JPH11190755A - Leakage point detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety in operation by easily detecting a leakage point in an electric path, insulating a power supply side from a measurement circuit side by an insulation transformer, and avoiding the risk of an electric shock accident due to small measurement current and voltage. SOLUTION: A device is provided with a measurement power supply part 1 being connected to a power supply, an insulation transformer 2 where one terminal of a secondary side is grounded and a power supply voltage at a primary side from a measurement power supply part 1 can be converted to a measurement voltage at a secondary side, a measurement current supply part 4 for allowing a measurement current to flow by connecting the other terminal at the secondary side of the insulation transformer 2 to an electric path whose leakage should be detected and then applying a measurement voltage between the electric path and the grounded, one terminal in the above at the secondary side of the insulation transformer 2, current measurement equipment 6 for measuring an electric path current that flows through the electric path, and a leakage display part 7 for displaying a leakage point according to the above electric path current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a leak location used for detecting a location where a leak has occurred, for example, in a general household or factory.

[0002]

2. Description of the Related Art The term "leakage" refers to a phenomenon in which electric current does not flow through a so-called electric circuit as a predetermined portion and leaks outside in electric wiring and electric equipment. Technical standards require that electrical circuits be insulated from the ground.Therefore, if the wiring and equipment are sound, no leakage will occur, but the leakage will occur due to deterioration of the insulation of the wiring and equipment, especially insulation between the ground and the earth. In the case of low-voltage wiring, the earth is provided as grounding work at the transformer at the transformer, so the leakage current returns from the equipment to the power supply via the ground, and if this leakage current is left In addition to not only disturbing the operation of the equipment and causing power loss, but also in the worst case, there is a risk of causing an electric leakage fire or electric shock, resulting in the installation of an earth leakage breaker on the power supply side of the circuit. Occurs It is configured to block the circuit et immediately the power supply side.

Conventionally, a so-called clamp-type leakage ammeter D has been used for this type of leakage point detecting operation. This instrument D has a zero-phase current transformer structure and can be opened and closed as shown in FIG. consists rings D ₁ and the handle portion D _2, in use, when no power outage voltage path, sandwiched segmented ring D ₁ into two wires of path to be detected, if the leakage is not occurring zero It has a structure that displays a value and measures and displays the value of leakage current when leakage occurs, and is widely used for maintenance and inspection of electric circuits.

[0004]

However, at the time of the work of detecting a leakage point using this meter, for example, as shown in FIG. 2, in a two-wire AC circuit, a main circuit L ₁ and L ₂ and a power supply M such as an AC commercial power supply are connected. Are connected to each other, a switch group S disposed on each circuit is selectively opened and closed according to each circuit to be measured, and two electric wires of each circuit are divided into two rings of a clamp-type leakage ammeter D. selectively sandwiched between D _1, because you have to look for leakage points by repeating the choice trial, very cumbersome before detect leakage location, leakage current with much workability is lowered a certain If the value exceeds the value, the leakage breaker R will instantly cut off the circuit within 0.1 seconds, making it difficult to measure the leakage current and making it impossible to detect and specify the leakage location. Yes, The detection work is performed without interruption of the voltage circuit. In the low-voltage wiring, since the earth E is provided as grounding work at the transformer H, the leakage current is transmitted from each device K to the power supply M via the ground Q. Therefore, there is a risk that the worker may get an electric shock, and the safety of the work may be reduced accordingly.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems. Among the present invention, the invention according to claim 1 includes a measuring power supply unit connected to a power supply,
One terminal on the secondary side is grounded, and an insulating transformer capable of converting a power supply voltage on the primary side from the measurement power supply unit to a measurement voltage on the secondary side, and the other terminal on the secondary side of the insulation transformer A measuring current supply unit for applying a measuring voltage between the electric circuit and the grounded one terminal on the secondary side of the insulating transformer to flow a measuring current; and There is provided a leakage point detection device, comprising: a current measuring device for measuring a path current flowing through a path; and a leakage display section for displaying a leakage point by the path current.

