JPH04174371A - Jig for inspecting wiring state of power plug socket with grounding electrode - Google Patents

Abstract

PURPOSE:To inspect simply whether the wiring between a panelboard and a plug socket is good or bad by comparing which of an electrode of the plug socket judged to connect to the U electrode of a panelboard and other electrodes the current is easy to flow into, and discriminating respectively electrodes to connect to the V electrode and the W electrode of the panelboard. CONSTITUTION:A terminal 3 and a U electrode of a panelboard (the rest is omitted) are connected by mistake if an LED 4d emits light when a switch frame 5 is touched after several terminals are connected to plug sockets. A test switch 6 is shut in the case not to emit. The lighting of a pilot lamp 12 indicates that either of terminals 1 and 2 connects with the U electrode in this case. Next, the terminal of higher voltage than the terminal 3 among input lines to the terminal 12 operates a photocoupler and shuts a relay contact 7c or 8c. The line to connect with the U electrode is discriminated by this and a discriminating circuit of lines to connect with the V electrode and the W electrode is formed. For example, the shutting of the relay contact 8c indicates that the terminal 1 connects with the U electrode and the emission of an LED 10 indicates that the current through the terminal 2 is large, namely, the terminal 2 connects with the V electrode. The emission of an LED 11 indicates that the current through the terminal 3 is large, namely, the terminal 3 connects with the V electrode.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides wiring to a single-phase AC power outlet with a grounding pole, and a grounding pole on the ungrounded side of the transformer and a grounding on the distribution board. A jig that allows you to easily, easily, and safely inspect the wiring condition, such as the presence or absence of cross-pole (mis)connection, and the presence or absence of cross-connection between the transformer's ground electrode and the distribution board's ground electrode. Regarding.

[Prior Art] Electrical equipment standards require that metal stands and casings of office automation equipment installed in office buildings that operate on single-phase alternating current must be grounded so that the grounding resistance is below a specified value. stipulated. Therefore, a grounded electrode is installed on the distribution board in the building so that the grounding resistance is below a predetermined value, and a power supply with a grounding electrode is installed to connect the drive power source of each OA equipment from the grounding electrode of this distribution board. Wiring is provided to connect to the outlet. On the other hand, for the single-phase transformer that supplies power to the above-mentioned distribution board, it is stipulated that one pole on the output side of the transformer should be grounded with a grounding resistance that is lower than the grounding electrode of the above-mentioned distribution board. There is.

Figure 2 is a diagram showing an example of the wiring state of a correctly wired power outlet with a grounding electrode. In the figure, 22 is a single-phase 100v transformer, and 23 is the output of the transformer, which has been grounded according to the electrical equipment standard type 2. 24 is a distribution board, 25 is a grounding electrode of the distribution board which is grounded according to electrical equipment standard type 3, 26 is a circuit breaker, and 27 is a power outlet with a grounding electrode. Here, it is assumed that the wiring from the transformer to the distribution board is done correctly, and from now on, the pole connected to the ungrounded output product of the transformer on the output side of the distribution board is the U pole, and the pole connected to the ungrounded output product of the transformer is The pole connected to the grounded output product of 1 is abbreviated as the V pole, and the pole connected to the ground pole of the 1-distribution board is referred to as the W pole.

Among the wires extending from the distribution board to the grounded power outlet, there are those that come from the U pole of the distribution board, those that come from the vIi, and those that come from the W pole.

There is no problem if the wiring between the grounded power outlet and the distribution board is connected correctly, but if there is a wiring error, it may involve other equipment and cause a burnout accident. Problems such as malfunctions may occur due to the influence of the operation of other devices.

If you mistake the wire coming from the U pole of the 1-minute switchboard for the wire coming from the W pole and connect it to the grounding electrode of the outlet, that is, the W pole, you will not notice the incorrect wiring and just insert the plug of the OA equipment. In that case, the V and W poles of the outlet are
Since they are designed and manufactured assuming that no large voltage will be applied between them and the poles, burnout accidents may occur.

