JP2984198B2 - Method and apparatus for determining connection of outlet with ground electrode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for accurately judging a connection state of a three-wire outlet with a ground electrode in an indoor wiring of a building or the like.

[0002]

2. Description of the Related Art In recent years, in indoor wiring of buildings and the like, the use of three-wire outlets with ground electrodes has been remarkable, and accidents due to erroneous connection or disconnection and adverse effects on OA equipment have been increasing. It is. Therefore, it is necessary to check the connection state after connecting these three-wire outlets. One of them is to use a commercially available checker. This checker is 2
It has a power detection, polarity determination, and ground diagnosis function for a pole outlet, and the power detection function can determine whether the voltage between contacts is 100 V or 200 V. The polarity determination function is a function of making a virtual ground from the touch panel via the human body and determining that the voltage side pole is the correct pole based on the minute current. In addition, the grounding diagnosis function connects auxiliary lead wires and makes them
It has a function of diagnosing that the electric device is grounded.

[0003] As another determination method, a buzzer and a ground fault resistor are connected to a target outlet, and the buzzer and the ELB are connected.
There is a method of determining by the reaction of The test method is shown in FIG.
As shown in (1), a method is first used in which a buzzer is connected between PN and a continuous sound is made, and then a resistor flowing about 300 mA is connected between P and E to check whether the ELB operates.

[0004]

The former commercially available checker is capable of detecting electric power, determining the polarity, and using a three-wire outlet.
Grounding diagnosis can be performed to some extent. However, in the case of a three-wire outlet, even if the intermediate phase and the ground electrode are switched, both the voltage detection and the polarity show a normal state. This is because even if the intermediate phase and the ground phase are interchanged, it cannot be detected. If a load is connected, the load current flows through the ground phase, so that a leakage breaker (hereinafter referred to as “ELB”) detects it as a difference current, Since the operation of opening the circuit is reached, it can be determined that it is not suitable for determining the connection of the three-wire outlet. In the latter determination method, the load current of the buzzer flows about 40 mA.
There is a case where the ELB is activated immediately by connection, and there are a plurality of states. Therefore, even if the correctness of the connection state can be determined, the connection state cannot be accurately specified.

SUMMARY OF THE INVENTION It is an object of the present invention to accurately specify a connection state, to improve security, and to enable a person with little experience to make a simple and accurate determination. In addition, since the operation is performed in a hot-line state, it is considered that a method of operating the existing device, that is, the ELB, and a method having no influence on the connected OA device and the like are essential conditions. In terms of workability, it was made possible to work alone or to work at the same time for multiple tasks.

[0006]

In the single-phase three-wire circuit, the outlet with the grounding electrode is a three-wire type. Therefore, when all the outlets are connected without disconnection, there are six types of combinations depending on the three-wire type. This is shown in circuits 1 to 6 in Table 1. In Table 1, the voltage side of the outlet circuit is P
Pole (potential), N pole on neutral side (neutral)
And the ground wire is the E pole (earth). When the first signal on the neutral wire is applied in each of these connection states, the presence / absence of the voltage between the three lines of the commercial power supply and the presence / absence of the signal between the lines are detected at each pole, and the presence of the detection is determined by 1 If no detection is displayed as 0, the number of detection results is six. These six combinations are all different in each circuit as shown in circuits 1 to 6 in Table 1.

As described above, there are six cases where all the lines are connected without disconnection, and as shown in Table 1, in each of these six connection states, one of the three lines is disconnected. In the case where the E-pole is disconnected, the circuit 13 to the circuit 1
If the N pole is disconnected up to 8
Up to 4, the case where the P pole is disconnected is included. Therefore, including the case without the disconnection, there are 24 types. In each of these connection states, when a second signal is applied to the ground line in addition to the first signal, as shown in Table 1, the presence or absence of the line voltage of each of the three lines of the commercial power supply, and the presence or absence of the first signal between the lines The presence / absence of the second signal between the ground of each line and the presence / absence of the voltage between the ground of the commercial power supply are respectively detected. When the detection is represented by 1 and the non-detection is represented by 0 in the same manner as above, the number of detection results is 12. Become. These twelve combinations are shown in Table 1 from circuit 1 to circuit 2
As shown in FIG. 4, all the circuits are different.

