TW201814761A - Switch contact status display apparatus - Google Patents

Abstract

The switch contact state display device is mainly used for displaying the contact state of an electrical switch to the outside of the switch after being read by the microprocessor through an electronic circuit. It can solve the inconvenience problem of maintenance for electrical equipment, in order to know the actual situation of the switch, the switch must be attached to additional components and used meter to read the required signals. The main technical characteristic is the electronic circuit is arranged inside the device, and is electrically connected with the primary side and the secondary side of the switch. The sensed signalsare sent to the microprocessor and calculated according to the set operating state logic. The user can easily know the true state of the switch contacts from the lightindicator. It enhances the safety, practicality, and can be quantified production standards. Therefore, the economic benefits can be achieved.

Description

 Switch contact state display device  

The invention relates to a display device capable of displaying the state of a switch contact. The electronic circuit is electrically connected to the primary side and the secondary side of the switch, and the signal sensed by the electronic circuit is input to the microprocessor to read the switch contact. Status and display the status of the contacts. In particular, it refers to the switch that is used for any specification, the state of the contact that is displayed, and can be connected to the desired position via the cable, so that it can be easily viewed, improve convenience, practicality, and enhance electrical safety.

In the general distribution box, the two types of line equipment protection devices are the most common. There are two types, one is a circuit breaker and the other is an electromagnetic switch. The former circuit breaker has overload protection, fault current protection, and leakage fault protection, and is used for protection of the power equipment switch of the system distribution box. The electromagnetic switch is overload protection or under-phase protection, which is used to protect the operating equipment from overload or phase loss. Originally, when the status display of the circuit breaker and the electromagnetic switch is solved, the related state display device is installed, usually inside the circuit breaker body, such as adding a micro switch as an auxiliary contact or an alarm contact, generally a mechanical Actuation by structural conduction is a skill well known in the art.

The use of circuit breakers is a very common product, and circuit breakers can generally be divided into form-cavity circuit breakers (MCCB), or no-fuse circuit breakers (NFB). The former is a component title for products in Europe and the United States, and the latter is a product of the Japanese state. Another product classification name is Leakage Circuit Breaker (ELCB), which is a relatively small capacity circuit breaker commonly referred to as MCB and ELB. Usually MCCB and ELCB circuit breakers are used for large interrupting capacity, commonly known as industrial circuit breakers. While MCB and ELB are used for small interrupting capacity, they are commonly known as household light plug-in circuit breakers. Their functions are mainly an isolation switch that protects equipment and line safety. When an overload occurs, tripping isolation and fault current are generated. Safe trip isolation. In the case of ELCB, the protection function of leakage fault tripping is added. The circuit breaker is used in various places and is the main isolation switch in the world as a protection device and line safety. It is also the most versatile product in the world.

The use of circuit breakers is so common that at present manufacturers of switchboards, due to space constraints, or because of economic costs, most of the circuit breakers and circuit breakers are adjacent to each other throughout the switchboard and distribution boxes. The configuration is then fixed on the plate fixing plate of the plate. Taiwan generally uses copper bars as conductive busbars (BUS) on the primary side, and wire and cable is generally used as the power source for primary circuit breakers in Europe. However, the connection power on the primary side, whether using copper bars or wires and cables, has almost no space between the circuit breaker and the circuit breaker inside the distribution box, and can be used as an additional function of the auxiliary function of the circuit breaker itself. When there is a new demand for functionality, there is almost no room for construction. In most cases, it is necessary to remove the copper platoon, remove the wire, remove the fixing screws, etc., remove all the equipment, remove the circuit breaker, install the required accessories, and then fix the circuit breaker in the distribution box. , redo wiring work. In addition to causing a lot of inconvenience, these can even cause a safety hazard.

