JP2002101505A - Switchboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switchboard adequate to an anti-lightning and anti-noise measure. SOLUTION: When a lighting surge comes in from a communication line 20, a voltage applied to a grounding electrode 13A at the contact of a PNPN lightning-protecting element 15 and the communication line is raised by the inductance of a common-mode choke coil 16 20 before the surge current becomes so large as to destroy apparatus in a building. Thereby, the PNPN lightning- protecting element 15 woks (brought into conduction) at high speed. Furthermore, a current-control element in a subscriber's protector 13 controls an increase of a current before such a large current that may destroy the PNPN lightning-protection element 15 is made to flow. Then, a gas-filled lightning conductor in the subscriber's protector 13 works (brought into conduction).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switchboard for drawing a power supply line and a communication line from the outside of a building into the inside of a building, and more particularly to a technique for forming a switchboard suitable for countermeasures against lightning and noise.

[0002]

2. Description of the Related Art In recent years, a large number of information devices and communication devices are used in buildings such as homes and offices, and power systems such as inverter devices for converting electricity generated by solar power generation into alternating current and air conditioners. Many electric appliances are also being used. As described above, electronic devices and electric appliances used in a building may malfunction or malfunction due to lightning or noise, so it is necessary to take appropriate measures against lightning and noise.

Generally, in a home or office building, high-power equipment such as a power supply line and low-power equipment such as a communication line are separately installed, and noise countermeasures are separately performed. For example, as shown in FIG. 5, in the building 100, a lightning arrester (varistor) 12 for the power supply is attached between the power supply line 10 and the ground electrode 12A for the power supply lightning arrester, while the communication line 20 is connected to the building 100 as a countermeasure against lightning. A subscriber protector 13 for communication is mounted between the ground electrodes 13A for personal protector. That is, different measures are taken for the power supply line and the communication line. Also, as shown in FIG. 6, an external lightning protection adapter 102A may be attached to each communication terminal device (such as an ISDN device) 102.

[0004]

However, in the countermeasures for lightning and noise shown in FIG. 5, the subscriber protector 13 and the varistor 12 are not provided.
Are separately installed and each lightning arrester is connected to a different ground electrode, so that the effect of lightning / noise countermeasures is small, so that failure and malfunction of the equipment may not be reduced.

As shown in FIG. 6, when a lightning protection adapter 102A is attached to each device, the cost of countermeasures increases in the case of a LAN to which many devices are connected. In addition, since there are many devices, there is a possibility that a failure occurs due to forgetting to attach them.

Further, when an inverter is used in a device, noise may enter the communication device from the power supply, causing noise or malfunction. At this time, a large amount of noise flows from the power supply to the building-side ground electrode 13A through the B-type ground electrode 10A of the power distribution transformer. This is a major factor in the fluctuation of the ground potential of the building, and effective measures cannot be expected even if countermeasures are taken only with communication equipment.

That is, even if lightning arresters are attached to the power supply line and the communication line, if each lightning arrester is connected to a different grounding pole, a current is applied to the grounding pole when a lightning surge enters from the power supply line or the communication line. Flows, the ground potential rises, and a potential difference is generated between the power supply line and the communication line, and the device breaks down. On the other hand, by installing lightning arresters on the power line and the communication line and connecting them to the same ground, the lightning surge generated on the power line flows out to the ground and the communication line. It is generally said that the communication line and the ground terminal can be equipotential, and a large voltage is not generated between the power line terminal, the ground terminal, and the communication line terminal of the equipment in the building, thereby preventing the equipment from being broken. The same applies to the case where a lightning surge comes in from a communication line.

However, the durability of the equipment differs depending on the equipment, and in a building where unspecified equipment is used, the lightning arrester of the power supply line and the communication line is connected to the power supply line and the communication line only by attaching to the same ground as described above. Equipment cannot be protected.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems.
An object of the present invention is to provide a switchboard suitable for noise suppression.

