Direct-current air switch and insulation reduction fault prompting method thereof

Abstract

The invention relates to a direct-current air switch and an insulation reduction fault prompting method thereof. The direct-current air switch comprises a direct-current air switch assembly and further comprises an input assembly arranged at the top of the direct-current air switch assembly, an output assembly is installed at the position, opposite to the input assembly, of the bottom of the direct-current air switch assembly, and an installation assembly is arranged on the back of the direct-current air switch assembly. The beneficial effects of the invention are that the micro insulation resistance sensors are installed on the outer side walls of the input binding post of the input assembly and the output binding post of the output assembly, and the sensor main bodies are embedded into the grooves preset in the top and bottom of the protective sleeve shell, so that the detection probes are attached to the binding posts to collect insulation resistance data in real time; the insulation state of a key conductive part is continuously and accurately monitored, sensor data are received through the signal processing module in the center of the interior of the protective sleeve shell, the processed sensor data are compared with a preset insulation threshold value, an early warning or fault tripping signal is generated, the fault level can be accurately distinguished, a corresponding mechanism is triggered, and errors caused by traditional manual judgment are avoided.

Description

Technical Field

[0001] This invention relates to the field of DC air switch technology, specifically to a DC air switch and a method for indicating insulation degradation faults. Background Technology

[0002] An air circuit breaker is an electrical component used in circuit systems to control the on / off state of a circuit and provide fault protection. It can manually or automatically connect or disconnect the circuit according to the circuit's operating status. In case of overload, short circuit, or other abnormal conditions, it can cut off the circuit through its internal protection mechanism, thereby preventing damage to the lines, electrical equipment, and personnel caused by overload or short circuit. The DC air circuit breaker mentioned in this document is specifically designed for DC circuit scenarios and has on / off control and basic protection functions for DC circuits. It is a key component for ensuring electrical safety in DC circuit systems.

[0003] However, in general, existing circuit breaker insulation degradation fault indications usually require staff to use portable testing instruments to periodically perform offline testing on the insulation resistance of the circuit breaker and related circuits. When the test data shows abnormal insulation resistance, staff need to manually check each connection point or circuit that may have insulation degradation problems. This operation method not only cannot keep track of changes in insulation status in real time, but also the fault location process is cumbersome and time-consuming, making it difficult to quickly and accurately find the source of the fault. At the same time, if the staff makes a mistake in judgment or operates improperly during the fault investigation and handling, there may be a situation where the fault is not completely eliminated before the circuit is manually closed, which may lead to secondary circuit faults or safety risks.

[0004] Based on this, the present invention provides a DC air switch and a method for indicating insulation degradation faults, in order to solve the aforementioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a DC air switch and a method for indicating insulation degradation faults, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention proposes a DC air circuit breaker, including a DC air circuit breaker assembly, an input assembly disposed on the top of the DC air circuit breaker assembly, an output assembly mounted on the bottom of the DC air circuit breaker assembly opposite to the input assembly, a mounting assembly disposed on the back of the DC air circuit breaker assembly, and a protective housing. A limit groove is formed on the front of the protective housing, and a tripping operation handle is mounted on each side of the limit groove. A main switch operation handle is mounted between the two tripping operation handles, and both the tripping operation handles and the main switch operation handle are rotatably connected to the protective housing.

[0007] Preferably, the mounting assembly includes two vertical slots on the top of the back of the protective housing, a T-shaped slot on the protective housing between the two vertical slots, and a horizontal slot on the protective housing at the bottom of the T-shaped slot and the vertical slots.

[0008] Preferably, the input component includes several input wiring ports opened on the top of the protective housing, and each input wiring port is threaded with an input terminal on one side of the protective housing. The output component includes several output wiring ports opened on the bottom of the protective housing, and each output wiring port is threaded with an output terminal on one side of the protective housing. The number of each input terminal and input wiring port, as well as the number of each output terminal and output wiring port, is the same as the number of tripping operation handles and main switch operation handles provided on the protective housing. A miniature insulation resistance sensor is fixed to the outer wall of each input terminal and the outer wall of each output terminal by means of a threaded connection.

