Electric leakage test plug and use method thereof

Abstract

The invention relates to the field of safe power utilization of civil power supply circuits, in particular to an electric leakage test plug and a use method thereof, and the circuit artificially generates electric leakage current greater than 30mA from a live wire of a power supply circuit to a ground wire to simulate the electric leakage phenomenon of the power supply circuit or electrical equipment, so that an electric leakage switch on the power supply circuit trips. Therefore, whether the electric leakage switch on the power supply line works normally or not is judged. The circuit can judge whether a grounding wire exists in a power supply line according to the state of the indicator lamp, and can judge whether the phase line and the zero line in the three-jack socket are correctly connected according to the state of the indicator lamp. The device is mainly used for an alternating current power supply circuit occasion, a user can conveniently and directly check whether an electric leakage switch and a grounding wire in the circuit are normal or not at an electric appliance power supply socket, and the user can more directly know whether the whole loop of electric leakage protection is effective or not.

Description

Technical Field

[0001] The invention relates to the field of safe electricity use of civil power supply circuits, and in particular to a leakage test plug and a use method thereof. Background Art

[0002] For a long time, accidents involving electric water heaters in the bathroom causing injuries have occurred from time to time, especially in rental houses in urban villages and old residential places in rural areas. The power supply lines are unqualified and unsafe. In addition, most young people who go out to work do not understand electrical knowledge to prevent electric shock, and cannot effectively control the actual status of leakage protection of electrical equipment in the residence. Electric shock accidents have occurred almost every year and have never stopped, causing casualties and bringing irreparable harm to families.

[0003] Therefore, in order to solve the above problems and facilitate users to better test whether there is a grounding wire in their own power supply line and whether the leakage switch is working normally, the present invention provides a leakage test plug, which can be tested directly at the power supply socket of the electrical equipment. The user will see more intuitively whether the leakage protection fails, that is, simulate the situation when the electrical equipment leaks, whether the leakage switch can normally cut off the power supply of the line, and help users to implement safe use of electricity. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a leakage test plug and a method for using the same. The technical problem to be solved by the present invention is that when users use electrical equipment, they are often unable to grasp the actual situation of the leakage protection function in the power supply line, and need to ask professional electricians to check. The whole process is time-consuming and troublesome. In this case, most users will not take the initiative to check the line before an incident occurs, which is not conducive to the user's safe use of electrical appliances. Therefore, the present invention can conveniently insert the leakage test plug of the present invention directly into the three-hole socket end of the power supply line in the user's home at any time to perform testing and inspection, so that people who do not understand electrical knowledge can operate it, and it is intuitive and clear for users to control electricity safety in their own hands. In particular, when users use high-risk bathroom electric water heaters and need to perform periodic inspections frequently, the convenience of the present invention will highlight its great practical value. The details are as follows:

[0005] A leakage test plug and a method of using the same, the leakage test plug comprising a three-wire plug, a power indication circuit, a leakage current circuit and a discrimination circuit;

[0006] The three-wire plug includes a live wire L, a neutral wire N and a ground wire E;

[0007] The power indicator circuit includes a blue power indicator light connected between L and N and a resistor 1;

[0008] The leakage current circuit includes a diode 1, a resistor 2, a resistor 3, a resettable temperature fuse and a buzzer power supply auxiliary circuit connected between L and E; wherein the diode 1, the resistor 2, the buzzer power supply auxiliary circuit and the resettable temperature fuse are connected in series, and the resistor 3 is connected in parallel with the resistor 2 and the buzzer power supply auxiliary circuit;

[0009] The discrimination circuit comprises a diode 2, a resistor 4 and a green indicator light connected between L and E; and a diode 3, a resistor 5 and a red indicator light connected between N and E.

[0010] Preferably, the buzzer power supply auxiliary circuit includes a buzzer and a power supply circuit.

[0011] Preferably, the specifications of the resistor 2 and the resistor 3 are 4.7KΩ / 3W; the specification of the resistor 1 is 200KΩ / 0.25W; the specifications of the resistor 4 and the resistor 5 are 47KΩ / 0.25W.

