JPH1073628A - Wiring state indicator and leak current measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm the wiring state of a receptacle easily by indicating the wiring state of commercial power supply for the receptacle based on the voltage between respective terminals of the receptacle inputted through the connection terminal of a plug. SOLUTION: Phototransistors PT1-PT3 of a leak current measuring apparatus 1 are arranged in the vicinity of neon lamps LA1-LC1. When the neon lamp LA1-LC1 is lighted, a collector current is fed and a detection signal of low level voltage is delivered to a CPU 34. On the other hand, the output voltage from a detection circuit 32 for detecting the absolute value of the voltage across a leak current detection resistor 31 is subjected to A/D conversion 33 and fed to the CPU 34 in order to operate a leak current. The CPU 34 inverts the logic of detection signals received from the phototransistors PT1-PT3 and makes a comparison with a data on the data table in a memory thus deciding whether the wiring state of a receptacle 3 is normal or not. When a decision is made that the wiring state is normal, the operation results indicative of the leak current value are presented on an indicator 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring status display device for displaying a wiring status of a commercial power supply connected to an outlet, and a leakage current measuring device using the same. The wiring condition of the outlet for connecting the leak current measuring device
The present invention relates to a wiring state display device particularly suitable for checking whether or not a normal state is specified in a leakage current measurement method, and a leakage current measurement device using the same.

[0002]

2. Description of the Related Art Generally, the leakage current of an electric device may exceed an allowable value due to deterioration of circuit components due to aging or the like. In such a case, particularly in the case of a medical electrical device, since the leakage current may affect the patient's body, it is necessary to periodically measure the leakage current and confirm that the leakage current is below the allowable value. .

[0005] In general, in indoor wiring of commercial AC 100 V and 200 V, as shown in FIGS. 5 and 6, for example, a transformer 2 installed in a power receiving room or the like has a single-phase high-voltage AC of 6600 V. Is a single-phase three-wire 100
V or single-phase three-wire 200V. in this case,
The center tap of the output winding of the transformer 2 is grounded to the ground or the like, and in the case of a single-phase three-wire 100V, as shown in FIG. 5, one end of the output winding has an AC output terminal of an AC 100V outlet 3. T1 (hereinafter, also referred to as "terminal T1")
, And a center tap is connected to an AC output terminal T2 (hereinafter, also referred to as “terminal T2”) of the outlet 3 and a ground terminal T3 (hereinafter, referred to as “terminal T3”) of the outlet 3.
(Also referred to as “terminal T3”). Therefore, the voltage difference between the terminals T1 and T2 and between the terminals T1 and T3 is 100 V AC, respectively,
The voltage difference between the three is 0V.

On the other hand, in the case of a single-phase three-wire 200V, FIG.
As shown in FIG. 3, one end and the other end of the output winding of the transformer 2 are connected to the terminals T1 and T
2 and the center tap is connected to the terminal T3 of the outlet 4. Therefore, the voltage difference between the terminals T1 and T2 is
Voltage difference between T3 and between terminals T2 and T3 is AC100V
It has become.

In the above normal wiring state,
By connecting the plug for AC input of the leak current measuring device (not shown) to the outlet 3 (or 4) and connecting the plug for AC input of the device under test to the outlet for AC output of the leak current measuring device, In addition, it is possible to measure the leakage current in the device under test.

However, in an operating room of a hospital, for example, as shown in FIG. 7, a transformer 5 for insulation is connected between a transformer 2 and an outlet 3 to reduce leakage current of the apparatus. May ensure patient safety. In such a case, even if an attempt is made to measure the leakage current of the device-under-test 6 using the outlet 3, an inherent path through which the leakage current flows is not formed, so that the leakage current is measured smaller than the actual leakage current. Specifically, as shown in the figure, the leakage current in this case is determined by the output winding of the transformer 5, one end of the outlet 3, the terminal T 1 of the outlet 3, and the plug 7 of the device under test 6.
Connection terminal, the insulation resistance R of the device under test 6, the device under test 6
Flows through a path RT composed of the case main body, the ground connection terminal of the plug 7, the terminal T3 of the outlet 3, the ground, and the primary winding of the transformer 5. Therefore, when the leakage current between the primary winding and the secondary winding in the transformer 5 is smaller than the leakage current of the device 6 to be measured, the measured value becomes equal to the leakage current of the transformer 5 and accurate measurement is performed. Can not do. Similarly, when the wiring is not in the normal wiring state shown in FIGS. 5 and 6, for example, in both figures, even when the terminal T3 is not grounded, a leak current path is not formed. Can not.