Therefore, the invention according to claim 1 is a method for judging the connection state of the outlet in the connection without disconnection. Specifically, in the circuit of a three-wire outlet with a grounding pole to which the ELB is connected,
A signal having a certain frequency is emitted as a signal. The frequency of this current is 500H at which the ELB in the circuit does not operate.
The frequency is in the frequency range of z to 10 KHz and is not an integer multiple of the frequency of the commercial power supply. In addition, a determination device is connected to the outlet, and the presence or absence of the line voltage of the commercial power supply at the outlet and the presence or absence of the signal between the lines are determined to determine the connection state of the outlet. The invention according to claim 2 is an apparatus used for this method.

In the above system and apparatus, it is possible to determine the presence or absence of disconnection, but it is not possible to specify which pole is disconnected.
Therefore, the invention of claim 3 proposes a method capable of specifying all of these connection states regardless of the presence or absence of disconnection. And as a specific configuration, in the circuit of a three-wire outlet with a ground electrode to which the ELB is connected,
Apply a first signal. This first signal is the EL signal in the above circuit.
The frequency is within a frequency range where B does not operate and is not an integral multiple of the frequency of the commercial power supply. In addition, a second signal having a frequency other than an integral multiple of the frequency of the commercial power supply and having a frequency other than the first signal within the above frequency range is applied from a ground line at a location different from the location to which the first signal is applied. Then, a judging device is connected to the outlet point, and the presence or absence of the line voltage of the commercial power supply at the outlet point, the presence or absence of the first signal between the lines, the presence or absence of the second signal between the grounds of each line, and the presence of the commercial power supply The method of determining the connection state of the outlet by detecting the presence / absence of the voltage between the power outlet and the power outlet. The invention according to claim 4 is an apparatus used for this method.

[0010]

According to the first and second aspects of the present invention, the presence or absence of the voltage between the three lines of the commercial power supply and the presence or absence of the signal between the lines are detected.
All connection states without disconnection can be determined.

According to the third and fourth aspects of the present invention, the presence or absence of the voltage between the three lines of the commercial power supply, the presence or absence of the first signal between the lines, and the second state between the grounds of the lines. By detecting the presence / absence of a signal and the presence / absence of a voltage between the commercial power supply and the ground, it is possible to specify all connection states including a disconnection state. Further, there may be a case of two-wire or three-wire disconnection or a power failure. However, in this case, no voltage appears between the poles, and it can be determined that the switch is in an off state or not connected. Therefore, the quality of all connections can be determined by this method.

[0012]

[Table 1]

[0013]

Embodiments of the present invention will be described below. First Embodiment As shown in Table 1, the system and apparatus of the first embodiment
The connection is determined as described above, and its state is accurately specified. In the circuit of a three-wire type outlet with a grounding pole shown in FIG. 1, a signal transmitter 2 installed on a distribution board 1 and a determiner 4 installed on an outlet 3 are provided, and a first signal for determination is divided. A current transformer (hereinafter, the current transformer is referred to as “CT”) is applied from the distribution board unit 1 to the neutral wire of the three wires. The signal and the commercial power supply are detected and determined at the outlet unit 3, and the detection results are all different depending on the connection state.
In this method, the state is accurately limited and displayed.

FIG. 1 shows a normal connection state. When a voltage side is a P-pole (potential), a neutral side is an N-pole (neutral), and a grounding line is an E-pole (earth), a normally connected outlet is shown. In, the commercial power supply can be detected between PN and PE, and there is no voltage between NE. Similarly, the superimposed first signal passes through the transformer unit and appears at the outlet unit 3, so that only the first signal is extracted through the band-pass filter, so that the signal between PN and NE is obtained. Can be detected, and the signal is in the same direction between PE and E, and the phase cancellation cannot be detected. Since the determination is made based on the detected commercial power and the first signal, the connection state can be accurately determined.

Next, FIG. 2 shows a neutral wire (N pole) and a ground wire (E
(Pole) is replaced. In this case, when looking at the commercial power supply, the voltage can be detected between PN and PE, but not between NE and E, and the detection result is exactly the same as that of a normal connection. However, in the normal state, the applied first signal does not appear between PN and disappears, and the signal appears between PE and E which could not be detected. Table 2 shows the detection results.

[0016]

[Table 2]

Similarly, Table 3 shows four detection results having different connection states. The combination of the detection results is not the same in any connection state, and the combination is different, so that the six connection states can be correctly specified.