In view of this, manufacturers of circuit breakers, such as world-renowned manufacturers Schneider, ABB, Siemens, singular, E-TN, SQ-D, Mitsubishi Electric, etc., respond to the customer's essential functional requirements for accessories, and the above The difficulty of actually changing the circuit breaker in the power distribution box body was first invented by the European and American manufacturers on the top of the circuit breaker body. There is a cover-type way to easily assemble a certain part of the common accessories to solve the future customer's cause. The troubles and inconveniences that arise when adding accessories must be added to functional requirements. At present, this method of solving the problem and the actual product are also the manufacturing methods that the circuit breaker manufacturers all over the world consistently follow, and are the mainstream of circuit breaker product design.

Circuit breaker products, with the advancement of materials application technology in the world, and the advancement of technology and environmental changes in the world, such as electronic information and frequency conversion technology, such as the use of nonlinear components, resulting in power quality problems... ...etc., as well as the requirements for special functions and requirements for differentiation, each manufacturer has become more compact, electronic, and communicable, etc., resulting in product diversification and size of circuit breakers that cannot be standardized and unified. It has also caused even the cover of the circuit breaker product to be covered, but its accessories are not uniform due to different sizes and specifications. As a result, the circuit breaker manufacturer's model products are complicated, and it is impossible to unify and standardize, resulting in economic waste, and it is very inconvenient for the customer to use. Therefore, the problem must be changed in the accessory combination method and method of the circuit breaker. To overcome the above difficulties.

In fact, the customer's power usage is different, and the condition of the circuit breaker is different. Even some circuit breaker manufacturers can only describe the specifications of the circuit breaker as "chaotic", so that in combination with the above factors, the customer often needs to be in the circuit breaker. It is difficult to add attachments, even to renovate, or to face the fate of having to redo. In particular, the common indication accessories of various manufacturers, such as auxiliary contacts and alarm contacts, are sometimes not universal. Moreover, the main component micro-switch may also malfunction, which may cause an incorrect indication condition to occur, and in the case of long-term loss, the contact state of the circuit breaker may not be able to obtain a correct status indication under actual action, such as micro-motion. Switch failure, displacement of mechanical components, gaps in contacts, and splices of contacts cause an indication of an external indication status error, resulting in interpretation or even affecting the safety of power usage. In the same way, the condition of the electromagnetic switch is also like a circuit breaker. In the role of the auxiliary contact, it may be ignored that the contact is not connected, or the phenomenon of contact welding is not known. In order to meet the needs of work safety and avoid waste of manufacturing resources, as well as to improve the maintenance, it is necessary to open the door and measure with the meter, and must remove the wire, remove the copper bar, remove the switch, etc., both in manufacturing and in future maintenance. Safety and economic concerns.

When the circuit breaker is in the OFF state, it is safe to work on the secondary side. In fact, if the circuit breaker is in the OFF state, it may be electrocuted on the secondary side. There is a problem of reverse power transmission (reverse phase), or in the case of poor grounding, there is a floating voltage on the secondary side, which may cause a power failure. This situation is sometimes heard because there is no good basis for judging the state of the device, which leads to misjudgment by the maintenance personnel and even a work safety accident.

In view of the above situation, for the indicator display unit of the disk surface, it is necessary to rely on the traditional old way to do a lot of wiring work on the circuit breaker or the electromagnetic switch, and it is necessary to spend a lot of manpower and material resources in design and manufacture, after the manufacturing is completed, It is also a great problem for the maintenance personnel in the quality control inspection. At present, it must rely on the meter instrument plus visual inspection and experience interpretation to deal with it, causing various problems.

In view of the above reasons, the present invention provides a device that is versatile and easy to install but has a reliable action indication, can solve the above problems, and can solve various needs of customers in various situations, regardless of the use of any circuit breaker and electromagnetic switch. The device overcomes the problems of different manufacturers, different specifications and sizes, and greatly improves the stability and economy of power consumption.

