JP5201448B2 - Distribution board - Google Patents

Description

The present invention relates to a distribution board that distributes power to a load circuit through an electric circuit. More specifically, the present invention relates to a ground in which an electrical terminal provided on the ground is electrically connected to the electrical terminal. The present invention relates to a distribution board having a device for confirming a grounding state, which is made by being electrically connected to a protective grounding conductor for grounding a device or the like via a wire.

Conventionally, the protection of wiring when overcurrent or short-circuit current flows in the circuit, the electrical fire in the case where a ground fault occurs due to the deterioration of the insulation of the circuit or the load device, and the insulation of the load device As a result of the deterioration of the battery, a potential is generated between the earth and the casing that constitutes the load device, and various electrical accidents such as electric shocks that may occur when the human body touches the load device cause human life and property damage. In order to ensure safety, various power distribution devices have been developed, including wiring breakers and earth leakage breakers.

In particular, in order to prevent electrical accidents caused by the electric shock of the human body, the installation of earth leakage circuit breakers was obligated by the Industrial Safety and Health Regulations in 1969, and the number of deaths due to electric shocks has been decreasing year by year.

In order to distribute power to the load circuit, these various types of power distribution equipment are housed in a cabinet, and a distribution board incorporating the power distribution equipment inside the cabinet has traditionally been used in factories and homes. It is used.

Well, it is well known that even before the installation of earth leakage circuit breakers became mandatory, protective grounding of equipment was carried out from the viewpoint of preventing electric shock accidents, and results were achieved in preventing electric shock accidents in the human body. It is.

For example, as shown in FIG. 9, even when the insulation of a load device installed in an electric circuit deteriorates and a ground voltage _Vg is generated between the ground and the housing of the load device, the ground resistance has no influence on the human body. Is as follows.

The R _B B type grounding resistance, represented the _{R D} D type grounding resistance, the _{V E} as path _{voltage, V g = {R D /} (R B + R D)} V E ··· ( Equation 1) and . Here, assuming that the resistance of the human body is 1 kΩ and the human body passage allowable current is 30 mA, which is limited to several minutes (electric shock current by Mr. Bigetzmeier and the physiological reaction of the human body), V _g = 30 V is assumed as the ground voltage. It is considered the upper limit of tolerance.

When path voltage _{V E} is 200V, by calculating by substituting _{V g} in Formula _{1, R B = 5.7R D ···} ( Equation 2), and the B type grounding resistance magnitude 10Ω In this case, since R _D ≈1.7Ω, the D-type ground resistance may be set to about 1.7Ω or less.

However, this ground resistance of 1.7Ω or less is actually a low ground resistance value that is difficult to obtain by normal installation work. When the ground is grounded, the soil is subjected to scientific treatment. For example, even if the ground resistance is obtained by using a ground resistance reducing agent using an inorganic high water content crystal, the ground resistance is maintained over time. In addition, it is difficult to check the grounding resistance over time because the surrounding environment often changes from the time when the grounding work was done, and it is difficult in practice. Was that.

In this way, electrical accidents due to electric shock from human bodies have been conventionally prevented by protective grounding of equipment, but in addition to grounding, by installing the above earth leakage breaker in the electrical circuit, If the insulation of the battery deteriorates and a leakage current of a predetermined magnitude is generated in the electric circuit, the leakage circuit breaker interrupts the electric circuit, thereby eliminating the risk of electric shock, and can be more effectively prevented. Is. However, even if the earth leakage breaker is installed in the electric circuit, if the grounding work is not sufficient, the time between the contact of the human body with the load equipment with deteriorated insulation and the breaking operation of the earth leakage breaker In this case, a leakage current flows through the human body, and the possibility of an electric shock accident cannot be completely denied.

Thus, grounding is very important to ensure the safety of human lives and property from various electrical accidents regardless of the presence or absence of the earth leakage breaker.

In view of the importance of such grounding, the distribution board also has a ground branch line terminal for connecting the ground pole wiring, that is, the ground branch line, for example, “Japan Wiring Equipment Manufacturers Association Standard JWDS 0007 Residential distribution board” ”Describes its structure.

As for the distribution board provided with such a ground wire branch terminal, for example, one having a ground relay terminal as shown in Patent Document 1 and Patent Document 2 is known.

By the way, when the grounding work is performed, the grounding resistance, that is, the resistance between the ground and the grounding electrode which is an electrical terminal provided on the ground, depends on the kind of grounding work. It is necessary to check whether or not a predetermined resistance value is satisfied.

The grounding work is as described in “Technical Standards for Electrical Equipment”. According to Article 19 of the Interpretation of Technical Standards,
“Grounding work shall be conducted in accordance with Article 13 (Electrical circuit insulation) No. 6 and No. 7 (a), Article 23 (Grounding of the service area entrance), Article 28 (Electrical equipment grounding) ] Paragraphs 1, 2 and 4 and Article 42 (Grounding of lightning arresters) Grounding under the provisions of No. 2 (a), (3) (a) and (b), and the same high voltage overhead wire as the special high voltage overhead wire Except for the case where grounding work is performed on the parts to be installed on the support, the following four types are listed in the left column, and the grounding resistance value in each grounding work depends on the type of grounding work listed in the left column of the table. According to the type of each grounding work, the grounding resistance value is 10Ω in the case of Class A grounding work, and in the case of Class B grounding work. Is the amperage of the 1-wire ground fault current of the high-voltage side or extra high-voltage side of the transformer (150 If the ground voltage of the low piezoelectric circuit exceeds 150V due to the contact between the extra high voltage circuit and the low voltage circuit, the operating voltage is less than 35,000V, and the high voltage circuit is automatically used within 2 seconds. 300 when installing a device that cuts off a special high voltage circuit with a voltage of 35,000 V or less, or 600) when installing a device that automatically cuts off a high voltage circuit within a second or a voltage of 35,000 V or less. In the case of class C grounding work, the number of ohms equal to the divided value is 10Ω (when installing a device that automatically shuts off the electric circuit within 0.5 seconds when grounding occurs on the electric circuit in a low piezoelectric circuit. , 500Ω), and 100Ω for Class D grounding work (500Ω when installing a device that automatically shuts off the electric circuit within 0.5 seconds when the electric circuit is grounded in a low-piezoelectric circuit) , Ground resistance value is defined.