According to a second aspect of the present invention, there is provided a current measuring unit capable of measuring the measured current, and a third aspect of the present invention provides the insulating transformer. And a voltage measuring unit for measuring the measurement voltage generated on the secondary side of the device. The invention according to claim 4 is capable of controlling a measurement current by the electric circuit current value. The present invention is characterized in that it comprises a variable transformer, and the invention according to claim 5 is characterized in that the current measuring device comprises a clamp-type leakage ammeter.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention. Reference numeral 1 denotes a measuring power supply unit, which is composed of an insertion plug connected to an outlet such as an AC commercial power supply.
It is configured to receive power via a transformer H with a more grounded E.

Reference numeral 2 denotes an insulating transformer. In this case, a compound winding transformer structure is employed. One of the terminals u and v on the secondary side is grounded to ground e ₂ . It is configured to convert the power supply voltage E ₁ of the primary side to the measuring voltage E ₂ of the secondary side.

In this case, a variable transformer 3 of so-called auto-transformer structure called so-called Slackack is interposed between the measuring power supply unit 1 and the insulating transformer 2. The measurement current I is automatically variably controlled based on the circuit current value, and the primary-side power supply voltage E _{1 of the} insulating transformer 2 is controlled.
Is configured to be adjustable. Incidentally, the variable transformer 3 may be manually adjusted.

[0010] 4 is a measured current supply portion, through this case the insulating transformer 2 of second-order side of the other terminal u the backbone should leak detection path L ₁ or L ₂ and the connecting line T ₁ It includes a connection terminal T electrically connected to Te, measurement voltage between the connection terminals T by paths L ₁ or L ₂ and the insulating transformer 2 on the secondary side of the ground e ₂ has been one terminal v E ₂ Is applied so that the measurement current I flows.

[0011] 5 is a current measuring unit, in this case, arranged so shunt resistor 5a in the connecting line T _1, is configured to detect the measuring current I flowing through the secondary side of the insulating transformer 2 I have.

Reference numeral 6 denotes a current measuring device. In this case, five high-sensitivity measuring devices having the same structure as the above-mentioned clamp-type leakage current meter are used. 7 to measure the circuit current values i ₁ , i _2, ... Flowing through the respective circuits, that is, the leakage current values of the respective circuits.

In the leakage display section 7, at least the circuit current values i ₁ , i _2.
The is configured to display the measured current I and the measurement voltage E ₂ of the total leakage current and displays for each path. Although not shown, the leakage display unit 7 is a liquid crystal display, and its driving power supply is configured to be taken in from the measurement power supply unit 1 or a separate power supply. In addition, it may be displayed by a lamp or a buzzer.

Reference numeral 8 denotes a voltage measuring unit configured to measure a measured voltage E ₂ generated on the secondary side of the insulating transformer 2.

Since this embodiment has the above configuration,
At the time of the earth leakage detection work, in FIG.
And the power supply M, and each of the electric circuits F _1.
Two electric wires of F ₂ ... Are sandwiched, and the connection terminal T is electrically connected to the main circuit L ₁ or L ₂ in FIG. 2 to detect the leakage with the other terminal u on the secondary side of the insulating transformer 2. Electric circuit L _{1 to be}
Or L _2, and a measurement voltage E _{2 is} applied between the electric circuit L ₁ or L ₂ and _one of the grounded terminals v on the secondary side of the insulating transformer _2.
Is applied to apply the measurement current I. At this time, if no leakage occurs, no current flows from each device K to the ground Q. The current value I is displayed as zero, and the circuit current values i ₁ , i _2, ... In the respective circuits F ₁ , F ₂ ,.
Therefore, it is recognized that there is no leakage, and when a leakage occurs, a leakage current flows from each device K to the ground Q. The electric circuit current value i is displayed, the electric circuit F that is not leaking is displayed as zero, and the electric leakage point can be easily recognized by displaying the electric leakage current for each of the electric circuits F ₁ , F _2. Therefore, the workability of the earth leakage detection can be improved accordingly.