[0012] Preferably, the method of use includes:

[0013] Insert this leakage test plug into the user's three-hole power socket, if:

[0014] a. The leakage switch on the user's power supply line trips immediately, that is, the indicator light flashes and goes out, indicating that the user's power supply line has leakage protection function;

[0015] b. The blue power indicator light is off, the red indicator light is on, and the green indicator light is on. This is a wiring error. The E position is connected to the live wire, and the other two are connected to the ground wire and the neutral wire at will.

[0016] c. The blue power indicator light is on, the red indicator light is on, and the green indicator light is off. This means that the live wire and the neutral wire are connected incorrectly, and the wiring positions are swapped;

[0017] d. The blue power indicator light is on, and the red and green indicators are off. This means there is no ground wire or the ground wire is faulty.

[0018] e. The blue power indicator light is on, the green indicator light is on, the red indicator light is off, and the buzzer keeps beeping. This means that the leakage switch is invalid or there is no leakage switch installed on the power supply line;

[0019] f. The blue power indicator light, the red indicator light, and the green indicator light are all on at the same time. This means that the wiring position is wrong and a ground wire or neutral wire is missing.

[0020] g. All three indicator lights are off. This means that only one wire is connected or there is no power in the power supply line.

[0021] The beneficial effects of the present invention are:

[0022] The device of the present invention can detect whether the live wire L and the neutral wire N of a three-hole socket are connected reversely, and if L and N are connected reversely at the entrance of the leakage switch of the user's power supply, no matter the leakage switch is tripped or closed, the leakage test plug indicator light can detect errors in the user's power supply line based on the phenomenon.

[0023] The present invention can be conveniently inserted into the three-hole socket end of the power supply line in the user's home at any time to test the leakage protection status, so that people who do not know electrical knowledge can operate it, and it is intuitive and clear for users to control the safety of electricity use. Especially when users use high-risk bathroom electric water heaters and need to do periodic inspections frequently, the convenience of the present invention will highlight its great practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 is a circuit schematic diagram of the present invention;

[0026] 100- three-wire plug, 11- diode one, 12- resistor two, 13- resistor three, 14- self-recovery temperature fuse, 15- buzzer, 16- buzzer power supply auxiliary circuit, 17- green indicator light, 18- resistor four, 19- diode two, 20- red indicator light, 21- resistor five, 22- diode three, 23- blue power indicator light, 24- resistor one, 200- power indication circuit, 300- leakage current circuit, 400- discrimination circuit. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] In the description of the embodiments of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invented product is usually placed when used. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0029] As shown in the figure, a leakage test plug includes a three-wire plug 100, a power indication circuit 200, a leakage current circuit 300 and a determination circuit 400;

[0030] The three-wire plug 100 includes a live wire L, a neutral wire N and a ground wire E;

[0031] The power indicator circuit 200 includes a blue power indicator light 23 connected between L and N and a resistor 24;

[0032] The leakage current circuit 300 includes a diode 11, a resistor 2 12, a resistor 3 13, a resettable temperature fuse 14 and a buzzer power supply auxiliary circuit 16 connected between L and E; wherein the diode 11, the resistor 2 12, the buzzer power supply auxiliary circuit 16 and the resettable temperature fuse 14 are connected in series, and the resistor 3 13 is connected in parallel with the resistor 2 12 and the buzzer power supply auxiliary circuit 16; the buzzer power supply auxiliary circuit 16 includes a buzzer 15 and a power supply circuit.

[0033] The discrimination circuit 400 includes a diode 2 19 , a resistor 4 18 and a green indicator light 17 connected between L and E; and a diode 3 22 , a resistor 5 21 and a red indicator light 20 connected between N and E.

[0034] The specifications of resistor two 12 and resistor three 13 are 4.7KΩ / 3W; the specifications of resistor one 24 are 200KΩ / 0.25W; the specifications of resistor four 18 and resistor five 21 are 47KΩ / 0.25W.

