Miniature residual-current circuit breaker
By adopting a dual-design approach combining electronic and electromagnetic leakage protection modules in miniature circuit breakers, along with transistor circuit boards and zero-sequence current transformers, the problems of temperature rise and insufficient breaking capacity of miniature circuit breakers under high current are solved, thereby improving high safety current carrying capacity and stability.
Patent Information
- Application Number
- CN202423074231.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2034-12-12
AI Technical Summary
Existing miniature residual current circuit breakers suffer from reduced temperature rise, insufficient breaking capacity, excessive weight, and inadequate safe current carrying capacity when the current exceeds 40A, leading to a decline in safety performance.
It adopts a two-in-one design of electronic and electromagnetic leakage protection modules, combined with transistor circuit board and zero-sequence current transformer, and enhances anti-interference performance through MOS layout mode, realizes multi-stage energy storage and concentric coaxial design, and improves breaking capacity and stability performance.
It achieves high safe current carrying capacity in a limited space, reduces standby power consumption, improves breaking capacity and operational stability, is suitable for lines with a rated current of 63A, and is compatible with various circuit breaker types.
Smart Images
Figure CN223552485U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of circuit breakers, and in particular to a miniature residual current circuit breaker. Background Technology
[0002] Miniature residual current circuit breakers (RCCBs) are small automatic switches used to protect circuits from overload and short-circuit damage. They are commonly used in power distribution systems in homes, commercial buildings, and industrial facilities. The main function of a miniature RCCB is to automatically cut off the power supply when it detects that the current exceeds a preset safety limit, thus preventing fires and other electrical accidents. Common RCCBs are classified into electronic and electromagnetic types.
[0003] In related technologies, a 1P+N residual current circuit breaker is a miniature circuit breaker, consisting of an L-pole breaking unit and an N-pole breaking unit. Currently, the current rating of the two modular 1P+N circuit breakers is basically limited to 40A. This means that when the current exceeds 40A, the existing modular 1P+N circuit breakers fail to meet safety requirements due to factors such as temperature rise, breaking capacity, excessive weight, and high standby power consumption. Their safe current carrying capacity cannot reach 63A. This is because the addition of a residual current tripping unit to the original two modular 1P+N circuit breakers overloads the components within the limited space. This overloading inevitably alters parameters related to safe current carrying capacity (such as creepage distance and arc-breaking distance), thus reducing the safe current carrying capacity.
[0004] In view of this, there is an urgent need to improve the structure of existing miniature residual current circuit breakers in order to adapt to different types of residual current circuit breakers and improve their breaking capacity. Utility Model Content
[0005] This application provides a miniature residual current circuit breaker that can adapt to different types of residual current circuit breakers while improving their breaking capacity.
[0006] The miniature residual current circuit breaker provided in this application adopts the following technical solution:
[0007] A miniature residual current circuit breaker includes an outer casing, the outer casing including a middle cover base, the middle cover base separating the outer casing into N pole and L pole;
[0008] The N pole is equipped with an N pole contact mechanism, a residual current protection mechanism, and an N pole tripping element; the residual current protection mechanism is used to sense the leakage current and control the N pole tripping element to trip, thereby driving the N pole contact mechanism to open the circuit breaker.
[0009] The L pole is equipped with an operating handle, an L pole contact mechanism, and an L pole tripping element. The operating handle is linked to the L pole tripping element. The L pole contact mechanism includes an L pole moving contact mounted on the L pole tripping element and an L pole stationary contact mounted inside the L pole. The L pole tripping element is used to drive the L pole moving contact and the L pole stationary contact to open / close. The L pole is also equipped with an overload protection mechanism and a short-circuit protection mechanism. Both the overload protection mechanism and the short-circuit protection mechanism are used to control the L pole tripping element to trip in order to drive the L pole contact mechanism to open.
[0010] The L-pole tripping component is provided with a trigger element, which extends into the N-pole. When the N-pole tripping component trips, the N-pole tripping component is used to push the trigger element to control the L-pole tripping component to trip.
[0011] A linkage shaft is also provided between the L-pole tripping component and the N-pole tripping component, and the L-pole tripping component drives the N-pole contact mechanism to open / close synchronously through the linkage shaft.