Further, a measurement power supply unit 1 connected to a power supply,
One terminal v of the secondary side is grounded e _2, the power supply voltage E ₁ of the primary side and the secondary side of the measuring voltage E ₂ convertible to insulation transformer 2 from the measurement power supply unit 1, isolation transformers 2 the secondary side of the connected other terminal u and paths L ₁ or L ₂ to be leakage detection, path L ₁ or L ₂ and the insulating transformer secondary side of the ground e ₂ has been one terminal v The measurement current supply unit 4 for applying the measurement voltage E ₂ and flowing the measurement current I between the circuit breaker and the circuit breaker. Moreover, the power supply side and the measuring circuit side are insulated by the insulating transformer 2 and this measuring current I is 1 m.
A to 5 mA and the measured voltage E2 are as small as about ₂₀ V to 100 V, so that the danger of electric shock accident can be avoided and the safety of work can be improved.

In this case, since the current measuring section 5 capable of measuring the measured current I is provided, the leak display section 7 displays the respective circuit current values i ₁ · i _2. Are displayed, and when a certain measured current value I is displayed on the leakage display section 7, the sum of the respective circuit current values i ₁ · i _2. Since they are in equal relation, for example, each electric circuit F ₁ to be detected
・ Even if the current measuring device 6 is not arranged in all of F ₂ .
A single or several current measuring devices 6 are arranged on an arbitrary electric circuit,
When a certain measured current value I is displayed on the earth leakage display unit 7 and the current measuring device 6 of the electric circuit F is displayed as zero, the current measuring device 6 is arranged on another electric circuit F. It is also possible to detect a leakage point, and also to measure the measured current value I displayed on the leakage display unit 7 and the circuit current i of the circuit path F.
Or, when the sum of the circuit currents is not equal, it is possible to recognize that a leakage has occurred in another circuit F, and therefore, by arranging the current measuring device 6 in the other circuit F, the leakage point can be determined. It is also possible to detect, and it is possible to surely detect a leakage point.

[0018] Also, in this case, is provided with the voltage measuring unit 8 for measuring the measuring voltage E ₂ generated in the secondary side of the insulating transformer 2, it is possible to recognize the voltage of the measuring circuit side,
In this case, the work safety can be improved. In this case, since the variable transformer 3 capable of controlling the measurement current with the above-described circuit current value is provided, the circuit current values i ₁ , i _2.
The measured current I can be changed in accordance with the magnitude of the leakage current as described above, and the leakage current can be reliably measured accordingly. In this case, since the current measuring device 6 comprises a clamp-type leakage current meter, The structure can be simplified and the leakage current value can be reliably measured.

The present invention is not limited to the above-described embodiment. In the above-described embodiment, the present invention is applied to leakage detection of an AC two-wire circuit, but is also applicable to an AC three-wire circuit. And the measured current supply unit 4,
The structure, form, circuit configuration, and the like of the current measuring device 6, the leakage display 7, and the like are appropriately designed and changed.

[0020]