[0009] This invention also proposes a method for indicating insulation degradation faults in DC air switches. The method is implemented based on a signal processing module and a wireless communication module, and includes the following steps: S1. Install the insulation monitoring sensor assembly; S2. Lay out and fix signal transmission lines; S3. Set insulation thresholds and signal processing rules; S4. Set local sound and light effects and trigger the indicator; S5. Upload and locate remote fault information; S6. Implement the fault linkage main switch disconnection operation.

[0010] Preferably, the implementation steps of step S1 are as follows: A miniature insulation resistance sensor is fixed to the outer wall of each input terminal of the input component and the outer wall of each output terminal of the output component via a threaded connection. The sensor body is embedded in the preset mounting grooves at the top and bottom of the protective housing. Its detection probe is in close contact with the surface of the terminal to collect the insulation resistance data between the terminal and the protective housing in real time. The power supply of the sensor is connected to the built-in power supply of the air switch through the reserved line inside the protective housing.

[0011] Preferably, the implementation steps of step S2 are as follows: the sensor signal cables corresponding to each input terminal are introduced into the protective housing through the wiring channel inside the input wiring port of the input component, and the sensor signal cables corresponding to each output terminal are introduced into the protective housing through the wiring channel inside the output wiring port of the output component; all signal cables are fixed along the slots preset on the inner wall of the protective housing, the outer layer of the cables is wrapped with flame-retardant insulating sleeves, and finally converge and are inserted into the signal processing module interface in the center of the protective housing.

[0012] Preferably, the implementation steps of step S3 are as follows: the insulation resistance warning threshold (e.g., ≤2MΩ) and the fault threshold (e.g., ≤1MΩ) are preset through the configuration port of the signal processing module; the signal processing module receives the insulation resistance data transmitted by each sensor in real time, performs filtering and noise reduction processing on the data, and compares it with the preset threshold; when the insulation resistance value of a certain input terminal or output terminal is detected to be lower than the warning threshold, a warning signal is generated; when it is lower than the fault threshold, a fault trip signal is generated.

[0013] Preferably, the implementation steps of step S4 are as follows: after the signal processing module generates the warning signal, it controls the yellow warning indicator light on the left side of the front limit groove of the protective casing to flash, and at the same time drives the buzzer to emit an intermittent warning sound; after generating the fault trip signal, it controls the red fault indicator light on the right side of the front limit groove of the protective casing to stay on, and the buzzer emits a continuous alarm sound.

[0014] Preferably, step S5 is implemented as follows: a wireless communication module is fixed in the T-shaped slot of the mounting component with bolts. The module is connected to the signal processing module via a data cable, and the antenna of the wireless communication module extends through the reserved hole at the top of the vertical slot of the mounting component. When an insulation degradation fault is detected, the signal processing module transmits the fault information (including fault type, fault terminal number, real-time insulation resistance value, and fault occurrence time) to the wireless communication module. The module then uploads the information to the remote monitoring platform via a 4G / 5G network to achieve remote fault alerts and location.

