Method for directly testing leakage protector in use circuit and testing instrument thereof

Abstract

The invention discloses a method for directly testing a leakage protector in a use circuit and a test instrument thereof, the method provided by the invention is simple to operate and easy to implement, and a first test end and a second test end (such as a test pen) of the test instrument are directly connected with a live wire and a ground wire of a tested circuit; then, a load element is connected to a tested circuit through a simulation test module, simulation leakage current is generated to test a leakage protector and a line, and if the leakage protector trips, it is judged that the leakage protector and the line are connected normally; otherwise, determining that a fault exists. The problem that only the leakage protector can be tested and line connection cannot be verified in the prior art is effectively solved, synchronous detection of the leakage protector and line connection is achieved, and potential safety hazards are eliminated. The test instrument provided by the invention can be integrated in a universal meter or a clamp meter, realizes multifunctional integrated design, does not need to additionally carry a special test instrument, is small in size and portable, adapts to a field rapid test scene, and brings convenience to use.

Description

Methods and testing instruments for directly testing residual current devices (RCDs) in circuits Technical Field

[0001] This invention relates to the field of residual current device (RCD) testing technology, and specifically to a method and testing instrument for directly testing RCDs in a circuit. Background Technology

[0002] Residual current devices (RCDs) are widely used in all distribution boxes. Engineers generally recommend labeling the box with a reminder to press the test button on the RCD at regular intervals, such as every three months, to check if it trips. If it trips, it's considered normal; otherwise, it's abnormal and requires maintenance. However, this testing method only verifies the RCD itself and cannot confirm the proper connection between the entire circuit (such as the connection between the socket and the ground wire) and the RCD. If there are problems with the wiring, even if the RCD itself is working properly, it cannot guarantee safe tripping in the event of a leakage, posing a certain safety hazard. Summary of the Invention

[0003] To address the aforementioned shortcomings, the present invention aims to provide an easy-to-operate method and testing instrument for directly testing residual current devices (RCDs) in a circuit.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for directly testing a residual current device (RCD) in a circuit, characterized by comprising the following steps:

[0006] S1. Connect the first and second test terminals of the test instrument to the live wire and ground wire of the circuit under test, respectively;

[0007] S2. The voltage signal of the circuit under test is acquired by the voltage sampling module in the test instrument and fed back to the main control module in the test instrument. After the main control module analyzes and processes the signal and confirms that the connection is normal, the voltage information is displayed by the display module of the test instrument.

[0008] S3. Trigger the simulation test module in the test instrument. The simulation test module connects the load element to the circuit under test to generate a simulated leakage current that can trigger the leakage current protector to trip.

[0009] S4. If the residual current device (RCD) in the circuit under test trips, it is determined that the RCD and the circuit connection are normal; if it does not trip, it is determined that there is a fault, and the test results are displayed on the display module at the same time.

[0010] In a preferred embodiment of the present invention, the first and second test terminals of the testing instrument are test pens. In step S1, the test pens of the testing instrument are inserted into the sockets connected to the circuit under test. The connection between the test terminals and the live and ground wires can be completed without additional wiring, simplifying the wiring operation. No professional electrician wiring skills are required, and ordinary personnel can quickly get started, making it suitable for convenient testing scenarios of everyday socket circuits.

[0011] As a preferred embodiment of the present invention, after completing step S2, the test instrument performs a test leakage current state, and the COM terminal of the main control module is connected through the common terminal C and normally closed terminal NC of the test switch to form a short-circuit circuit with the load element.

[0012] In step S3, pressing the test switch connects the common terminal C of the test switch to the normally open terminal NO, thus connecting the load element to the circuit under test to form a loop and generate simulated leakage current. The mechanical switch enables rapid switching of the load loop, resulting in a simple and reliable structure. The load element can be either a resistor or a capacitor, adapting to the testing requirements of different circuit scenarios.

