1470 results about "Fuse cutout" patented technology

The invention provides an active and passive integrated protection intelligent fuse with a single excitation source. The active and passive integrated protection intelligent fuse comprises a first conducting bar, a signal melt, a second conducting bar, a circuit board and an excitation source, the circuit board is provided with the relay and the excitation source. The relay is connected with an external control unit, the excitation source, the first conducting bar and the second conducting bar. The first conducting bar, the signal melt and the second conducting bar are connected in sequence; an isolating layer is arranged on the relay, and the isolating layer is used for shielding crosstalk of external voltage on the relay; after a plurality of pins of the relay are welded on the circuit board, an insulation processing mode is adopted among the plurality of pins; and in an inspection working condition, the external control unit outputs a first inspection signal to the relay so as to control the relay to be switched into an inspection state, and feeds back the working state of the excitation source to the external control unit.

The invention relates to the technical field of state monitoring, in particular to an intelligent fuse comprising a monitoring module, and the fuse comprises a data analysis module, a steady state recognition module, a temperature analysis module, a coupling calculation module and a state calibration module. According to the method, time consistency verification and corresponding matching are carried out on temperature and current sampling, abnormal interference is eliminated in a stable current-carrying interval, a continuous sequence is formed, and a definite time relation is established between thermal response and a current-carrying state by combining analysis of accumulated deviation and change turning of the temperature along with time; the abnormal trend of slow evolution is amplified and presented, correction is carried out according to the direction consistency of multi-segment time difference change, progressive features before fusing are recognized in advance, early warning continuity and operation decision reliability are improved, misjudgment is reduced, continuous updating of state evaluation is supported, and stability of a control closed loop is improved.

The invention specifically relates to a standardized fuse fault monitoring and diagnosis system, and relates to the technical field of power system protection equipment monitoring. A signal processing and impedance spectrum calculation module; an intelligent diagnosis and state evaluation module; and a benchmark management and personalized tracking module. According to the invention, controllable micro test signals are actively injected to obtain frequency domain impedance fingerprints, and accurate capture of microscopic degradation is realized; non-intrusive coupling and signal injection are adopted, the topology of a main loop does not need to be changed, the inherent protection characteristic of the fuse is guaranteed, and power frequency interference can be penetrated; the recognition amount of budding faults such as contact oxidation and melt corrosion is improved in advance, and power failure accidents caused by fault expansion are avoided.

The invention provides an intelligent fuse, and belongs to the technical field of circuit protection, and the intelligent fuse is characterized in that an upper housing is provided with at least one excitation chamber, the excitation chamber is internally provided with at least one excitation part and at least one impact part, and the excitation part releases high-pressure gas when receiving any one of an external trigger signal and an internal trigger signal; the lower shell is provided with at least one cooling cavity; the current-conducting plate is arranged between the upper shell and the lower shell, and the impact part moves towards the direction where the cooling cavity is located under the thrust action of the high-pressure gas so as to cut off the current-conducting plate; the self-control module is arranged outside the shell and comprises a current detection unit and a processing unit, and the current detection unit is used for detecting a current signal on the conductive plate; the processing unit is used for generating an internal trigger signal according to the current signal. The beneficial effects of the invention are that a dual-trigger mechanism and redundancy design of an internal trigger signal and an external trigger signal are adopted, so that normal action can still be ensured when any signal fails, and the breaking reliability is improved.

The utility model discloses an electronic protection device and a power utilization device, and belongs to the field of fuses. The electronic protection device comprises a conductive element used for being connected to a circuit to be tested; the first excitation fuse and the second excitation fuse are connected in series on the conductive element; the arc extinguishing fuse is connected with the second excitation fuse in parallel; and the controller is used for detecting the value of a current flowing through the conductive element of a circuit to be detected, and is in communication connection with the first excitation fuse and the second excitation fuse. The first excitation fuse and the second excitation fuse are connected in series, the arc extinguishing fuse and the second excitation fuse are connected in parallel, and the controller outputs a trigger signal according to the detected current, so that the electronic protection device switches the first working mode or the second working mode, and the circuit can be protected when the circuit is overloaded or short-circuited.