Therefore, conventionally, prior to the measurement of the leakage current, a voltmeter probe is inserted into each terminal T1 to T3 of the outlet 3 (or 4) to measure the voltage between the terminals T1, T2 and T3. In addition to the measurement, an inspection driver is applied to the terminal T3 to check whether or not the terminal T3 is grounded.
If it can be confirmed that the wiring is normal, the measurement of the leakage current has started.

[0008]

However, in the conventional checking method, the voltage between the three terminals T1, T2 and T3 is measured, and it is checked whether the terminal T3 is grounded. And there is a problem that extremely complicated work must be performed.

The present invention has been made in view of the above problems, and provides a wiring state display device capable of easily confirming the wiring state of an outlet, and a leakage current measuring device using the same. The main purpose is.

[0010]

According to a first aspect of the present invention, there is provided a wiring status display apparatus comprising: a plug for connecting to an outlet whose wiring status is to be displayed; A first display unit for displaying a wiring state of a commercial power supply in the outlet based on a voltage between terminals of the outlet. In this case, the wiring state display by the first display means includes a visual display in which each terminal voltage is represented by a numerical value, a symbol, or the like, a language indicating that each terminal voltage or all terminal voltages are normal, This includes visual and auditory displays using symbols and light.

In this wiring state display device, it is not necessary to insert a probe of a voltmeter or the like into each terminal of the outlet and measure the voltage between the terminals. By inserting a plug into the outlet, the first display means can be connected to the outlet. Displays the wiring status of the commercial power supply. Therefore, it is possible to extremely easily confirm whether or not the wiring state is normal.

According to a second aspect of the present invention, there is provided the wiring status display device according to the first aspect, wherein the outlet for displaying the wiring status is a single-phase three-wire outlet, and the first display means includes a terminal. The discharge lamp comprises three discharge lamps which are turned on when the inter-voltage is within a specified voltage range. One discharge lamp is connected between two AC output terminals of an outlet via a connection terminal of a plug, and the other two discharge lamps are connected. The discharge lamp is configured such that one end is connected to one or the other of the two AC output terminals via a connection terminal of the plug, and the other end is connectable to the ground terminal of the outlet. It is characterized by the following.

Normally, AC 100 V is applied between two AC output terminals of a single-phase three-wire outlet for AC 100 V, and 0 V is applied between each of the two AC output terminals and a ground terminal.
V and AC100V are applied respectively. On the other hand, AC200V is applied between two AC output terminals of a single-phase three-wire outlet for AC200V, and AC100V is applied between each of the two AC output terminals and the ground terminal.
Are respectively applied. Therefore, since the three discharge lamps are lit according to the voltage between the terminals, the wiring state of the outlet can be determined at a glance by checking the lighting state.

According to a third aspect of the present invention, there is provided the wiring status display device according to the second aspect, wherein the other end of each of the other two discharge lamps is alternately switched and connected to the ground terminal of the outlet. It is characterized by further comprising means.

If the ground terminal is not grounded, 2
Two discharge lamps respectively connected between each of the three AC output terminals and the ground terminal are connected to a 100 V AC (or A
C200V) as an equivalent circuit connected in series between lines. Therefore, when the rated voltage of two discharge lamps connected in series between the AC 100 V lines is set to AC 100 V, both discharge lamps are in a state in which an AC voltage of substantially half of the rated voltage is applied, and therefore, each of them is dimly lit. I do. Further, when the rated voltage of two discharge lamps connected in series between the AC 200 V lines is set to AC 100 V, both the discharge lamps are turned on. Therefore, it may not be possible to reliably determine whether the ground terminal is grounded.

On the other hand, in this wiring state display device, the connection switching means alternately switches the other ends of the two discharge lamps and connects them to the ground terminal. Thus, for example, A
In the case of an outlet for C100V and an outlet for AC200V, when the ground terminals are not grounded, the other ends of both discharge lamps are in an open state, and therefore, each of the discharge lamps is connected between the AC output terminal and the ground terminal. 2
Lamps do not light up. Therefore, it can be reliably determined that the ground terminal is not connected.