As described above, according to the first aspect of the present invention, at the time of the earth leakage detecting operation, the measuring power supply unit is connected to the power supply, and the current measuring device is arranged on each electric circuit to be earth leakage detecting. Then, connect the other terminal on the secondary side of the insulation transformer to the electric circuit to be earth leakage detected, and apply a measurement voltage between the electric circuit and one of the grounded terminals on the secondary side of the insulation transformer. In this case, the measured current value is displayed as zero on the ground fault display unit because the current does not flow from each device to the ground if a current leak does not occur. The circuit current value in each circuit is also displayed as zero, and it is recognized that there is no leakage, and if leakage occurs, leakage current flows from each device to the ground,
The leak current display unit displays the current values of the respective leaked circuits in correspondence with the leaked circuits, the zero leaked circuits are displayed, and the leak location is easily recognized by displaying the leak current of each separate circuit. The workability of the earth leakage detection can be improved accordingly, and the measurement power supply unit connected to the power supply and one terminal on the secondary side are grounded, and the primary power supply voltage from the measurement power supply unit Is connected to the other terminal on the secondary side of the insulation transformer and the electric circuit to be detected for earth leakage, and the electric circuit is connected to the ground on the secondary side of the insulation transformer. Since a measurement current supply unit for applying a measurement voltage and flowing a measurement current between the one terminal and the measurement terminal is provided, a breaking phenomenon of the earth leakage breaker can be avoided, and a leakage point can be reliably detected. Moreover, the power supply side and the measurement circuit side are insulated by the insulation transformer. For measuring current and the measuring voltage is smaller can increase the safety of the work can also be avoided the danger of electric shock.

According to the second aspect of the present invention, since the electric current measuring section capable of measuring the measured current is provided, the electric leakage current display section displays the measured values of the respective electric circuit current values and the total leakage current. Each current value is displayed, and when a certain measured current value is displayed on the leakage display unit, the sum of the respective circuit current values is in a relationship equal to the measured current value. Even if it is not necessary to arrange current measuring devices in all, one or several current measuring devices are arranged in an arbitrary electric circuit, and when a certain measured current value is displayed on the leakage display section, the current measurement of the electric circuit is performed. If the device is displayed as zero, the leak location can be detected by arranging a current measuring device on another electrical circuit, or the measured current value displayed on the Equal to the sum of current or circuit current In this case, it is possible to recognize that leakage has occurred in other electric circuits, and therefore, by locating a current measuring device in other electric circuits, it is possible to detect the leakage points, and to ensure that Can be detected.

According to the third aspect of the present invention, since a voltage measuring section for measuring a measurement voltage generated on the secondary side of the insulating transformer is provided, the voltage on the measurement circuit side can be recognized. In addition, in the invention according to the fourth aspect, since a variable transformer capable of controlling the measurement current by the above-mentioned circuit current value is provided, the circuit current can be reduced. The measured current can be changed in accordance with the magnitude of the leakage current as a value, and the leakage current can be reliably measured by that much. In the invention according to claim 5, the current measuring device is a clamp type. Since a leak current meter is used, the structure can be simplified and the leak current value can be measured reliably.

As described above, the intended purpose can be sufficiently achieved.

[Brief description of the drawings]

FIG. 1 is an overall explanatory circuit diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a circuit for detecting a leakage point.

FIG. 3 is a front view of a clamp-type leakage ammeter.

[Explanation of symbols]

I Measurement current E ₁ Power supply voltage E ₂ Measurement voltage i Circuit current e ₂ Ground 1 Measurement power supply 2 Insulation transformer 3 Variable transformer 4 Measurement current supply 5 Current measurement 6 Current measurement 7 Leakage display 8 Voltage measurement Department

Claims (5)

[Claims] A measurement power supply unit connected to a power supply and an insulation transformer capable of converting a primary power supply voltage from the measurement power supply unit to a secondary measurement voltage with one terminal on a secondary side grounded. And the other terminal on the secondary side of the insulation transformer and the electric circuit to be detected for earth leakage, and the measured voltage is applied between the electric circuit and the one grounded terminal on the secondary side of the insulation transformer. And a current measuring device that measures a circuit current flowing through the circuit, and a leakage display unit that displays a leakage location by the circuit current. Electric leakage point detection device. 2. The leak detecting device according to claim 1, further comprising a current measuring unit capable of measuring the measured current. 3. The leak detecting device according to claim 1, further comprising a voltage measuring unit for measuring the measured voltage generated on a secondary side of the insulating transformer. 4. The leakage detecting device according to claim 1, further comprising a variable transformer capable of controlling a measurement current by the electric circuit current value. 5. The leak detecting device according to claim 1, wherein the current measuring device comprises a clamp-type leak ammeter.