The main object of the present invention is to provide a switch contact state display device with simple structure, convenient installation and correct identification function, which can comprehensively use the solution of any of the above various functional requirements of any brand, specification and size, so that the switch is connected. The state of the point is correct and the display device becomes simple and feasible, practical and convenient, and replaceable, improving the safety and economy in the use of electrical equipment.

In order to achieve the above object, the switch contact state display device of the present invention must have the following basic functions: 1 phase voltage indication function, 2 power supply indication function, 3 phase loss state indication, 4 reverse power transmission indication function, 5 ON, OFF, and Trip indication function. ; 6 contact welding indication function, 7 leakage status display, 8 overload status display, 9 phase sequence status indication, 10 accident status indication function. Must be able to be displayed together on a panel, or can be added or removed at will, and can be extended to add more commonly used functions.

In order to meet the requirements of the power indication function and the voltage indication function of each phase, the phase power supply on the switching power supply side and the phase power supply on the switching load side of the switch can be electrically connected to one of the boxes next to the switch. Through the internal power conversion circuit of the box, it is judged whether the incoming call is made, and the relative electrical properties are displayed and displayed on the panel, so that the functions of the voltage display and the power display of each phase of the switch contact can be achieved.

In order to achieve the under-phase status indication function, the contacts on the switching power supply side and the load side are electrically connected to the device. If the power supply side and the load side are not equipotential, the under-phase state can be interpreted, and the microprocessor outputs The switch state signal is electrically connected to the display panel, so that the above functions can be achieved.

In order to achieve the reverse power status indication function, the contacts on the switching power supply side and the load side are electrically connected to the device. If there is no power on the power supply side, but the load is powered, the reverse power transmission state can be read. The output switch status signal is electrically connected to the display panel, so that the above functions can be achieved.

In order to achieve the switch ON state indication function, the contacts on the switching power supply side and the load side are electrically connected to the device. If there is power on the power supply side and there is power on the load side, the switch ON state can be read. In order to achieve the switch OFF state or the Trip state indication function, the contacts on the switching power supply side and the load side are electrically connected to the device. If there is power on the power supply side and there is no power on the load side, the switch can be read as OFF or Trip. In this state, an OFF auxiliary contact, such as a micro switch, can be added to the outside or inside the CB to resolve the state of OFF or Trip. At this time, the switch output signal of the microprocessor output is electrically connected to the display panel. This will meet the requirements of the above functions.

In order to achieve the switch contact welding state indication function, the contact point on the switching power supply side and the load side is electrically connected to the device, and at this time, a shunt trip coil is added, and when the shunt trip coil is actuated, the switch secondary load is applied. If the side is equipotential to the power source, it means that the switch contact has a fusion phenomenon. Similarly, the trip button of the switch can be manually held, and it is visually determined whether the current switch has a joint fusion phenomenon, and whether the welding must be performed under the permission, such as the old repair or the test is safe and flawless, and The system will not cause damage due to testing.

In order to achieve the function of indicating the leakage state of the switch, it is possible to know whether there is any circuit in the circuit of the line switch by adding zero current comparator or leakage detection protection power to the secondary load side of the switch. In the state of leakage, the switch state signal outputted by the microprocessor is electrically connected to the display panel, so that the above functions can be achieved.

In order to achieve the state that the switch can understand whether the system is overloaded, the electromagnetic switch on the system can be utilized to use the contact point of the thermal overload electric power of the electromagnetic switch to achieve the indication state function of the overload state, and the other embodiment is in the electronic circuit. In the design, there is a set loop and a comparison loop to know whether it is overloaded, so that the function of the overload indication state can be achieved.

In the same way, in order to achieve the indication function that the switch can have a phase sequence state, the electronic circuit can be electrically connected to the primary power supply side of the switch, and the internal internal key has a phase sequence sequence detecting device, so that when the phase sequence in the system loop must be interpreted, , no need to use instrument testing, and can ensure the safety of the system loop.