On the other hand, since the power supply voltage is not normally supplied to the equipment connected to the outlet, the equipment will not operate, and people who come into contact with the housing will also receive an electric shock. Therefore, this condition can be recognized immediately, but an accident will occur before it is recognized (however, the insulation of the electrodes of the outlet itself is usually good, so if the wiring is incorrectly connected to the outlet and nothing is connected to the outlet, an accident will occur). On the other hand, if you mistake the wire coming from the V pole of the distribution board for the wire coming from the W pole and connect it to the W pole of the outlet, there will be no burnout accident. , one pole of the OA equipment, which is originally supposed to be connected to the grounded output product of the transformer via an extremely small wiring resistance, is connected to the grounded output of the transformer via a class 3 grounding resistor or a class 2 grounding resistor. Therefore, the potential of the V pole of the outlet (including that of other devices) fluctuates depending on the operating state, and the devices connected to the outlet sometimes malfunction depending on the operating state.

Therefore, conventionally, the wiring condition from the distribution board to the grounded power outlet has been inspected to see if it is incorrect before connecting a device to the outlet.

[Problems to be Solved by the Invention] Conventionally, a so-called tester has generally been used to inspect the state of wiring connection to a power outlet with a ground electrode.

If the wiring to the outlet has already been completed, connect the W pole of the power outlet with a grounding pole, that is, the pole that is supposed to be connected to the W pole of the distribution board, to something that is actually close to the ground potential, such as the floor of the building. Check the potential difference between them with a tester, and if there is a considerable potential difference.

Of the output product of the distribution board, only the U pole of the distribution board has a significant potential difference with respect to the floor of the building, so the wire connected to the U pole may be incorrectly wired to the W pole of the outlet. You can tell right away that it's there. However, it is not so easy to see that the wire connected to the V pole of the distribution board is incorrectly wired to the W pole of the outlet.

Therefore, in the past, in order to inspect the wiring connection state to a power outlet with a ground electrode, a temporary wiring was laid from the W terminal of the distribution board to the vicinity of the outlet to be inspected, and the end of this temporary wiring was connected to the outlet. If the resistance value between the W pole and the W pole is small, the wiring is correct, and if a significant resistance value equivalent to type 2 or 3 grounding is detected, the wire coming from the V pole of the distribution board is incorrectly connected. It was determined that this had been done. However, in reality, it often takes a lot of man-hours to lay the temporary wiring used for the above inspection.

In addition, there are testers on the market that can detect if the wire connected to the V pole of the distribution board is incorrectly wired to the W pole of the outlet, but it is already known that the wire is correctly wired. It is necessary to compare the measurement results for the outlet being tested with the measurement results for the outlet to be tested, which increases the number of inspection steps, and in some cases, it may be difficult to operate earth leakage circuit breakers, which have become more common in distribution panels in recent years due to lack of sensitivity. The present invention does not have the problems of the above-mentioned conventional methods and equipment, and even if the test current passes through the worker's body during the inspection, the The value is so small that it does not cause discomfort at all.

To provide a wiring condition inspection jig for a power outlet with a grounding electrode, which is highly sensitive so that there is no fear of activating an earth leakage breaker, and allows inspection results to be visually confirmed very clearly.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, the grounding electrode of the outlet (hereinafter abbreviated as W pole of the outlet) and the thing actually at ground potential (for example, the floor of the building) are connected to each other. A means for testing whether there is incorrect wiring from the U pole of the distribution board to the W pole of the outlet by connecting the two through high impedance and checking whether or not a predetermined amount of current is flowing between the two; U of
The W pole of the outlet or the wiring that has been confirmed not to be incorrectly connected to the W pole of the outlet (when the said incorrect connection is discovered, the wire that was incorrectly connected to the W pole of the outlet and the U of the outlet)
As a general rule, replace the wire that was incorrectly connected to the pole and reconnect it, but if you are in a hurry, remove the connection between the outlet pole and the wiring, and inspect the end of the wire. If it is not discovered, it is certain that the wire connected to the W pole of the outlet is not the wire connected to the U pole of the distribution board, but is it really the wire connected to the W pole of the distribution board? or V
(I don't know if it is the wire connected to the terminal) and the other two electrodes of the outlet or two other wires,
Remove electrodes or wires found to have high voltage from the U of the distribution board.
It is determined that the electrical outlet is connected to the pole, and the ease with which current flows between the electrode or wire of the outlet determined in this way and the other two electrodes or two wires is compared, and the current flows more easily. Each of the above operations is automatically performed in sequence to identify the electrode or wiring of the outlet connected to the V pole of the distribution board, or the one through which current does not flow easily, as the electrode or wiring of the outlet connected to the W pole of the distribution board. We decided to create a jig that combines the means and means into one easy-to-use structure.