According to a fourth aspect of the present invention, there is provided a leakage current measuring device, comprising: a wiring state display device according to any one of the first to third aspects; and a terminal for determining whether a wiring state is a normal state defined in the leakage current measuring method. It is characterized by comprising a determining means for determining based on the inter-voltage and a second display means for displaying that the leakage current measurement is impossible when the determining means does not determine the normal state.

In this leakage current measuring device, the judging means comprises:
It is determined whether the wiring state of the outlet is a normal state specified in the leakage current measuring method based on the voltage between the terminals. For this reason, the measurer can start the measurement of the leakage current when it can be determined that the normal wiring state has been determined by the determining means based on the display content of the second display means. As a result, it is possible to avoid inaccurate measurement of the leakage current due to incorrect wiring of the outlet or the like.

According to a fifth aspect of the present invention, there is provided a leakage current measuring device, wherein the wiring state display device according to the second or third aspect is used to determine whether or not the wiring state is a normal state defined in the leakage current measuring method. And a second display unit for displaying that the leakage current measurement is impossible when the determination unit does not determine the normal state. In this case, it is also possible to configure the leakage current measuring device so that the measurement of the leakage current does not start when the first display means or the second display means displays that the wiring state is not normal.

The judging means can also judge whether the wiring state of the outlet is normal or not based on the voltage between the terminals of the outlet. On the other hand, if the determination is made based on the lighting state of the discharge lamp, the wiring state based on the display content of the first display means matches the wiring state based on the display content of the second display means. For this reason, the measurer can start or stop the measurement by checking the display content of the display means that is easier to see.

According to a sixth aspect of the present invention, there is provided a leakage current measuring apparatus according to the fifth aspect, wherein the determining means includes a photoelectric conversion means for performing photoelectric conversion of lighting light of the discharge lamp,
It is characterized in that it is determined whether the state is normal based on the output voltage of the photoelectric conversion means.

In this leak current measuring device, the photoelectric conversion means directly photoelectrically converts the lighting light of the discharge lamp. Therefore, the wiring state based on the display content of the first display means always matches the wiring state based on the display content of the second display means.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a leakage current measuring device in which a wiring state display device and a leakage current measuring device according to the present invention are integrally formed will be described with reference to the accompanying drawings. The same components as those described with reference to FIGS. 5 to 7 are denoted by the same reference numerals, and detailed description is omitted.

FIG. 2 is an external view of the leakage current measuring device 1. As shown in FIG.
Plug 11 for connecting to outlet 3 (see FIG. 1)
And an outlet 12 for connecting a power plug 7 of the device 6 to be measured. On the front of the main body, the lamp is lit according to a voltage between terminals T1 to T3 of the outlet 3 and a rated voltage of 100 V AC neon. A lamp display unit 13 composed of lamps LA1, LB1, and LC1 (corresponding to a discharge lamp in the present invention), whether the wiring state of the outlet 3 is normal, a measured value of leakage current, and the like are displayed on a liquid crystal or the like. And a display 14.

In the leak current measuring apparatus 1, the plug 11 is connected to the outlet 3 when measuring the leak current of the device 6 to be measured.
If the terminal T3 is grounded, the voltage between the terminals T1 and T2 of the outlet 3, the voltage between the terminals T1 and T3, the voltage between the terminals T2 and T3, and whether or not the terminal T3 is grounded are displayed on the lamp display unit 13 and the display unit 14. And can be confirmed with. In this case, if the lamp display unit 13 does not enter the predetermined lighting state and the display 14 indicates that the wiring state of the outlet 3 is not normal, the leak current measurement device 1 does not start measuring the leak current. Thereby, the measurer can avoid erroneous measurement of the leakage current due to erroneous wiring of the outlet 3 or the like. On the other hand, when the wiring state of the outlet 3 is normal, the leakage current measuring device 1 automatically starts the measurement and then displays the measured value on the display 14.

Next, a specific configuration of the leakage current measuring device 1 will be described with reference to FIG.