In order to achieve the protection function of the switch in the accident state, the development side can be electrically connected to the electronic circuit and the comparison circuit of the accident value can be set, so that the state indication at the time of the accident can be achieved. If it is not the above fault state, and it is interpreted as the Trip state, it can be determined as a short circuit accident state.

The above embodiment case is a detection method when the system is powered. When the system has no power input, the input button of the device has the input of the backup battery pack, and can perform the function of detection and simple test when there is no power input condition. .

The above switch contact status display device can be used in the normal power supply to know all the status functions, and if there is no power supply, the built-in electronic circuit and the internal or external battery pack can be used to understand the status. And in the middle between the box body and the indication state display panel, the cable can also be connected in a line manner, so that the state display panel can be indicated on the disk surface or the disk, thereby greatly improving the quality of power consumption.

10‧‧‧Circuit breaker

11‧‧‧ Circuit breaker power supply side

12‧‧‧ Circuit breaker load side

15‧‧‧Button button switch

16‧‧‧Handles

17‧‧‧Auxiliary micro switch

18‧‧‧Split trip coil

20‧‧‧Switch contact status display device

21‧‧‧ terminals

22‧‧‧Box

23‧‧‧Dial switch Dip sw

24‧‧‧ display panel

25‧‧‧ dry contact output terminal

26‧‧‧Display panel terminals

27‧‧‧Box terminal

28‧‧‧ cable

30‧‧‧Electronic circuits

32‧‧‧Microprocessor (CPU)

41‧‧‧ Under-phase indicator

42‧‧‧Reverse phase indicator

43‧‧‧ON indicator

44‧‧‧OFF indicator

45‧‧‧Trip indicator

46‧‧‧Leakage indicator

47‧‧‧Overload indicator

48‧‧‧Short-circuit indicator

49‧‧‧phase sequence indicator

50‧‧‧ welding indicator

51‧‧‧Power indicator

52‧‧‧R phase indicator

53‧‧‧S phase indicator

54‧‧‧T phase indicator

55‧‧‧N phase indicator

56‧‧‧U phase indicator

57‧‧‧V phase indicator

58‧‧‧W phase indicator

59‧‧‧G phase indicator

70‧‧‧Leakage protection

71‧‧‧ Thermal protection

72‧‧‧ Zero comparator

80‧‧‧ phase sequence protection

90‧‧‧Power storage device

91‧‧‧External power input terminal block

Fig. 1 is a schematic view showing the appearance of the switch contact state display device of the present invention on the CB.

Fig. 2 is a schematic view showing the appearance of the switch contact state display device of the present invention beside the CB.

Fig. 3 is a perspective view showing the connection between the display panel and the main body of the switch contact state display device of the present invention.

Fig. 4 is a logic diagram showing the operation state of the switch contact state display device of the present invention.

Fig. 5 is a block flow chart showing the operation sequence of the switch contact state display device of the present invention.

Figure 6 is a circuit diagram of an electronic circuit of the switch contact state display device of the present invention.

Figure 7 is a schematic diagram of the internal device of the switch contact state display device of the present invention.

Fig. 8 is a schematic view showing the branching tripping and the auxiliary microswitch of the switch contact state display device switch of the present invention.

According to the switch contact state display device 20 of the present invention, a preferred embodiment of the device is implemented. As shown in FIG. 1, the switch contact state display device 20 is fixed above the circuit breaker 10, and the inside of the casing 22 is provided with electrons. The circuit 30 and the microprocessor 32 (refer to FIG. 6), the terminals of the power supply side 11 and the load side 12 of the circuit breaker 10 are electrically connected to the corresponding terminals 21 of the switch contact state display device 20 to the electronic circuit 30, respectively. . Above the box 22 is a dip switch 23, which can be selected according to system requirements. At this time, the voltage value of each point to the ground can be measured by the electronic circuit 30 to see if there is a voltage value. Please refer to FIG. 6 , whether the signal with voltage value at each point is electrically connected to the microprocessor 32, according to the preset operation state logic table of FIG. 4, the calculation is performed to know the state of the switch contact, and the state thereof is The output from the microprocessor 32 to the display panel 24 controls the lighting of the corresponding indicator number. Its state can be electrically connected to the dry contact output terminal 25 as an output contact for other applications.

