JPH0138263B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present application relates to an insulation defect detection device for electrically resistant insulating gloves used in live line work, etc., and in particular is capable of detecting insulation defects at any time and easily.

Electrical insulating gloves, which are generally used for live wire work, are manufactured in accordance with the regulations of JIST-8112 (rubber gloves for electrical use) and JIST-8010 (withstand voltage test method for insulating protective equipment and protective equipment). The product is shipped after being tested by the manufacturer, and the customer who purchased the product is required to check the specified voltage (for example, A 1.5KV or more for seeds,
Insulation performance is required to be periodically tested using a 1-minute test method at a voltage of 6KV or higher for Class B and 10KV or higher for Class C, and this is carried out by the customer.

However, during the period until the next periodic insulation performance test, insulated gloves are still being used in many places, and even during this period, insulated gloves are damaged, which can lead to electric shock accidents when working with live wires. There is a risk that this will happen. Therefore, in the workplace, the appearance of insulated gloves is usually visually inspected during use, and air is blown through the cuffs of the gloves to check for damage caused to the gloves or pores in the fingertips. We are checking to see if there are any.

However, this method of inspecting insulated gloves for damage and pores using human senses is extremely insufficient and unreliable, and not only does it pose a risk of electric shock, but the inspection process itself is difficult. Testing the insulating performance of insulating gloves by applying high voltage each time they are used not only requires expensive withstand voltage test equipment and skilled technicians, but also requires Testing by applying a high voltage has disadvantages such as degrading the physical properties of the insulated gloves themselves and shortening their service life.In addition, there are inconveniences such as the inability to perform tests easily and at any time. This method has the disadvantage of increasing time and economic burden.

Therefore, the present invention uses a switching control method to obtain DC voltage from a commercial power source, applies it to an insulated glove that is a test object, and detects damage or pores in the insulated glove depending on the magnitude of the weak current that flows at that time. 1 is a rectifier connected to a commercial power supply, and a first rectifier is connected to the output side of the rectifier. light emitting diode LED ₁ , buzzer BZ, and photothyristor R′ _h
an abnormality display circuit 2 consisting of; a capacitor C ₆ ;
The oscillation circuit 3 includes a resistor R ₆ , a diode D ₂ , and a transistor Q ₂ , and a control transistor Q ₁ that stops the oscillation operation of the oscillation circuit 3 when the abnormality display circuit 2 becomes energized. In addition, a protection circuit 4 for stabilizing the oscillation circuit 3 is connected to each of them. T is the oscillation coil of the oscillation circuit 3
A high-frequency transformer that has P ₁ on the primary side, a secondary coil P ₂ that induces a test voltage (about 300 V) on the secondary side, and a tertiary coil P ₃ that induces a rotating operating voltage (about 10 V). The secondary coil P ₂ includes a rectifier circuit 5 consisting of a diode D ₇ and a smoothing capacitor C ₉ , a variable resistor R ₂₂ for setting a boundary current for pass/fail judgment, and connection terminals t ₁ and t ₂ . The test circuit 6 has a diode D ₈ in the tertiary coil P ₃ .
and a smoothing capacitor _C10 .
, a comparator CO that compares the voltage of the rectifier circuit 7 and a voltage drop caused by the current flowing through the test circuit 6, a second light emitting diode LED ₂ that indicates the normal state, and a comparator CO that uses the output of the comparator CO. A detection circuit 8 consisting of a transistor Q ₃ that operates the light emitting element P _h is connected to each of the detection circuits 8 . Reference numeral 9 indicates an insulating glove which is a test object, and during the test, an electrode rod connected to one output terminal _t1 of the test circuit 6 is placed in water injected into the inside of the insulating glove 9. 10 is arranged and immersed in the water tank 11,
Further, the other output terminal _t2 of the test circuit 6 is connected to an electrode rod 12 which is introduced into the water tank 11, that is, into the water outside the glove to be tested.

FIG. 2 is a perspective view showing a housing that houses the detection device of the present application and is configured to be easily portable;
This housing A includes a display section 13 for a power lamp PL,
A display section 14 is provided at a position facing the first light emitting diode LED ₁ and covered with, for example, red glass, and a display section 14 is provided at a position facing the second light emitting diode LED ₂ and covered with, for example, green glass. a display section 15; a sounding window 16 of the buzzer BZ;
A power switch SW, a power cord 17, etc. are provided.

Then, the insulating glove 9 to be tested is inserted into a water tank 11 (for example, a nearby bucket may be used), and while holding it with clips or the like, the electrode rod 10 is inserted into the inside of the glove.
An electrode rod 12 also intervenes in the water tank 11.