As a method for measuring the ground resistance value, the following method has been proposed conventionally.

First, in addition to the ground electrode for measuring the desired ground resistance, two auxiliary electrodes are used, and each electrode is placed in the soil at intervals of several meters so that it becomes the apex of the triangle. This is a so-called Kolash Bridge method in which the target ground resistance is measured by measuring the resistance between vertices.

Second, in addition to the ground electrode that measures the target ground resistance, two auxiliary electrodes are used and each electrode is placed in a straight line in the soil, and the target ground resistance is measured at one end. A ground electrode is disposed, one auxiliary electrode is installed at the other end separated by several tens of meters, and the other auxiliary electrode is disposed between the ground electrode and the other auxiliary electrode. This is a so-called electrode voltage drop method in which a target ground resistance is measured by passing a current between the auxiliary electrode and the ground electrode and measuring a voltage generated between the other auxiliary electrode and the ground electrode.

Thirdly, without using the auxiliary electrode, several tens of meters of electric wire is put on the ground, and the capacitor component formed between the electric wire and the ground and the inductance component existing in the electric wire are used to achieve the target. By applying a high-frequency signal via a known resistor between the ground electrode for measuring the ground resistance and the electric wire and resonating, the capacitor component and the inductance component are canceled out, and the high-frequency voltage at the time of resonance and the terminal This is a method using so-called resonance in which the ground resistance is measured by measuring the voltage.

However, in these measurement methods, it is necessary to drive each auxiliary electrode used in the measurement into the soil, and to arrange each electrode on a triangle or a straight line with a certain distance, and therefore, between the electrodes. The distance and the length of the wire used for measurement are several tens of meters. Actually, it is necessary for the measurement because the surrounding area is paved with concrete or asphalt, and the neighbors and fences are installed. In many cases, it is difficult to ensure a width of several tens of meters, and it is difficult to measure the ground resistance.

In addition, it is necessary to drive each auxiliary electrode used for measurement into the soil, and to place each electrode on a triangle or straight line with a distance of several tens of meters. Was very laborious and labor intensive.

Based on the importance of grounding and the effort of measuring grounding resistance, the technology for adjusting the grounding resistance value to be within the specified range and the measurement in places where grounding resistance measurement is difficult have been improved. Patent Documents 3 to 5 disclose techniques for improving work efficiency as follows.
Japanese Patent Laid-Open No. 2000-201402 FIG. Japanese Patent Laid-Open No. 2000-201407 FIG. JP 2006-275623 A FIG. Japanese Patent Laid-Open No. 2007-163139 FIG. Japanese Patent Laid-Open No. 2007-127558 FIG.

However, there is no disclosure of a device that simply checks the grounding resistance after grounding work, or a device that checks the grounding resistance over time, and when measuring the grounding resistance as described above. , The measurement work requires labor. In addition, even if the grounding work itself is done properly, the grounding system functions for the first time when the above-mentioned protective grounding conductor and the grounding electrode are properly connected. Although it is important to confirm whether or not the system is in a functioning state, there is no disclosure of a technique for confirming whether or not such a grounding system is in a functioning state.

Moreover, the grounding resistance is expected to change depending on the environmental conditions surrounding the grounding system over time, taking into account the deterioration of functionality due to aging of various connection parts in the grounding system. It is desirable to be able to easily confirm whether or not the grounding system is in a functioning state.

In view of such a problem, the present invention can perform grounding resistance measurement work without any effort after grounding work is performed, and can confirm grounding resistance over time, that is, Whether the work required for measuring ground resistance can be reduced as much as possible at the place where the distribution board is installed, and the grounding work itself has been done correctly, and whether the grounding system is functioning properly over time. It is an object of the present invention to provide a distribution board equipped with a grounding system connection state confirmation device capable of confirming the above in a very simple manner.

In order to achieve the above object, claim 1 of the present invention provides:
Among the voltage lines and neutral wires of the transformer secondary winding that intervene in the electric circuit, the neutral wire side is grounded by providing a first electrical terminal on the ground, and is connected to the ground on the load-side electric circuit of the transformer. A configuration in which the second electrical terminal provided is electrically connected to a protective ground conductor that performs grounding of the device or the like via a ground wire electrically connected to the second electrical terminal. A lead-in wire connected to the load-side electric circuit of the transformer in a circuit having a grounding system connected to the cabinet, and a current limiter / main switch connected to the lead-in wire and connected to the main switch a distribution board for distributing power to a plurality of load circuits provided with the internal equipment such as branch switches being, the該分board, grounding system connection state confirmation device for confirming the connection state of the ground line A distribution board characterized by having It is intended.

According to such a distribution board, it is possible to check the connection status of the grounding system at the place where the distribution board is installed in factories and homes, etc., and to reduce the labor required for measuring the ground resistance as much as possible. In addition, the grounding work itself can be performed correctly, and it can be very easily confirmed whether the grounding system is functioning normally over time.

In addition, the grounding system connection state confirmation device may constitute a distribution board characterized in that the grounding system connection state confirmation device is placed on an insole which is a mounting plate to which the internal device is attached in place of a part of the branch switches. .

According to such a distribution board, it is not necessary to secure a new place in the distribution board when the grounding system connection state confirmation device is provided, and can be applied to an existing distribution board. It is.

In addition, the grounding system connection state confirmation device may be provided with a distribution board characterized in that it is provided in an additional circuit space provided in the insole.

According to such a distribution board, when the grounding system connection state confirmation device is provided, it can be placed in the distribution board without reducing the number of branch switches already installed. It can also be applied to other distribution boards.

In addition, the grounding system connection state confirmation device may provide a distribution board characterized by being installed in the accessory mounting space when the accessory mounting space is provided in the cabinet.

According to such a distribution board, when the grounding system connection state confirmation device is provided, it can be placed in the distribution board without reducing the number of branch switches. It is also possible to apply.

Further, the grounding system connection state confirmation device is disposed adjacent to the outside of the cabinet constituting the distribution board via a connection portion with the electrical conductor provided on the distribution board. An electrical board may be provided.

According to such a ground system connection status check device, even if installation inside the distribution board cannot be performed due to restrictions on the installation space of the branch switch or attached equipment, it can be performed adjacent to the distribution board, It is possible to determine whether or not the grounding system is connected at the place where the distribution board is installed, and it is possible to check the connection state of the grounding system even though it is a very simple method.

