the actuator 23 rotates counterclockwise and separates from the auxiliary switch 23, and in response thereto, each micro switch of the auxiliary switch is turned off. That is, the withstand voltage test switch 21 in FIG. 1 is opened, and the power supply circuit between the leakage detection circuit 7 and the main circuit 1 is disconnected. Therefore, if a withstand voltage test is performed in this state, the leakage detection circuit 7 can be protected from the test voltage.
[0025]
When the operation handle 4 is returned to the ON position in FIG. 3A and the main contact is closed after the end of the test, the contact holder 16 pivots counterclockwise and separates from the actuator 23, thereby assisting. The switch 23 is automatically turned ON to return to the steady state in which the leakage detection circuit 7 receives power supply from the main circuit 1.
According to this embodiment, since the attached switch 22 is used as the withstand voltage test switch 21, it can be implemented with a simple configuration without greatly changing the earth leakage breaker. In the configuration of FIG. 2, the auxiliary switch 22 is stored in the accessory storage section of the main body case 11, but the installation location of the auxiliary switch is not limited to the illustrated example, and may be located near the trip crossbar. If so, it may be installed outside the main body case.
[0026]
[Example 2]
Next, the configuration and operation of an embodiment according to claims 3 to 5 of the present invention will be described with reference to FIGS.
In this embodiment, the function of the withstand voltage test switch 21 in FIG. 1 is further developed. That is, in this embodiment, the withstand voltage test switch 21 is a manually operated switch, and this switch is linked to the trip crossbar of the opening / closing mechanism 3 as described later. When the withstand voltage test switch 21 is manually turned off during the withstand voltage test and the power supply circuit of the power supply line 9 wired between the main circuit 1 and the leakage detection circuit 7 is disconnected, the power supply circuit 9 is interlocked with this. The switching mechanism 3 trips and the main contact 1 is opened, thereby preparing for the withstand voltage test. When the earth leakage breaker is returned to the normal use state after the withstand voltage test is completed, unless the withstand voltage test switch 21 is operated to return to the ON position or the operation handle 4 is moved to the RESET position, The latch mechanism cannot be reset to prevent the main contact from being turned on, so that the withstand voltage test switch 21 is forgotten to be turned on.
[0027]
For this purpose, as shown in FIG. 4, the above-mentioned manually operated withstand voltage test switch 21 is arranged on the side of the operation handle 4 and mounted above the trip crossbar 20 of the opening / closing mechanism. The upper cover 11b of the main body case is provided with a small sliding cover 11b-1 so that the withstand voltage test switch 21 can be turned on and off from the outside.
Next, a specific assembly structure of the withstand voltage test switch 21 is shown in FIGS. That is, the withstand voltage test switch 21 includes a number of slide switches 24 corresponding to the number of contacts, a dish-shaped switch case 25 for accommodating the slide switches 24 arranged side by side, and a cover over the switch case 25. It comprises an assembly with a slide-type switch cover 26 that engages with the operation knob 24a of the slide switch 24 and collectively turns on and off each slide switch 24. The switch cover 26 has legs extending downward. A piece-shaped actuator 26a is integrally formed. In the illustrated example, two slide switches 24 are provided for a three-phase earth leakage breaker, but one slide switch 24 is used for a single-phase earth leakage breaker.
[0028]
When the withstand voltage test switch 21 is assembled at the position shown in FIG. 4, the tip of the actuator 26a faces the trip crossbar state of the opening / closing mechanism at this position, and FIG. 6 (a), (b) Is interlocked between the actuator 26a and the trip crossbar 20.
FIG. 6A shows the switch 21 for the withstand voltage test shown in FIG. 5 which is slid to the right to hold the slide switch 24 in the ON position and set the operation handle 4 to the ON position. In this state, the contact of the withstand voltage test switch 21 in FIG. 1 is closed and the main circuit 1 is connected to the earth leakage detection circuit 7 via the power supply line 9 when the movable contact 15 is closed. It corresponds to the state where power is supplied. In this state, the trip crossbar 20 holds and holds the latch 18 of the opening / closing mechanism 3 without being restrained by the actuator 26a, as shown in FIG.
[0029]
To perform the withstand voltage test from this state, the switch cover 26 of the withstand voltage test switch 21 is slid to the OFF position by an external operation. Thereby, the contact of the slide switch 24 is turned off to disconnect and disconnect the power supply circuit of the leakage detection circuit 7 shown in FIG. 1 from the main circuit 1, and at the same time, to the switch cover 26 as shown in FIG. The provided actuator 26a pushes the trip cross bar 20 from behind, and rotates the trip cross bar 20 counterclockwise around the support shaft 20a. As a result, the latch 18 previously locked and held by the trip crossbar 20 is released, the opening / closing mechanism 3 trips, the movable contact 15 is opened, and the main contact 2 is turned off. If a withstand voltage test is performed in this state, the leakage detection circuit 7 is separated from the main circuit 1 and can be safely protected from a high test voltage applied between the phases of the main circuit 1.