[0035] In the power supply line with normal working leakage protection and grounding protection, the correct wiring method is that L corresponds to the live wire, N corresponds to the neutral wire, and E corresponds to the grounding wire. The leakage switch will automatically trip when the leakage current in the power supply line exceeds 30mA (Note: Because there are single-pole leakage switches on the market (see Figure 2), the tripping here means that the leakage switch only cuts off the live wire L, while the neutral wire N remains in the on state; it is necessary to explain the meaning of the identifier N on the leakage switch: N stands for normally on, which is the first letter of Normal, and does not mean the neutral wire). Therefore, a power supply line with reliable leakage protection must meet the following conditions: a. The leakage switch must work normally, b. There is a reliable grounding protection line, c. The wiring position of the live wire L and the neutral wire N at the leakage switch must be correct and cannot be reversed, otherwise even if the leakage switch trips, the live wire cannot be cut off.

[0036] According to the above conditions, when the leakage test plug is inserted into the user's three-hole power supply socket, the current at the L end node of the three-wire plug flows to three branches:

[0037] The first branch circuit is a power indication circuit 200, indicated by a blue power indicator light 23;

[0038] The second branch circuit is the ground wire identification and live and neutral wire position identification circuit 400 (return path: L-diode 2 19-resistor 4 18-green indicator light 17-E), and the identification principle is explained as follows: First, regardless of whether the L and N wiring of the three-hole socket is correct, as long as the blue power indicator light is on, it means that there is a 220V power supply voltage between LN; if the green indicator light is on, it means that there is current flowing through diode 2 19, resistor 4 18, and green indicator light 17, and because there are reverse-connected diodes in the other node loops of the entire connected circuit, according to the unidirectional conduction characteristics of the diode, the currents in each loop are isolated and will not be connected in series, so the loop current must be formed between LE, and it can be confirmed that there must be a ground wire in the power supply line to form a loop, and at the same time, it can be confirmed that the positive connection at the L position of the three-hole socket It is the live wire. This can be verified by combining the state of the red indicator light in the current loop on the other side (return path: N-diode three 22-resistor five 21-red indicator light 20-E) to verify whether the live wire is connected to the L end. At this time, the red indicator light should be off. The reason is that according to international standards, the neutral line and the grounding line in the power supply line will eventually be connected to the earth. The potentials of N and E are almost equal to zero potential. There is no potential difference between NE and the red indicator light cannot be turned on. Therefore, as long as there is a grounding wire in the line, only one of the red and green indicators will be on, and the side that is lit is the live wire. If there is no grounding wire or the grounding wire is poor in the user's three-hole power supply socket, then the red and green indicators cannot form a loop with any circuit, and both lights are off.

[0039] The third branch circuit is a circuit 300 that generates a leakage current greater than 30mA. The purpose is to detect whether a leakage switch is installed in the power supply line or whether the leakage switch is in normal operation. Similarly, there must be a grounding wire in the line to form a complete current loop; assuming that the user's power supply line has reliable leakage protection, when the leakage test plug is inserted for an instant, the status of the three indicator lights and the buzzer are: the blue power indicator light 23 and the green indicator light 17 appear and flash and then go out, the red indicator light 20 is not on, the buzzer 15 stops as soon as it sounds, the leakage switch in the power supply line is tripped, and the live wire of the power supply line is cut off.

[0040] The present invention uses a resistor as a return load (see Figure 1 Resistor 2 12 and resistor 3 13) are connected across the phase line L and the neutral line E to artificially create a leakage circuit. The current calculation formula of resistor 2 12 and resistor 3 13 is: I = U ÷ R, the voltage after half-wave rectification of the diode is U = 220V × 0.45 = 99V, I = 99V ÷ 4.7KΩ ≈ 21mA, and the sum of the two currents is approximately equal to 42mA, which exceeds the IAn value (30mA) of the leakage switch. It should be noted that the leakage test plug does not limit the type and specific structure of the electronic components on the return path, which can be passive devices such as resistors, capacitors, and inductors, or transistors, etc. The resistors used here are used to illustrate the principle.

[0041] In order to ensure that in the event of a failure of the leakage switch (or a bad ground wire), when the user uses an artificial leakage plug, the resistor is heated for a long time and causes the danger of overheating, a self-resetting temperature fuse is connected in series in the circuit (see Figure 1 Self-resetting temperature fuse 14), when the temperature reaches 73 degrees, the self-resetting temperature fuse automatically disconnects the loop current to ensure circuit safety.