[0018]

[Table 3]

Next, the first signal used in the present invention will be described. To make a determination without causing the ELB to malfunction during energization, the ELB must not be operated by applying this signal to the circuit. A commercially available ELB performs a trip operation by detecting a difference current using an insulating current transformer, and the sensitivity changes depending on a change in frequency due to the characteristics of CT. The frequency characteristics of commercially available ELBs are as shown in FIG. 3, and it was determined that the frequency range between 500 Hz and 10 kHz was unaffected and had no influence. Taking into account that the frequency of the signal does not become an integral multiple of the commercial power supply, a frequency of 980 Hz was selected in this case.

The level was set to 0.1 V so that the current would not flow as much as possible so as not to operate even if the sensitivity was good, and to avoid the influence on the connected equipment. A split type CT is adopted as a signal application method, and the output of the signal transmitter 2 is applied to the CT from a neutral line in the distribution board unit 1.
This is a method that is safe and has good workability without removing the wiring by clamping the split-type CT. The neutral line becomes a common line in a 100 V circuit and can be superimposed on the U-phase and V-phase simultaneously.

The determination of the presence or absence of these signals is made by the determination unit of FIG. 4 and the logic unit of FIG. FIG. 4 includes two parts, a part for determining the presence or absence of the line voltage of the commercial power supply and a part for detecting and determining the first signal between the lines. The voltage determination section takes out the voltage via the insulating transformer 5, rectifies the voltage with the rectifier 6, compares the voltage with the threshold value by the comparator 7, and determines the presence or absence of the voltage. The signal determination unit applies a bypass filter 9 and a band-pass filter 10 to detect only a signal value via the insulating transformer 8, amplifies the signal with the amplifier 11, and compares the signal value with a threshold value through the rectifier 12 and the comparator 13. These determination signals are processed by the logic unit 14, and the display unit 15 indicates the determination result. The terminals A1, A2, and A3 of the logic unit 14 are input terminals of line voltages between the PN, the PE, and the NE of the commercial power supply, and S1, S2, and S3 are terminals between the PN, PE
Input terminal of the first signal between the respective lines between lines N and E. As shown in FIG. 5, the logic unit 14 is constituted by a logic circuit, and displays the circuits 1 to 6 shown in Table 1 above. Also displayed is a case where there is a disconnection in these connection states.

Second Embodiment In the first embodiment, it is possible to determine the presence or absence of disconnection.
It cannot be specified which of the line and the E line is disconnected. In the method of the second embodiment, not only the first signal but also the second signal is added. The frequency of the second signal is different from the frequency of the first signal and is not a multiple of the frequency of the commercial power supply or the first signal. That is, the frequency of the region divided by the bypass filter and the band-pass filter is obtained. Of course, in that case, the above ELB
Is in the frequency range of 500 Hz to 10 KHz at which the operation does not work. Further, this second signal is applied by a split type CT separately provided in the signal transmitter 2.

As shown in FIG. 6, the second signal is applied from a different ground line (E pole). Both the first signal and the second signal are superimposed on the commercial power and appear on the outlet 3. The auxiliary signal is grounded to compensate for the case where no signal appears in the determinator 16 of the outlet unit 3, and the second signal is detected between the ground. Further, the detection of the commercial power supply is also performed between the auxiliary grounded pole and the P, N, and E poles.

The determination unit 16 in this case has the configuration shown in the block diagram of the determination unit in FIG. 7 and the block diagram of the detection circuit in FIG. That is, the detection circuit 17 of the determination unit in FIG. 7 includes a portion 17a for detecting the presence or absence of the line voltage of the commercial power supply and a portion 17b for detecting the first signal between the lines.
Each of these outputs is input to the logic unit 18. The detection circuit 19 of FIG. 8 includes a portion 19a for determining the presence or absence of a ground voltage at each pole of the commercial power supply and a portion 19b for determining the presence or absence of a ground voltage of the second signal of each pole. Is input to the logic unit 18 in FIG. Accordingly, for the overall determination, the combination of the signals in FIGS. 7 and 8 is determined by the logic unit 18, and the correctness or incorrectness of the connection is comprehensively determined and displayed on the display unit 20. The configuration of the logic unit 18 is substantially the same as the configuration of the logic unit 14 of the first embodiment. FIG. 9 shows the flow of the logical judgment.

The results of the determination in the second embodiment are the results of the determination in the first embodiment, that is, the presence or absence of the line voltage of the commercial power supply between the poles and the presence or absence of the first signal between the poles. In addition to six,
Since the second signal and the commercial power supply are respectively detected between the ground electrodes, there are six determination results. Therefore, a method of making a determination using 12 signals is adopted. The detection results of those detailed signals are shown in Table 1 above.
Is shown as a judgment list.