[0030]
In the state shown in FIG. 6B in which the withstand voltage test switch 21 is slid to the OFF position, the trip crossbar 20 pushed by the actuator 26a of the switch is held at the release position of the latch 18. Therefore, after the withstand voltage test is completed, unless the switch 21 for withstand voltage test is returned to the original ON position, even if the operation handle 4 is moved from the trip position to the RESET position, the latch mechanism is not reset. The main contact 1 cannot be turned on again. As a result, it is possible to prevent a situation in which the ground fault detection of the earth leakage breaker and the earth leakage protection function do not work due to forgetting to turn on the withstand voltage test switch 21.
[0031]
The trip crossbar 20 of the opening / closing mechanism 3 is urged clockwise toward the engagement position (reset position) with the latch 18 by the spring force of a relatively weak return spring (not shown). Therefore, if the mechanical holding force at the ON / OFF position of the slide switch 24 shown in FIG. 4 is set to be greater than the return spring force of the trip crossbar 20, the withstand voltage test switch 21 is set. 6B, the trip crossbar 20 is held at the latch release position against the return spring. Therefore, after the withstand voltage test is completed, the trip crossbar 20 does not return unless the withstand voltage test switch 21 is returned from the OFF position to the ON position. There is no reset, which prevents closing of the main circuit contacts. This makes it possible to prevent a mistake in forgetting to return the withstand voltage test switch 21 when returning the earth leakage breaker to the energized state after the end of the withstand voltage test.
[0032]
Further, in addition to setting the ON / OFF holding force of the withstand voltage test switch 21 to be higher than the return spring force of the trip crossbar 20 as in the above-described embodiment, the present invention may be implemented by an interlock mechanism as described below. it can. That is, when the withstand voltage test switch 21 is moved to the OFF position, the switch is restrained and held at the OFF position. When the operation handle 4 is moved from the TRIP position to the RESET position after the end of the withstand voltage test, the switch is interlocked therewith. Then, when the trip crossbar 20 is returned to the reset position and the switch 21 for withstand voltage test is returned to the ON position by the return spring force of the trip crossbar 20, an interlock is performed in the same manner as in the previous embodiment. When the earth leakage breaker is returned to the energized state after the end of the withstand voltage test, it is possible to prevent a mistake in turning on the withstand voltage test switch 21.
[0033]
In the illustrated embodiment, the slide switch 24 is employed as the withstand voltage test switch 21, but the present invention is not limited to this. For example, a toggle switch may be employed.
[0034]
【The invention's effect】
As described above, according to the present invention, an earth leakage circuit breaker having overcurrent protection and ground fault protection functions, comprising a main contact, an opening / closing mechanism, an operation handle, an overcurrent trip device, and an earth leakage detection circuit. In the apparatus, the leakage detecting device including the leakage detecting device is collectively provided in the main body case, and as a power supply of the leakage detecting circuit, an inter-phase voltage of the main circuit is supplied via a power supply line wired between the main circuit and the leakage detecting circuit. ,
In the first invention, there is provided a withstand voltage test switch for turning on and off the power supply circuit of the power supply line connected to the leakage detection circuit in conjunction with the ON / OFF operation of the main contact. In the second invention, a manually operated withstand voltage test switch for turning on and off the power supply circuit of the power supply line connected to the earth leakage detection circuit is provided in the main body case, and the switch is connected to a main contact opening / closing mechanism. By interlocking with the switch, the opening and closing mechanism is tripped in conjunction with the OFF operation of the withstand voltage test switch, and the main contacts are opened.
When conducting a withstand voltage test on a product of an earth leakage breaker, there is no need for troublesome preparation work such as opening the case of the circuit breaker and disconnecting the power line of the earth leakage detection circuit from the main circuit as in the past. By simply turning off the main contact or turning off the manually operated withstand voltage test switch provided in the main body case, the leak detection circuit can be separated from the main circuit and the withstand voltage test can be performed safely.
[0035]
As a result, even if a withstand voltage test is carried out on the user side, as is currently performed in various foreign countries, the test of the earth leakage breaker product shipped from the manufacturer can be safely performed by a simple operation. In addition, when the earth leakage breaker is returned to a normal use state after the end of the withstand voltage test, in the first invention, by turning on the main contact with the operation handle, the withstand voltage test switch is automatically operated in conjunction with this. To the ON position.
Further, in the second invention, the main contact cannot be turned on unless the manually operated withstand voltage test switch is returned from OFF to ON or the operation handle is reset.
