JP6936547B1 - Current breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current breaker capable of reducing the size and cost of the entire device and lowering the limiting voltage of a secondary side device of an earth-leakage circuit breaker. SOLUTION: The circuit breaker MCCB1 to MCCBn connected to the secondary side of the main circuit breaker MCCB0, the leakage breaker ELCB1 to ELCBn, and the power supply surge protection device SPD0 are provided, and the power supply surge protection device is provided. SPD0 is a fuse F1 to F3 and a temperature separator TF1 connected in series between the distribution wires 101 to 103 on the secondary side of the main circuit breaker MCCB0 and the first and second common grounding electrodes 11 and 12. ~ TF3, metal oxide varistor MOV1 to MOV3, and gas-filled discharge tubes GDT1 and GDT2 are provided, and the common grounding electrode 11 and the grounding terminal of the secondary side equipment of the circuit breakers MCCB1 to MCCBn are connected by a common grounding wire 11b. Then, the common grounding electrode 12 and the grounding terminal of the secondary side device of the leakage breakers ELCB1 to ELCBn are connected by the common grounding wire 12b. [Selection diagram] Fig. 1

Description

The present invention relates to a current cutoff device such as a distribution board, a power board, or a lamp board provided with a surge protector (SPD) for a power source.

Generally, the distribution board, power board, and light board installed in the building have a circuit that protects overcurrent only by the molded case circuit breaker (MCCB) on the secondary side of the main circuit breaker (main MCCB). , A circuit for overcurrent protection and electric shock protection by an earth-leakage circuit breaker (ELCB) is provided. In these two protection circuits, if the grounding resistance value cannot be suppressed to 2 [Ω] or less, it is necessary to perform class D grounding individually, so two independent grounding terminals for distribution boards, etc. Is provided to separate the secondary side device of the MCCB and the secondary side device of the ELCB and ground them.

In addition, when a power supply surge protection device is built into the distribution board or the like to protect the above secondary side equipment from lightning surge current that has entered the distribution line, power supply surge protection is provided on the primary or secondary side of the main MCCB. The device is connected and its grounding terminal is connected to the grounding terminal of the distribution board.
Here, as described above, when the distribution board or the like is provided with the ground terminals for MCCB and ELCB, respectively, the power supply surge protection device is mounted by the following method.

First, the first method of mounting the power supply surge protector is as shown in FIG.
2, 20 is the distribution board, 100,101～103 three-phase distribution lines, MCCB ₀ is the breaker for the main trunk line, the secondary side of the trunk circuit breaker MCCB _0, blocking wire The devices MCCB _{1 to MCCB n} , the earth-leakage circuit breakers ELCB _{1 to ELCB n} , and the first and second power supply surge protection devices SPD ₁ and SPD ₂ are connected in parallel to each other. Although not shown, various secondary side devices that should be protected from lightning surges are connected to the secondary sides of the molded case circuit breakers MCCB _{1 to MCCB n} and the earth-leakage circuit breakers ELCB _{1 to ELCB n, respectively.} ing.

In the first and second power supply surge protectors SPD ₁ and SPD ₂ , a fuse F, a temperature separator TF, and a metal oxide varistor MOV as a voltage limiting element are connected in series for each of the three phases. It is provided with _{gas-filled discharge tubes GDT 1} and GDT ₂ as voltage switching type elements connected between the collective connection point and the common grounding electrodes 11 and 12, respectively.

As is well known, the fuse F has a function of blowing due to an overcurrent, and the temperature separator TF melts the terminal-to-terminal connection portion (solder) when the metal oxide varistor MOV is overheated and rises to a predetermined value. It has a function to cut off the circuit.
Further, the metal oxide varistor MOV and the gas-filled discharge tubes GDT ₁ and GDT ₂ are all elements having non-linear voltage-current characteristics, and in the metal oxide varistor MOV, the current increases when the voltage across the ends exceeds a predetermined value. Even so, the amount of heat generated increases because the voltage across the ends remains almost constant. On the other hand, in the gas-filled discharge tubes GDT ₁ and GDT ₂ , when the voltage across the ends exceeds the arc voltage, the voltage across the ends drops sharply, and after that, even if the current increases, the voltage across the ends is kept at a low value and the amount of heat generated. Is relatively small.