[0013] In a preferred embodiment of the present invention, after completing step S2, the testing instrument enters the leakage current test state. When the power switch is pressed, the main control module transmits a PWM signal to the thyristor via an optocoupler, causing the load resistor connected between the first and second test terminals to form a loop with the circuit under test, generating a simulated leakage current. Precise control of the load connection is achieved through electronic components. The PWM signal can adjust the leakage current magnitude to accommodate leakage current protectors of different sensitivities. The optocoupler provides signal isolation, enhancing the safety of the testing process.

[0014] In a preferred embodiment of the present invention, in step S4, while the display module displays the test results, the prompting module of the testing instrument also prompts the test status. This achieves dual visual and auditory prompts, avoiding misjudgments of test results due to ignoring information on the display screen, and improving the accuracy and intuitiveness of the test.

[0015] A testing instrument for implementing the method of directly testing a residual current device (RCD) in a circuit includes first and second test terminals, and also includes a main control module.

[0016] A voltage sampling module electrically connected to the main control module is used to collect the voltage of the circuit under test;

[0017] The analog test module, which is electrically connected to the main control module, is used to connect the load element to the circuit under test to form a loop and generate a simulated leakage current.

[0018] The system also includes a display module and a prompt module electrically connected to the main control module. The voltage sampling module is responsible for voltage acquisition, the analog test module generates leakage current, the main control module coordinates signal analysis and command transmission, and the display and prompt modules synchronously provide test information. All modules work together to complete the entire testing process. This achieves integrated testing functionality, requiring no additional equipment, and is compact, portable, and suitable for rapid on-site testing scenarios.

[0019] In a preferred embodiment of the present invention, the voltage sampling module is composed of several resistors connected in series. One end of the voltage sampling module is connected to the first test terminal, and the other end is connected to the control terminal P1 of the main control module. The series resistor structure is simple and low in cost. It adopts the principle of resistor voltage division to convert high voltage into a low voltage signal that the main control module can process. The voltage signal sampling is stable and compatible with the integrated design of multimeters and clamp meters, without the need for additional complex sampling components.

[0020] In a preferred embodiment of the present invention, the simulation test module includes a test switch and a load element. The normally open terminal (NO) of the test switch is electrically connected to the first test terminal. The common terminal (C) of the test switch is electrically connected to the second test terminal and the COM terminal of the main control module via the load element. The normally closed terminal (NC) of the test switch is electrically connected to the COM terminal of the main control module. The load element is a load resistor or a load capacitor, offering strong compatibility and adaptability for sensitivity testing of different leakage current circuit breakers. By switching the state of the test switch, the load element can be connected and disconnected, generating a simulated leakage current. The operation is simple and convenient.

[0021] In a preferred embodiment of the present invention, the simulation test module includes an optocoupler, a thyristor, a power switch, and a load element. The power switch is electrically connected to the signal input terminal of the main control module and is used to trigger a test signal. The input terminal of the optocoupler is electrically connected to the PWM signal output terminal of the main control module. The control electrode of the thyristor is electrically connected to the output terminal of the optocoupler. The anode of the thyristor is connected in series with a load resistor RL and then connected to the first test terminal. The cathode of the thyristor is electrically connected to the second test terminal and the COM terminal of the main control module. The load element is a load resistor. The MCU outputs a PWM signal, which triggers the thyristor through optocoupler isolation, causing RL to be connected to the circuit and generating a simulated leakage current. The main control module outputs a PWM signal, which triggers the thyristor through optocoupler isolation, causing the load resistor to be connected to the circuit and generating a simulated leakage current.

[0022] In a preferred embodiment of the present invention, the device is integrated into a multimeter or clamp meter, and further includes a wireless communication module, which is any one or more of WIFI, Bluetooth, 3G, 4G, 5G, or 6G communication modules. This adds leakage current testing functionality to the existing structure of a multimeter or clamp meter, achieving a multi-functional integrated design that eliminates the need for additional dedicated testing instruments, thus improving ease of use. Test results can be transmitted to terminal devices (such as mobile phones or computers) via the wireless communication module, enabling data storage and remote viewing.