[0012] Preferably, the N-pole contact mechanism includes an N-pole moving contact and an N-pole stationary contact; a swing element is rotatably disposed inside the N-pole, and the N-pole moving contact is disposed on the swing element; one end of the swing element is linked to the linkage shaft, and an energy storage spring is disposed on the N-pole moving contact, the other end of which is disposed on the middle cover base; the energy storage spring is used to drive the N-pole moving contact to rotate away from the N-pole stationary contact.
[0013] Preferably, the rotation shaft of the N-pole tripping component is coaxial with the rotation shaft of the L-pole tripping component.
[0014] Preferably, the N-pole tripping component is provided with a return section, and a tripping lever is provided inside the N-pole between the residual current protection mechanism and the return section. One end of the tripping lever is rotatably mounted on the middle cover base. When the N-pole tripping component trips, the return section rotates with the N-pole tripping component and pushes the tripping lever to control the residual current protection mechanism to automatically return to its original position.
[0015] Preferably, the N-pole tripping component is rotatably provided with a locking latch and a tripping latch; an N-pole rotating shaft coaxial with the operating handle is rotatably provided inside the N-pole, and a connecting rod is provided between the N-pole rotating shaft and the locking latch; when the N-pole tripping component is in the closed state, the locking latch and the tripping latch are kept locked together under the force of the connecting rod; the tripping latch is opposite to the tripping lever, and when the residual current protection mechanism detects leakage current, the residual current protection mechanism pushes the tripping latch to disengage from the locking latch through the tripping lever, at which time the N-pole tripping component is in the disengaged state.
[0016] Preferably, the N-pole tripping component is provided with a reset lever opposite to the trigger component. When the N-pole tripping component trips, the reset lever is used to push the trigger component to control the L-pole tripping component to trip; when the L-pole tripping component closes, the trigger component is used to push the reset lever to control the N-pole tripping component to close.
[0017] Preferably, the residual current protection mechanism is an electronic leakage current protection module or an electromagnetic leakage current protection module.
[0018] In summary, this application includes at least one of the following beneficial technical effects:
[0019] The electronic leakage current protection module and the electromagnetic leakage current protection module occupy the same module size. The overall product size is small, and the two functions of electronic and electromagnetic can be realized in a length of only 81.5mm. It is widely applicable to the assembly of electronic and electromagnetic leakage current protection modules, which reduces costs.
[0020] Suitable for AC 230V / 400V, 50Hz / 60Hz circuits with rated current up to 63A, featuring overload, short circuit and residual current protection functions;
[0021] The transistor circuit board adopts a MOS layout mode, and enhances the ESD effect through integrated chips, improving its anti-interference performance and line stability to reach EMC 4KV, reducing the standby power consumption of the miniature leakage circuit breaker, which is superior to similar products on the market.
[0022] It achieves multi-stage energy storage and a multi-stage concentric and coaxial design, ensuring the product's synchronization performance, improving the product's breaking capacity and stable operation, and also effectively improving the product's temperature rise.
[0023] The outer casing 1 is also compatible with the installation of similar circuit breaker products of class 63A, 1P+N, 2P, 3P, 3P+N, 4P, etc. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the overall structure of the 1P+N dual-handle system of this application;
[0025] Figure 2 This is a schematic diagram of the overall structure of the 3P+N single handle of this application;
[0026] Figure 3 yes Figure 1 A schematic diagram highlighting the local structure of the L pole;
[0027] Figure 4 yes Figure 1 A schematic diagram highlighting the local structure of the N pole;
[0028] Figure 5 yes Figure 4A partial structural diagram of the L-pole tripping element and the N-pole tripping element;
[0029] Figure 6 yes Figure 5 A schematic diagram highlighting the partial structure at the L-pole tripping component and the linkage shaft;
[0030] Figure 7 This is a schematic diagram of the overall structure of the 4P single handle of this application;
[0031] Figure 8 This is a schematic diagram of the overall structure of the 1P+N single handle of this application.