[0026]

According to the present invention, it takes a lot of time and effort to check the connection of a three-wire outlet with a ground electrode.
According to the invention of claim 2 and claim 2, many effects can be expected, such as accurate correct / wrong determination of all connection states without disconnection and the result of determination of the connection state displayed. (1) Not only can the connection state be determined as good or bad, but also the state can be accurately limited, so that even inexperienced workers can easily perform the test and collection work. (2) After the signal power supply device is installed on the distribution board, it can be unattended, so that the outlet can be operated continuously by one person and can be tested efficiently. (3) Since a plurality of determination devices can correspond to one power supply device,
Simultaneous work by multiple workers is also possible, and testing can be performed in a short time.

According to the third and fourth aspects of the present invention,
In addition to the effects of the first and second aspects of the invention, it is possible to determine any state such as incorrect connection or disconnection in the connection of the three-wire outlet.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a normal connection state in a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing an erroneous connection state in the first embodiment of the present invention.

FIG. 3 is a graph showing frequency characteristics of ELB.

FIG. 4 is a block circuit diagram showing a determination unit according to the first embodiment of the present invention.

FIG. 5 is a block circuit diagram showing a logic unit according to the first embodiment of the present invention.

FIG. 6 is a circuit diagram showing a normal connection state according to a second embodiment of the present invention.

FIG. 7 is a block circuit diagram showing a determination unit according to a second embodiment of the present invention.

FIG. 8 is a block circuit diagram showing a detection circuit according to a second embodiment of the present invention.

FIG. 9 is a flowchart of a logic unit according to the second embodiment of the present invention.

FIG. 10 is a circuit diagram showing a conventional example.

[Explanation of symbols]

1 Distribution board part 2 Signal transmitter 3 Outlet part 4 Judgment device 16 Judgment device

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-184627 (JP, A) JP-A-8-184628 (JP, A) JP-A-6-6916 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) G01R 31/04

Claims (4)

(57) [Claims] In a three-wire outlet circuit with a grounding pole to which an ELB is connected, an ELB is connected to a neutral wire of a distribution board section.
A signal of a frequency other than an integral multiple of the frequency of the commercial power supply within a frequency range of 500 Hz to 10 KHz at which the power supply does not operate, the presence or absence of the line voltage of the commercial power supply at the outlet, and the signal between the lines A method for determining the connection of an outlet with a grounding electrode, comprising detecting the presence or absence of an outlet and determining the connection state of the outlet. 2. A neutral wire of a distribution board portion of a circuit of a three-wire outlet with a grounding pole to which an ELB is connected, which is an integral multiple of the frequency of a commercial power supply within a frequency range of 500 Hz to 10 KHz where the ELB does not operate. And a signal transmitter for applying a signal having a frequency other than the above, connected to the outlet, and detects the presence or absence of a line voltage of the commercial power supply and the presence or absence of the signal between the lines to determine a connection state of the outlet. A connection judging device for an outlet with a ground electrode, comprising: a judging device. 3. In a circuit of a three-wire outlet with a grounding electrode to which an ELB is connected, an ELB is connected to a neutral wire of a distribution board section.
A first signal having a frequency other than an integral multiple of the frequency of the commercial power supply in a frequency range of 500 Hz to 10 KHz in which the first power supply does not operate, A second signal having a frequency other than the signal is applied from a ground wire at a location different from the location to which the first signal is applied, and the presence or absence of the line voltage of the commercial power supply at the outlet location; A method for judging the connection of an outlet with a ground electrode, comprising detecting the presence or absence of a second signal between the ground of each wire and the presence or absence of a voltage between the commercial power supply and the ground to determine the connection state of the outlet. 4. A neutral line of a distribution board part of a circuit of a three-wire outlet with a grounding pole to which an ELB is connected, which is an integral multiple of the frequency of a commercial power supply within a frequency range of 500 Hz to 10 KHz where the ELB does not operate. And applying a second signal having a frequency other than an integer multiple of the frequency of the commercial power supply and a frequency other than the first signal within a region different from the application region of the first signal. A signal transmitter applied from a ground line, connected to the outlet and auxiliary grounded to determine whether there is a line voltage of the commercial power supply,
A grounding electrode comprising: a presence / absence of a signal, presence / absence of a second signal between the ground of each line, and presence / absence of a ground voltage of a commercial power supply, and a determination unit for determining a connection state of the outlet. Outlet connection determination device.