As shown in Fig. 2, the second embodiment of the present invention is provided. If there is still space on the side of the circuit breaker 10, the switch contact state display device 20 can be designed on the side of the circuit breaker 10. The inside of the casing 22 is provided with an electronic circuit 30, a power storage device 90, a thermal protection device 71, a leakage protection device 70, a phase sequence protection device 80, and a microprocessor 32 (refer to FIG. 7), and the circuit breaker 10 thereof. The terminals of the power supply side 11 and the load side 12 are electrically connected to the electronic circuit 30 to the corresponding terminals 21 of the switch contact state display device 20, respectively. Above the box 22 is a dip switch 23, which can be selected according to system requirements. At this time, the voltage value of each point to the ground can be measured by the electronic circuit 30 to see if there is a voltage value. Please refer to FIG. 6 , whether the signal with voltage value at each point is electrically connected to the microprocessor 32, according to the preset operation state logic table of FIG. 4, the calculation is performed to know the state of the switch contact, and the state thereof is The output from the microprocessor 32 to the display panel 24 controls the lighting of the corresponding indicator number. Its state can be electrically connected to the dry contact output terminal 25 as an output contact for other applications. The code and function of the switch contact state display device 20 are the same as in FIG.

Referring to FIG. 3, it is a third embodiment of the present invention. For example, when some applications must display the state of the switch contacts on the surface of the power distribution box, the display panel 24 of the switch contact state display device 20 must be connected to the box. The body 22 adopts a separate design. The display panel 24 and the casing 22 are respectively provided with signal connection terminal blocks 26 and 27, and the terminal blocks 26 and 27 are designed in a male-female foolproof manner, and signals are connected via the cable 28 so that the display panel 24 can be mounted on the display panel 24 The corresponding position.

FIG. 4 is a schematic diagram showing the system circuit of the switch contact state display device 20 of the present invention and a corresponding operation state logic table. Through the measurement by the electronic circuit 30, it is known whether the voltages of the respective phases on the primary side and the secondary side are present. The measured signal of each phase voltage is sent to the microprocessor 32, and the state of the switch contact is known via the action state logic table. For example, the first column and the secondary side of the first column each have a voltage, which represents that the switch state is ON. At this time, the lamps of the display panel 24 are illuminated with lights 51, ON 43, R 52, S 53, T 54 , N 55, U 56, V 57, W 58, G 59. Whether it is a fusion or not can be further determined when the test is allowed or repaired at a later age (described later).

For example, when the voltages of the respective phases enter the electronic circuit 30, when there is a voltage on the primary power supply side 11 and there is no voltage phenomenon on the voltages of the secondary load side 12, the microprocessor 32 outputs a signal to the display panel 24 to make the phase-out phase The indicator light 41 is on. The microprocessor 32 outputs a signal representative of the state of the switch and is coupled to the dry contact output terminal block 25 for use as an output contact for other applications.

Similarly, when the voltages of the above phases are fed into the microprocessor 32 via the electronic circuit 30, according to the functional requirements on the logic table of the operation state, when the primary side 11 has no voltage and the secondary load side 12 has voltage, then The phenomenon of reverse power transmission can be interpreted, and the microprocessor 32 outputs a signal to the display panel 24 to cause the reverse phase indicator light 42 to illuminate. The microprocessor 32 outputs a signal representative of the state of the switch and is coupled to the dry contact output terminal block 25 as an output contact for other applications.

