JPH09233622A - Distribution panel with built-in lightening guard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent unnecessary operation of an earth leakage breaker during the invasion of a surge voltage by connecting a voltage dependency resistor element and a disconnecting element in series for a lightening guard connected between input power supply wires of the earth leakage breaker and between the input power supply wire and a grounding line. SOLUTION: A distribution panel 18 with a built-in lightening guard connects the lightening guard 2 connected with a voltage dependency resistor element and a fuse disconnecting mechanism in series between the input power supply wires 3 of an earth leakage breaker and between the wires and a grounding line. By doing this, a large surge voltage invaded from the input power supply wires 3 is absorbed by a power distribution panel 18 as a lead-in inlet for the input power supply wires 3 supplying power to various electronic and electric equipment, by which various electronic and electric equipment 19 connected are protected and a surge voltage lower than unnecessary operation level can be restricted. Also, if a large energy greater than the rating is applied to the lightening guard 2, a disconnecting mechanism is operated and the breakage of the lightening guard 2 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distribution board with a built-in arrester for protecting various electronic and electric devices from surge voltage such as lightning.

[0002]

2. Description of the Related Art In recent years, in the advanced information age, various electronic devices, information devices, and large-capacity electric devices have spread not only in factories and offices but also in households. The installation of equipment, protection of equipment such as neutral line open-phase protection function, and the addition of functions to prevent injury to humans and accidents are becoming widespread.

A conventional distribution board will be described below. A conventional distribution board is one in which a main switch, a branch switch, a branch circuit breaker, an earth leakage circuit breaker, a current limiter, etc. are all or partly assembled inside a cabinet. Various electronic and electric devices are connected to the load side, and the electric power supplied from the power supply line is supplied to the various electronic and electric devices through a branch circuit in the distribution board.

FIG. 5 shows the structure of a conventional distribution board, showing a distribution board for residential use of a single-phase three-wire type electric line.
1 is an earth leakage breaker or main switch, 3 is an input power line, 4 is a branch circuit breaker, 5 is a branch power line, 6 is a cabinet containing the earth leakage breaker or main switch 1, and the branch circuit breaker 4, 7 is It is a ground wire. Moreover, FIG. 6 shows the pole transformer 17 to FIG.
FIG. 4 is a low-voltage distribution line route diagram in a single-phase three-wire type electric circuit leading to various electronic and electric devices 19 through the distribution board shown in FIG. 19, and 19 is a television or fax machine connected to the load side of the branch circuit breaker 4. Various electronic and electric devices such as, a line-to-line surge absorber connected between the power lines of the electronic device 19 and 21, a line-ground connected between the power line of the electronic device 19 and ground It is a surge absorber for space use.

The operation of the conventional distribution board configured as described above will be described with reference to the circuit diagram of the single-phase 3-wire residential distribution board shown in FIG. The electric power supplied from the input power supply line 3 is supplied to various electronic and electric devices 19 via the branch power supply line 5 in the distribution board. If leakage occurs on the load circuit side connected to the distribution board, the earth leakage breaker 1 operates to electrically disconnect the load side circuit to prevent an accident such as electric shock. Further, when an overcurrent occurs in the circuit, the overcurrent interruption function of the branch circuit breaker 4 or the earth leakage circuit breaker 1 operates to electrically disconnect the circuit on the load side and prevent damage to various electronic and electric devices 19.

[0006]

Now, consider a case where a surge voltage enters from the input power line 3 due to lightning or the like. The surge voltage that has entered is absorbed by the line-to-line surge absorber 20 and the line-to-ground surge absorber 21 connected to the electronic / electrical device 19. In this way, when the surge absorber 21 connected between the wire and the ground operates, the surge current is discharged to the ground. There is a problem that the earth leakage breaker 1 senses the surge current discharged to the ground as an earth leakage current and the earth leakage breaker 1 operates unnecessarily.

Therefore, an object of the present invention is to provide a distribution board with a built-in arrester, which prevents unnecessary operation of the earth leakage breaker when a surge voltage enters.

[0008]

In order to achieve this object, a distribution board with a built-in arrester of the present invention comprises an earth leakage breaker, an input power supply line of the earth leakage breaker, and an input power supply wire and a ground wire. A lightning arrester connected in between is provided, and this lightning arrester has a voltage-dependent resistance element and a disconnection mechanism connected in series, whereby the above object can be achieved.