[Function] Only the end of the wire connected to the U pole of the distribution board (connection point to the outlet) is the end of the wire connected to the V pole of the distribution board, or the wire connected to the W pole of the distribution board. The wire connected to the U pole of the distribution board can be easily identified because it shows a large voltage at the end of the wire.

On the other hand, as mentioned above, it is not so easy to distinguish between the wire connected to the V pole of the distribution board and the wire connected to the W pole of the distribution board. There is very little wiring resistance between the end of the wire connected to the W pole of the distribution board and the grounded output pole of the transformer, whereas the end of the wire connected to the W pole of the distribution board and the grounded output pole of the transformer This is because, in addition to the wiring resistance, the second type grounding resistance and the third type grounding resistance are interposed between the terminal and the output pole.

If you check the ease with which current flows between the end of the wire connected to the U pole of the distribution board and the ends of the other two wires, the one with easier current flow will be connected to the V pole of the distribution board. The electrode or wire of the outlet connected to the W terminal of the distribution board can be identified from the one through which current flows less easily.

[Embodiment] Fig. 1 is a schematic connection diagram of an embodiment of the present invention, and in the figure, 1 indicates an input (of the jig) that should originally be connected to the line coming from the U or V pole of the distribution board. Terminal 2 is the terminal to be connected to the V pole or U pole (corresponding to "or" in the case of terminal 1), 3 is the terminal to be connected to the W pole, 4a is the LED, 4b is the photodiode, and both of these are connected. Forming one photocoupler, 4
d is an LED, and 5 is connected to the terminal 3 via a photocoupler LE04a and a resistor, surrounding a test switch 6 for operating this jig (discriminating between the line coming from the V pole and the line coming from the W pole). A switch frame whose metal surface is exposed outside the jig housing, 7a is a photocoupler LED, 7b is a photocoupler photodiode, 7c is a photodiode 7
b is a relay contact that becomes conductive and closes when relay coil 7d is energized; 8a is a photocoupler LED; 8b is a photocoupler photodiode; 8c is a relay contact that becomes conductive and closes when relay coil 8d is energized; 9 is a high inductance element , 10 is an LED that emits light when terminal 3 is connected to the W pole of the distribution board, 1
1 is an LED that emits light when terminal 3 is connected to the V pole of the distribution board, 12 is a pilot lamp that indicates that a high voltage is being applied between terminals 1 and 2, and 13 is a resistor 1
14 is a comparator whose output is high when the voltage drop in resistor 19 is greater than the voltage drop across resistor 19, and low when the output of comparator 13 is high, and vice versa. 15 is a comparator that outputs in the opposite direction to that of comparator 14 in response to the high or low output of comparator 13, 16 is an exclusive OR (EX-OR) gate, and 20 is a built-in DC power supply of the jig. , 21 are changeover switches which are normally used in the state shown.