[0023] In a preferred embodiment of the present invention, the main control module uses HC32F460, STM32F407, SD2830, or DM1107 series chips. Mature, mass-produced chip models are selected, ensuring stable performance and fast processing speed. The main control module is responsible for receiving voltage sampling signals, analyzing connection status, sending PWM control signals, processing test results, and driving the display and prompt modules.

[0024] The optocoupler can be either MOC3052 or TLP160. It enables signal isolation transmission between the main control module and the thyristor, avoiding control signal distortion caused by circuit interference and ensuring the accuracy of the thyristor's on / off state.

[0025] The thyristor can be any of the models such as Q4004D or Q4004LT. The thyristor conducts upon triggering, allowing current to flow through the load resistor and generating leakage current. Precise control of the load resistor's connection and disconnection ensures that the generated simulated leakage current remains stable and meets the required standards.

[0026] The prompting module is a buzzer, which is low-cost, consumes little power, and provides clear prompts, making it suitable for the design requirements of portable instruments. The main control module drives the buzzer to emit prompts, simultaneously displaying feedback information from the display module. The audible prompts are intuitive, eliminating the need to look directly at the display module; for example, a long beep indicates a fault, and a short beep indicates normal operation, enhancing the interactive experience during testing.

[0027] The display module is an LCD screen, which has low power consumption and clear display. It can be adapted to the miniaturized design of multimeters and clamp meters and is used to display information such as voltage and test status.

[0028] The beneficial effects of this invention are as follows: The method for directly testing a residual current device (RCD) in a circuit is simple to operate and easy to implement. It involves directly connecting the first and second test terminals (such as test leads) of a testing instrument to the live and ground wires of the circuit under test. Then, a load component is connected to the circuit under test via a simulation test module to generate a simulated leakage current to test the RCD and the circuit. If the RCD trips, the RCD and circuit connection are considered normal; otherwise, a fault is identified. This effectively solves the problem that traditional methods can only test the RCD itself and cannot verify the circuit connection, achieving simultaneous detection of the RCD and the circuit connection, thus eliminating safety hazards. The testing instrument provided by this invention can be integrated into a multimeter or clamp meter, achieving a multi-functional integrated design. It eliminates the need to carry additional dedicated testing instruments, is compact and portable, and is suitable for rapid on-site testing scenarios, bringing convenience to users. Attached Figure Description

[0029] Figure 1 is a circuit schematic diagram of Embodiment 1 of the present invention.

[0030] Figure 2 is a schematic diagram of the structure of Embodiment 1 of the present invention applied to a first type of multimeter.

[0031] Figure 3 is a schematic diagram of the structure of Embodiment 1 of the present invention applied to a second type of multimeter.

[0032] Figure 4 is a schematic diagram of the structure of Embodiment 1 of the present invention applied to a third type of multimeter.

[0033] Figure 5 is a schematic diagram of the structure of Embodiment 1 of the present invention applied to the first type of clamp meter.

[0034] Figure 6 is a schematic diagram of the structure of Embodiment 1 of the present invention applied to the second type of clamp meter.

[0035] Figure 7 is a schematic diagram of the structure of Embodiment 1 of the present invention applied to the third type of clamp meter.

[0036] Figure 8 is a schematic diagram of the structure of Embodiment 1 of the present invention applied to the fourth type of clamp meter.

[0037] Figure 9 is a circuit schematic diagram of Embodiment 2 of the present invention. Detailed Implementation

[0038] Example 1: Referring to Figures 1-8, this example provides a method and testing instrument for directly testing a residual current device (RCD) in a circuit.

[0039] The testing instrument includes a first test terminal 1, a second test terminal 2, a main control module 3, an analog test module 4, a display module 5, a prompt module 6, a wireless communication module 7, and a voltage sampling module 8. The wireless communication module 7 can be any one or more of WIFI, Bluetooth, 3G, 4G, 5G, or 6G communication modules. Test results can be transmitted to terminal devices (such as mobile phones or computers) via the wireless communication module 7 for data storage and remote viewing.

[0040] The main control module 3 is responsible for receiving voltage sampling signals, analyzing connection status, sending PWM control signals, processing test results, and driving the display and prompt module 6. The main control module 3 preferably uses HC32F460, STM32F407, SD2830, or DM1107 series chips. Mature, mass-produced chip models are selected, ensuring stable performance and fast processing speed.