The grounding terminal of the first power supply surge protection device SPD ₁ that protects the secondary side equipment of the wiring breakers MCCB _{1 to MCCB n} is grounded to class D via the common grounding electrode 11 and the grounding wire 11a, resulting in electric leakage. The grounding terminal of the second power supply surge protection device SPD ₂ that protects the secondary side equipment of the breakers ELCB _{1 to ELCB n} is grounded in class D via the common grounding electrode 12 and the grounding wire 12a.
In FIG. 2, 11b is a common grounding wire connecting the common grounding electrode 11 and _{the grounding terminals of the secondary side devices of the wiring breakers MCCB 1 to MCCB n} , and 12b is the common grounding electrode 12 and the earth-leakage circuit breaker ELCB _1. This is a common grounding wire that connects to the grounding terminal of the secondary side device of _{ELCB n.}

Next, the second method of mounting the power supply surge protector is as shown in FIG.
In the distribution board 30 of FIG. 3 _{, instead of the second power supply surge protection device SPD 2 in FIG. 2, a grounding surge protection device SPD 3} composed of a gas-filled discharge tube is connected between the common grounding electrodes 11 and 12. Has been done. Other configurations are the same as in FIG.

As another prior art, as shown in FIG. 4, Patent Document 1 includes a leakage breaker ELCB with an overcurrent protection function and a breaker (wiring breaker) BR connected to each phase on the secondary side thereof. , The power surge protection device 41 equipped with a series circuit of a fuse and a metal oxide varistor in each of the three phases, its ground terminal E, and the ground terminal of the secondary side device (not shown) of the breaker BR are collectively. A distribution board 40 including a centralized grounding terminal 42 for connecting to and grounding is described.

Japanese Unexamined Patent Publication No. 2011-10483 (Fig. 1A, etc.)

In the conventional technique of FIG. 2, since two power supply surge protection devices SPD ₁ and SPD ₂ are built in the distribution board 20, there is a problem that the device as a whole becomes large and costly.
Further, in the prior art of FIG. 3, while the ground-to-ground surge protection device SPD ₃ is small and relatively inexpensive, the power supply surge protection device SPD ₁ and the ground-to-ground surge protection device SPD ₃ are connected in series. , The protection performance of the leakage breakers ELCB _{1 to ELCB n for} the secondary side equipment is the sum of the protection performance of the power supply surge protection device SPD _{1 and} the protection performance of the grounding surge protection device SPD _3. There was a problem that the limiting voltage for the next device increased.
Further, the prior art of FIG. 4 targets a distribution board 40 provided with only a breaker BR, that is, a circuit breaker for wiring, and as shown in FIGS. 2 and 3, an earth-leakage circuit breaker to which a secondary side device is connected is used. No mention is made of the equipped distribution board.

Therefore, the problem to be solved by the present invention is a distribution board, a power board, a light board, etc., which are provided with a circuit breaker for wiring and an earth-leakage circuit breaker, and also have a built-in surge protection device for power supply for protecting these secondary side devices. An object of the present invention is to provide a current circuit breaker capable of reducing the size and cost of the entire device and lowering the limiting voltage of the secondary side device of the earth-leakage circuit breaker.

In order to solve the above problem, in the invention according to claim 1, a wiring breaker and a leakage breaker are connected in parallel to each other on the secondary side of the main wiring breaker, and the wiring breaker and the leakage breaker are connected to each other. In the current circuit breaker in which the secondary side equipment is connected to the circuit breaker and the power supply surge protection device is connected between the secondary side of the main circuit breaker and the ground.
The power supply surge protector is
A fuse for overcurrent protection connected in series between the distribution line on the secondary side of the main wiring breaker and the first common grounding electrode and the second common grounding electrode, and temperature separation separated at the time of overheating. Equipped with a device, a voltage limiting type element, and a voltage switching type element,
The first common grounding electrode and the grounding terminal of the secondary side device of the wiring breaker are connected by the first common grounding wire, and the second common grounding electrode and the secondary of the earth-leakage circuit breaker are connected. It is connected to the ground terminal of the side device by a second common ground wire.