[0042] According to the above working principle, when this leakage plug is inserted into the three-hole socket of the user's power supply, the leakage switch on the user's power supply line must trip immediately (the indicator light flashes and goes out completely) to indicate that the user's power supply line has the leakage protection function. The status of any other indicator lights and the status of the buzzer indicate that there is a problem with the line and it should be suspended. Please ask a qualified technician with an electrician certificate to come to the site for maintenance and inspection as soon as possible.

[0043] The following are several indicator light states when the leakage switch does not trip or the wiring is wrong, to provide convenience for electrician maintenance personnel:

[0044] a. The leakage switch on the user's power supply line trips immediately, that is, the indicator light flashes and goes out, indicating that the user's power supply line has leakage protection function;

[0045] b. The blue power indicator light 23 is off, the red indicator light 20 is on, and the green indicator light 17 is on. This is a wiring error. The E position is connected to the live wire, and the other two are connected to the ground wire and the neutral wire at will.

[0046] c. The blue power indicator light 23 is on, the red indicator light 20 is on, and the green indicator light 17 is off. This state means that the live wire and the neutral wire are connected incorrectly and the connection positions are swapped. In this state, even if the user's leakage switch works normally, the artificial leakage plug of the present invention will not cause the leakage switch to trip. The reason is that the resistance of resistor 5 21 is 47kΩ, and the leakage current to the ground is about 2mA, which is much smaller than the gate threshold value of 30mA of the leakage switch. The calculation formula is: I = U ÷ R, the voltage after the diode half-wave rectification is U = 220V × 0.45 = 99V, I = 99V ÷ 47KΩ ≈ 2mA).

[0047] d. The blue power indicator light 23 is on, and the red indicator light 20 and the green indicator light 17 are not on. This means there is no ground wire or the ground wire is faulty.

[0048] e. The blue power indicator light 23 is on, the green indicator light 17 is on, the red indicator light 20 is off, and the buzzer keeps beeping. This means that the leakage switch is invalid or there is no leakage switch installed on the power supply line;

[0049] f. The blue power indicator light 23, the red indicator light 20, and the green indicator light 17 are all on at the same time. This means that the wiring position is wrong and a ground wire or neutral wire is missing.

[0050] g. All three indicator lights are off. This means that only one wire is connected or there is no power in the power supply line.

[0051] Resistor 2 12, resistor 3 13, and self-recovery temperature fuse 14 constitute a power resistor self-recovery temperature fuse integrated component, wherein the power resistor self-recovery temperature fuse integrated component and the buzzer are intended to solve the problem that when the user's leakage switch fails, the leakage test plug of the present invention is mistakenly inserted into the power supply line, the power resistor is always heating, and when the temperature is too high, the self-recovery temperature fuse will automatically cut off the return path to ensure safety in the event of misuse; on the other hand, the power resistor is always heating and the buzzer is always ringing, the purpose of which is to remind the user to unplug the artificial leakage plug as soon as possible, and to inform the user that the leakage protection has failed and an electrician with a qualified certificate should be found for repair as soon as possible.

[0052] For those "electricians" who do not have a work permit or who are negligent in their work and randomly connect the wiring positions of L and N, resulting in wiring errors, the present invention designs the circuit so that among the two ports L and N, only the L end connected to the live wire can generate a leakage current greater than 30mA, causing the leakage switch to trip, and this is supported by combining the blue power indicator light and the green indicator light. If L and N are reversely connected, a current greater than 30mA will not be generated, and the leakage switch will not trip, because the resistance value of the resistor 5 21 is 47KΩ, thereby detecting the user's power supply line wiring error problem.

[0053] There is another phenomenon. If the user uses a single-pole leakage switch (see Figure 2), those "electricians" who do not have a work permit or the electricians are negligent in their work and reverse the positions of the L and N wires at the entrance of the leakage switch. At the same time, L and N are also reversed at the three-hole socket. Although the leakage switch will trip when the leakage test plug of the present invention is inserted, the live wire of the power supply line is not cut off at this time, only the neutral wire is cut off, and the user's other electrical equipment cannot work. However, the indicator light of the leakage test plug of the present invention will still play a role. The indicator light will light up to inform the user that there is a wiring error in the power supply line. There is still a problem of electric shock, which endangers personal safety.