The inspection worker (wearing work shoes with particularly low resistance soles to prevent static electricity from forming on the body and creating a high potential) connects each terminal of the jig to the electrodes or wiring of the outlet, and then Touch the switch frame 5 with your finger to turn on the LED.
See if 4d emits light. If it emits light, connect terminal 3
Since the wire from the U terminal of the distribution board was mistakenly connected to the U terminal of the distribution board, in principle, the inspection should be stopped at this point and the wire that was connected to terminal 3 should be connected to the U terminal of the outlet. Restart the inspection after replacing the wire with the one that was connected to it. In this way, the wire from the U pole of the distribution board is definitely connected to terminal 1 of the jig, but is the wire connected to terminal 3 coming from the W pole of the distribution board? , ■ If you do not know whether it came from the terminal 3 or if the LED 4d does not emit light even when you touch the switch frame, close the test switch 6 and continue the inspection. Did the wire connected to the switchboard come from the W pole or the ■ pole?
Also, it is unclear whether the wires connected to terminals 1 and 2 came from the U pole or the ■ pole of the distribution board. It is said that a normal person will die if a current of 30 mA or more is passed between their hands and feet, and that sensitive people will feel a slight sensation if a current of 0.2 mA or more is passed between their hands and feet.
The amount of current in the photocoupler LED 4a is 0, 2 mA.
The pilot lamp 12 will also light up if the wire from the U pole of the distribution board is connected to either terminal 1 or 2. It should be.

Next, among the input lines to terminals 1 and 2, the one having a higher potential than the input line to terminal 3 is a photocoupler consisting of an LED 7a and a photodiode 7b.

Alternatively, one of the photocouplers made of the LED 8a and the photodiode 8b is activated, and accordingly, one of the relay coils 7d or 8d is energized and one of the relay contacts 7c or 8c is closed. Due to the above action.

The jig forms a circuit that distinguishes the line coming from the U pole of the distribution board, and further distinguishes between the line coming from the V pole and the line coming from the W pole of the distribution board. The electromotive force of the built-in DC power supply of the jig and the electromotive force of the transformer are connected in series and current flows through the resistors 18 and 19, respectively. The high inductance element 9 is for suppressing the alternating current component, and in this embodiment, the high inductance element 9 is 3 mA.
It is kept to a minimum.

Further, the capacitor connected between the input lines of the comparator 13 short-circuits the AC component, and the diode limits the DC input voltage to the comparator to a predetermined value or less.

When the relay contact 8C is closed, the wire coming from the U pole of the distribution board is connected to the terminal 1, and one end of the resistor 18 is connected to the terminal 2. Normally LED 7a or 8
Only one of a is in a light emitting state, and exclusive OR gate 1
Since only one input of 6 is high, the output of this gate is normally high. As mentioned above, when the voltage drop across resistor 18 is greater than the voltage drop across resistor 19, the output of comparator 14 is low, so that LED lo illuminates. The fact that the voltage drop across resistor 18 is greater than the voltage drop across resistor 19 means that the current through terminal 2 is greater, i.e. terminal 2 is connected to the line coming from the V pole of the distribution board, and the remaining Terminal 3 is connected to the wire coming from the W pole of the distribution board. In this case, the actual wiring is exactly as specified. Furthermore, if the relay contact 8C is closed but the voltage drop across the resistor 18 is smaller than the voltage drop across the resistor 19, the output of the comparator 14 will be high and the LEDIO will not light up. Furthermore, since the output of the comparator 15 becomes low, the LEDll lights up. In this state, the current flowing through terminal 3 is larger, that is, the wire coming from the V pole of the distribution board is connected to terminal 3, and the wire coming from the W pole of the distribution board is connected to terminal 2. Show that. In addition, when it was found that the wire from the U pole of the distribution board was incorrectly connected to the W pole of the outlet, and the test switch 6 was pressed inadvertently, the LEDs 7a, 8a, photodiode 7b,
Both photocouplers 8b operate, both relay contacts close, and the relay coil circuit is cut off via the exclusive OR gate 16 to prevent burnout of electronic components that are sensitive to overvoltage. I'm letting you do it.

Relay contact 7c closes when the wire coming from the U pole of the distribution board is connected to terminal 2 of the jig, and in this case, the LED
If IO emits light, the line coming from the V pole of the distribution board is connected to terminal 1, and the line coming from the W pole of the distribution board is connected to terminal 3.