[0010] The purpose of the present invention is to provide:

[0011]

According to a first aspect of the present invention, there is provided a switchboard for drawing a power supply line and a communication line from outside the building to the inside of the building. A lightning arrester circuit provided between the line and the ground terminal of the switchboard; and between the communication line and the ground terminal, or interposed between the communication lines, and provided sequentially from outside to inside the building. Protector, PN
A lightning arrester circuit using a PN semiconductor element and a common mode choke coil are provided.

According to the present invention, a "subscriber protector" capable of withstanding a large current but having a relatively high operating voltage is installed in order from the outside of the building as a protector of the communication line. "PNPN" which operates quickly and at low voltage
`` Common mode choke coil '' is installed to prevent lightning surge current from flowing into equipment in the building even if the endurance of communication terminal equipment is low, as well as installing `` lightning circuit using elements ''. A large lightning surge that flows into a building from a communication line can be reduced to a level that does not affect even low-tolerance communication devices such as ISDN devices, thereby preventing device failure and malfunction. . Further, since the lightning protection circuit is also provided on the power supply line, it is possible to prevent equipment failure or malfunction due to lightning surge from the power supply line.

According to a second aspect of the present invention, in the switchboard according to the first aspect, a capacitor or a series resonance frequency is set to 20 kHz to 100 kHz in parallel with a lightning arrester provided on the power supply line. A series circuit of a capacitor and an inductor is connected.

According to the present invention, the noise from the inverter equipment or the like inside the building flows through the power supply line, the capacitor or the series circuit, and the ground terminal and returns to the ground terminal of the inverter equipment. The inconvenience flowing out to the distribution line can be prevented.
In addition, by connecting the capacitor and the inductor in series, the impedance between the power supply line and the ground terminal at the resonance frequency of the inductor can be further reduced, so that it is possible to effectively take measures against lightning and noise.

According to a third aspect of the present invention, in the switchboard according to the first or second aspect, the wiring from the power supply line to the equipment inside the building and the wiring from the ground terminal of the equipment to the ground terminal are provided. It is characterized by being applied to the same route.

According to the present invention, since the power supply line to the equipment inside the building and the wiring from the ground terminal of the equipment to the ground terminal are provided on the same path, the area of a closed circuit formed by these wirings is provided. , The fluctuation of the ground potential due to the outflow of noise from the power supply line to the outside of the building can be reduced, and the influence of the induced noise on surrounding devices can be reduced.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a configuration diagram of a switchboard 1 according to a first embodiment of the present invention. The switchboard 1 is provided in a building 100 and has a power supply breaker 11, varistors 12, 12, and a subscriber protector 1 having two built-in switches.
3, a ground terminal 14, PNPN lightning arresters 15, 15, and a common mode choke coil 16.

Each phase 1 of the power supply line drawn into the switchboard 1
Reference numerals 0 and 10 are attached to a power supply line attachment portion (not shown). One end of each of the varistors 12 is connected to the power supply lines 10 via a switch of the power supply breaker 11, and the other end of each of the varistors 12 is connected to the ground terminal 14. The ground terminal 14 is connected to a ground electrode 13A for the subscriber protector 13. The power lines 10, 10 constructed in this manner are connected to a power supply circuit of a communication terminal device or the like in the building 100 (hereinafter referred to as a "device in the building").
The power lines 10, 10 are connected to a class B ground electrode 10A of a distribution transformer such as a substation.

On the other hand, each conductor 20, 20 of the communication line drawn from the telephone station to the switchboard 1 is connected to a subscriber protector 13 attached to a communication subscriber protector mounting portion (not shown).
Are connected to the station side terminals 13-1 and 13-2, respectively.

FIG. 2 is a diagram showing a circuit configuration of the subscriber protector 13.