The utility model relates to an intelligent excitation fuse (100). The intelligent excitation fuse (100) comprises a partially hollow insulating shell; at least one copper bar (106) in which a plurality of fractures (106A) are laid; a plurality of breaking devices (200); the control circuit board (300) is used for triggering the plurality of on-off devices (200) to carry out on-off actions; the signal fuse wire (301) is connected with at least one copper bar (106) in parallel, and the signal fuse wire (301) is electrically connected with the control circuit board (300) through a signal connecting wire (302), so that when current flowing through the signal fuse wire (301) exceeds preset threshold current, the signal fuse wire (301) is fused and is electrically connected with the control circuit board (300); wherein the control circuit board (300) responds to the fusing of the signal fuse (301) and sends an action signal to the plurality of on-off devices (200) which are connected in series.

The utility model relates to the field of electric power facilities, in particular to a stable and reliable drop-out fuse, which comprises an insulator, an upper terminal, a lower terminal, a fuse tube, an upper static contact and a lower static contact. A fuse is arranged in the fuse tube, an upper moving contact is arranged at the upper end of the fuse tube, a lower moving contact is arranged at the lower end of the fuse tube, and the lower moving contact is movably connected to the lower static contact through a trunnion; the lower moving contact is also provided with an elastic wire pressing plate which assists in tensioning the fuse wire. The lower moving contact is provided with a first line pressing terminal, the lower static contact is provided with a second line pressing terminal, and the lower end of the fuse is led out from the fuse tube, penetrates through the first line pressing terminal and then is connected with the second line pressing terminal. And an insulating sheath is arranged at a position where the fuse wire is connected with the elastic wire pressing plate. The sheath is additionally arranged at the contact position of the tail end of the fuse wire and the fuse wire pressing plate to form insulation isolation, so that current does not pass through two sides of the trunnion by the fuse wire, and the heating defect caused by poor contact between the trunnion and the lower static contact is avoided.

The invention provides a vertically-installed fuse preparation method based on secondary forming and a related device. The method comprises the steps that preparation parameters of a target vertically-installed fuse are acquired to determine preparation steps; when the preparation step is conductor preparation, obtaining a first parameter from the preparation parameters; preparing a conductor according to the first parameter; when the preparation step is first-time forming, a second parameter is obtained from the preparation parameters; carrying out injection molding according to a second parameter to obtain a base inserted with a conductor; when the preparation step is pipe body blank preparation, a third parameter is obtained from the preparation parameters; preparing a tube body blank according to the third parameter; when the preparation step is second-time forming, a fourth parameter is obtained from the preparation parameters; forming the tube body blank on the base and the electric conductor according to a fourth parameter to obtain an integrally formed initial fuse; when the preparation step is post-processing, acquiring a fifth parameter from the preparation parameters; and performing post-processing on the initial fuse according to the fifth parameter to obtain a target vertically-installed fuse.

The invention provides a combined full-range controllable protection device, which belongs to the technical field of circuit protection and comprises a trigger body, a breaker and a fuse. The trigger body and the breaker are connected in series, and the trigger body and the breaker which are connected in series are connected in parallel with the fuse; when the circuit is abnormal, the trigger body is fused to carry out primary protection on the circuit, the fused trigger body also generates an electric signal and transmits the electric signal to the breaker, the breaker cuts off the circuit to carry out secondary protection on the circuit, current flowing through the trigger body and the breaker is merged into a branch where the fuse is located, and the fuse is fused to form third-level protection on the circuit; therefore, multi-stage protection is realized through the trigger body, the breaker and the fuse, and the time sequence cooperation of multi-stage protection actions not only avoids misoperation, but also can provide redundancy protection when a serious fault occurs, so that quick response and reliable cut-off when the circuit is abnormal are realized on the basis of keeping low loss when the circuit is normal, and the circuit breaker can be suitable for high-voltage and large-current breaking.