[0032] Explanation of reference numerals in the attached drawings: 1. Outer shell; 10. Middle cover base; 11. Linkage shaft; 2. N pole contact mechanism; 20. N pole moving contact; 21. N pole stationary contact; 22. Swinging component; 23. Energy storage tension spring; 3. Residual current protection mechanism; 4. N pole tripping component; 40. Return part; 41. Tripping lever; 42. Lock; 43. Jumping component; 44. N pole rotating shaft; 440. Reset lever; 45. Connecting rod; 5. Operating handle; 6. L pole contact mechanism; 60. L pole moving contact; 61. L pole stationary contact; 7. L pole tripping component; 70. Trigger; 8. Overload protection mechanism; 80. Bimetallic strip; 81. Push plate; 9. Short circuit protection mechanism; 90. Short circuit tripping device. Detailed Implementation
[0033] The present application will be further described in detail below with reference to the accompanying drawings.
[0034] This application discloses a miniature residual current circuit breaker.
[0035] Reference Figure 1 This is a schematic diagram of the overall structure of the miniature residual current circuit breaker assembled in this application. Figure 2 This is a schematic diagram of the overall structure of the miniature residual current circuit breaker (RCCB) assembled within the 3P+N single-handle unit of this application. It includes a housing 1, which includes a middle cover base 10 that separates the interior of the housing 1 into the N and L poles. The miniature RCCB of this application is mainly suitable for AC 230V / 400V, 50Hz / 60Hz circuits with a rated current up to 63A, and features overload, short-circuit, and residual current protection functions.
[0036] like Figure 3 , Figure 4 As shown, the N pole is equipped with an N pole contact mechanism 2, a residual current protection mechanism 3, and an N pole tripping component 4. The residual current protection mechanism 3 is an electronic leakage current protection module or an electromagnetic leakage current protection module.
[0037] The electronic leakage current protection module includes a zero-sequence current transformer, a transistor circuit board, and a trip unit. The zero-sequence current transformer, made of microcrystalline material, is used to detect leakage current. The transistor circuit board adopts a MOS layout, enhancing ESD performance through integrated chips, improving its anti-interference performance and line stability to EMC 4KV, and reducing the standby power consumption of the miniature leakage current circuit breaker, which is superior to similar products on the market. The transistor circuit board is electrically connected to the zero-sequence current transformer, and is used to receive and amplify the leakage current to generate an operating signal. The trip unit receives the operating signal and drives the N-pole trip element 4 to complete the tripping action.
[0038] The electromagnetic leakage current protection module includes a zero-sequence current transformer and an electromagnetic leakage current trip unit. The electromagnetic leakage current trip unit generates an operating electrical signal based on the leakage current detected by the zero-sequence current transformer and drives the N-pole trip unit 4 to complete the tripping action.
[0039] Electronic and electromagnetic leakage current protection modules occupy the same module size, resulting in a small overall product size. The combined electronic and electromagnetic functions can be achieved in a length of only 81.5mm, making it widely applicable to the assembly of electronic and electromagnetic leakage current protection modules and reducing costs.
[0040] like Figure 5 , Figure 6 As shown, the L-pole contains an operating handle 5, an L-pole contact mechanism 6, and an L-pole tripping element 7. Both the operating handle 5 and the L-pole tripping element 7 are rotatably mounted within the L-pole. One end of the operating handle 5 extends outside the outer casing 1, and the operating handle 5 and the L-pole tripping element 7 are linked together. The L-pole contact mechanism 6 includes an L-pole moving contact 60 fixedly mounted on the L-pole tripping element 7 and an L-pole stationary contact 61 fixedly mounted within the L-pole. The L-pole moving contact 60 is hot-riveted.
[0041] like Figure 5 , Figure 6 As shown, the L-pole trip unit 7 is used to drive the L-pole moving contact 60 and the L-pole stationary contact 61 to open / close. A reset torsion spring is provided on the L-pole trip unit 7. When the L-pole trip unit 7 trips and opens, the reset torsion spring drives the L-pole trip unit 7 to rotate the L-pole moving contact 60 away from the L-pole stationary contact 61. At this time, the L-pole contact mechanism 6 remains in the open state. When the L-pole trip unit 7 is closed by rotating the operating handle 5, the L-pole trip unit 7 will rotate in a direction that overcomes the torque of the reset torsion spring until the L-pole moving contact 60 rotates to maintain contact with the L-pole stationary contact 61. At this time, the L-pole contact mechanism 6 remains in the closed state.