As shown in FIG.
Includes the three neon lamps LA1 to LC1 described above. The neon lamp LA1 is connected between the two terminals T1 and T2 via the connection terminal of the plug 11, and the neon lamps LB1 and LC1 are connected to the plug 11 Are connected to the terminals T2 and T1, respectively, and the other ends thereof are connected to two input terminals 21 of a switch circuit (corresponding to connection switching means in the present invention) 21.
a, 21b. FIG. 3A shows the connection relationship between the neon lamps LA1, LB1, LC1 and the outlet 3 in this case.

The switch circuit 21 has a common input terminal 21c.
Is connected to the terminal T3 of the outlet 3 via the connection terminal of the plug 11, and the other end of each of the neon lamps LB1, LC1 is alternately connected to the terminal T3 under the control of the CPU 34 described later. The switch circuits 21 shown in FIGS. 1 and 3 are functionally displayed, and are actually configured by a known circuit including a relay or a plurality of FETs operated under the control of the CPU 34. In the case of using an FET, the switching operation can be performed by alternately switching in synchronization with an AC frequency (50 Hz or 60 Hz) input through the plug 11, or the switching operation can be performed by self-excited oscillation. It can also be done.

Further, the leakage current measuring device 1 includes a phototransistor (corresponding to a photoelectric conversion means in the present invention) P
T1 to PT3, and the phototransistor PT1
PT3 are disposed in the vicinity of the neon lamps LA1 to LC1, respectively, receive the lighting light, perform photoelectric conversion, and output the detection voltage to the CPU 34. More specifically, the phototransistors PT1 to PT3 have their collectors pulled up by resistors 22 to 24 and their emitters connected to the ground, respectively. Therefore, each of the phototransistors PT1 to PT3 outputs a low-level voltage detection signal to the CPU 34 by flowing a collector current when the neon lamps LA1 to LC1 in the vicinity are lit. Thereby, the CPU 34 can determine the lighting state of each of the neon lamps LA1 to LC1 based on the detection signal.

The leak current measuring device 1 further includes a resistor 31 for detecting a leak current, a detection circuit 32 for detecting the absolute value of the voltage across the resistor 31, and an A / D converter for converting the output voltage of the detection circuit 32 from analog to digital. D conversion circuit 33, A / D
A CPU (corresponding to a determination unit in the present invention) 34 for receiving the digital signal converted by the conversion circuit 33 and calculating the leakage current. The resistance 31
Is connected between the terminal T3 of the outlet 3 via the connection terminal of the plug 11 and the ground terminal 7a of the power plug 7 in the device under test 6 via the outlet 12. The components of the leakage current measurement device 1 except the resistor 31, the detection circuit 32, and the A / D conversion circuit 33 constitute a wiring state display device according to the present invention.

Next, the operation of the leakage current measuring device 1, particularly,
The wiring state display processing for displaying the wiring state of the outlet 3 will be mainly described.

First, when the plug 11 is connected to the outlet 3, the leakage current measuring device 1 stabilizes AC 100V supplied from the outlet 3 to a predetermined DC voltage by a power supply circuit (not shown), and converts the stabilized DC to each circuit. To supply. In this case, the neon lamps LA1 to LC1 are turned on or off according to the wiring state of the outlet 3 shown in the upper section of FIG. Specifically, FIG.
Indicates the lighting state of each of the neon lamps LA1, LB1, and LC1 in each wiring state of the outlet 3 shown in the upper column, and “1” and “0” indicate “lighting state” and “non-lighting”, respectively. State ". Therefore, as shown in FIG. 1, when the wiring state of the outlet 3 is normal, between the terminals T1 and T2, between the terminals T2 and T3, and between the terminals T1 and T3, 100 V AC,
Since 0 V and 100 V AC are applied, the neon lamps LA1 and LC1 are turned on, and the neon lamp LB1 is not turned on, as shown in the leftmost column of FIG.

On the other hand, when the terminal T3 is not grounded, no AC 100 V is applied between the terminals T1 and T3, and the AC 100 V is applied between the terminals T1 and T2 via the terminal T3.
Is applied. In this case, since the switch circuit 21 alternately switches the other ends of the neon lamps LB1 and LC1 to connect to the terminal T3 of the outlet 3, as shown in the second column from the left in FIG. The neon lamp LA1 is turned on, and the neon lamps LB1 and LC1 are not turned on.