Disclosed is a switchgear cabinet with a magnetic blow-out load switch, comprising a cabinet body, wherein a cable compartment, a mechanism compartment, a sealed gas compartment, and a fuse compartment are arranged within the cabinet body. A three-phase top insulating sleeve is arranged at the top of the sealed gas compartment, a three-phase bottom insulating sleeve is arranged at the bottom of the fuse compartment, and the three-phase bottom insulating sleeve penetrates into the cable compartment to connect to an incoming cable and an outgoing cable. A three-phase magnetic blow-out load switch is installed within the sealed gas compartment, and an operating mechanism for the load switch is installed at an upper part within the mechanism compartment and located on an outer side of a front panel of the sealed gas compartment. A three-phase fuse is arranged within the fuse compartment, a fuse striker-pin tripping mechanism is installed at a bottom part within the mechanism compartment, and a small fuse grounding switch is further installed within the fuse compartment. The present invention uses a magnetic blow-out arc extinguishing assembly to increase a strong magnetic field to directionally guide and concentrate electrons and ions of an electric arc, and performs rapid arc interruption and arc extinguishing by means of an arc extinguishing apparatus, effectively improving the arc extinguishing capacity of the load switch, and solving the technical problem of load switches in high-voltage load switch cabinets having low arc extinguishing capacity.

A degradation determination device determines whether each of a first opening / closing device and a fuse provided on a power path is in a degraded state. The power path has a positive electrode-side power line and a negative electrode-side power line. The first opening / closing device and the fuse are provided on the negative electrode-side power line. The degradation determination device is provided with a first potential detection unit that detects a first potential at one end of the first opening / closing device and a second potential at the opposite end thereof, a second potential detection unit that detects a first potential at one end of the fuse and a second potential at the opposite end thereof, and a control unit that determines whether each of the first opening / closing device and the fuse is in a degraded state, based on a potential difference between the first and second potentials.

The invention discloses a fuse fault detection method and device of a battery system and the battery system, and relates to the technical field of energy storage systems.The method comprises the steps that for each battery cluster, when a first relay is closed, a first voltage between a positive input end and a negative output end and a second voltage between the positive input end and the negative input end are collected, whether the first fuse breaks down or not is determined; when the second relay is closed, third voltage between the positive input end and the negative input end and fourth voltage between the positive output end and the negative output end are collected, and whether the second fuse breaks down or not is determined; when the first relay and the second relay are both closed, cluster current and bus voltage are collected, and whether the first fuse and the second fuse in each battery cluster break down or not is determined. Through voltage difference detection and cluster current and bus voltage analysis when the relay is closed, the fuse fault can be accurately identified without additional hardware, and the cost and the false alarm rate are reduced.

The invention discloses integrated three-phase intelligent safe electric equipment, belongs to the technical field of safe electric utilization, and aims to solve the problems that when a fuse is installed and arranged, the position is inconvenient to adjust, when the fuse fails and the fuse cannot be normally fused due to overlarge current, a device is easily burnt to cause circuit fire, and a connecting contact is easily subjected to dust deposition and oxidation in the long-time use process, so that the service life of the fuse is prolonged. The device comprises a box body, vertical guide rails are symmetrically and fixedly connected in the box body, the side walls of the two vertical guide rails are jointly connected with a plurality of transverse rows in a sliding mode, and each transverse row is movably provided with a plurality of arrangement assemblies. According to the invention, through the arrangement of the arrangement assembly, position adjustment can be carried out without overall disassembly after the fuse is connected, through the arrangement of the protection mechanism and the cut-off mechanism, when the fuse breaks down and is not normally fused due to overlarge current, the melt part of the fuse is physically cut off, and through the arrangement of the driving mechanism and the maintenance mechanism, the safety of the fuse is improved. And the metal connecting part is maintained and protected, dust accumulation is reduced, and contact oxidation is slowed down.