[0042] like Figure 3As shown, the L pole also includes an overload protection mechanism 8 and a short-circuit protection mechanism 9. Both the overload protection mechanism 8 and the short-circuit protection mechanism 9 are used to push the L pole tripping element 7 to trip, thereby opening the L pole contact mechanism 6. The overload protection mechanism 8 includes a bimetallic strip 80 for electrical connection with an external line and a push plate 81 mounted on the L pole tripping element 7. The bimetallic strip 80 is composed of two metal materials with different coefficients of thermal expansion tightly bonded together. When current passes through the bimetallic strip 80, if the current exceeds the set safety range, the generated heat will cause the bimetallic strip 80 to bend and deform due to the greater thermal expansion of one side of the metal compared to the other side. The push plate 81 is located on the bending deformation path of the bimetallic strip 80. When an overload occurs in the circuit, as the bimetallic strip 80 bends, it pushes the push plate 81, causing the L pole tripping element 7 to trip and open the circuit. Once the fault is cleared and the bimetallic strip 80 cools down, it will return to its original shape.
[0043] like Figure 3 As shown, the short-circuit protection mechanism 9 includes a short-circuit tripping device 90. The working principle of the short-circuit tripping device 90 is based on the electromagnetic effect. It contains an electromagnetic coil, a push rod, and a spring. When the current suddenly increases to above the set threshold, the coil generates a strong magnetic field. The force of this magnetic field is sufficient to drive the push rod to overcome the resistance of the spring. As the push rod pushes outward, it will push the L-pole tripping piece 7 to quickly trip. At this time, the L-pole contact mechanism 6 will quickly open the circuit, thereby cutting off the circuit and realizing short-circuit protection.
[0044] like Figure 5 , Figure 6 As shown, the L-pole tripping component 7 is equipped with a trigger element 70, one end of which passes through the middle cover base 10 and extends into the N-pole. When the N-pole tripping component 4 trips, the N-pole tripping component 4 pushes the trigger element 70 to control the L-pole tripping component 7 to trip synchronously. A linkage shaft 11 is also provided between the L-pole tripping component 7 and the N-pole tripping component 4, and the L-pole tripping component 7 drives the N-pole contact mechanism 2 to open / close synchronously through the linkage shaft 11.
[0045] like Figure 5 , Figure 6 As shown, the N-pole contact mechanism 2 includes an N-pole moving contact 20 and an N-pole stationary contact 21 arranged opposite to each other. A swing member 22 is rotatably arranged inside the N-pole, and the N-pole moving contact 20 is fixedly arranged on the swing member 22. One end of the swing member 22 is rotatably arranged on the linkage shaft 11, and the end of the linkage shaft 11 away from the swing member 22 is arranged on the L-pole tripping member 7.
[0046] like Figure 4 , Figure 5 as well as Figure 6As shown, an energy storage spring 23 is provided on the N-pole moving contact 20. One end of the energy storage spring 23 is connected and fixed to the N-pole moving contact 20, and the other end of the energy storage spring 23 is fixedly mounted on the middle cover base 10. The energy storage spring 23 is used to drive the N-pole moving contact 20 to rotate away from the N-pole stationary contact 21. The rotation shaft of the N-pole tripping component 4 is coaxial with the rotation shaft of the L-pole tripping component 7. Under the action of the energy storage spring 23, the N-pole moving contact 20 realizes multi-pole energy storage and multi-pole concentric and coaxial design, ensuring the synchronous performance of the product, improving the product's breaking capacity and stable operation performance, and also effectively improving the product's temperature rise.
[0047] like Figure 4 , Figure 5 as well as Figure 6 As shown, a return section 40 is integrally formed on the N-pole trip unit 4. A tripping lever 41 is disposed inside the N-pole, located between the residual current protection mechanism 3 and the return section 40. One end of the tripping lever 41 is rotatably mounted on the middle cover base 10. A return spring is also provided on the N-pole trip unit 4. When the N-pole trip unit 4 trips, the return section 40 will move towards the tripping lever 41 under the push of the return spring, until the tripping lever 41 automatically returns the trip unit of the residual current protection mechanism 3 to its original position. This eliminates the need for manual leakage current reset by the user, improving the convenience of using the miniature residual current circuit breaker.