Furthermore, if the relay contact 7c is closed and the LED II emits light, this indicates that the terminal 1 is connected to the W pole of the distribution board, and the wire coming from the V pole of the distribution board is connected to the terminal 3.

The jig of the present invention uses a DC element that can easily increase sensitivity to distinguish between the line coming from the V pole and the line coming from the W pole of the distribution board, thereby suppressing the alternating current component superimposed on the test current. There is. In recent years, earth leakage circuit breakers, which have come to be often installed in distribution boards, focus on the fact that if you combine the alternating current magnetic fields generated in opposite directions on a round trip line, only the magnetic field corresponding to the leakage current remains. It is designed to operate when a predetermined value is reached, and if a large ground current, or leakage current, is passed to inspect the wiring condition,
There is a risk that the earth leakage circuit breaker will trip and cause a power outage. In order to prevent such problems from occurring in the jig of the present invention, the alternating current component superimposed on the test current was strictly suppressed.

[Effects of the Invention] As explained above, if the jig of the present invention is used, one worker will be able to check the quality of the wiring from the distribution board to the power outlet with a grounding electrode without feeling physically uncomfortable or operating the earth leakage breaker. It can be easily and easily inspected without having to do anything.

[Brief explanation of drawings]

FIG. 1 is a schematic connection diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing an example of the wiring state of a correctly wired power outlet with a ground electrode. 1.2.3...Input terminal, 4a...L of photocoupler
ED, 4b...Photocoupler photodiode, 4d
...LED, 5...Switch frame, 6
...Test switch, 7a, 8a... Photocoupler LED, 7b, 8b... Photocoupler photodiode, 7c, 8 c-Relay contact, 7d, 8
d - Relay coil, 9... High inductance element. 10.11...LED to display connection status, 13゜1
4.15...Comparator, 16...Exclusive logic sum gate, 18.19...Resistor for current amount comparison, 20...Built-in DC power supply, 22...Single phase 100V
Transformer, 23... Grounded output pole of transformer, 2
5...Grounding electrode of the grounded distribution board, 27...Power outlet with grounding electrode.

Claims (1)

[Claims] 1. Connect the grounding terminal of the outlet and the one actually at ground potential through a high impedance, and depending on whether or not a predetermined amount of current is flowing between them, the output side of the single-phase transformer can be adjusted. Means for testing for the presence of incorrect wiring from the ungrounded pole to the grounding pole of the outlet, and the grounding pole or wiring of the outlet that is confirmed by this means to be free from misconnection to the ungrounded pole of the transformer. and the other two electrodes of the outlet or the other two
The magnitude of the voltage between the wire and the electrode or wire found to have a large voltage is determined to be connected to the ungrounded pole of the transformer, and the electrode or wire of the outlet determined in this way is Compare the ease of current flow between the wiring and the other two electrodes of the outlet or two other wirings, and select the one that allows the current to flow more easily between the electrode or wire connected to the grounded pole on the output side of the transformer, and the current Wiring for a power outlet with a grounding electrode for single-phase alternating current, characterized in that it is equipped with a means for sequentially and automatically performing each action to identify the side where the flow is difficult as the electrode or wiring connected to the grounded electrode of the distribution board. Condition inspection jig. 2. Claim 1, characterized in that the current in the high impedance circuit of the means for inspecting the presence or absence of incorrect wiring from the ungrounded pole on the output side of the single-phase transformer to the grounded pole of the outlet is 0.2 mA or less. A jig for inspecting the wiring condition of the power outlet with a grounding electrode as described. 3. A jig is used to compare the ease of current flow and identify the electrodes or wiring connected to the grounded pole on the output side of the transformer and the electrodes or wiring connected to the grounded pole of the distribution board. Wiring for a power outlet with a grounding terminal according to claim 1, characterized in that it operates based on a difference in a DC comparison test current generated by a DC power supply built into the unit, and that an AC component superimposed on the test current is suppressed to 3 mA or less. Condition inspection jig.