The subscriber protector 13 includes an office terminal 13-1,
13-2, indoor terminals 13-3 and 13-4, and a ground terminal 13-5. Station side terminal 13 of subscriber protector 13
A triode gas surge arrester is connected between -1 and 13-2,
The ground wire of the triode gas-containing arrester is connected to the ground terminal 13-5. Further, each connection point between the office-side terminals 13-1 and 13-2 and the arrester containing triode gas is connected to the indoor-side terminal 13-.
3, 13-4, a fuse or a positive temperature coefficient thermistor (hereinafter collectively referred to as "current suppressing element") is connected in series.

Returning to FIG. 1, the communication lines 20, 2 drawn from the indoor terminals 13-3, 13-4 of the subscriber protector 13 will be described.
PNPN lightning arresters 15 and 15 are connected between the grounding terminal 14 and the ground terminal 14 of the switchboard 1. The ground terminal 13-5 of the subscriber protector 13 is connected to the ground terminal 14. Communication line 20,
A common mode choke coil 16 is inserted from the connection point between the PNPN lightning arresters 20 and the PNPN lightning arresters 15 and 15 to the indoor communication lines 20 and 20 and connected to the input terminals of equipment in the building (not shown). . The common mode choke coil 1
As 6, the effective frequency is the same as that of the lightning surge.

Next, the operation of the switchboard 1 will be described. For example, it is assumed that a lightning surge has entered from the communication line 20. When the dielectric strength of the equipment in the building is low, or when the semiconductor element or the like of the equipment in the building operates at a low pressure, current flows through the equipment in the building. However, before this current becomes large enough to destroy the equipment in the building, the inductance of the common mode choke coil 16 causes the PNPN lightning arrester 15 to communicate with the communication line 2.
The voltage of the connection point with 0 to the ground electrode 13A increases. Thereby, the PNPN lightning arrester 15 operates (conducts) at high speed. Therefore, according to the switchboard 1, it is possible to suppress an increase in the voltage of the equipment in the building due to the lightning surge.

Further, before a large current that destroys the PNPN lightning arrester 15 flows, a current suppressing element inside the subscriber protector 3 suppresses an increase in current. Thus, the gas-filled lightning arrester in the subscriber protector 13 operates (conducts). As a result, the lightning surge current flows through the ground terminal 14 to the ground electrode 13A. For this reason, destruction and malfunction of the equipment in the building can be prevented more safely.

Further, when the ground resistance of the ground electrode 13A is high, the power line 1
Although the voltage of 0 rises, in this case, the pariser 12 operates (conducts), and the potential difference between the power supply line 10 and the communication line 20 is eliminated, so that the power supply circuit of the equipment in the building can be protected. In the power supply breaker 11, the contact is opened by the current when the palister 12 is broken and the continuity occurs, so that the overcurrent at the time of the varistor 12 failure can be prevented. Furthermore, the common mode choke coil 13 is also effective against inverter noise in the same frequency range as lightning, so that it is possible to prevent the inverter noise from flowing out to the communication line 20.

As a result, since it is not necessary to attach the lightning protection adapter to each device one by one, it is possible to suppress an increase in the cost of lightning and noise countermeasures in a LAN or the like. Further, by separating the power supply breaker 11 from the power supply line 10, maintenance and replacement work of the parister 12 can be easily performed.

[Second Embodiment] FIG. 3 is a configuration diagram of a switchboard 1A according to a second embodiment. Switchboard 1A
Is constructed by providing capacitors 17, 17 in parallel with each varistor 12 of the switchboard 1. In the building 100, a device (referred to as an inverter device) 101 using an inverter is provided, and a ground terminal of the inverter device 101 is connected to a ground terminal 14 of the switchboard 1 via a ground wire 101A.

Before describing the operation of the switchboard 1A, a case where the capacitors 17 and 17 are not provided will be described. Noise flowing from the inverter device 101 to the power supply line 10 passes through the grounding electrode 10A for class B and enters the ground electrode 13A, and returns to the inverter device 101 through the ground line 101A, so that potential fluctuation of the ground electrode 13A can be avoided. Did not.