[0054] In short, when the artificial leakage plug of the present invention is inserted, the blue power indicator light must be on, the green indicator light must be on, and the red indicator light must be off. At the moment of insertion, the user's leakage switch trips, and the indicator light flashes and goes out. Only in this case can it be proved that the user's power supply line has a leakage protection function. Any other state indicates that the user's power supply line is incorrect and the leakage protection function is at risk. Based on the above characteristics, the leakage test plug of the present invention and its use method are convenient for users to test the leakage protection of the power supply line, so as to master the safe use of electricity in their own hands.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A leakage test plug, used to test the leakage protection switch and the grounding protection line at the power supply line socket, and is a test device for testing whether the leakage switch can trip normally when the leakage current in the line is greater than 30mA, characterized by: The leakage test plug comprises a three-wire plug (100), a power indication circuit (200), a leakage current circuit (300) and a discrimination circuit (400); The three-wire plug (100) comprises a live wire L, a neutral wire N and a ground wire E; The power indicator circuit (200) comprises a blue power indicator light (23) connected between L and N and a resistor 1 (24); The leakage current circuit (300) comprises a diode 1 (11) connected between L and E, a resistor 2 (12), a resistor 3 (13), a self-resetting temperature fuse (14) and a buzzer power supply auxiliary circuit (16); wherein the diode 1 (11), the resistor 2 (12), the buzzer power supply auxiliary circuit (16) and the self-resetting temperature fuse (14) are connected in series, and the resistor 3 (13) is connected in parallel with the resistor 2 (12) and the buzzer power supply auxiliary circuit (16); The discrimination circuit (400) comprises a diode 2 (19), a resistor 4 (18) and a green indicator light (17) connected between L and E; and a diode 3 (22), a resistor 5 (21) and a red indicator light (20) connected between N and E.

2. The leakage test plug according to claim 1, characterized in that: The buzzer power supply auxiliary circuit (16) comprises a buzzer (15) and a power supply circuit.

3. The leakage test plug according to claim 1, characterized in that: The specifications of the resistor 2 (12) and the resistor 3 (13) are 4.7KΩ / 3W; the specifications of the resistor 1 (24) are 200KΩ / 0.25W; the specifications of the resistor 4 (18) and the resistor 5 (21) are 47KΩ / 0.25W.

4. The leakage test plug according to claim 1, characterized in that: Usage methods include: Insert this leakage test plug into the user's three-hole power socket, if: a. The leakage switch on the user's power supply line trips immediately, that is, the indicator light flashes and goes out, indicating that the user's power supply line has leakage protection function; b. The blue power indicator light (23) is off, the red indicator light (20) is on, and the green indicator light (17) is on. This is a wiring error. The E position is connected to the live wire, and the other two are connected to the ground wire and the neutral wire at will. c. The blue power indicator light (23) is on, the red indicator light (20) is on, and the green indicator light (17) is off. This means that the live and neutral wires are connected incorrectly and the wiring positions are swapped. d. The blue power indicator light (23) is on, and the red indicator light (20) and the green indicator light (17) are not on. This means there is no ground wire or the ground wire is faulty. e. The blue power indicator light (23) is on, the green indicator light (17) is on, the red indicator light (20) is off, and the buzzer keeps beeping. This means that the leakage switch is invalid or there is no leakage switch installed on the power supply line; f. The blue power indicator light (23), the red indicator light (20), and the green indicator light (17) are all on at the same time. This means that the wiring position is wrong and a ground wire or neutral wire is missing. g. All three indicator lights are off. This means that only one wire is connected or there is no power in the power supply line.

5. The leakage test plug according to claim 4, characterized in that: This device is used to detect whether the live wire L and the neutral wire N of a three-hole socket are reversely connected, and if the L and N at the entrance of the leakage switch of the user's power supply are reversely connected, no matter whether the leakage switch is tripped or closed, combined with the indicator light phenomenon, it is detected that there is an error in the user's power supply line.

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