In addition, a distribution board is provided, characterized in that the distribution system includes the grounding system connection state confirmation device provided with a connection part for connecting the voltage line and the grounding system or the neutral line and the grounding system in the cabinet. Good.

According to such a distribution board, by confirming the connection state with respect to the voltage line and the ground system or the neutral line and the ground system, labor for measuring the ground resistance can be reduced as much as possible. It can be confirmed very simply whether the construction itself has been performed correctly and the grounding system is functioning normally over time.

According to the present invention, after the grounding work is performed, the measurement work of the grounding resistance can be performed without exerting labor, and the grounding resistance can be confirmed with the passage of time. At the place where the panel is installed, it is possible to reduce the labor required for measuring the ground resistance as much as possible, and to make sure that the grounding work itself has been done correctly and that the grounding system is functioning properly over time. It is possible to provide a distribution board having a grounding system state confirmation device that can be easily confirmed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each of the embodiments, a lead-in wire connected to the load-side electric circuit of the transformer interposed in the electric circuit is drawn into the cabinet of the distribution board, and the current limiter and the main switch are connected to the lead-in wire. Or a distribution board having a main switch and having an internal device such as a branch switch connected to the main switch, and distributing power to a plurality of load circuits, A neutral wire side of the secondary winding of the transformer is grounded by providing a first electrical terminal on the ground, and a second electrical terminal provided on the ground is provided on the distribution board side, The connection state of the grounding system configured by electrical connection with the protective grounding conductor for grounding equipment such as an outlet with a grounding electrode through the grounding wire electrically connected to the electrical terminal Indicates a distribution board equipped with a grounding system connection status confirmation device to be confirmed. It is intended. In addition to general electric equipment, equipment includes general equipment that needs to be grounded, such as building equipment, copper strips provided in buildings, electric wires, and cubicle housings. Also, in this application, as defined in JEAC8001, an extension regulation electrical equipment usage facility edition published by the Japan Electric Association, a neutral wire is a wire connected to the neutral pole of a power source of a multi-wire circuit. A neutral wire or a grounded wire that is grounded according to technical requirements in the low piezoelectric path is called a grounded electric wire. For example, in a single-phase three-wire circuit, there are L1 and L2 poles as voltage poles and N poles as neutral poles. In the single-phase two-wire circuit, there is a ground-side electric wire that is grounded with the voltage electrode.

First, the grounding system connection status confirmation device will be described.

Since the grounding system connection state confirmation device has a plurality of modes depending on the method of measuring the grounding system connection state, the modes of the respective measuring methods are shown in FIGS.

(First form)
FIG. 1 shows a first form of a grounding system connection state confirmation device.

In the first embodiment, an electrical terminal 203 provided on the ground 1 is grounded via an earthing connection 202 electrically connected to the electrical terminal 203. A protective earthing conductor (protective earthing conductor) 201 and a grounding state formed by being electrically connected to the neutral wire 102 side of the secondary winding of the transformer 100 interposed in the electric circuit, and the protection A grounding system connection state confirmation device 300 for judging and confirming by applying a voltage between the grounding conductor 201 and the grounding conductor 201 is shown.

The neutral wire 102 side of the transformer 100 interposed in the electric circuit is grounded by the first electric terminal 103 and constitutes a load-side electric circuit together with the voltage line 101.

Here, the neutral wire 102 side of the secondary winding of the transformer 100 is grounded by the first electrical terminal 103 is Class B grounding as indicated in the technical standards for electrical equipment, On the side, the ground where the protective ground conductor 201 is made by the second electrical terminal 203 via the ground wire 202 is a D-type ground.

At this time, when the B-type grounding and the D-type grounding are performed, the protective ground conductor 201 includes the grounding wire 202, the second electrical terminal 203, the ground 1, and the first electrical terminal. It is in a state of being connected to the neutral wire 102 via 103. That is, if the B class ground resistance is R _B and the D class ground resistance is R _D , the combined resistance between the protective ground conductor 201 and the neutral wire 102 is
R _Total = R _B + R _D (Expression 3)

In this case, the power supply device 301 is connected to the neutral wire 102 and the protective ground conductor 201 on the load side of the electric circuit, and a voltage (voltage is set to E) is applied. The power supply device 301 may use an AC power supply or a DC power supply. An insulated power source in which the primary side and the secondary side are insulated may be used as the power source. Moreover, you may comprise using a capacitor | condenser as a DC power supply, for example.

Next, the current (meaning I) flowing between the neutral wire 102 and the protective ground conductor 201 is measured by the current measuring means 302. The current measuring means 302 may be configured using a current transformer (CT) or a Hall element, or may be configured using other general current sensors. Here, when the B type grounding and the D type grounding are performed, the combined resistance between the protective ground conductor 201 and the neutral wire 102 is R _Total = R as shown in (Equation 3). _Since it is expressed as _B + _RD , when voltage E is applied,
E / (R _B + R _D ) (Formula 4)
Is detected by the current measuring means 302.

At this time, when the current I is detected, it is a case where the B type grounding and the D type grounding are performed, so that the determination unit 303a determines that the grounding system is connected. .
If the current I is not detected, the protective ground conductor 201 is connected to the neutral wire 102 via the ground wire 202, the second electrical terminal 203, the ground 1, and the first electrical terminal 103. Since it is not connected, it is determined that the grounding system is not connected.
The determination unit 303a may be configured by using a microcomputer or IC, and may perform the determination by setting a threshold value for the detection current represented by the relationship of (Equation 4), or may be a resistor / diode. The determination may be made by configuring an electronic circuit using an operational amplifier or the like and detecting the magnitude of the detection current.

In this way, the ground system connection state confirmation device mode 1 is configured such that the ground system connection state is determined by applying a voltage between the neutral wire in the electric circuit and the protective ground conductor, and the neutral wire and the protective ground conductor. This can be confirmed by detecting the current flowing between the two.

As a modification of the first embodiment, the determination is made by applying a voltage between the voltage line 101 side of the secondary winding of the transformer 100 interposed in the electric circuit and the protective ground conductor 201. You may comprise.