[0041] The voltage sampling module 8 is electrically connected to the main control module 3 and is used to collect the voltage of the circuit under test. In this embodiment, the voltage sampling module 8 consists of several resistors connected in series, specifically three resistors: resistors R1, R2, and R3 are connected in series. One end of resistor R1 is connected to the first test terminal 1, and the other end of resistor R3 is connected to the control terminal P1 of the main control module 3. The series resistor structure is simple and low in cost. It uses the principle of resistor voltage division to convert high voltage into a low voltage signal that the main control module 3 can process. The voltage signal sampling is stable and compatible with the integrated design of multimeters and clamp meters, without the need for additional complex sampling components.

[0042] The simulation test module 4 is electrically connected to the main control module 3 and is used to connect the load element to the circuit under test to form a loop and generate a simulated leakage current.

[0043] In this embodiment, the simulation test module 4 includes a test switch 41 and a load element. The normally open terminal NO of the test switch 41 is electrically connected to the first test terminal 1. The common terminal C of the test switch 41 is electrically connected to the second test terminal 2 and the COM terminal of the main control module 3 via the load element. The normally closed terminal NC of the test switch 41 is electrically connected to the COM terminal of the main control module 3. The load element is either a load resistor RL or a load capacitor CL, offering strong compatibility and adaptability for sensitivity testing of different leakage current protectors. By switching the state of the test switch 41, the load element can be connected and disconnected, generating a simulated leakage current. The operation is simple and convenient.

[0044] The display module 5 and the prompting module 6 are electrically connected to the main control module 3. The prompting module 6 is preferably a buzzer, which is low-cost, consumes little power, and provides clear prompts, meeting the design requirements of portable instruments. The main control module 3 drives the buzzer to emit a prompt sound, simultaneously providing feedback information from the display module 5. The audible prompts are intuitive, eliminating the need to look directly at the display module 5; for example, a long beep indicates a fault, and a short beep indicates normal operation, improving the interactive experience during testing. The display module 5 is preferably an LCD screen, which consumes little power, provides clear display, and is compatible with the miniaturized design of multimeters and clamp meters, used to display information such as voltage and test status.

[0045] The testing instrument can be combined with a traditional multimeter or clamp meter. As shown in Figures 2, 3, and 4, it can be applied to different types of multimeters. As shown in Figures 5, 6, 7, and 8, it can be applied to different types of clamp meters. In other words, it adds leakage current testing functionality to the existing structure of a multimeter or clamp meter, achieving a multi-functional integrated design that eliminates the need for carrying additional dedicated testing instruments, thus providing convenience for users.

[0046] The testing process includes the following steps:

[0047] S1. Connect the first test terminal 1 and the second test terminal 2 of the testing instrument to the live wire and ground wire of the circuit under test, respectively. The first test terminal 1 and the second test terminal 2 of the testing instrument are preferably test probes. In step S1, the test probes of the testing instrument are inserted into the socket holes connected to the circuit under test. No additional wiring is required to connect the test terminals to the live wire and ground wire, simplifying the wiring operation. No professional electrician wiring skills are required, and ordinary personnel can quickly get started, making it suitable for convenient testing scenarios of everyday socket circuits.

[0048] S2. The voltage signal of the circuit under test is acquired by the voltage sampling module 8 in the test instrument and fed back to the main control module 3 in the test instrument. After the main control module 3 analyzes and processes the signal and confirms that the connection is normal, the voltage information is displayed by the display module 5 of the test instrument. After completing step S2, the test instrument is put into the test leakage state. The COM terminal of the main control module 3 is connected to the common terminal C and the normally closed terminal NC of the test switch to form a short circuit with the load element.

