When we stepped into the production line, the first thing the substitute teacher told us was safety. According to the monitor, even in Chaochuan, blindness, broken fingers, crushed legs and feet, etc. Problems caused by negligence and tampering with equipment have all appeared. This sounds terrible. Indeed, if safety issues are ignored at the scene, it is easy to cause accidents. Of course, it is yourself who suffers. Therefore, when we gather at work every day, we will shout the slogan together: "Safety first". In order to tell myself to think twice before doing anything. Don't rely entirely on your own feelings and experience.
After that, the leader on duty arranged for us to go online for production. I didn't know anything when I first started surfing the internet, and everything was slow. I am not familiar with the use of those fixtures and gauges, and even some fixtures and gauges are new to our school. So during my internship, I always feel that what I learned at school is really limited. It is difficult to combine the learned theory with practice. However, after months of training by substitute teachers, team leaders and their leaders, I finally learned some basic operations, maintenance and problems that are easy to appear on measuring tools and machine tools. However, there are still many things to learn about turning, milling and drilling machines. Therefore, with curiosity and interest in those unknown knowledge, I must seize every learning opportunity and open up unlimited space for my development in Chaochuan.
* * * * * In the process of internship, I have gained a lot from technology, teamwork and professional quality. Technically, this internship gave me an opportunity to apply what I have learned to solve practical problems. During the internship, a lot of previously unskilled knowledge was gradually understood, and many aspects that I didn't notice were consolidated. In the process of finding and solving problems, I learned a lot of new things. In addition to the technical requirements mentioned in the textbook, I have a deeper understanding in the following aspects:
First of all, team spirit is particularly important in internship, because we work in the same group. First, we should make an accurate plan and have a clear division of labor. In the process of measurement, we should not only do our own work well, but also consider the work of the same group to bring convenience to others as much as possible. The cooperation of team members is very important, and the atmosphere of the internship team greatly affects the progress of the experiment.
Second, we must preview the measurement methods and related calculation formulas in time before the internship, and follow the arrangement of the instructor during the internship to avoid mistakes and mistakes caused by wrong measurement methods. Be familiar with the use of instruments, understand the sources of errors and measures to reduce errors, and master a set of scientific measurement methods. In the measurement, we should follow certain measurement principles, such as "from the whole to the part", "control the part first" and "from high to low", and check step by step. This can not only prevent the accumulation of errors and find them in time, but also improve the efficiency of measurement.
Third, the calculation in the industry must be very careful, because any small error may lead to the overall error, and error testing is also very important, and all data should be controlled within the allowable range.
Fourth-class leveling, longitudinal leveling and site copying average need to check the tolerance, and must be re-measured when it exceeds the tolerance. Because of the hot weather, I initially held an exclusive attitude towards this internship, but when I saw that my classmates were seriously measuring and practicing, I was infected. I also joined the survey with them, scrambling to operate the instruments and seizing every opportunity to improve my growth. Although the weather was very hot, we successfully completed the measurement through the joint efforts of everyone. After many days of cooperation, every classmate's face is much kinder. When all the work was finished, we reviewed the initial suffering together and found that there was nothing. We persisted and made achievements, and everyone was sweeter than anything else.
Through practical surveying practice, I learned a lot of real things, such as being more proficient in the operation of practical instruments, and learning things that I can't do in class, such as topographic mapping and the measurement of broken parts, which greatly improved my hands-on ability and brain ability, and also expanded my communication and cooperation ability with my classmates. It is not enough to complete a measurement practice only by one person's strength and conception. Only the cooperation and unity of the group can make the exercise complete quickly and efficiently. ******
In the third year of college, we have entered the study of professional courses. In order to further combine professional knowledge with practice, we conducted cognitive practice. In fact, cognitive practice can not fully learn some professional knowledge, but as a direct contact between college students and the actual environment, and it is the first time, it will certainly be helpful for future professional study and personal development.