The utility model discloses a fuse link, a fuse and an electric device, and belongs to the field of fuses. The fuse link is provided with a fusing part, a first end used for being connected with a negative electrode and a second end used for being connected with a positive electrode, the fuse link is provided with a first narrow-diameter part between the fusing part and the first end, and the fuse link is provided with a second narrow-diameter part between the fusing part and the second end; the distance between the fusing part and the adjacent first narrow part is smaller than the distance between the fusing part and the adjacent second narrow part. The fusing part is arranged at the first narrow-diameter part on the side, closer to the negative electrode, of the fusing body, when current is overloaded, the fusing part is fused, arcing occurs at the fusing part, an electric arc ignites the first narrow-diameter part and the second narrow-diameter part which are located on the two sides of the fusing part, the fusing part is closer to the negative electrode, the distance of firing towards the positive electrode is reduced, the electric arc is made to be away from a high-temperature area, and the service life of the fuse body is prolonged. The influence of temperature on arc burning is reduced, and rapid arc extinguishing can be realized.

The invention belongs to the technical field of electrical system loops, and relates to a system loop matching design method and device, computer equipment and a storage medium, and the method comprises the steps: obtaining load parameters in a system loop; calculating a load current according to the load parameter; according to a load current, selecting a fuse, defining a temperature resistance grade, and selecting a cable diameter; according to the selected fuse, the defined temperature resistance grade and the selected cable diameter, performing overcurrent matching checking, judging whether the overcurrent matching checking is passed or not, and if yes, performing temperature rise checking; judging whether the temperature rise checking is passed or not, and if so, checking the fuming time; and judging whether the verification of the fuming time is passed or not, and if so, carrying out electrical performance test confirmation. Multiple aspects such as electrical element performance, environmental factors and frequency factors are comprehensively considered, and the accuracy and reliability of the high-voltage system in the design process are ensured; failure risks can be effectively avoided, the safety and stability of the system are improved, and powerful support is provided for electric development of automobiles.

The invention belongs to the field of power distribution network automation, and discloses a controllable drop-type intelligent fuse and a control method thereof. The controllable drop-type intelligent fuse comprises a measurement and control module which is arranged at the lower part of a fusion tube and is used for measuring the working current of the fuse, the high voltage of a line, the temperature of a fuse wire, the poor contact state of the fusion tube and the drop state of the fusion tube through a sensor and a corresponding measurement circuit, and communicating with a background server through a wireless communication function; the measurement and control module is connected with a configured micro motor and a measurement and control module torque output rotating shaft; the lower contact is provided with a novel tensioning structure which is used for enabling the fuse to be controlled to fall off. On the basis of keeping the function of an original traditional drop-out fuse as a short-circuit protection switch, a measurement control and wireless communication circuit is added; working current, fuse wire temperature and drop state can be measured, drop of the fuse can be controlled automatically or wirelessly and remotely when primary current is larger than a set value, and therefore load overcurrent protection is achieved.

The invention belongs to the field of fuses, and provides an intelligent fuse which comprises a conductor used for bearing main loop current; the fuse body is connected in the conductor in series and can be fused when the current of the main loop exceeds a preset threshold value; a first cutting unit configured to cut off the melt based on an external trigger signal; and a second cutting unit configured to cut off the conductor based on an internal trigger signal, where the internal trigger signal is a voltage signal across the melt. The intelligent fuse solves the technical problems that an intelligent fuse in the prior art is complex in structure and high in cost, and is low in cost, small in size, simple in structure and easy to operate.