The invention according to claim 2 is the current interrupting device according to claim 1.
The molded case circuit breaker and the earth-leakage circuit breaker are connected in parallel to the three-phase distribution wire on the secondary side of the main circuit breaker.
The power supply surge protector is
A series circuit of the fuse, the temperature separator, and the voltage limiting element is provided for three phases, and one end of each of these series circuits is connected to the three-phase distribution wire, and the other ends of the series circuit are collectively connected. Then, the collective connection point is connected to the first common grounding electrode via the first voltage switching type element, and to the second common grounding electrode via the second voltage switching type element. It is connected.

The invention according to claim 3 is the current interrupting device according to claim 1 or 2.
The voltage limiting type element is a metal oxide varistor, and the voltage switching type element is a gas-filled discharge tube.

According to the present invention, by incorporating a single power supply surge protection device between the distribution wire on the secondary side of the main circuit breaker and the ground, the configuration of the current circuit breaker can be simplified and downsized. The cost can be reduced, and the voltage limit of the earth-leakage circuit breaker for the secondary side device can be suppressed to a low value to reduce the withstand voltage of the secondary side device.

It is a block diagram of the distribution board which concerns on embodiment of this invention. It is a block diagram of a conventional distribution board. It is a block diagram of a conventional distribution board. It is a block diagram of the distribution board described in Patent Document 1.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a current cutoff device according to the present embodiment, and is a configuration diagram when the present invention is applied to the distribution board 10.
Similar to FIGS. 2 and 3, the molded case _{circuit breakers MCCB 1 to MCCB n} and the leakage breaker ELCB _{1 to ELCB n} are parallel to each other on the distribution wires 101 to 103 on the secondary side of _{the main wiring breaker MCCB 0.} It is connected to the.

Further, a single power supply surge protection device SPD ₀ having the configuration described below is connected to the distribution lines 101 to 103.
This power supply surge protector SPD ₀ includes a first series circuit consisting of a fuse F ₁ , a temperature separator TF ₁ , and a metal oxide varistor MOV _{1 , a fuse F 2} , a temperature separator TF ₂ , and a metal oxide varistor MOV. _{A second} series circuit composed of 2 and a _third series circuit composed of a fuse F 3, a temperature separator TF ₃ , and a metal oxide varistor MOV ₃ are provided. Each end of each of the first to third series circuits is connected to the distribution wires 101 to 103, and the other ends of the first to third series circuits are collectively connected and then the first gas-filled discharge tube GND. _The class D is grounded via the 1 and the first common grounding electrode 11, and the class D is grounded via the second gas-filled discharge tube GDT ₂ and the second common grounding electrode 12.
Similar to FIG. 2, the first common grounding electrode 11 is connected to the grounding terminal of the secondary side equipment (not shown) of _{the wiring breakers MCCB 1 to MCCB n via the first common grounding wire 11b.} , The second common grounding electrode 12 is connected to the grounding terminal of the secondary side equipment (not shown) of _{the leakage breakers ELCB 1 to ELCB n via the second common grounding wire 12b.}

As described above, the power supply surge protector SPD ₀ of FIG. 1 removes the second power supply surge protector SPD ₂ in FIG. 2, and the fuse F, in the _first power supply surge protector SPD 1. The connection point between the first to third series circuits composed of the temperature separator TF and the metal oxide varistor MOV and the first gas-filled discharge tube GDT ₁ is commonly grounded via the second gas-filled discharge tube GDT _2. It is configured to be connected to the pole 12.
That is, for the secondary side equipment connected between the distribution wires 101 to 103 on the secondary side of _{the wiring breakers MCCB 1 to MCCB n and the common ground wire 11b, the power supply surge protector SPD 0} is included. A circuit in which the first to third series circuits are star-connected and a series circuit of the first gas-filled discharge tube GND ₁ are connected in parallel, and on the secondary side of the _{leakage breakers ELCB 1 to ELCB n.} For the secondary side equipment connected between the distribution wires 101 to 103 and the common ground wire 12b, a circuit in which the first to third series circuits in _{the power supply surge protector SPD 0 are star-connected. A series circuit with the second} gas-filled discharge tube GND 2 will be connected in parallel.