If you turn on the power switch SW in this state,
The power indicator lamp PL lights up, and the DC voltage of, for example, 300V induced in the test circuit 6 is applied to the electrode rod 10.
and the electrode rod 12. On the other hand, a DC voltage of, for example, 10 V is induced in the detection circuit 8, which is applied to the comparator CO and the second light emitting diode LED ₂ , causing the diode LED ₂ to emit light, thereby producing a green display.

In the above, if the variable resistor R 22 is variably adjusted so that the comparison voltage applied to the comparator CO is equal to the reference voltage, for example 10V, then _{the variable resistor R 22 and} the fixed resistor
A potential difference of 10V is applied to the comparator CO through R ₂₁ , its output voltage becomes zero, and the transistor
Q ₃ is left in the OFF state.

This state is maintained as long as the insulating glove 9 is completely insulated and no leakage current flows, or as long as an allowable small amount of leakage current flows. Therefore, the second light emitting diode LED ₂ emits light to display a green color. Therefore, the user can know that the insulating gloves 9 are safe. On the other hand, if there is damage or pores in the insulating glove 9, and as a result, the leakage current flows beyond the threshold value, the comparison voltage generated across the variable resistor _R22 applied to the comparator CO increases,
A voltage above the boundary is generated on the output side of the comparator CO, this voltage is applied to the base of the transistor _Q3 , the transistor _Q3 is turned on, current flows to the light emitting diode _Rh , and the diode _Rh emits light. . Then, the photothyristor R′ _h receives light and becomes conductive, and a current flows through the abnormality display circuit 2. This causes the first light emitting diode LED ₂ to emit light and display a red display, and the buzzer BZ sounds to disable the test object. This indicates that the insulating glove 9 has poor insulation. On the other hand, transistor Q ₁ whose base is connected to this is ON
As a result, the transistor of oscillation circuit 3
Q ₂ is turned OFF, the oscillation operation is stopped, the operating voltage of the test circuit 6 and the detection circuit 7 becomes zero, and the light emission of the second light emitting diode LED ₂ disappears.

As described above, according to the present application, using a commercial power source,
It is configured to detect the weak current flowing between the inner and outer surfaces of the insulating glove being tested, and detect the insulation performance of the insulating glove by light emission from a light emitting diode, so it is not a dielectric strength test device that applies a high voltage like the conventional one. It has the advantage of being able to provide a device that is much smaller and lighter in weight than when using a conventional method, and therefore has the advantage of being conveniently portable and allowing detection work to be carried out easily and at any time. Even if the detection work is repeated, the insulating performance of the insulated gloves will deteriorate due to it.
There is no risk of shortening the service life, and since DC is used as the test voltage according to the present application, measurement errors due to water between the two electrodes and stray capacitance on the surface of the test object are avoided, as in the case of the AC method. This has the advantage of providing a device that is safe to use and highly reliable.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an electric circuit diagram, and FIG. 2 is a perspective view of a casing housing the device of the present invention. In the figure, 1 is a rectifier, 2 is an abnormality display circuit, 3 is an oscillation circuit, 4 is a protection circuit, 5 and 7 are rectifier circuits, 6 is a test circuit, 8 is a detection circuit, LED ₁ and LED ₂ are light emitting diodes, R' _h is a photothyristor, Q ₁ and Q ₃ are transistors, T is a high frequency transformer, P ₁ is an oscillation coil,
P ₂ is the secondary coil, P ₃ is the tertiary coil, R ₂₂ is the variable resistor, t ₁ and t ₂ are the connection terminals, CO is the comparator,
Ph is a light emitting element.

Claims (1)

[Claims] 1. An abnormality display circuit that causes a first light emitting diode to emit light by conduction of a photothyristor on the output side of a rectifier connected to a commercial power source, an oscillation circuit for obtaining a test voltage, and an abnormality display circuit that causes a first light emitting diode to emit light when the abnormality display circuit is activated. A secondary coil that induces a test voltage on the secondary side of a high frequency transformer that is connected to a protection circuit having a transistor that stops oscillation of the oscillation circuit and has an oscillation coil of the oscillation circuit on the primary side; A test circuit that has an induced voltage rectifier circuit, a variable resistor that sets and adjusts a boundary current value for determining the quality of a test object, and an output terminal; a tertiary coil that induces a circuit operating voltage; and a rectifier circuit for the induced voltage. and a second light emitting diode that emits light according to the rectified voltage.
A detection circuit having a comparator that uses the rectified voltage as a reference voltage and compares it with a comparison voltage from the test circuit, and a light emitting element that emits light based on the output voltage from the comparator to operate the photothyristor is connected to each detection circuit. A defect detection device for voltage-resistant insulating gloves.