[0048] like Figure 5 , Figure 6 As shown, the N-pole trip unit 4 is rotatably equipped with a latch 42 and a tripping element 43. An N-pole rotating shaft 44, coaxial with the operating handle 5, is rotatably mounted inside the N-pole. A connecting rod 45 is provided between the N-pole rotating shaft 44 and the latch 42. When the N-pole trip unit 4 is in the closed state, the latch 42 and the tripping element 43 are held together by the combined force of the connecting rod 45 and the return spring. One end of the tripping element 43 is opposite to the tripping lever 41. When the residual current protection mechanism 3 detects leakage, the trip unit of the residual current protection mechanism 3 will push the tripping element 43 to disengage from the latch 42 via the tripping lever 41. At this time, the N-pole trip unit 4 will complete the tripping under the push of the return spring.
[0049] like Figure 5 , Figure 6 As shown, a reset lever 440 is fixedly mounted on the N-pole trip unit 4, opposite to the trigger member 70. When the N-pole trip unit 4 trips, the reset lever 440 will push the trigger member 70 to control the L-pole trip unit 7 to trip synchronously. When the L-pole trip unit 7 closes, the trigger member 70 will push the reset lever 440 to control the N-pole trip unit 4 to close synchronously.
[0050] When an overload or short circuit occurs in the circuit, the L-pole tripping element 7 will trip, controlling the N-pole contact mechanism 2 and the L-pole contact mechanism 6 to simultaneously trip. At this time, the operating handle 5 will trip independently without causing the N-pole tripping element 4 to trip. When residual current occurs, the N-pole tripping element 4 will trip under the drive of the residual current protection mechanism 3. At this time, the reset lever 440 will push the trigger 70 to control the L-pole tripping element 7 to trip. Simultaneously, the L-pole operating handle 5 and the N-pole rotating shaft 44 will trip, allowing users to accurately identify leakage current in the circuit.
[0051] Figure 7 This is a schematic diagram of the overall structure of the miniature residual current circuit breaker assembled in this application. Figure 8 This is a schematic diagram of the overall structure of the present application assembled in a 1P+N single-handle miniature residual current circuit breaker. When the present application is a single-handle structure, the distinguishing feature from the dual-handle structure is that the N-pole rotating shaft 44 is concealed.
[0052] The implementation principle is as follows: Operating handle 5 and N-pole shaft 44 have user identification functions. When overload and short-circuit protection occurs, operating handle 5 trips, while N-pole shaft 44 remains closed (at this time, N-pole contact mechanism 2 and L-pole contact mechanism 6 are in an open state), and the user identifies an overload or short circuit. When leakage occurs, operating handle 5 and N-pole shaft 44 will trip simultaneously, and the user identifies a leakage in the circuit. The housing 1 is also compatible with similar circuit breaker products of class 63A, 1P+N, 2P, 3P, 3P+N, and 4P.
[0053] The L-pole moving contact 60 is hot-riveted and welded. The N-pole moving contact 20, under the action of the energy storage spring 23, realizes multi-pole energy storage and multi-pole concentric and coaxial design, which ensures the synchronous performance of the product, improves the breaking capacity and stable operation performance of the product, and can also effectively improve the temperature rise of the product.
[0054] The zero-sequence current transformer is made of microcrystalline material and is used to detect leakage current. The transistor circuit board adopts a MOS layout and enhances ESD performance through integrated chips, improving its anti-interference performance and line stability to EMC 4KV. This also reduces the standby power consumption of the miniature leakage circuit breaker, outperforming similar products on the market. The transistor circuit board is electrically connected to the zero-sequence current transformer and receives and amplifies the leakage current to generate an operating signal. The trip unit receives the operating signal and drives the N-pole trip element 4 to complete the tripping action.
[0055] When the N-pole trip unit 4 trips, the return part 40 will move towards the trip lever 41 under the push of the return spring, until the trip lever 41 pushes the trip unit of the residual current protection mechanism 3 to automatically return to its original position. This eliminates the need for manual leakage current reset by the user, improving the ease of use of the miniature residual current circuit breaker.