Further, when the wirings of the terminals T1 and T2 are interchanged, that is, when the terminal T1 is connected to the center tap of the transformer 2 instead of the terminal T2, the terminal T2 and the terminal T2 , T3 and between terminals T1, T3, respectively.
V and 0V are applied. For this reason, as shown in the third column from the left in FIG.
B1 is turned on, and the neon lamp LC1 is not turned on. When power is not supplied to the outlet 3 such as at the time of a power failure, all the neon lamps LA1, LB1, and LC1 naturally do not light as shown in the rightmost column of FIG.

As described above, each of the neon lamps LA1, LB1, and LC1 is turned on or off according to the state of each wiring. Therefore, the measurer can determine the wiring state of the outlet 3 at a glance by checking the lighting state of each of the neon lamps LA1, LB1, and LC1.

On the other hand, the phototransistors PT1 to PT3
Outputs a low-level signal to the CPU 34 when each of the neon lamps LA1, LB1, and LC1 is turned on. The CPU 34 previously stores, for example, a data table corresponding to the relationship diagram shown in FIG. 4 in the built-in memory, and after inverting the logic of the input detection signals of the respective phototransistors PT1 to PT3, By performing the comparison, it is determined whether or not the wiring state of the outlet 3 is normal. Next, when determining that the measurement is not normal, the CPU 34 displays on the display 14 that the measurement of the leakage current is impossible, and does not start the measurement of the leakage current. Note that C
If it is determined that the PU 34 is not in the normal state, the display 1 indicates which state the wiring state is as shown in FIG.
4 may be specifically displayed.

On the other hand, when it is determined that
34 starts the measurement of the leakage current. In this case, the leakage current depends on the non-ground terminal 7b of the power plug 7, the insulation resistance R, the main body case of the device under test 6, and the ground terminal 7 of the power plug 7.
a, corresponding ground connection terminal of outlet 12, resistor 3
1, flows through a path consisting of a ground connection terminal of the plug 11 and a terminal T3 of the outlet 3. For this reason, a voltage based on the leakage current is generated at both ends of the resistor 31. Then
The detection circuit 32 converts the voltage across the resistor 31 into a DC voltage by detecting the absolute value of the voltage. Next, the A / D conversion circuit 33 converts the output voltage of the detection circuit 32 from analog to digital, and outputs it to the CPU 34. The CPU 34
The leak current is calculated based on the digital signal converted by the D conversion circuit 33, and the result of the calculation is displayed on the display unit 14.

As described above, according to the leakage current measuring apparatus 1 according to the present embodiment, it is not necessary to insert a probe of a voltmeter or the like into each terminal of the outlet 3 whose wiring status is to be displayed and measure the voltage between the terminals. Instead, when the plug 11 is inserted into the outlet 3, the lamp display unit 13 displays the wiring state of the commercial power supply in the outlet 3. Therefore, the measurer can very easily confirm whether or not the wiring state of the outlet 3 is normal.

Further, the measurer can start the measurement of the leakage current only when the measurement of the leakage current is not displayed on the display unit 14 as a result. Inaccurate measurement of the current can be avoided. In this case, the CPU 34 sets the neon lamp LA
1, LB1, LC1, the neon lamps LA1, LB1, LC1 are used to determine whether or not the wiring is normal.
The wiring state based on the lighting state of 1 and the wiring state based on the display contents of the display unit 14 always match. For this reason, the measurer can avoid being confused by the difference in the wiring state based on the two, and determine whether or not it is possible to measure the leakage current by checking the display content that is easier to see. be able to.

In the present embodiment, an example in which the wiring status of the outlet 3 for AC 100 V is displayed, but the present invention is not limited to this, and the wiring status of the outlet 3 for AC 200 V can also be displayed. . In this case, instead of the neon lamp LA1, the rated voltage is AC2.
A neon lamp of 00V may be used, and FIG.
A neon lamp LA2 having a rated voltage of 200 V AC and a neon lamp LB having a rated voltage of 100 V AC
FIG. 4B shows the neon lamps LA2, LB1, and LC1 in the respective wiring states of the outlet 4 and the like.
Shows the lighting state of.