At this time, when the B-type grounding and the D-type grounding are performed, the protective ground conductor 201 includes the grounding wire 202, the second electrical terminal 203, the ground 1, and the first electrical terminal. 103, the neutral wire 102, and the voltage wire 101 side are connected through the secondary winding of the transformer. That is, if the class B ground resistance is R _B , the class D ground resistance is R _D , and the impedance of the secondary winding of the transformer is Z _L (= jωL: L is the inductance of the coil), The combined impedance with the sex line 102 is
Z _Total = R _B + R _D + Z _L (Expression 5)

In this case, the power supply device 301 is connected to the voltage line 101 and the protective ground conductor 201 on the load side of the electric circuit, and a voltage (voltage is set to E) is applied.

Next, a current flowing between the voltage line 101 and the protective ground conductor 201 (current is I) is measured by current measuring means. Here, when the B type grounding and the D type grounding are performed, the combined resistance between the protective grounding conductor 201 and the voltage line 101 is Z _Total = R _{B as shown in} (Equation 5). Since + R _D + Z _L , when voltage E is applied,
_{E / (R B + R D} + Z L) ··· ( Formula 6)
A current I expressed by the magnitude of is detected.

At this time, when the current I is detected, it is a case where the B type grounding and the D type grounding are performed, so that the determination unit 303a determines that the grounding system is connected. . When the current I is not detected, the protective ground conductor 201 is connected to the ground wire 202, the second electrical terminal 203, the ground 1, the first electrical terminal 103, the neutral wire 102, the transformer. Therefore, it is determined that the grounding system is not connected because it is not connected to the voltage line 101 side through the secondary winding.

In this way, the connection state of the ground system is confirmed by applying a voltage between the voltage line in the electric circuit and the protective ground conductor, and detecting the current flowing between the voltage line and the protective ground conductor. Therefore, it is possible to reduce the labor required for measuring the grounding resistance as much as possible and to easily confirm that the grounding work itself is correctly performed.

(Second form)
FIG. 2 shows a second form of the grounding system connection state confirmation device.

In the second embodiment, an electrical terminal 203 provided on the ground 1 is connected to a protective ground conductor 201 for grounding a device or the like via a ground line 202 electrically connected to the electrical terminal 203, By measuring the voltage between the neutral wire 102 side of the secondary winding of the transformer 100 interposed in the electric circuit and the protective ground conductor 201, the state of grounding that is achieved by being connected to the electrical circuit is measured. A grounding system connection state confirmation device 300 for judging and confirming is shown.

The neutral wire 102 side of the transformer 100 interposed in the electric circuit is grounded by the first electric terminal 103 and constitutes a load-side electric circuit together with the voltage line 101.

Here, the neutral wire 102 side of the secondary winding of the transformer 100 is grounded by the first electrical terminal 103 is Class B grounding as indicated in the technical standards for electrical equipment, On the side, the ground where the protective ground conductor 201 is made by the second electrical terminal 203 via the ground wire 202 is a D-type ground.

At this time, when the B-type grounding and the D-type grounding are performed, the protective ground conductor 201 includes the grounding wire 202, the second electrical terminal 203, the ground 1, and the first electrical terminal. It is in a state of being connected to the neutral wire 102 via 103. That is, if the B class ground resistance is R _B and the D class ground resistance is R _D , the combined resistance between the protective ground conductor 201 and the neutral wire 102 is
R _Total = R _B + R _D (Expression 3)

In this case, the voltage measuring means 304 measures the voltage between the neutral wire 102 and the protective ground conductor 201 on the load side of the electric circuit. The voltage measuring means 304 may be configured by an electronic circuit, or may be configured by using a microcomputer, IC, or other voltage sensor having a voltage measuring function.

Here, when the B type grounding and the D type grounding are performed, the combined resistance between the protective ground conductor 201 and the neutral wire 102 is R _Total = R as shown in (Equation 3). _Since it is expressed as _B + R _D , the voltage between the neutral wire 102 and the protective ground conductor 201 simply corresponds to the open-circuit voltage of the resistance circuit in which the composite resistor is interposed, and the neutral wire and the voltage A measured voltage value of approximately zero volts is detected with respect to the line-to-line voltage.

Further, when the B type grounding and the D type grounding are not performed, an open section exists in the middle of the resistance circuit in which the combined resistance is interposed, and the voltage is not stable. In other words, the measured voltage value is not approximately zero volts with respect to the line voltage between the neutral line and the voltage line.

When a measured voltage value of approximately zero volts is detected with respect to the line voltage between the neutral line and the voltage line, it is the case where the B type grounding and the D type grounding are performed. It is determined in 303b that the grounding system is connected. In addition, when the measured voltage value is not approximately zero volts with respect to the line voltage between the neutral line and the voltage line, the protective ground conductor 201 is connected to the ground line 202 and the second electrical line. Since it is in a state where it is not connected to the neutral wire 102 via the target terminal 203, the ground 1, and the first electrical terminal 103, it is determined that the grounding system is not connected.
The determination unit 303b may be configured using a microcomputer or IC, and may perform the determination by setting a threshold value for the detection voltage, or may be configured as an electronic circuit using a resistor, a diode, an operational amplifier, or the like. However, the determination may be made by detecting the magnitude of the detection.

As described above, the ground system connection state confirmation device mode 2 can confirm the connection state of the ground system by measuring the voltage between the neutral wire in the electric circuit and the protective ground conductor. .

(Third form)
FIG. 3 shows a third form of the grounding system connection state confirmation device.

In the third embodiment, an electrical terminal 203 provided on the ground 1 is connected to a protective ground conductor 201 for grounding a device or the like via a ground line 202 electrically connected to the electrical terminal 203, Is determined by measuring the voltage between the voltage line 101 side of the secondary winding of the transformer 100 interposed in the electric circuit and the protective ground conductor 201. This shows a grounding system connection state confirmation device to be confirmed.

The voltage line 101 side of the transformer 100 interposed in the electric circuit constitutes a load side electric circuit together with the neutral line 102 grounded by the first electric terminal 103.

Here, the neutral wire 102 side of the secondary winding of the transformer 100 is grounded by the first electrical terminal 103 is Class B grounding as indicated in the technical standards for electrical equipment, On the side, the ground where the protective ground conductor 201 is made by the second electrical terminal 203 via the ground wire 202 is a D-type ground.