The invention relates to the technical field of power equipment fault diagnosis, in particular to a fault detection method for a cable branch box, and aims to solve the problem that in the prior art, when a power distribution network cable branch box operates in an underground humid and multi-loop load fluctuation environment, the fault of the cable branch box cannot be detected. And the problem of coupling risk of leakage to the ground of a protective layer or short circuit fault and loop overcurrent, short circuit and fuse fault is generally faced. According to the invention, by synchronously acquiring loop and sheath parameters and establishing a collaborative diagnosis mechanism, collaborative detection of sheath grounding faults and loop faults can be realized, early insulation aging hidden dangers are effectively identified, a fault coupling relationship is accurately judged, and the method has the advantage of remarkably improving timeliness and accuracy of fault diagnosis.

The invention discloses a fault monitoring and positioning method for a high-voltage drop-out fuse, and relates to the technical field of power equipment fault monitoring, and the method comprises the steps: obtaining original monitoring sequences corresponding to current and voltage sensors disposed at upper and lower ports of a target fuse; activating a working mode recognizer to execute working mode recognition of the target fuse, establishing a global mode label, executing adaptive matching of a mode fingerprint database, and establishing a standard comparison fingerprint with a trust identifier; establishing residual spectrum characteristics; and establishing a fault discrimination vector, carrying out space fault positioning by using the fault discrimination vector, and generating a fault positioning result. According to the invention, the technical problems of insufficient fault monitoring and positioning accuracy, lack of visual presentation capability and low monitoring and positioning efficiency of the high-voltage drop-out fuse in the prior art are solved, and accurate positioning and visual presentation of the fault of the high-voltage drop-out fuse are realized. And the accuracy and efficiency of fault monitoring and positioning are improved.

The invention discloses an electrically-operated drop-out fuse and a control method, and relates to the field of circuit devices for power supply or distribution, the electrically-operated drop-out fuse comprises a protective insulator, an intelligent control module, a drop-out assembly, a driving mechanism and a transmission mechanism, the protective insulator is of a longitudinally-penetrating groove structure, the top of the protective insulator is provided with a closed upper cover, and the intelligent control module is connected with the drop-out assembly; two sides of the protective insulator extend downwards to form side walls, the side walls and the insulator form a shield used for shielding the upper static contact and the upper moving contact, a closed cavity is arranged at the rear part of the protective insulator, and a driving mechanism is arranged in the cavity; the intelligent control module is electrically connected with the driving mechanism, the driving mechanism is connected with the transmission mechanism, and the intelligent control module controls the driving mechanism to drive the falling assembly through the transmission mechanism to realize opening or closing; according to the fuse and the control method provided by the invention, remote intelligent switch-on and switch-off can be realized, the operation is safe and reliable, the structure is compact, and the protection performance is excellent.

The invention relates to the technical field of product detection and marking, in particular to a resistance test marking machine which comprises a rack, a feeding structure, a workbench and a discharging structure are arranged on the rack, and a temperature detection structure, a resistance detection structure and a marking structure are sequentially arranged on the workbench. The feeding structure is used for sequentially conveying a plurality of fuses to the workbench, the temperature detection structure is used for detecting the temperature of terminals at the two ends of the fuses, the resistance detection structure is used for detecting the resistance values of the fuses, and the marking structure is used for marking the detected fuses to end covers of the fuses. And the discharging structure is used for conveying the detected and marked fuses away from the workbench. The fuse testing device has the advantages that the fuse is conveyed to the workbench through the feeding structure, accurate testing and direct marking of the resistance value of the fuse are achieved on the workbench, and the testing accuracy is improved. And due to cooperative work of a plurality of stations, automatic production is realized, and the production efficiency is greatly improved.

The invention discloses a new energy high-voltage direct current protection device comprehensive test platform, and relates to the technical field of new energy high-voltage direct current system core protection device test, and the platform comprises a power supply and energy storage module which is used for converting a 380V alternating current into a stable and adjustable direct current and storing the stable and adjustable direct current as an energy source required by a high-voltage large-current test, different test voltage requirements are met through series-parallel topology switching; and the power control and load simulation module is used for controlling on-off and adjustment of current in the test loop. By adopting the modular combination design of the super-capacitor energy storage unit, the adjustable pulse inductor and the load module, the comprehensive compatibility of high-voltage direct-current protection devices such as a relay and a fuse in various test scenes such as short circuit resistance, electric service life and limit on-off is realized, meanwhile, the system can work only by being powered by a conventional 380Vac laboratory, and the test efficiency is greatly improved. The method does not depend on an industrial high-voltage power grid or a special transformer, greatly reduces the equipment deployment threshold, and improves the test response efficiency.