Next, FIG. 4B will be described. The upper column of the figure shows the wiring state and the like in the outlet 4, and the leftmost column shows the lighting states of the neon lamps LA2, LB1, and LC1 in the normal wiring state. In this case, the voltage between the terminals T1 and T2, the voltage between the terminals T1 and T3, and the voltage between the terminals T2 and T3 are 200 V AC and 10 V AC.
Since 0 V and 100 V AC are applied, all the neon lamps LA2, LB1, and LC1 are turned on. The second column from the left shows the lighting state when the terminal T3 is not grounded. In this case, the neon lamp LB is switched by the switch circuit 21.
As a result, both ends of the neon lamps LB1 and LC1 are not turned on. The third column from the left shows the lighting state when AC 100 V is erroneously wired to the outlet 4, and in this case, the terminals T1 and T1,
AC100V is applied between T2 and between terminals T1 and T3, respectively, and the voltage between terminals between terminals T2 and T3 is 0V.
become. For this reason, the neon lamp LA2 is dimly lit, the neon lamp LC1 is lit, and the neon lamp L2 is turned on.
B1 does not light. Further, the rightmost column shows a lighting state at the time of a power failure. In this case, all the neon lamps L
A2, LB1, and LC1 do not light up naturally. Therefore, the measurer can determine at a glance the wiring state of the outlet 4 based on the lighting state of the neon lamps LA2, LB1, and LC1.

In the above case, similarly to the case of displaying the wiring state of the outlet 3 for 100 VAC,
The CPU 34 previously stores a data table corresponding to the relationship diagram shown in FIG. 4B in the built-in memory, inverts the logic of the input output signals of the respective phototransistors PT1 to PT3, and compares the inverted data with the data in the data table. By doing so, it is possible to determine whether the wiring state of the outlet 4 is normal.

In the above-described embodiment, whether the wiring state of the outlet 3 (or 4) is normal or not is determined by the neon lamps LA1 (or LA2), LB1, and L2.
Although the display is performed based on the lighting state of C1, the present invention is not limited to this. For example, outlet 3 (or 4)
By providing a voltmeter for measuring the voltage between the terminals, the wiring state may be displayed on the display 14 or the like based on the measurement value measured by the voltmeter. Further, in the present embodiment, the CPU 34 controls the phototransistor PT
Although it is determined whether or not the wiring state is normal based on the detection signals 1 to PT3, the determination may be made based on the measurement value of the voltmeter, and the determination result may be displayed on the display unit 14.

Further, the wiring status display device according to the present invention comprises a wiring status display device for AC100V and an AC200V
And a separate wiring state display device.

[0045]

As described above, according to the wiring state display device of the first aspect, the plug for connecting to the outlet whose wiring state is to be displayed, and each terminal of the outlet input through the connection terminal of the plug. The first display means for displaying the wiring state of the commercial power supply in the outlet based on the voltage between the outlets, so that it is not necessary to insert a probe of a voltmeter or the like into each terminal of the outlet to measure the voltage between the terminals. , By inserting the plug into the outlet,
Can display the wiring state of the commercial power supply. Thus, the measurer can very easily confirm whether the wiring state of the outlet is normal or not.

According to the wiring state display device of the second aspect, since the first display means is composed of three discharge lamps connected between the terminals of the outlet, the lighting state is confirmed. Thus, the wiring state of the outlet can be determined at a glance.

Further, according to the wiring state display device of the third aspect, the connection switching means alternately switches the other ends of the other two discharge lamps and connects them to the ground terminal. Outlet and AC200V
If the grounding terminals are not grounded in the case of a power outlet, the two discharge lamps connected between each of the AC output terminals and the grounding terminal do not turn on, so make sure that the grounding terminal is not connected. Can be determined.

According to the fourth aspect of the present invention, the determining means determines whether or not the wiring state is a normal state defined by the leak current measuring method based on the voltage between the terminals. The measurer can start measuring the leakage current only when it can be determined based on the display content of the second display means that the determination means has determined that the wiring state is normal. As a result, the measurer can avoid inaccurate measurement of the leakage current due to incorrect wiring of the outlet.