At this time, when the B-type grounding and the D-type grounding are performed, the protective ground conductor 201 includes the grounding wire 202, the second electrical terminal 203, the ground 1, and the first electrical terminal. 103, the neutral wire 102, and the voltage wire 101 side are connected through the secondary winding of the transformer. That is, if the class B ground resistance is R _B , the class D ground resistance is R _D , and the impedance of the secondary winding of the transformer is Z _L (= jωL: L is the inductance of the coil), The combined impedance with the sex line 102 is
Z _Total = R _B + R _D + Z _L (Expression 5)

In this case, the voltage between the voltage line 101 and the protective ground conductor 201 on the load side of the electric circuit is measured. The voltage measuring means 304 may be configured by an electronic circuit, or may be configured by using a microcomputer, IC, or other voltage sensor having a voltage measuring function.

Here, when the B type grounding and the D type grounding are performed, the combined impedance between the protective ground conductor 201 and the voltage line 101 is Z _Total = R _{B as shown in} (Equation 5). + R _D + Z _L , the voltage between the voltage line 101 and the protective ground conductor 201 simply corresponds to the voltage at the open end of the resistor-coil series circuit in which the combined impedance is interposed. A measured voltage value approximately equal to the line voltage between the sex line and the voltage line is detected.

When the B type grounding and the D type grounding are not performed, an open section exists in the middle of the resistance circuit in which the combined impedance is present, and the voltage is not stable. That is, a measured voltage value that is not substantially equal to the line voltage between the neutral line and the voltage line is measured.

When a measurement voltage value that is substantially equal to the line voltage between the neutral line and the voltage line is detected, the B-type grounding and the D-type grounding are performed, so the determination unit 303c Thus, it is determined that the grounding system is connected. When the measured voltage value is not substantially equal to the line voltage between the neutral line and the voltage line, the protective ground conductor 201 is connected to the ground line 202 and the second electrical line. Since the terminal 203, the ground 1, the first electrical terminal 103, the neutral wire 102, and the secondary winding of the transformer are not connected to the voltage line 101 side, the ground system is connected. Judge that it is not.

The determination unit 303c may be configured using a microcomputer or IC, and may perform the determination by setting a threshold value for the detection voltage, or may be configured as an electronic circuit using a resistor, a diode, an operational amplifier, or the like. However, the determination may be made by detecting the magnitude of the detection.

In the third aspect of the ground system connection state confirmation device, the ground system connection state can thus be confirmed by measuring the voltage between the voltage line in the electric circuit and the protective ground conductor.

(Fourth form)
FIG. 4 shows a fourth embodiment of the grounding system connection state confirmation device.

In the fourth embodiment, an electrical terminal 203 provided on the ground 1 is connected to a protective ground conductor 201 for grounding a device or the like via a ground line 202 electrically connected to the electrical terminal 203, Providing a connection portion for electrically connecting the grounding state made by being electrically connected to the voltage line and neutral line of the electric circuit and the grounding system;
When the determination unit determines the connection state of the ground system, the voltage line and the ground system or the neutral line and the ground system can be selectively connected among the electric circuit and the ground system connected by the connection unit. A connection state switching unit is provided, and the determination shown in any one of the first to third embodiments is selectively performed, or the determinations shown in the first to third embodiments are combined. It shows a grounding system connection state confirmation device to be carried out.

A connection state switching unit 305 may be configured using a relay so as to selectively switch the connection between the voltage line and the neutral line, or electronically selects a connection inside the microcomputer or IC. You may comprise with a semiconductor switch.

When the voltage line is selected, the determination unit 304d performs the above-described third form determination, and when the neutral line is selected, the determination unit 304d has a function of performing the above-described second form determination. It is good to compose them. Moreover, you may comprise so that judgment of the 1st form mentioned above may be performed in the selected electrical circuit.

Furthermore, the determination unit 304d may be configured to combine the determinations of the first to third aspects described above and combine them in the electric circuit selected by the connection state switching unit 305.

(Fifth form)
FIG. 5 shows a fifth embodiment of the grounding system connection state confirmation device.

In the fifth embodiment, an electrical terminal 203 provided on the ground 1 is connected to a protective ground conductor 201 for grounding a device or the like via a ground line 202 electrically connected to the electrical terminal 203, Display data generation unit for generating display data and display data generated by the display data generation unit based on the determination result by the determination unit described above A grounding system connection state confirmation device for providing and confirming the judgment shown in any one of the first to fifth embodiments described above is provided.

Reference numeral 306 denotes a display data generation unit that generates display data to be displayed on the display unit 307 based on the determination result output from the determination unit. Specifically, it may be constituted by a microcomputer or a driver having a character generator function. The display data generates data that can grasp the status of the grounding system, such as the state of the grounding system connection, the measured current value, the measured voltage value, and the grounding resistance value obtained as a result of the judgment unit calculation. It is preferable to output to 307.

Also, in a simpler manner, the green LED is lit when it is determined that the ground connection is good, and the red LED is lit when it is determined that the ground connection is not good. It may be configured.

The display unit 307 is configured using a liquid crystal display. The liquid crystal display appropriately displays the character display data described above. The display unit 307 may be configured using an organic EL display having a display function visible from the outside, an LED, or the like.

(Sixth form)
FIG. 6 shows an example of the sixth form of the grounding system connection state confirmation device.

In the sixth embodiment, an electrical terminal 203 provided on the ground 1 is connected to a protective ground conductor 201 for grounding a device or the like via a ground line 202 electrically connected to the electrical terminal 203, In the embodiment shown in any one of the first to sixth embodiments, a repeater confirming means 501 is provided for confirming the grounding state made by the connection at a predetermined time interval. This shows a grounding system connection status confirmation device that performs judgment and repeatedly checks over time.

The iterative confirmation unit 501 may be configured using an electronic timer or a programmed microcomputer so that the series of determinations described above are performed periodically.

Since the repeater 501 can check the connection state of the grounding system at predetermined time intervals, the grounding resistance that changes over time and the functionality deterioration due to aging of various connection parts in the security system grounding system can be easily performed. I can confirm.

In addition to the repetitive confirmation means 501, storage means for accumulating data such as the measured current value, voltage value, ground state confirmation result, etc. in the above-described embodiment over time, such as a microcomputer internal memory or an external memory Provided that the data such as the current value, voltage value, ground state confirmation result, etc. can be called and confirmed over time, and various data obtained each time a series of judgments are made are displayed on the display unit. It can be used in various ways such as being able to be displayed.