[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A miniature residual current circuit breaker, comprising a housing (1), the housing (1) including a middle cover base (10), the middle cover base (10) separating the housing (1) into an N pole and an L pole; characterized in that: The N pole is provided with an N pole contact mechanism (2), a residual current protection mechanism (3) and an N pole tripping element (4); the residual current protection mechanism (3) is used to sense the leakage current and control the N pole tripping element (4) to trip, thereby driving the N pole contact mechanism (2) to open. The L pole is provided with an operating handle (5), an L pole contact mechanism (6), and an L pole tripping element (7); the operating handle (5) is linked with the L pole tripping element (7); the L pole contact mechanism (6) includes an L pole moving contact (60) disposed on the L pole tripping element (7) and an L pole stationary contact (61) disposed inside the L pole; the L pole tripping element (7) is used to drive the L pole moving contact (60) and the L pole stationary contact (61) to open / close; the L pole is also provided with an overload protection mechanism (8) and a short circuit protection mechanism (9); the overload protection mechanism (8) and the short circuit protection mechanism (9) are both used to control the L pole tripping element (7) to trip in order to drive the L pole contact mechanism (6) to open; The L-pole tripping member (7) is provided with a trigger member (70), which extends into the N-pole. When the N-pole tripping member (4) trips, the N-pole tripping member (4) is used to push the trigger member (70) to control the L-pole tripping member (7) to trip. A linkage shaft (11) is also provided between the L-pole tripping component (7) and the N-pole tripping component (4). The L-pole tripping component (7) drives the N-pole contact mechanism (2) to open / close synchronously through the linkage shaft (11).
2. The miniature residual current circuit breaker according to claim 1, characterized in that: The N-pole contact mechanism (2) includes an N-pole moving contact (20) and an N-pole stationary contact (21); a swing member (22) is rotatably arranged inside the N-pole, and the N-pole moving contact (20) is arranged on the swing member (22); one end of the swing member (22) is linked to the linkage shaft (11), and an energy storage spring (23) is arranged on the N-pole moving contact (20), and the other end of the energy storage spring (23) is arranged on the middle cover base (10); the energy storage spring (23) is used to drive the N-pole moving contact (20) to rotate away from the N-pole stationary contact (21).
3. The miniature residual current circuit breaker according to claim 2, characterized in that: The rotating shaft of the N-pole tripping component (4) is coaxial with the rotating shaft of the L-pole tripping component (7).
4. The miniature residual current circuit breaker according to claim 2, characterized in that: The N-pole tripping member (4) is provided with a return part (40), and the N-pole is provided with a tripping lever (41) located between the residual current protection mechanism (3) and the return part (40). One end of the tripping lever (41) is rotatably mounted on the middle cover base (10). When the N-pole tripping member (4) trips, the return part (40) rotates with the N-pole tripping member (4) and pushes the tripping lever (41) to control the residual current protection mechanism (3) to automatically return to its original position.
5. The miniature residual current circuit breaker according to claim 4, characterized in that: The N-pole trip unit (4) is rotatably provided with a latch (42) and a tripping fastener (43); the N-pole is rotatably provided with an N-pole rotating shaft (44) coaxial with the operating handle (5), and a connecting rod (45) is provided between the N-pole rotating shaft (44) and the latch (42); when the N-pole trip unit (4) is in the closed state, the latch (42) and the tripping fastener (43) are locked together by the force of the connecting rod (45); the tripping fastener (43) is opposite to the tripping lever (41), and when the residual current protection mechanism (3) detects leakage, the residual current protection mechanism (3) pushes the tripping fastener (43) and the latch (42) to disengage through the tripping lever (41), at which time the N-pole trip unit (4) is in the disengaged state.
6. The miniature residual current circuit breaker according to claim 5, characterized in that: The N-pole trip unit (4) is provided with a reset lever (440) opposite to the trigger (70). When the N-pole trip unit (4) trips, the reset lever (440) is used to push the trigger (70) to control the L-pole trip unit (7) to trip. When the L-pole trip unit (7) closes, the trigger (70) is used to push the reset lever (440) to control the N-pole trip unit (4) to close.
7. The miniature residual current circuit breaker according to claim 1, characterized in that: The residual current protection mechanism (3) is an electronic leakage current protection module or an electromagnetic leakage current protection module.