Here, as an operation of the power supply surge protection device SPD ₀ , when a lightning surge current enters between the distribution wires 101 to 103 and the D-class grounding, the metal oxide varistor MOV _{1 to MOV 3} and the gas-filled discharge tube GDT _1. GDT ₂ absorbs the lightning surge current, and when the metal oxide varistor MOV _{1 to MOV 3} is overheated, the temperature separators TF _{1 to TF 3} operate to cut off the current, and the metal oxide varistor MOV ₁ The _{fuses F 1 to} F ₃ are blown to cut off the current against an overcurrent caused by a short circuit failure of the _{MOV 3.}
It is possible to output an alarm or display a failure by converting the current cutoff operation due to the blowing of the temperature separators TF _{1 to TF 3} or the fuses F _{1 to} F _{3 into a mechanical operation and taking it out.}

As described above, in the present embodiment, the single power supply surge protection device SPD ₀ having a configuration in which the gas-filled discharge tube GND _{2 is added to the first power supply surge protection device SPD 1 in FIG. 2 or FIG.} 1, respectively connected to the second ground terminal of the common ground electrode 11, 12 and the secondary-side instrument of the common ground line 11b, circuit breaker via 12b MCCB ₁ ~MCCB _n and ELCB ELCB ₁ ~ELCB _n By doing so, it is possible to configure a lightning surge protection system for all secondary equipment.
Therefore, the configuration of the distribution board 10 can be simplified, downsized, and the cost can be reduced, and as shown in FIG. 3 _{, two surge protection devices SPD 1} on the power input side of the _{earth-leakage circuit breakers ELCB 1 to ELCB n.} , SPD ₃ are not connected in series, and the limiting voltage for the secondary side equipment of _{the earth-leakage circuit breakers ELCB 1 to ELCB n} can be suppressed to a low value by a _{single power supply surge protector SPD 0.} Therefore, it is possible to reduce the withstand voltage of the secondary side devices of the earth-leakage circuit breakers ELCB _{1 to ELCB n.}

The current cutoff device according to the present invention can also be applied to a power board or a lamp board other than the distribution board.

10: Distribution board 11: First common grounding electrode 12: Second common grounding electrode 11a, 12a: Grounding wire 11b: First common grounding wire 12b: Second common grounding wire 100, 101-103: Arrangement Electric wire MCCB ₀ : Molded case circuit breaker MCCB _{1 to MCCB n} : Molded case circuit breaker ELCB _{1 to ELCB n} : Earth-leakage circuit breaker SPD ₀ : Surge protection device for power supply F _{1 to} F ₃ : Fuse TF _{1 to TF 3} : Temperature Separator MOV _{1 to MOV 3} : Metal oxide varistor GDT ₁ : First gas-filled discharge tube GDT ₂ : Second gas-filled discharge tube

Claims (3)

A circuit breaker for wiring and a circuit breaker for leakage are connected in parallel to each other on the secondary side of the circuit breaker for main wiring, and a secondary device is connected to the circuit breaker for wiring and the circuit breaker for leakage, respectively, and the main wiring. In a current circuit breaker in which a power surge protection device is connected between the secondary side of the circuit breaker and the ground.
The power supply surge protector is
A fuse for overcurrent protection connected in series between the distribution line on the secondary side of the main wiring breaker and the first common grounding electrode and the second common grounding electrode, and temperature separation separated at the time of overheating. Equipped with a device, a voltage limiting type element, and a voltage switching type element,
The first common grounding electrode and the grounding terminal of the secondary side device of the wiring breaker are connected by the first common grounding wire, and the second common grounding electrode and the secondary of the earth-leakage circuit breaker are connected. A current circuit breaker characterized in that the ground terminal of a side device is connected by a second common ground wire. In the current interrupting device according to claim 1,
The molded case circuit breaker and the earth-leakage circuit breaker are connected in parallel to the three-phase distribution wire on the secondary side of the main circuit breaker.
The power supply surge protector is
A series circuit of the fuse, the temperature separator, and the voltage limiting element is provided for three phases, and one end of each of these series circuits is connected to the three-phase distribution wire, and the other ends of the series circuit are collectively connected. Then, the collective connection point is connected to the first common grounding electrode via the first voltage switching type element, and to the second common grounding electrode via the second voltage switching type element. A current cutoff device characterized by being connected. In the current interrupting device according to claim 1 or 2.
A current cutoff device characterized in that the voltage limiting type element is a metal oxide varistor and the voltage switching type element is a gas-filled discharge tube.

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