[0009]

The invention according to claim 1 of the present invention comprises an earth leakage breaker and a lightning arrester connected between an input power line of the earth leakage breaker and a ground wire.
It is a distribution board with a built-in lightning arrester in which a voltage-dependent resistance element and a disconnection mechanism are connected in series, and is a lead-in port for the input power supply line that supplies a large surge voltage that has entered from the power supply line to various electronic and electrical devices. It is possible to absorb a variety of electric and electronic devices connected to the distribution board, suppress surge voltage below the unnecessary operation level of the earth leakage breaker, and protect the surge arrester from energy above the rated level. When added, the disconnection mechanism operates to prevent damage to the lightning arrester.

According to a second aspect of the present invention, a ceramic varistor mainly composed of zinc oxide is used as a voltage-dependent resistance element, and a large surge voltage that has entered from a power supply line can be applied to various electronic and electrical devices. Absorbed by the distribution board that is the inlet of the input power supply line that supplies power to the equipment, protects various connected electronic and electrical equipment, and suppresses surge voltage below the unnecessary operation level of the earth leakage breaker. It is possible to prevent the destruction of the lightning arrester by operating the disconnection mechanism when the surge arrester receives energy more than the rated value.

According to a third aspect of the present invention, a current fuse or a temperature fuse is used as the disconnection mechanism, and a large surge voltage that has entered from the power supply line is supplied to various electronic and electric devices. It is possible to absorb by the distribution board that is the inlet of the input power line, protect various connected electronic and electrical devices, and suppress the surge voltage below the unnecessary operation level of the earth leakage breaker. Moreover, when energy exceeding the rated value is applied to the lightning arrester, the disconnection mechanism operates to prevent damage to the lightning arrester.

FIG. 1 shows an embodiment of the present invention.
~ It demonstrates using FIG. First, the present embodiment will be described using a distribution board with a built-in arrester used in a single-phase three-wire type distribution system. A ceramic varistor mainly composed of zinc oxide is used as the voltage-dependent resistance element of the lightning arrester, and a current fuse is used between the power supply lines and a temperature fuse is used between the power supply line and the ground as a disconnection mechanism. FIG. 1 is an external configuration diagram of a distribution board with a built-in arrester of the present embodiment, and FIG. 2 is a schematic diagram showing a circuit configuration of a distribution board with a built-in arrester of the present embodiment in a single-phase three-wire system. Figure 3 shows the circuit diagram of the arrester in the single-phase three-wire type electric circuit. In FIG. 1, 1 is an earth leakage breaker, 2 is a lightning arrester connected between the power supply lines on the power supply line input side of the earth leakage breaker 1 and between the line and ground, 3 is an input power supply line, 4 is a branch circuit breaker, 5 is a A branch power line, 6 is a cabinet that houses the earth leakage breaker 1, the lightning arrester 2 and the branch breaker 4, 7 is a ground line, 8 is a ceramic varistor connected between the power lines, and 9 is a power line ~ Ceramic varistor connected between the ground, 10 is a current fuse serially connected to the ceramic varistor 8, 11 is a thermal fuse serially connected to the ceramic varistor 9, 12 is an LED connected in parallel to the ceramic varistor 8 , A lamp such as a neon lamp, 13 is a resistor connected in series to the lamp 12,
14 is a diode connected in parallel to the lamp 12, 15
Indicates a power supply line connection terminal, and 16 indicates a ground line connection terminal. The lamp 12, the resistor 13 and the diode 14 form a display circuit showing the operation status of the ceramic varistor 8 and 9.
The ceramic varistor 8 and 9 are connected in parallel, and the ceramic varistor 9 and the thermal fuse 11 are well thermally coupled. The power supply line connection terminal 15 is connected to the input power supply line 3, and the ground line connection terminal 16 is connected to the ground line 7.