[0036]
As a result, when the earth leakage breaker is returned to the normal use state after the withstand voltage test, the ground fault detection and the earth leakage protection of the earth leakage breaker function when the main circuit is energized due to the mistake of forgetting to turn on the withstand voltage test switch. It is possible to prevent an unusual situation such as no longer being performed.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of an earth leakage breaker according to an embodiment of the present invention.
FIG. 2 is a configuration perspective view showing the inside of an earth leakage breaker corresponding to Embodiment 1 of the present invention in which an auxiliary switch is employed as a withstand voltage test switch in FIG.
3A and 3B are explanatory diagrams of the operation of the auxiliary switch in FIG. 2, wherein FIGS. 3A and 3B show operating states corresponding to ON and OFF of a main contact, respectively.
FIG. 4 is a configuration perspective view of an earth leakage breaker corresponding to a second embodiment of the present invention employing a manually operated switch as the withstand voltage test switch in FIG. 1;
5 (a) is a perspective view of an assembled state of the withstand voltage test switch in FIG. 4, and FIG. 5 (b) is an exploded perspective view of FIG. 4 (a).
6 (a) and 6 (b) are explanatory diagrams of a linking structure of a withstand voltage test switch of FIG. 5 and an opening / closing mechanism of a circuit breaker main body and an opening / closing operation. Diagram showing the operating state corresponding to OFF
FIG. 7 is a conventional circuit diagram of an earth leakage breaker to which the present invention is applied.
FIG. 8 is a sectional view of the configuration of an earth leakage breaker corresponding to FIG. 7;
[Explanation of symbols]
1 Main circuit
2 Main contacts
3 opening and closing mechanism
4 Operation handle
5 Overcurrent trip device
6 Zero-phase current transformer
7 Leakage detection circuit
8 Trip coil unit for earth leakage trip
9 Power line
11 Body case
11a Lower case
11b Top cover
14 Fixed contact
15 Movable contact
16 Contact holder
18 Opening / closing mechanism latch
20 Trip Crossbar
21 Withstand voltage test switch
22 Auxiliary switch (accessory for earth leakage breaker)
24 slide switch
26 Switch cover
26a Actuator

Claims (6)

An earth leakage circuit breaker with overcurrent protection and ground fault protection functions. The earth leakage trip device including the main contacts, switching mechanism, operation handle, overcurrent trip device, and leakage detection circuit is collectively installed in the body case. Equipped with, as a power supply of the leakage detection circuit, to supply power via a power supply line wired between the main circuit and the leakage detection circuit of the main circuit,
An earth leakage breaker comprising a withstand voltage test switch for turning on and off the power supply circuit of the power supply line connected to the earth leakage detection circuit in conjunction with ON / OFF operation of a main contact. The earth leakage breaker according to claim 1, wherein an auxiliary switch, which is an accessory of the earth leakage breaker, is used as a withstand voltage test switch. An earth leakage circuit breaker with overcurrent protection and ground fault protection functions. The earth leakage trip device including the main contacts, switching mechanism, operation handle, overcurrent trip device, and leakage detection circuit is collectively installed in the body case. Equipped with, as a power supply of the leakage detection circuit, to supply power via a power supply line wired between the main circuit and the leakage detection circuit of the main circuit,
A manually operated withstand voltage test switch for turning on and off the power supply circuit of the power supply line connected to the leakage detection circuit is provided in the main body case, and the switch is interlocked with a main contact opening / closing mechanism to withstand the withstand voltage. An earth leakage breaker characterized in that an opening / closing mechanism is tripped in conjunction with an OFF operation of a test switch to open a main contact. 4. The withstand voltage test switch according to claim 3, further comprising: an actuator that is driven by ON / OFF operation of the withstand voltage test switch provided on the withstand voltage test switch; and connecting the actuator to a trip crossbar of the opening / closing mechanism. When the trip switch is turned off, the trip crossbar is driven to the latch release position to trip the opening / closing mechanism, and the trip crossbar is restrained to the latch release position to prevent the main contacts from being turned on. An earth leakage breaker characterized in that the trip crossbar is released from restraint by an ON return operation. 4. The withstand voltage test switch according to claim 3, further comprising: an actuator that is driven by ON / OFF operation of the withstand voltage test switch provided on the withstand voltage test switch; and connecting the actuator to a trip crossbar of the opening / closing mechanism. The trip crossbar is driven to the latch release position by turning off the switch for tripping and the opening / closing mechanism is tripped, and the trip crossbar is driven to the latch lock position by resetting the handle to reset the latch mechanism. A withstand voltage test switch is returned to ON via a circuit breaker. 6. The earth leakage breaker according to claim 4, wherein the withstand voltage test switch is a slide switch or a toggle switch, and an actuator is provided on an operation member connected to the operation knob. .

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