According to the functional requirements on the operating state logic table, the voltages of the respective phases are sent to the microprocessor 32 via the electronic circuit 30. When the primary power supply side 11 has power and the secondary load side 12 has no power supply, there are two possibilities. One is the state of turning off the OFF, and the other is the state of tripping the Trip. At this time, the signal enters the internal microprocessor 32. If it is better on the circuit breaker 10, there is an auxiliary micro switch 17 in the internal position of the circuit breaker 10, and an auxiliary micro switch 17 in the OFF position (see Fig. 8). When there is an action, it means that it is currently in the OFF state. If not, it means that it is currently in a state of jumping off the Trip. At this time, the microprocessor 32 outputs a signal to the display panel 24 to turn off the OFF indicator 44 or the Trip indicator 45 to light, and the microprocessor 32 outputs a signal representing the state of the switch, and is connected to the dry contact output terminal block 25, As an output contact for other applications.

As described above, when both the power source side 11 and the secondary load side 12 have a voltage signal, it indicates that the switch state signal is ON or welded. During the test, the branch trip coil 18 can be arranged inside the circuit breaker 10 (please refer to FIG. 8). Under the premise that the circuit breaker 10 is tripped, the microprocessor 32 sends out the control of the split trip coil 18 to be triggered. The signal causes the trip coil to operate. At this time, if there is no voltage on the secondary load side 12, it means that the circuit breaker 10 contact is not welded, and when the secondary load side 12 still has a voltage source, it represents that the circuit breaker 10 contact has already been The phenomenon of welding. If the trip coil 18 is not added, the trip button switch 15 on the circuit breaker 10 can be pressed in a manual manner. If the trip button switch 15 is pressed, the ON indicator 43 is always on, that is, the expression is In the spliced state, the fused indicator light 50 illuminates.

According to the design of the switch contact state display device 20 of the present invention, the zero current comparator 72 can be added to the primary power supply side 11 and the secondary load side 12 (refer to FIG. 6), if the primary power supply side 11 input current is not equal to The secondary side 12 outputs current, that is, ΣI ≠ 0, so that it can be understood whether there is a leakage condition. At this time, the microprocessor 32 outputs a signal to the display panel 24 to light up the leakage indicator light 46, and the microprocessor 32 outputs a signal representing the state of the switch, and is connected to the dry contact output terminal block 25 for other applications. Output contact. Another embodiment is (refer to FIG. 7). If the leakage protection device 70 is externally connected, when the leakage state occurs, the contact signal of the leakage protection device 70 is input to the microprocessor inside the device 20. 32 to do the interpretation, can also achieve the above functions.

Similarly, according to the design of the switch contact state display device 20 of the present invention, if a device for accumulating heat protection device 71 is designed (refer to FIG. 7), when the overload occurs, the heat generating device 71 acts, and the heat generating device 71 is operated. The contact signal input to the microprocessor 32 inside the device 20 is interpreted to indicate an overload (see Figure 6). At this time, the microprocessor 32 outputs a signal to the display panel 24 to light up the overloaded indicator light 47, and the microprocessor 32 outputs a signal representing the state of the switch, and is connected to the dry contact output terminal block 25 for other applications. Output contact.

According to the design of the switch contact state display device 20 of the present invention, if the phase sequence protection device 80 (see FIG. 7) is designed, the action state contact is directly input to the device 20, and via the internal microprocessor 32. At the same time, the microprocessor 32 outputs a switch status signal to the display panel 24 to cause the phase sequence indicator light 49 to illuminate, the microprocessor 32 outputs a signal representative of the switch state, and is connected to the dry contact output terminal block 25, As an output contact for other applications.

According to the design of the switch contact state display device 20 of the present invention, when the voltage source input of the primary power supply side 11 and the secondary load side 12 is input, the internal microprocessor 32 is analyzed and compared, if it is not the operation state logic table of FIG. The switch status is indicated as an accident status. At this time, the microprocessor 32 sends a set of signals to the display panel 24 to light the shorted indicator light 48, and the microprocessor 32 outputs a signal representing the state of the switch, and is connected to the dry contact output terminal block 25 as a Output contacts for other applications.