[0015] Preferably, the implementation steps of step S6 are as follows: after the signal processing module generates the fault trip signal, it reserves a time delay of 0.5-1 seconds for manual intervention and outputs the tripping drive signal to the electromagnetic drive mechanism corresponding to the main switch operating handle. The electromagnetic drive mechanism pushes the main switch operating handle to rotate clockwise around the rotation connection point of the protective housing by a certain angle, so that the main switch operating handle switches from the closed position to the open position, thereby cutting off the main circuit of the DC air switch. After the main switch operating handle is turned to disconnect, the mechanical elastic button on the top of the main switch operating handle is triggered to pop out, preventing the main switch operating handle from being manually closed until the fault is cleared and the elastic button is manually reset; only after the elastic button is reset can the main switch operating handle be closed. Meanwhile, the signal processing module uploads the fault trip status to the remote monitoring platform via the wireless communication module.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes miniature insulation resistance monitoring sensors installed on the outer walls of the input terminals of the input component and the output terminals of the output component. The sensor body is embedded in a pre-set groove on the top and bottom of the protective housing, allowing the detection probe to be in contact with the terminals to collect insulation resistance data in real time. This enables continuous and accurate monitoring of the insulation status of key conductive parts. The sensor data is received by a signal processing module in the center of the protective housing, processed, and compared with a preset insulation threshold to generate an early warning or fault trip signal. This accurately distinguishes the fault level and triggers the corresponding mechanism, avoiding the errors of traditional manual judgment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the DC circuit breaker assembly structure of the present invention (top front). Figure 2 This is a schematic diagram of the output component structure of the present invention (lower front). Figure 3 This is a schematic diagram of the installation component structure of the present invention (top rear). Figure 4 This is a schematic diagram of the internal structure of the present invention; Figure 5 This is a flowchart of the insulation degradation fault indication method for DC air switch of the present invention.

[0018] Legend: 1. DC circuit breaker assembly; 11. Opening operation handle; 12. Main switch operation handle; 13. Protective housing; 14. Limit slot; 15. Yellow warning indicator light; 16. Red fault indicator light; 17. Flexible button; 2. Input component; 21. Input terminal block; 22. Input wiring port; 3. Output components; 31. Output terminals; 32. Output wiring ports; 4. Installation components; 41. Vertical slot; 42. T-shaped slot; 43. Horizontal slot.

[0019] 10. Shunt trip unit, 20. Release spring, 30. Linkage rod with locking hook, 40. Lever with locking hook, 50. Overcurrent trip unit, 60. Undervoltage trip unit, 70. Bimetallic thermal trip unit, 71. Resistance thermal wire, 80. Main contact, 90. Shaft, 100. Trip relay. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figures 1 to 4This invention proposes a DC air circuit breaker, including a DC air circuit breaker assembly 1, and an input assembly 2 disposed on the top of the DC air circuit breaker assembly 1. An output assembly 3 is installed at the bottom of the DC air circuit breaker assembly 1 opposite to the input assembly 2. An installation assembly 4 is disposed on the back of the DC air circuit breaker assembly 1. The DC air circuit breaker assembly 1 includes a protective housing 13. A limit groove 14 is formed on the front of the protective housing 13. A tripping operation handle 11 is installed on each side of the limit groove 14. A main switch operation handle 12 is installed between the two tripping operation handles 11. Both the tripping operation handles 11 and the main switch operation handle 12 are rotatably connected to the protective housing 13. In an optional embodiment, specifically, the mounting component 4 includes two vertical slots 41 formed on the top of the back of the protective housing 13, a T-shaped slot 42 formed on the protective housing 13 between the two vertical slots 41, and a horizontal slot 43 formed on the protective housing 13 at the bottom of the T-shaped slot 42 and the vertical slots 41. Please see Figures 1 to 3 In practical applications, the DC circuit breaker assembly 1 is installed in a suitable working position through the vertical slot 41, the T-shaped slot 42, or the horizontal slot 43.

[0022] In an optional embodiment, specifically, the input component 2 includes a plurality of input wiring ports 22 opened on the top of the protective housing 13, and each input wiring port 22 is threadedly connected to an input terminal 21 on one side of the protective housing 13. The output component 3 includes a plurality of output wiring ports 32 opened on the bottom of the protective housing 13, and each output wiring port 32 is threadedly connected to an output terminal 31 on one side of the protective housing 13. The number of each input terminal 21 and input wiring port 22, as well as the number of output terminal 31 and output wiring port 32, is the same as the number of trip operation handles 11 and main operation handles 12 provided on the protective housing 13. A miniature insulation resistance sensor is fixed to the outer wall of each input terminal 21 and the outer wall of each output terminal 31 by means of threaded connection.