In addition to confirmation at predetermined time intervals, confirmation may be performed when it is desired to confirm manually at a predetermined timing, for example, at the turn of the season. In addition, a sensor for measuring a change in weather, temperature, and humidity may be provided to check when there is a predetermined change.

(Seventh form)
FIG. 7 shows a seventh embodiment of the grounding system connection state confirmation device.

In the seventh embodiment, a plurality of protective grounding conductors 201 are provided for grounding a device or the like via a grounding wire 202 electrically connected to the electrical terminal 203. A connecting portion that is electrically connected to the centralized ground terminal that collects the protective grounding conductor 201 is provided, and the above-mentioned centralized grounding terminal is replaced with the centralized grounding terminal. The earthing | grounding system connection state confirmation apparatus which implements and confirms the judgment of the form shown in any one of the 1st form thru | or the 7th form is shown.

The centralized grounding terminal 601 is provided for the purpose of sharing the grounding wire 202 electrically connected to the second electrical terminal 203 when a plurality of the protective grounding conductors 201 for grounding a device or the like are provided. This is for collectively connecting the protective ground conductors 201.

When a plurality of protective ground conductors are provided by performing a series of determinations on the concentrated ground terminal 601 instead of the protective ground conductor 201 in the first to seventh embodiments described above. This is effective in that the grounding state for all the protective ground conductors 201 can be confirmed by a single determination without making a determination for each of the protective ground conductors 201 one by one.

As described above, grounding in various surrounding environments is expected in an environment where a grounding system is provided. Therefore, when checking the grounding system connection status using the grounding system connection status confirmation device, one measurement method is used. The grounding system connection state confirmation device is provided with a configuration for performing a plurality of measurements assuming that the grounding system connection state is confirmed and a case where various measurement methods are combined. As a result, even if the connection state of the grounding system cannot be confirmed successfully by one measurement method, it is possible to appropriately confirm the connection state by performing another measurement method.

Next, an external view of the grounding system connection state confirmation apparatus is shown in FIG. The grounding system connection state confirmation device 600 has a housing with an outer shape substantially the same as a branch switch provided in a cabinet of a distribution board. The housing includes power connection terminals 607 and 608 for connection to a branch line provided on the bus bar and an attachment portion 606 for attachment to the inner bottom, similarly to the branch switch.

In addition, the power supply device 301, the current measurement unit 302, the determination unit 303, the voltage measurement unit 304, and the like as described above are housed in the housing.

In addition, a display unit 602 for displaying the current value and voltage value measured by the current measuring unit and the voltage measuring unit, and the connection state of the grounding system is provided on the front surface in the drawing. Further, when confirming the connection state of the push button type manual operation confirmation unit 603, the grounding system, which is operated when it is desired to manually confirm the operation, the voltage line and the grounding system or the middle of the electric circuit and the grounding system are checked. There is provided a connection state switching unit 604 that can selectively connect the wire to the ground system.

The manual operation confirmation unit 603 is connected to the determination unit inside the housing, and when the manual operation confirmation unit 603 is pressed, a trigger is activated, and the connection state of the grounding system is measured when the manual operation confirmation unit 603 is pressed. Do. The manual operation check 603 may be a touch sensor type in addition to the push button type, or any other type that can manually output the trigger signal.

Further, the operation check lamp 605 is an indicator lamp that can be visually recognized from outside whether or not the grounding system connection state check apparatus 600 is operating. In this embodiment, an LED is used. In addition, a symbol or a mark may be displayed on the display unit 602 to indicate the operation state.

Reference numeral 601 denotes a connection unit for connecting the electric circuit, the grounding system, and the grounding system connection state confirmation device 600. The connection portion 601 is provided with a plurality of terminal portions, and is configured to be connected to a voltage line, a neutral line, and a ground system by a connector, respectively. In addition, when confirming about several electric circuit and earthing | grounding system, it is good to connect using each connection part 601. FIG.

Next, the distribution board of the present invention equipped with the grounding system connection state confirmation device described above will be described.

(First embodiment)
FIG. 9 shows a first embodiment of the distribution board of the present invention.

In the first embodiment, a lead-in wire connected to the load-side electric circuit of a transformer interposed in the electric circuit is drawn into the cabinet 501, and the main switch 502 and the main switch 502 connected to the lead-in line An internal device such as a branch switch 503 to be connected is provided, and a distribution board 500 that distributes power to a plurality of load circuits is provided with the grounding system connection state confirmation device 600.

In addition, the distribution board 500 has a protective ground conductor for grounding equipment connected to the second electrical terminal provided on the ground and subjected to the above-described D-type grounding work via a grounding wire. It is installed.

The ground line and the protective ground conductor are connected to the ground branch line terminal provided on the distribution board 500.

In the present embodiment, the grounding system connection state confirmation device 600 is placed on the middle bottom, which is a mounting plate to which the branch switch 503 is attached, instead of some branch switches 503. Further, since the outer shape of the casing of the ground system connection state confirmation device 600 is configured to be substantially the same as the branch switch, when facing the distribution board 500, the main switch 502 and the branch switch The display unit 602, the manual operation confirmation unit 603, the connection state switching unit 604, and the operation confirmation lamp 605 provided on the front surface of the grounding system connection state confirmation device 600 so that the state of the operation handle of the device 503 can be visually recognized. it can.

In this way, the connection state of the grounding system can be easily confirmed when facing the distribution board, and can be manually performed when confirmation of the connection state of the grounding system is necessary. In addition, it is possible to confirm with the operation confirmation lamp 605 whether or not the operation of the grounding system connection state confirmation device 600 is being performed. Further, when the grounding system connection state confirmation device 600 is provided, it is not necessary to secure a new placement place in the distribution board 500, and the present invention can also be applied to an existing distribution board.

(Second embodiment)
In the second embodiment, the distribution system 500 is configured by placing the grounding system connection state confirmation device 600 in an additional circuit space provided in the bottom of the mounting plate to which the branch switch 503 is attached. It is. When placed in the additional circuit space, a part of the cover constituting the cabinet 501 of the distribution board 500 is cut out in accordance with the place of placement, and the front surface of the ground system connection state confirmation device 600 is separated from the cover. Configure as desired. In the case of a distribution board provided with an additional circuit space, a detachable lid is provided on the cover at a position corresponding to the additional circuit space.