The operation of the lightning arrester built-in switchboard constructed as described above will be described with reference to FIG. FIG.
1 is a schematic view of a low-voltage distribution line route in a single-phase three-wire type electric line connecting the distribution board with built-in arrester of the present embodiment. In FIG. 4, 17 is a pole transformer, 18 is a distribution board with a built-in arrester of the present embodiment, and 19 is a distribution board with a built-in arrester 18
Various electronic and electric devices connected to the load side of the device, 20 is an inter-line surge absorber connected between the power lines of the electronic device 19 and 21 is connected between the power line of the electronic device 19 and the ground. Shows the surge absorber for the wire to ground. In addition, the surge arrester 2 is arranged so as to suppress the surge voltage below the operating voltage of the line-to-ground surge absorber 21.
Set the operation start voltage of. Now, when a large line surge voltage or a line-ground surge voltage that exceeds the ratings of the surge absorbers 20 and 21 from the input power line 3 due to lightning or the like enters, the surge arrester 2 operates and energy with a large surge voltage is entered. Energy of the remaining surge voltage not absorbed by the lightning arrester 2 is absorbed by the line-to-line surge absorber 20 and the line-to-ground surge absorber 21.
9 and protects between lines surge absorber 2
It is possible to prevent the surge absorber 21 for 0, wire-to-ground from being overloaded far exceeding the rating. In addition, since the surge arrester 2 suppresses the surge voltage to the operating voltage of the line-to-earth surge absorber 21 or less, the line-to-earth surge absorber 21 is not discharged to the earth and the leakage of electricity is interrupted in the distribution board. When the device 1 is adopted, unnecessary operation of the earth leakage breaker 1 does not occur. Also,
When a surge voltage greatly exceeding the rating enters the arrester 2 and the ceramic varistor 8 is deteriorated and damaged, in most cases,
Although a short-circuit breakdown occurs, the current fuse 10 operates due to the short-circuit current at this time, whereby the current fuse 10 is electrically disconnected from the circuit, and it is possible to prevent the arrester from being destroyed. When the ceramic varistor 9 is deteriorated and damaged, the temperature fuse operates due to the heat generated from the element, and the destruction of the lightning arrester is prevented. When the ceramic varistor 9 is connected between the wire and the ground as in the case of the ceramic varistor 9, even if the ceramic varistor 9 causes a short circuit breakdown, the short circuit current may be limited due to the ground resistance, and the current fuse may not operate. Therefore, it is effective to use a thermal fuse. When the ceramic varistors 8 and 9 are operating normally, the lamp 12 connected in parallel with the ceramic varistor 8 and 9 is lit by a current flowing,
When the current fuse 10 or the temperature fuse 11 is operated at the time of abnormality as described above, no current flows to the lamp 12 and the lamp is extinguished, so that the operating condition can be easily visually confirmed from the outside.

In the present embodiment, the single-phase three-wire type electric circuit has been described, but the power distribution method is also effective for the single-phase two-wire type electric line and the three-phase three-line type electric line. Also, as a fuse to the lightning arrester built into the distribution board,
You may use the thing provided with the mechanism which mechanically isolate | separates the low melting point alloy which selected thickness, width, and the material with a spring. Also, it is effective to use a temperature fuse and a current fuse connected in series as a disconnecting mechanism.

[0015]

As described above, in the distribution board with a built-in arrester of the present invention, a surge arrester in which a voltage-dependent resistance element and a disconnecting mechanism such as a fuse are connected in series is used between the input power lines of the earth leakage breaker and the line to ground. With the structure connected between them, a large surge voltage that invades from the input power line
It absorbs in the distribution board that is the inlet of the input power supply line that supplies electric power to the electric equipment, protects various connected electronic and electric equipment, and protects the surge voltage below the unnecessary operation level of the earth leakage breaker. It is possible to suppress the surge arrester, and it is possible to prevent the destruction of the lightning arrester by operating the disconnection mechanism when a large amount of energy exceeding the rated voltage is applied to the surge arrester, and it is possible to realize high reliability and safety. It is a thing.

[Brief description of drawings]

FIG. 1 is a structural diagram showing a distribution board with a built-in arrester according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a distribution board with a built-in arrester according to an embodiment of the present invention.

FIG. 3 is a circuit diagram of a lightning arrester that constitutes a distribution board with a built-in arrester according to an embodiment of the present invention.

FIG. 4 is a low-voltage distribution line route diagram in a single-phase three-wire type electric line for explaining the operation of the distribution board with a built-in arrester in one embodiment of the present invention

FIG. 5 is a structural diagram showing a conventional distribution board.

FIG. 6 is a low-voltage distribution line route diagram in a single-phase three-wire type electric line for explaining the operation of a conventional distribution board.

FIG. 7 is a circuit diagram of a conventional distribution board.

[Explanation of symbols]

 1 Earth Leakage Breaker 2 Lightning Arrester 8, 9 Ceramic Varistor 10 Current Fuse 11 Thermal Fuse

Claims (3)

[Claims] 1. An earth leakage circuit breaker, a lightning arrester connected between the input power supply lines of the earth leakage circuit breaker, and between the input power supply line and a ground line. The lightning arrester is separated from the voltage-dependent resistance element. A distribution board with a built-in lightning arrester that is a series connection with the mechanism. 2. The lightning arrester built-in distribution panel according to claim 1, wherein a ceramic varistor mainly containing zinc oxide is used as the voltage-dependent resistance element. 3. The distribution board with a built-in arrester according to claim 1, wherein a current fuse or a temperature fuse is used as the disconnection mechanism.