[0023] The DC air circuit breaker contains, in sequence, a release spring 20, a main contact 80, a connecting rod 30 with a locking hook, and a lever 40 with a locking hook (hinged within the housing via a shaft 90). It also includes an overcurrent trip unit 50, an undervoltage trip unit 60, a bimetallic thermal trip unit 70 (interacting with a heating resistance wire 71 inside the air circuit breaker), and a shunt trip unit 10 (connected to a trip relay 100, controlled by a signal processing module, which in turn controls the shunt trip unit). An arc-extinguishing grid is also installed. The overcurrent trip unit 50 includes a movable armature and an electromagnet and spring acting upon it. The undervoltage trip unit 60 also includes a movable armature and an electromagnet and spring acting upon it. The shunt trip unit 10 includes a movable armature and an electromagnet and spring that act with it. The circuit of the shunt trip unit is connected to a trip relay 100. The trip relay is controlled by a fault trip signal issued by a signal processing module. The signal processing module receives signals from the miniature insulation resistance sensors corresponding to each output terminal and input terminal.

[0024] Under normal circumstances, the armature of the overcurrent trip unit is released. In the event of a severe overload or short circuit, the coil connected in series with the main circuit generates a strong electromagnetic force that pulls the armature downwards, opening the lever 40 with its locking hook and causing the main contacts to open. After the problem is resolved, the spring force resets the armature, thus resetting the lever and closing the main contacts. The undervoltage trip unit operates in the opposite way. When the voltage is normal, the electromagnetic force holds the armature, allowing the main contacts to close. If the voltage drops significantly or power is lost, the armature is released, causing the main contacts to open. After the problem is resolved, the spring force resets the armature, resetting the lever and closing the main contacts. When the power supply voltage returns to normal, the circuit breaker must be reset before the unit can operate, thus achieving undervoltage protection. When a general overload occurs in the circuit, although the overload current cannot cause the electromagnetic trip unit to operate, it can generate a certain amount of heat in the thermal element, causing the bimetallic strip to bend upwards and push the lever to disengage the hook from the latch, thus breaking the main contacts and cutting off the power supply. After the problem is resolved, the bimetallic strip straightens back to its original position, causing the lever hook to fall back to its original position and the main contacts to connect.

[0025] In the shunt trip circuit, under normal conditions, when power is off, the resilient button 17 is normally closed, and the contacts controlled by the trip relay 100 are normally open. When the trip relay receives a trip drive signal, its contacts close, energizing the circuit. The electromagnet of the shunt trip unit attracts the armature, causing the lever 40 with its locking hook to open, thus disconnecting the main contacts. The spring 20 rotates the operating handle of the main contacts, causing its connected mechanical mechanism to engage the resilient button 17, which then springs open, preventing the main contacts from resetting. After the problem is resolved, the contacts controlled by the trip relay reset open, the electromagnet of the shunt trip unit is de-energized, the armature resets, and the lever locking hook resets. Manually pressing the resilient button 17 closes it, allowing the main contacts to connect without obstruction. The resilient button 17 can be connected to this circuit or not; its main function is as a reset button to prevent the main contacts from closing.

[0026] In specific implementation, in practical applications, the present invention is based on a method for indicating insulation degradation faults using a DC air switch, specifically including the following steps: S1. Install the insulation monitoring sensor assembly; S2. Lay out and fix signal transmission lines; S3. Set insulation thresholds and signal processing rules; S4. Set local sound and light effects and trigger the indicator; S5. Upload and locate remote fault information; S6. Implement a fault-linked main switch disconnection operation; In an optional embodiment, specifically, step S1 is implemented as follows: On the outer wall of each input terminal 21 of input component 2 and the outer wall of each output terminal 31 of output component 3, a miniature insulation resistance sensor is fixed by threaded connection. The sensor body is embedded in the preset mounting grooves at the top and bottom of the protective housing 13. Its detection probe is in close contact with the surface of the terminal to collect the insulation resistance data between the terminal and the protective housing 13 in real time. The power supply terminal of the sensor is connected to the built-in power supply of the air switch through the reserved line inside the protective housing 13. The air switch has a built-in power supply and can be connected to a step-down circuit from the main circuit to provide ≤5V power to the sensor.