In this way, the connection state of the grounding system can be easily confirmed when facing the distribution board, and can be manually performed when confirmation of the connection state of the grounding system is necessary. In addition, it is possible to confirm with the operation confirmation lamp 605 whether or not the operation of the grounding system connection state confirmation device 600 is being performed. In addition, when the grounding system connection status confirmation device is provided, it can be installed without reducing the number of branch switches already installed in the distribution board, and can be applied to existing distribution boards. Is possible.

(Third embodiment)
FIG. 10 shows a third embodiment of the distribution board of the present invention.

In the third embodiment, a lead-in wire connected to the load-side electric circuit of the transformer interposed in the electric circuit is drawn into the cabinet 501, and the main switch 502 and the main switch 502 connected to the lead-in line A distribution board 500 for distributing power to a plurality of load circuits, including internal devices such as branch switches 503 to be connected, an accessory mounting space for attaching the accessory devices, and the protective grounding conductor retracted. In addition, the grounding system connection state confirmation device 600 is provided.

The attachment to the attachment device attachment space may be carried out by attaching the grounding system connection state confirmation device 600 after attaching the insole, or providing a dedicated attachment portion. In addition, the front surface of the grounding system connection state confirmation device 600 is configured by partially cutting off the cover where the accessory mounting space is provided so that it can be seen when facing the distribution board 500. .

In this way, the connection state of the grounding system can be easily confirmed when facing the distribution board, and can be manually performed when confirmation of the connection state of the grounding system is necessary. In addition, it is possible to confirm with the operation confirmation lamp 605 whether or not the operation of the grounding system connection state confirmation device 600 is being performed. Further, when the grounding system connection state confirmation device is provided, it can be placed in the distribution board without reducing the number of branch switches, and can also be applied to an existing distribution board. In addition, when a large space is required for attaching the accessory device, the size of the casing of the grounding system connection state confirmation device 600 is configured to be large and the display unit 602 is also configured to increase the amount of information that can be displayed at one time. It can be configured to increase the visual efficiency of necessary information.

(Fourth embodiment)
FIG. 11 shows a fourth embodiment of the distribution board of the present invention.

In the fourth embodiment, a lead-in wire connected to the load-side electric circuit of the transformer interposed in the electric circuit is drawn into the cabinet 501, and the main switch 502 and the main switch 502 connected to the lead-in wire An internal device such as a branch switch 503 to be connected is provided, and is further adjacent to the outside of the cabinet 501 constituting the distribution board 500 through a connection portion with an electric conductor provided in the distribution board 500. The grounding system connection state confirmation device 600 is provided.

In this way, the connection state of the grounding system can be easily confirmed when facing the distribution board, and can be manually performed when confirmation of the connection state of the grounding system is necessary. In addition, it is possible to confirm with the operation confirmation lamp 605 whether or not the operation of the grounding system connection state confirmation device 600 is being performed. In addition, even if installation inside the distribution board is not possible due to restrictions on the branch switch and attached equipment installation space, it can be performed adjacent to the distribution board at the place where the distribution board is installed. It is possible to determine whether or not the grounding system is connected, and it is possible to check the connection state of the grounding system even though it is a very simple method. It can also be applied to existing distribution boards.

Further, in the first to fourth embodiments described above, among the electric conductor portions provided in the cabinet 501 constituting the distribution board 500, the voltage line and the ground system or the neutral line and the ground system The grounding system connection state confirmation device 600 may be configured to include a connection unit that performs the connection. Thus, when the connection state of the grounding system is confirmed, the connection state switching unit 604 that can selectively connect the voltage line and the grounding system or the neutral line and the grounding system out of the electric circuit and the grounding system. By switching, as described above, it is possible to select the form of the measurement method of the grounding system connection state confirmation device 600 and more appropriately confirm the connection state of the grounding system.

It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately applied as necessary without departing from the gist of the invention.

For example, as shown in FIG. 12, an external connection unit 609 may be provided at the end of the grounding system connection state confirmation device 600 so that measurement data can be output. As a result, it is possible to exchange data with external devices other than the connection portion 601 provided around the casing.

In addition, since the connecting portion 601 protruding around the housing may interfere with peripheral devices and members depending on the mounting location, in such a case, the connecting portion 601 is removed and the surrounding of the housing is removed. In this case, it may be formed in a substantially box shape so that there is no projecting portion, and the external connection portion 609 may be connected to an electric circuit or the like. As a result, the perimeter of the housing is almost the same as that of the branch switch, and even if it is mounted on the insole instead of some of the branch switches as described above, the mounting location is not limited. Is possible.

In addition, for example, in order to confirm in more detail whether the grounding system is in a normally functioning state, the state in which the B type grounding and the D type grounding are normally performed is used as a basic state. When the measurement current value and the measurement voltage value shown in the above-described embodiment in the basic state are stored in the storage unit as basic data, and the determination is repeated over time, the obtained measurement current value and By comparing the measured voltage value data with the basic data in the determination unit, it is determined whether or not there is a deviation from the normal state, and when the magnitude of the deviation becomes a predetermined magnitude The determination unit may be configured to determine that the grounding state is not functioning normally.

In addition, as the basic data stored in the storage unit, resistance value data in the grounding system is actually obtained, and the measurement current value and the measurement voltage value obtained as a result of repeating the determination over time are obtained. The determination unit may be configured to determine resistance value data from the data, and to determine that the grounding state is not functioning normally when the difference between the respective resistance value data becomes a predetermined magnitude. .

Further, resistance value data obtained from the ground data obtained from the basic data, and measured current value and measured voltage data obtained as a result of repeating the above-mentioned process over time, are described above. For example, it is judged by the judging section whether or not the ground resistance value is within 100Ω in the case of class D grounding work described in the technical standards for the electrical equipment. The determination unit may be configured to determine that is not functioning normally.

In addition, the ground system connection state confirmation device 600 is provided with a communication unit, and the basic data described above, measurement current value and measurement voltage value data obtained by repeating the above-described process over time, and these data. Whether the installation status is functioning normally on the external device by making it possible to obtain the resistance value data obtained from the above and data such as whether the grounding status is normal on the external device. The determination unit may be configured so that it can be confirmed.