On the other hand, the switchboard 1A has a capacitor 1
7 and 17, noise from the inverter device 101 of the building 100 is generated by the power supply lines 10 and 10, the capacitors 17 and 17, the ground terminal 14, and the inverter device 10.
Since the current returns to the first ground line 101A and the inverter device 101, the potential fluctuation of the ground electrode 13A can be prevented. It should be noted that the switchboard 1A is a switchboard 1 for lightning surge.
It has the same function and effect as described above. Further, the common mode choke coil 13 can prevent the inverter noise from leaking to the communication line 20 as in the case of the switchboard 1.

[Third Embodiment] FIG. 4 is a configuration diagram of a switchboard 1B according to a third embodiment. Switchboard 1B
Is constructed by connecting coils (inductors) 18 and 18 in series to the capacitors 17 and 17 of the switchboard 1A, respectively. The series resonance frequency of the capacitor 17 and the coil 18 is set in accordance with the frequency range of noise from the inverter device 101.

Also, the switchboard 1B is connected to the inverter equipment 10
1 and a ground wire 101A from the inverter device 101 to the ground terminal 14 are wired together on the same route in the building 100, for example. In FIG. 4, the portion indicated by the arrow Y is wired in this manner.

Next, the operation of the switchboard 1B will be described. First, the noise from the inverter device 101 efficiently flows to the ground terminal 14 by the coils 18, 18, so that the ground electrode 10 passes through the power supply line 10 from the inverter device 101.
The current flowing to A can be further reduced.

On the other hand, power supply line 1 to inverter device 101
0 and the ground line 101A from the inverter device 101 are wired on the same route in the building 100, so that the area of a loop (closed circuit) formed by the power line 10 and the ground line 101A is reduced, and noise concentrates on this loop. Flows. For this reason,
Outdoor power lines 10, 10, ground electrode 10A, ground electrode 1
It is possible to prevent the potential fluctuation of the ground electrode 13A due to the noise flowing through 3A. Further, since the inductance of the loop is reduced, the magnetic field generated around the loop is reduced, and the induction noise is reduced. For this reason, the influence on surrounding devices can be reduced.

[0035]

As described above, according to the switchboard according to the present invention, it is possible to take measures against lightning and noise in the equipment in the building, thereby preventing the equipment from malfunctioning and malfunctioning. it can.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a switchboard 1 according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a circuit configuration of a subscriber protector 13;

FIG. 3 is a configuration diagram of a switchboard 1A according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a switchboard 1B according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a conventional lightning / noise countermeasure method.

FIG. 6 is a diagram showing another conventional lightning / noise countermeasure method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1A, 1B Switchboard 10 Power supply line 10A Grounding electrode for class B grounding 20 Communication line 11 Power supply breaker 12 Lightning arrester (varistor) for power supply line 12A Lightning arrester grounding electrode for power supply line 13 Subscriber protector 13A Grounding electrode for protector 14 Grounding terminal 15 PNPN lightning arrester 16 Common mode choke coil 17 Capacitor 18 Coil 100 Building 101 Inverter equipment 101A Ground wire

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02H 9/06 H02H 9/06 (72) Inventor Seiya Kuwahara 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo 5G013 AA05 BA03 CA02 CA16 CA18 CB21 CB23 DA02 DA08 5G016 AA01 CE01 CE10

Claims (3)

[Claims] 1. A power distribution panel for drawing a power supply line and a communication line from the outside of a building into a building, comprising: a lightning arrester circuit provided between the power supply line and a ground terminal of the distribution panel; Or a lightning arrester circuit using a PNPN semiconductor element and a common mode choke coil, which are provided between the communication line and the communication line and sequentially provided from outside to inside of the building. Switchboard characterized by the following. 2. A capacitor or a series resonance frequency of 20 kHz in parallel with a lightning arrester provided on the power supply line.
2. The switchboard according to claim 1, wherein a series circuit of a capacitor and an inductor, which is set to 100 kHz, is connected. 3. The wiring from the power supply line to the equipment inside the building and the wiring from the ground terminal of the equipment to the ground terminal are provided in the same path. Switchboard.