According to the leakage current measuring device of the present invention, the judging means judges whether or not the wiring state is a normal state defined by the leakage current measuring method based on the display state of the discharge lamp. When the second display means does not determine the normal state by the determination means, it displays that the leakage current measurement is not possible, so that the wiring state based on the display content of the first display means, The wiring state based on the display content of the display means matches. As a result, the measurer can start or stop the measurement by checking the display content of the display means that is easier to see.

Further, according to the leakage current measuring device of the present invention, the judging means judges whether or not the lamp is in a normal state based on the output voltage of the photoelectric conversion means which photoelectrically converts the lighting light of the discharge lamp. The wiring state based on the display contents of the first display means always matches the wiring state based on the display contents of the second display means. As a result, the measurer can avoid a situation in which the measurement is confused by the difference in the wiring state based on the both, and can determine whether or not the leakage current can be measured by confirming the display content that is easier to see. be able to.

[Brief description of the drawings]

FIG. 1 is a circuit diagram including a leakage current measuring device and peripheral devices according to an embodiment of the present invention.

FIG. 2 is an external view of a leakage current measuring device and a device to be measured according to an embodiment of the present invention.

FIG. 3 (a) shows AC10 in an embodiment of the present invention.
It is a circuit diagram which shows the neon lamp when the leak current measuring device is connected to the outlet for 0V, and the connection relationship with the outlet, (b) The neon lamp when the leak current measuring device is connected to the outlet for AC200V. FIG. 3 is a circuit diagram showing a connection relationship between the power supply and the outlet.

FIG. 4 (a) shows AC10 according to an embodiment of the present invention.
It is explanatory drawing showing the relationship between the wiring state etc. of an outlet, and the lighting state of a neon lamp when a leak current measuring device is connected to an outlet for 0V, and (b) is a figure which connects a leak current measuring device to an outlet for AC200V. FIG. 7 is an explanatory diagram showing a relationship between a wiring state of an outlet and a lighting state of a neon lamp in the case where the power is turned on.

FIG. 5 is a circuit diagram showing indoor wiring of commercial AC 100V.

FIG. 6 is a circuit diagram showing indoor wiring of the commercial AC200.

FIG. 7 is a circuit diagram in the case where an insulating transformer is connected between a transformer and an outlet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Leakage current measuring device 3 Outlet 4 Outlet 11 Plug 13 Lamp display part 14 Indicator 21 Switch circuit 34 CPU LA1 Neon lamp LB1 Neon lamp LC1 Neon lamp LA2 Neon lamp PT1 Phototransistor PT2 Phototransistor PT3 Phototransistor

Claims (6)

[Claims] 1. A plug for connecting to an outlet whose wiring status is to be displayed, and a wiring status of a commercial power supply at the outlet is displayed based on a voltage between terminals of the outlet input through a connection terminal of the plug. First
A wiring state display device comprising: 2. The outlet as a wiring state display target is a single-phase three-wire type outlet, wherein the first display means includes three discharge lamps that are turned on when the terminal voltage is within a specified voltage range. The one discharge lamp is connected between two AC output terminals of the outlet via a connection terminal of the plug, and the other two discharge lamps are connected via a connection terminal of the plug, 2. The terminal according to claim 1, wherein one end of each of the AC output terminals is connected to one of the AC output terminals, and the other end of the AC output terminal is connectable to a ground terminal of the outlet. Wiring status display device. 3. The wiring according to claim 2, further comprising connection switching means for alternately switching the other end of each of the other two discharge lamps to connect to the ground terminal of the outlet. Status display device. 4. The wiring state display device according to claim 1, wherein whether the wiring state is a normal state defined by a leakage current measuring method is determined based on the voltage between the terminals. A leakage current measuring device comprising: a judging means; and a second display means for displaying, when the judging means does not judge a normal state, that leakage current measurement is impossible. 5. The wiring state display device according to claim 2, wherein a determination unit determines whether the wiring state is a normal state defined by a leakage current measuring method based on a lighting state of the discharge lamp. And a second display means for displaying that the leakage current measurement is not possible when the determination means does not determine the normal state. 6. The method according to claim 1, wherein the determination unit includes a photoelectric conversion unit that performs photoelectric conversion of the lighting light of the discharge lamp, and determines whether the state is the normal state based on an output voltage of the photoelectric conversion unit. The leakage current measuring device according to claim 5.