The switch state display principle described above, the main decision core is the microprocessor 32, and the program execution flow chart of the microprocessor 32 is as shown in FIG.

In the design of the switch contact state display device 20 of the present invention, in principle, when the power supply side has a power supply, the above-mentioned actions are achieved as scheduled, and the external power source is connected via the power input terminal block 91. However, when there is no external power input, the device 20 is not functionally usable. Therefore, a set of power storage devices 90 is provided inside the switch contact state display device 20, and when the external power source fails, the power storage device 90 can also be powered. The switch contact state display device 20 is normally operated, and the appearance is as shown in FIG.

In summary, the switch contact state display device of the present invention can be installed next to each switch, and has a cable connected to the disk surface, and through the electronic circuit and other peripheral measuring switches, the phase and voltage of each phase and current of the secondary side The signal is protected by the microprocessor, and the state of the switch is determined by the microprocessor according to the action logic state table to be displayed on the display panel, and has a dry contact output terminal, which can solve various special requirements through the internal mechanical structure and internal control components. The application, the use of the industry, and the related products in the market and the approved patent announcements, do not see the same technical features as the essence of the present invention, and also meet the statutory patent application requirements of novelty and progress. . To apply for a patent application in accordance with the law, you are requested to give the examination committee an early grant of the patent to ensure the applicant's rights and interests. However, the present invention is not limited to the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and any equivalent changes or modifications made in accordance with the spirit of the present invention are still covered by the scope of the present invention. in.

Claims (10)

 A switch contact state display device comprises a box body having a primary side and a secondary side voltage input terminal, an external input connection terminal, and a terminal block group for connecting an internal electronic control circuit board; a display panel, The display panel has a light state indicator light group in a switch state.    The switch contact state display device according to claim 1, wherein the electronic control circuit board of the box body comprises an electronic circuit for sensing a voltage signal of the primary side and the secondary side of the switch; According to the input signal, the switch contact state is determined, and the switch contact state is electrically connected to the display of the display panel, and the output connection of the contact state.    For example, the switch contact state display device described in claim 1 is characterized in that the built-in program of the micro-processor is based on the presence or absence of a voltage signal of each phase sequence of the primary side and the secondary side of the switch, and the overloaded thermal power and leakage protection power The signal contacts of the 驿 and phase sequence protection 驿 are used to determine the state of the contact of the calculation switch.    The switch contact state display device according to claim 1, wherein the electronic circuit is electrically connected to the primary side of the switch and the phase sequence of the secondary side and the ground, and is connected in series with a plurality of resistors for voltage division and rectification. Each phase sequence has an electrical and no electrical signal to the microprocessor.    The switch contact state display device according to claim 1, wherein the display panel is integrally disposed on the surface of the box body; or is disposed separately from the box body, and the terminal block of the box body and the display panel is connected by a cable. It is convenient to install the display panel to the desired position.    For example, the switch contact state display device described in claim 1 is provided with a dip switch Dip sw above the box body, which can be used to switch the specifications of the input power source.    The switch contact state display device according to claim 1, wherein the display panel has a power display, and each phase voltage display is closed ON, turned off OFF, tripped Trip, owed phase display, reverse phase display, and leakage display , overload display, phase sequence display, welding display and short circuit display function, various display functions, and can be adjusted according to actual needs.    The switch contact state display device according to claim 1, wherein the device can be disposed above the switch, on the side, on the disk surface, or on the disk body.    A switch contact state display device according to claim 1, wherein the switch has a branch jump switch therein and an auxiliary contact connected to the device, and when the system is faulty, Make the switch do the tripping action.    A switch contact state display device according to claim 1, wherein the case body has an internal power storage circuit and an external input standby power supply terminal.