The invention discloses a drop-out fuse, and relates to the technical field of power system protection, and the drop-out fuse comprises an insulator, the middle part of the insulator is fixedly provided with a fixed installation plate used for installing a fuse, one end of the insulator is fixedly provided with a lower end contact, and the other end of the insulator is fixedly provided with an upper end contact. The lower end contact is fixedly provided with a lower wiring terminal, the upper end contact is fixedly provided with an upper wiring terminal, and the lower wiring terminal is rotatably provided with a fuse tube assembly used for power-off protection. The fuse tube assembly comprises a fuse outer tube, the lower end of the fuse outer tube is provided with a lower connecting tube connected with the lower end contact, the upper end of the fuse outer tube is provided with an upper connecting tube, and the upper connecting tube is provided with a conductive head conductively connected with the terminal duck tongue plate; the invention has the advantages that the fuse can be quickly switched without high-altitude replacement, and the fusing arc can be effectively isolated to protect the standby fuse assembly.

The utility model provides a tensile detection device for a wiring terminal of a drop-out fuse, and relates to the technical field of tensile detection equipment. The flat plate is detachably mounted on the tension detector through bolts, and a first clamping part and a second clamping part are arranged on the flat plate; the driving assembly is arranged on the flat plate and can drive the first clamping part to wrap the connecting position of the wire and the wiring terminal and drive the second clamping part to clamp the wire at the same time, so that the wiring terminal and the wire are synchronously positioned. When the first clamping part is driven to position the wiring terminal part, the second clamping part is driven to synchronously fix the wire part, so that the wiring terminal and the wire can be positioned in one step, the operation steps and the consumed time required for clamping the wiring terminal and the wire by personnel are reduced, the batch detection requirement is met, and the production and detection efficiency is improved.

The excitation fuse comprises a shell provided with a cavity, a conducting bar is arranged in the shell in a penetrating mode in a sealed mode, a piston and an ignition device are arranged in the cavity of the shell on one side of the conducting bar, and a displacement channel for the impact end of the piston to penetrate through is arranged at the position, needing to be disconnected, of the conducting bar. A sealing plate is arranged at the end, facing the piston, of the displacement channel and makes close contact with the shell on the periphery of the displacement channel, and a sealing structure is arranged between the sealing plate and the shell on the periphery of the displacement channel. The sealing plate is provided with a profiling through hole corresponding to the displacement channel, the profiling through hole allows the impact end of the piston to penetrate through and imitates the peripheral size and shape of the impact end of the piston, arc extinguishing chambers are arranged on the shell on the other side, away from the piston, of the conducting bar, and when the number of the arc extinguishing chambers is multiple, the arc extinguishing chambers are independently arranged. According to the invention, by arranging the sealing plate with the profiling through hole and the sealing structure, the sealing performance and the breaking reliability of the product are improved.

Techniques and apparatuses for forming electrical connection are presented in which an apparatus may include an in-line fuse having terminals comprising terminal exterior surfaces and terminal recesses, and electrical cables comprising a conductor and a insulation sleeve and having an exposed portion and an unexposed portion. The exposed portion of an electrical cable is at least partially inserted into a respective terminal recess of the in-line fuse. The apparatus may further comprise one or more temperature-activated sealing members that circumferentially surround and form a seal against portions of the terminal exterior surfaces of the in-line fuse and portions of the insulation sleeves of the electrical cables. The apparatus may also comprise an inner mold encapsulating the in-line fuse and at least partially of the one or more temperature-activated sealing members, and an outer mold encapsulating the inner mold.