[0027] In an optional embodiment, step S2 is specifically implemented as follows: The sensor signal cables corresponding to each input terminal 21 are introduced into the protective housing 13 through the wire passage inside the input wiring port 22 of the input component 2, and the sensor signal cables corresponding to each output terminal 31 are introduced into the protective housing 13 through the wire passage inside the output wiring port 32 of the output component 3. All signal cables are fixed along the pre-set slots on the inner wall of the protective housing 13. The outer layer of the cables is wrapped with flame-retardant insulating sleeves, and finally converges and is inserted into the signal processing module interface in the center of the protective housing 13.

[0028] In an optional embodiment, step S3 is specifically implemented as follows: The insulation resistance warning threshold (e.g., ≤2MΩ) and fault threshold (e.g., ≤1MΩ) are preset through the configuration port of the signal processing module. The signal processing module receives the insulation resistance data transmitted by each sensor in real time, performs filtering and noise reduction on the data, and then compares it with the preset threshold. When the insulation resistance value of a certain input terminal 21 or output terminal 31 is detected to be lower than the warning threshold, a warning signal is generated. When the value falls below the fault threshold, a fault trip signal is generated.

[0029] In an optional embodiment, specifically, step S4 is implemented as follows: After the signal processing module generates a warning signal, it controls the yellow warning indicator 15 on the left side of the limit groove 14 on the front of the protective housing 13 to flash (there are a total of 6 yellow warning indicator lights, each numbered, and each indicator light indicates the sensor with its corresponding number and the insulation resistance of its corresponding terminal). At the same time, it drives the buzzer to emit an intermittent warning sound. After a fault trip signal is generated, the red fault indicator 16 on the right side of the limit groove 14 on the front of the control protective housing 13 remains constantly lit (there are a total of 6 red warning indicator lights, each numbered, with one indicator light indicating the sensor corresponding to its number and the insulation resistance of a certain terminal), and the buzzer emits a continuous alarm sound.

[0030] In an optional embodiment, step S5 is specifically implemented as follows: The wireless communication module is fixed in the T-shaped slot 42 of the mounting component 4 by bolts. The module is connected to the signal processing module via a data cable. The antenna of the wireless communication module extends through the reserved hole at the top of the vertical slot 41 of the mounting component 4. When an insulation degradation fault is detected, the signal processing module transmits the fault information (including fault type, fault terminal number, real-time insulation resistance value, and fault occurrence time) to the wireless communication module. The module then uploads the information to the remote monitoring platform via a 4G / 5G network, enabling remote fault alerts and location.

[0031] In an optional embodiment, step S6 is specifically implemented as follows: After the signal processing module generates a fault trip signal, it reserves a time for manual intervention and outputs a trip drive signal to the electromagnetic drive mechanism (shunt trip unit 10) corresponding to the main switch operating handle 12 after a delay of 0.5-1 seconds. The electromagnetic drive mechanism pushes the main switch operating handle 12 to rotate clockwise around the rotation connection point of the protective housing 13 by a certain angle, so that the main switch operating handle 12 switches from the closed position to the open position, cutting off the main circuit of the DC air switch. After the main switch operating handle 12 is turned to disconnect, the mechanical elastic button 17 on the top of the main switch operating handle 12 is triggered to pop out, making the main switch operating handle 12 unable to be manually closed until the fault is cleared and the elastic button is manually reset; the main switch operating handle can only be closed after the elastic button is reset. Meanwhile, the signal processing module uploads the fault trip status to the remote monitoring platform via the wireless communication module, and simultaneously displays the words "Insulation Fault - Tripped" on the status display screen on the front of the protective housing 13.