As the communication unit, a serial communication unit using RS-232C is provided, or a communication unit based on the Ethernet (registered trademark) system defined by IEEE 802.3 is provided so that it can be connected to a general residential LAN. It may be configured. In addition, a wireless communication unit such as a specific low power wireless or wireless LAN method, or a power line carrier communication unit that superimposes data on the power line may be provided. Specifically, it may be configured using a connection portion 601 provided around the casing of the grounding system connection state confirmation device 600 or an external connection portion 609.

The external device may be a mobile phone that can be connected to the general Internet, a computer, or a dedicated data processing device that stores the various data described above, performs arithmetic processing, and displays the data. In addition, the data obtained by the grounding state confirmation device 300 is accumulated on a data storage server provided on the Internet via the gateway device and the Internet network, and the power company side accesses the data storage server. Then, by referring to the data from the target grounding system connection state confirmation device 600, it may be configured to confirm whether or not the grounding state is functioning normally.

As a result, in the past, when checking the grounding condition, it was necessary to check at the relevant site, but the power company side can check the grounding condition. Whether in or outside the jurisdiction, it is possible to statistically check the state of grounding over a wide range without any regional restrictions.

Furthermore, by obtaining changes in the data over time from the obtained grounding state data, it is possible to determine how the grounding state has changed over time, and to determine the determined grounding resistance value. If it exceeds, or if it is likely to exceed a predetermined grounding resistance value, for example, the grounding state at the location can be confirmed, and improvement can be made in advance so that the grounding state becomes normal.

In addition, the ground system connection state confirmation device 600 is provided with a notification unit, and the above basic data, measurement current value and measurement voltage value data obtained by repeating the above determination over time, and these data When the resistance value data obtained from the above and data such as whether the grounding state is normal exceed a predetermined value or greatly deviate from the notification unit, the grounding state is normal. It may be configured to notify that it is not, and to check the grounding state in the surroundings.

Further, bidirectional communication is performed between the server on the power company side and the grounding system connection state confirmation device 600, and the grounding state grasped on the power company side is notified from the notification unit. , The state of grounding can be confirmed more appropriately.

For the sound data to be notified, a microcomputer may be provided in the grounding system connection state confirmation device 600, and an assumed sound may be stored in the microcomputer in advance. Alternatively, the voice data may be transmitted to the communication unit of the grounding system connection state confirmation device 600 via the Internet network, and the voice data may be notified from the notification unit.

The present invention can be applied to an apparatus for confirming a grounding state in a grounding system. This is mainly effective for confirming the grounding in the distribution board that houses various distribution devices. The distribution board can be applied to residential distribution boards as well as industrial distribution boards, so that the state of grounding can be controlled against grounding in various locations, whether residential or industrial. There is a possibility that a device that can be confirmed can be provided.

The figure which showed the form 1 of the measuring method of a grounding system connection state confirmation apparatus. The figure which showed the form 2 of the measuring method of a grounding system connection state confirmation apparatus. The figure which showed the form 3 of the measuring method of a grounding system connection state confirmation apparatus. The figure which showed the form 4 of the measuring method of a grounding system connection state confirmation apparatus. The figure which showed the form 5 of the measuring method of a grounding system connection state confirmation apparatus. The figure which showed the form 6 of the measuring method of a grounding system connection state confirmation apparatus. The figure which showed the form 7 of the measuring method of a grounding system connection state confirmation apparatus. The figure which showed the external appearance of the earthing | grounding system connection state confirmation apparatus. The figure which showed the external appearance of the distribution board in 1st embodiment. The figure which showed the external appearance of the electricity distribution panel in 3rd embodiment. The figure which showed the external appearance of the distribution board in 4th embodiment. The figure which showed the other Example of the earthing | grounding system connection state confirmation apparatus. Illustration of ground voltage and ground resistance when insulation of load equipment installed in electric circuit deteriorates

DESCRIPTION OF SYMBOLS 1 Earth 100 Transformer 101 Voltage line 102 Neutral line 103 1st electrical terminal 201 Protective ground conductor 202 Ground line 203 2nd electrical terminal 300 Ground state confirmation apparatus 301 Power supply apparatus 302 Current measurement means 303 Determination part 304 Voltage Measuring unit 305 Connection state switching unit 306 Display data generation unit 307 Display unit 401 Switching unit 501 Repetition confirmation unit 600 Grounding system connection state confirmation device 601 Connection unit 602 Display unit 603 Manual operation confirmation unit 604 Connection state switching unit 605 Operation confirmation lamp 606 Mounting portion 607 Power connection portion 608 Power connection portion 609 External connection portion

Claims (6)

Among the voltage lines and neutral wires of the transformer secondary winding that intervene in the electric circuit, the neutral wire side is grounded by providing a first electrical terminal on the ground, and is connected to the ground on the load-side electric circuit of the transformer. A configuration in which the second electrical terminal provided is electrically connected to a protective ground conductor that performs grounding of the device or the like via a ground wire electrically connected to the second electrical terminal. In a circuit with a grounded system,
Pull the pull line connected to a load-side electrical path of the transformer inside the cabinet, the internal equipment such as branch switches which are connected to a current limiter / main switch and the main switch connected to the the cited inclusive line A distribution board for distributing power to a plurality of load circuits provided,
The distribution board includes
A distribution board comprising a ground system connection state confirmation device for confirming a connection state of a ground system by being electrically connected to the protective ground conductor .
2. The distribution board according to claim 1, wherein the grounding system connection state confirmation device is placed on an inner bottom, which is a mounting plate for mounting the internal device, instead of a part of branch switches.
3. The distribution board according to claim 2, wherein the grounding system connection state confirmation device is provided in an additional circuit space provided in the inner bottom.
2. The distribution board according to claim 1, wherein the grounding system connection state confirmation device is installed in the accessory installation space when the accessory installation space is provided in the cabinet.
The grounding system connection state confirmation device is disposed adjacent to the outside of the cabinet constituting the distribution board via a connection portion with an electric conductor provided on the distribution board. The distribution board according to 1.
6. The grounding system connection state confirmation device provided with a connection part for connecting a voltage line and a grounding system or a neutral line and a grounding system inside the cabinet. The distribution board as described in any one of them.

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