The invention relates to the technical field of fuse production, and particularly discloses an automatic welding device and method for a fuse. A fuse wire and a terminal electrode are transferred through a multi-station transfer system, and a visual positioning system scans the positions of the fuse wire and the terminal electrode; a welding path is calculated through an image acquisition preprocessing module, a feature extraction and positioning module, a welding path calculation and error compensation module and a closed-loop feedback and self-learning module, and mechanical errors are compensated in real time; the self-adaptive welding device dynamically adjusts the current, the temperature and the welding time according to the material of the fuse wire; the online quality detection system monitors a welding temperature curve through an infrared thermal imager, detects the shape of a welding spot through an image recognition system, and sorts unqualified products; and the intelligent control system realizes self-optimization of welding parameters. According to the automatic welding device and method for the fuse, the cooperation problem of high-precision positioning, parameter self-adaption and closed-loop optimization is solved, and then the production efficiency and the yield are improved.

The application provides a kind of drop-out fuse monitoring device, it is related to the technical field of measurement electric variable, it includes fixed part and module part, fixed part and module part can be detached connection.Fixed part is installed at fuse static contact, including protective shell, current sensor, temperature sensor and pressure detection component;Protective shell surrounds part static contact conductive circuit, current sensor is covered in the conductive circuit, temperature sensor is installed on the side of line, and the detection end of pressure detection component is in contact with static contact, and the detection end is in compression state when closing.The module part and the fixed part are plug-in connected, including module shell, embedded module and power supply, the embedded module and the power supply are arranged in the shell, and each sensor is connected through the sliding electrical connection structure of the module shell.The application has simple structure, low cost, modular design will easily failure maintenance main circuit independent packaging, simplifies operation and maintenance;Pressure detection component can also long-term accurate monitoring closing state and contact reliability, realize early warning.

The invention relates to the technical field of drop-out fuse installation, in particular to a drop-out fuse moving contact assembling device and assembling method.The drop-out fuse moving contact assembling device comprises an equipment frame and a moving contact assembling mechanism, and the equipment frame comprises a base, a workbench fixedly installed on the upper surface of the base and a stand column fixedly installed on the upper surface of the base. According to the drop-out fuse moving contact assembling device and method, the drop-out fuse can be preliminarily positioned through the positioning part, then the driving part can drive the positioning groove of the sleeve on the moving contact assembling mechanism to make contact with the moving contact on the drop-out fuse, and the compression spring is driven to be compressed; proper assembling pressure is provided, then the first motor is driven to rotate to drive the moving contact and the shackle fixing piece to be in threaded connection, the magnetic coupling is automatically disengaged when the preset torque is reached, on one hand, the assembling efficiency is improved, and on the other hand, the situation that connection between the moving contact and the shackle fixing piece is not firm enough or over-screwing is prevented can be avoided.

The invention discloses a method for searching a ground fault point of a low-voltage cable by using a safe direct-current power supply, which is suitable for searching the ground fault point of the low-voltage cable of a preset street lamp along the street, comprises a plurality of lamp poles which are distributed at intervals, and is characterized in that a PE (Poly Ethylene) wire of the low-voltage cable is connected with a ground terminal of a control cabinet; a positive wire outlet end provided with a safe direct-current power supply is connected with a direct-current 0.5 A fuse in series, the other end of the fuse is respectively clamped on A, B, C and N phases of a cable, a negative wire outlet end is connected with an mA meter in series, the other end of the mA meter is clamped on a cable head of a PE (Poly Ethylene) wire, when a certain phase of cable is grounded and short-circuited, the mA meter is equivalent to a grounding resistor which is connected in series in a loop, and the direct current of the loop is measured, so that the grounding short circuit of the cable is measured. And searching positions of a fault phase and a ground fault point. The invention discloses a method for safely, quickly and reliably searching a grounding fault point of a low-voltage cable.