[0049] S3. Trigger the simulation test module 4 in the test instrument. The simulation test module 4 connects the load element to the circuit under test, thereby generating a simulated leakage current that can trigger the leakage current protector to trip. Specifically, in step S3, press the test switch 41, and connect the common terminal C of the test switch 41 to the normally open terminal NO, so as to connect the load element to the circuit under test to form a loop and generate a simulated leakage current. The load loop is quickly switched through a mechanical switch, which is simple and reliable. The load element can be selected as a resistor or capacitor to adapt to the test requirements of different circuit scenarios.

[0050] S4. If the residual current device (RCD) in the circuit under test trips, it is determined that the RCD and the circuit connection are normal; if it does not trip, it is determined that there is a fault, and the test results are displayed through the display module 5 and the test status is indicated through the prompt module 6.

[0051] Example 2: Referring to Figure 9, this example provides a method and testing instrument for directly testing a leakage current protection device in a circuit.

[0052] The testing instrument described herein is basically the same in structure as that in Example 1, except that the structure of the simulation testing module 4 is different and the testing method is also different. Specifically, the simulation testing module 4 includes an optocoupler OC, a silicon controlled rectifier T, an on / off switch S1, and a load element.

[0053] The on / off switch S1 is electrically connected to the signal input terminal of the main control module 3 and is used to trigger the test signal.

[0054] The input terminal of the optocoupler OC is electrically connected to the PWM signal output terminal of the main control module 3. The optocoupler OC can be either MOC3052 or TLP160. This achieves signal isolation transmission between the main control module 3 and the SCR T, avoiding control signal distortion caused by circuit interference and ensuring the accuracy of the SCR T's on / off state.

[0055] The control electrode of the thyristor T is electrically connected to the output terminal of the optocoupler OC. The thyristor T is preferably any one of models such as Q4004D or Q4004LT. The thyristor T conducts under a trigger signal, allowing current to flow through the load resistor and generating leakage current. Precise control of the connection and disconnection of the load resistor ensures that the generated simulated leakage current is stable and meets the required standards.

[0056] The anode of the thyristor T is connected in series with the load resistor RL and then connected to the first test terminal 1. The cathode of the thyristor T is electrically connected to the second test terminal 2 and the COM terminal of the main control module 3. The load element is the load resistor RL. The MCU outputs a PWM signal, which triggers the thyristor through optocoupler isolation, causing the load resistor RL to be connected to the circuit, generating a simulated leakage current. The main control module 3 outputs a PWM signal, which triggers the thyristor through optocoupler isolation, causing the load resistor to be connected to the circuit, generating a simulated leakage current.

[0057] The testing process includes the following steps:

[0058] S1. Connect the first test terminal 1 and the second test terminal 2 of the testing instrument to the live wire and ground wire of the circuit under test respectively; the first test terminal 1 and the second test terminal 2 of the testing instrument are preferably test pens. In step S1, the test pens of the testing instrument are inserted into the sockets connected to the circuit under test.

[0059] S2. The voltage signal of the circuit under test is acquired by the voltage sampling module 8 in the test instrument and fed back to the main control module 3 in the test instrument. After the main control module 3 analyzes and processes the signal and confirms that the connection is normal, the voltage information is displayed by the display module 5 of the test instrument.

[0060] S3. Trigger the simulation test module 4 in the test instrument. The simulation test module 4 connects the load element to the circuit under test to generate a simulated leakage current that can trigger the leakage current protector to trip. Specifically, after completing step S2, the test instrument enters the leakage current test state. Press the start switch S1. The main control module 3 sends a PWM signal to the thyristor through the optocoupler OC, so that the load resistor is connected between the first test terminal 1 and the second test terminal 2 to form a loop with the circuit under test to generate a simulated leakage current.

[0061] S4. If the residual current device (RCD) in the circuit under test trips, it is determined that the RCD and the circuit connection are normal; if it does not trip, it is determined that there is a fault, and the test results are displayed through the display module 5 and the test status is indicated through the prompt module 6.

[0062] The test instrument in Example 2 achieves precise control of load connection through electronic components. The PWM signal can adjust the leakage current and adapt to leakage current protectors with different sensitivities. Compared with the test instrument in Example 1, it has a wider range of applications and greater flexibility.