[0032] Through the above steps, this invention installs miniature insulation resistance monitoring sensors on the outer walls of the input terminals of the input component and the output terminals of the output component. The sensor body is embedded in a pre-set groove at the top and bottom of the protective housing, allowing the detection probe to fit against the terminal and collect insulation resistance data in real time, thus achieving continuous and accurate monitoring of the insulation status of key conductive parts. The sensor data is received by a signal processing module in the center of the protective housing, processed, and compared with a preset insulation threshold to generate an early warning or fault trip signal. This accurately distinguishes the fault level and triggers the corresponding mechanism, avoiding errors from traditional manual judgment. Yellow / red indicator lights and a buzzer on both sides of the limit groove on the front of the protective housing, combined with audible and visual prompts, simultaneously trigger the mechanical elastic button on the top of the main switch operating handle to lock the handle, providing a clear indication of the fault and preventing accidental closing of the circuit breaker before the fault is resolved, improving clarity and operational safety. A wireless communication module (connected to the signal processing module, with the antenna extending from the vertical slot) is bolted into the T-shaped slot of the installation component, uploading key fault information to a remote monitoring platform. This allows maintenance personnel to remotely monitor the situation in real time and accurately locate the fault, reducing manual troubleshooting time and workload. The electromagnetic drive mechanism corresponding to the main switch operating handle receives the opening command and pushes the handle to open the circuit. At the same time, the opening status is uploaded and displayed on the protective housing display screen, which can promptly cut off the main circuit to prevent the fault from escalating, allowing staff to know the status simultaneously and ensuring the safety of the circuit system.

[0033] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A direct current air switch comprising a DC air switch assembly (1), characterized in that, It also includes an input component (2) disposed on the top of the DC circuit breaker assembly (1), an output component (3) installed at the bottom of the DC circuit breaker assembly (1) opposite to the input component (2), an installation component (4) disposed on the back of the DC circuit breaker assembly (1), the DC circuit breaker assembly (1) includes a protective housing (13), a limit groove (14) is opened on the front of the protective housing (13), a tripping operation handle (11) is installed on each side of the limit groove (14), a main switch operation handle (12) is installed between the two tripping operation handles (11), and both the tripping operation handle (11) and the main switch operation handle (12) are rotatably connected to the protective housing (13).

2. A DC air switch according to claim 1 wherein, The mounting assembly (4) includes two vertical slots (41) on the top of the back of the protective housing (13), a T-shaped slot (42) is provided on the protective housing (13) between the two vertical slots (41), and a horizontal slot (43) is provided on the protective housing (13) at the bottom of the T-shaped slot (42) and the vertical slots (41).

3. A DC air switch according to claim 2 wherein, The input component (2) includes several input wiring ports (22) opened on the top of the protective housing (13). Each input wiring port (22) is threaded with an input terminal (21) on one side of the protective housing (13). The output component (3) includes several output wiring ports (32) opened on the bottom of the protective housing (13). Each output wiring port (32) is threaded with an output terminal (31) on one side of the protective housing (13). The number of each input terminal (21) and input wiring port (22), as well as the number of output terminal (31) and output wiring port (32), is the same as the number of trip operation handles (11) and main switch operation handles (12) provided on the protective housing (13). A miniature insulation resistance sensor is fixed to the outer wall of each input terminal (21) and the outer wall of each output terminal (31) by means of threaded connection.

4. The insulation degradation fault indication method applied to the DC air switch according to any one of claims 1-3, wherein the method is implemented based on a signal processing module and a wireless communication module, and characterized in that, Includes the following steps: S1. Install the insulation monitoring sensor assembly; S2. Lay out and fix signal transmission lines; S3. Set insulation thresholds and signal processing rules; S4. Set local sound and light effects and trigger the indicator; S5. Upload and locate remote fault information; S6. Implement the fault linkage main switch disconnection operation.