[0063] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention. Other instruments or methods obtained using the same or similar structures as described in the above embodiments of the present invention are all within the protection scope of the present invention.

Claims

1. A method for directly testing a residual current device (RCD) in a circuit, characterized in that, It includes the following steps: S1. Connect the first and second test terminals of the test instrument to the live wire and ground wire of the circuit under test, respectively; S2. Collect the voltage signal of the circuit under test through the voltage sampling module in the test instrument and feed it back to the main control module in the test instrument. After the main control module analyzes and processes the signal and confirms that the connection is normal, display the voltage information through the display module of the test instrument; S3. Trigger the simulation test module in the test instrument. The simulation test module connects the load element to the circuit under test to generate a simulated leakage current that can trigger the leakage current protection device to trip. S4. If the residual current device (RCD) in the circuit under test trips, it is determined that the RCD and the wiring connection are normal. If the circuit breaker does not trip, a fault is determined to exist, and the test results are displayed on the display module.

2. The method for directly testing a leakage current protection device in a circuit according to claim 1, characterized in that, The first and second test terminals of the testing instrument are test pens. In step S1, the test pens of the testing instrument are inserted into the sockets connected to the circuit under test.

3. The method for directly testing a leakage current protection device in a circuit according to claim 1, characterized in that, After completing step S2, the test instrument is in the state of leakage current under test. The COM terminal of the main control module is connected to the common terminal C and the normally closed terminal NC of the test switch to form a short-circuit circuit with the load element. In step S3, the test switch is pressed, and the common terminal C of the test switch is connected to the normally open terminal NO to form a circuit and generate a simulated leakage current.

4. The method for directly testing a residual current device (RCD) in a circuit according to claim 1, characterized in that, After completing step S2, the test instrument enters the leakage current test state. When the power switch is pressed, the main control module sends a PWM signal to the thyristor through the optocoupler, so that the load resistor is connected between the first test terminal and the second test terminal to form a loop with the circuit under test to generate a simulated leakage current.

5. The method for directly testing a residual current device (RCD) in a circuit according to any one of claims 1-4, characterized in that, In step S4, while the display module displays the test results, the test status is also indicated by the prompting module of the test instrument.

6. A testing instrument for implementing the method of directly testing a residual current device (RCD) in a circuit as described in any one of claims 1-5, comprising a first and a second test terminal, characterized in that, It also includes a main control module, a voltage sampling module electrically connected to the main control module for collecting the voltage of the circuit under test, an analog test module electrically connected to the main control module for connecting load elements to the circuit under test to form a loop and generate simulated leakage current, and a display module and a prompt module electrically connected to the main control module.

7. The testing instrument according to claim 6, characterized in that, The voltage sampling module is composed of several resistors connected in series. One end of the voltage sampling module is connected to the first test terminal, and the other end is connected to the control terminal P1 of the main control module.

8. The testing instrument according to claim 6, characterized in that, The simulation test module includes a test switch and a load element. The normally open terminal NO of the test switch is electrically connected to the first test terminal. The common terminal C of the test switch is electrically connected to the second test terminal and the COM terminal of the main control module through the load element. The normally closed terminal NC of the test switch is electrically connected to the COM terminal of the main control module. The load element is a load resistor or a load capacitor.

9. The testing instrument according to claim 6, characterized in that, The simulation test module includes an optocoupler, a thyristor, a power switch, and a load element. The power switch is electrically connected to the signal input terminal of the main control module and is used to trigger the test signal. The input terminal of the optocoupler is electrically connected to the PWM signal output terminal of the main control module. The control electrode of the thyristor is electrically connected to the output terminal of the optocoupler. The anode of the thyristor is connected in series with the load resistor RL and then connected to the first test terminal. The cathode of the thyristor is electrically connected to the second test terminal and the COM terminal of the main control module. The load element is a load resistor.

10. The testing instrument according to any one of claims 6-9, characterized in that, It is integrated into a multimeter or clamp meter, and also includes a wireless communication module, which is any one or more of the following: WIFI, Bluetooth, 3G, 4G, 5G or 6G communication modules.

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