5. A DC air switch and its insulation degradation fault indication method according to claim 4, characterized in that, The implementation steps of step S1 are as follows: On the outer wall of each input terminal (21) of the input component (2) and on the outer wall of each output terminal (31) of the output component (3), a miniature insulation resistance sensor is fixed by a threaded connection. The sensor body is embedded in the preset mounting grooves at the top and bottom of the protective housing (13). Its detection probe is in close contact with the surface of the terminal to collect the insulation resistance data between the terminal and the protective housing (13) in real time. The power supply end of the sensor is connected to the built-in power supply of the air switch through the reserved line inside the protective housing (13).

6. The DC air switch and its insulation degradation fault indication method according to claim 5, characterized in that, The implementation steps of step S2 are as follows: the sensor signal cables corresponding to each input terminal (21) are introduced into the protective housing (13) through the wire passage inside the input wiring port (22) of the input component (2), and the sensor signal cables corresponding to each output terminal (31) are introduced into the protective housing (13) through the wire passage inside the output wiring port (32) of the output component (3); all signal cables are fixed along the slots preset on the inner wall of the protective housing (13), the outer layer of the cables is wrapped with flame-retardant insulating sleeves, and finally converge and insert into the signal processing module interface in the center of the protective housing (13).

7. A DC air switch and its insulation degradation fault indication method according to claim 6, characterized in that, The implementation steps of step S3 are as follows: the insulation resistance warning threshold and fault threshold are preset through the configuration port of the signal processing module; the signal processing module receives the insulation resistance data transmitted by each sensor in real time; the data is filtered and noise-reduced; and then compared with the preset threshold. When the insulation resistance value of a certain input terminal (21) or output terminal (31) is detected to be lower than the warning threshold, a warning signal is generated; When the value falls below the fault threshold, a fault trip signal is generated.

8. A DC air switch and its insulation degradation fault indication method according to claim 7, characterized in that, The implementation steps of step S4 are as follows: After the signal processing module generates the warning signal, it controls the yellow warning indicator (15) on the left side of the front limit groove (14) of the protective casing (13) to flash, and at the same time drives the buzzer to emit an intermittent prompt sound; after generating the fault trip signal, it controls the red fault indicator (16) on the right side of the front limit groove (14) of the protective casing (13) to stay on, and the buzzer emits a continuous alarm sound.

9. A DC air switch and its insulation degradation fault indication method according to claim 8, characterized in that, The implementation steps of step S5 are as follows: the wireless communication module is fixed in the T-shaped slot (42) of the mounting component (4) by bolts. The module is connected to the signal processing module by a data cable. The antenna of the wireless communication module extends through the reserved hole at the top of the vertical slot (41) of the mounting component (4). When an insulation reduction fault is detected, the signal processing module transmits the fault information (including fault type, fault terminal number, real-time insulation resistance value, and fault occurrence time) to the wireless communication module. The module uploads the information to the remote monitoring platform through the 4G / 5G network to realize remote fault reminder and location.

10. A DC air switch and its insulation degradation fault indication method according to claim 9, characterized in that, The implementation steps of step S6 are as follows: After the signal processing module generates the fault trip signal, it reserves a time delay of 0.5-1 seconds for manual intervention and outputs the trip drive signal to the electromagnetic drive mechanism corresponding to the main switch operating handle (12). The electromagnetic drive mechanism pushes the main switch operating handle (12) to rotate around the rotation connection point of the protective shell (13) by a certain angle, so that the main switch operating handle (12) switches from the closed position to the open position and cuts off the main circuit of the DC air switch. After the main switch operating handle (12) is turned off, the mechanical elastic button (17) on the top of the main switch operating handle (12) is triggered to pop out, making the main switch operating handle (12) unable to be manually closed until the fault is cleared and the elastic button is manually reset. Meanwhile, the signal processing module uploads the fault trip status to the remote monitoring platform via the wireless communication module.

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