Through practice, I not only got the basic knowledge of automation, but also got familiar with the general operation flow, production mode and technological flow of automation production, the working principle and typical structure of main processing methods and the safe operation technology of main equipment used, which strengthened the practice of integrating theory with practice, improved the practical ability and cultivated the engineering quality of learning from workers and field technicians. Professionally: consolidate the relevant knowledge of professional basic courses and some professional courses, and make necessary knowledge preparation for subsequent professional courses; Through practice, learn the actual production skills of this major, understand more professional technical knowledge and application status, and broaden professional knowledge; Cultivate students' work style of integrating theory with practice, establish the production concept of safety first, and improve their ability to analyze and solve problems independently; Through practice, we can deepen students' understanding and knowledge of majors and create conditions for further study of professional courses. The internship report mainly includes three parts: 1, introduction of internship institutions, contents of internship methods and internship experience.
Graduation Practice Report of the Department of Electrical and Electronic Engineering Internship Time: Wuzhai Coal Mine and Baodian Coal Mine of Tian Li Co., Ltd. of Pingdingshan Coal Group have enjoyed excellent geographical location and convenient transportation since they were put into production in 1986. This mine is a large-scale modern mine designed and built by China with an annual output of 3 million tons, and is equipped with a coal washing plant with an annual washing capacity of 3 million tons. At present, the actual annual output reaches 6.36 million tons, and the clean coal reaches 36 1 10,000 tons.
I. Purpose of internship: 1. Graduation practice is a very important part of our university. Through practice, I have further mastered the professional knowledge of electrical engineering and automation, combined theoretical knowledge with production practice, applied and practiced knowledge, and consolidated knowledge in practice, paving the way for us to adapt to the work more quickly when we are about to embark on the job. 2. Through graduation practice, I really understand the different ideas and methods of practical work and theoretical study during my school years. We should integrate into the work as soon as possible with a new look, a new attitude and a new way of thinking to meet the requirements of the work. 3. In the process of graduation practice, we should not only see the gap between theory and reality, but also see their connection and importance. We can't give up any of them. We are leaving school soon, but we still can't give up the theory, but we should strengthen the theoretical study of field work. 4. Recognize the importance of strictly obeying the leadership, going to work on time, sticking to the post and professionalism, and lay a good foundation for the work after graduation.
Part I Electrical Safety Management 1. Safety inspection of power lines in factories. Power lines are an important part of power system and undertake the important task of transmitting electric energy. However, at present, in some factories, the safety inspection and operation and maintenance of power lines are often not paid enough attention, which leads to the reduction of the safety of power lines in individual sections and increases the possibility of electrical accidents. Therefore, it is very necessary (1) to strengthen the safety inspection of power lines in factories. Generally, the overhead lines of the factory should be inspected 1 time every month. In case of strong wind, heavy rain, failure and other special circumstances, it is necessary to temporarily increase the number of safety inspections. The safety inspection of overhead lines should focus on the following items:
1. Whether the telephone pole is inclined, deformed, decayed, damaged or the foundation sinks. 2. Whether flammable, explosive and corrosive substances are piled up on the ground along the line. 3. Are there any dangerous buildings around the route? We should try our best to ensure that these buildings will not damage the lines in thunderstorm season and windy season. 4. Whether there are branches, kites and other sundries hanging on the line. 5, stay and sheet pile are in good condition, stay is tight and reliable. 6, wire connector is in good contact, with or without overheating, redness, serious aging, corrosion or broken phenomenon; Whether the insulator is polluted and discharged. 7, lightning protection grounding device is in good condition, grounding wire corrosion. Before the thunderstorm season comes, we should focus on inspection.
(II) Safety inspection of cables Cables are generally laid underground. To do a good job in the safe operation and inspection of cables, it is necessary to fully understand the laying mode, structural layout, routing direction and cable head position of cables. Generally, 1 safety inspection is carried out on cables every quarter, and the load and heat are often monitored. In case of special circumstances and faults such as rainstorm and flood, it is necessary to temporarily increase the number of safety inspections. The safety inspection of cable lines should focus on the following items: 1, cable terminals and porcelain bushings for damage and discharge traces. Also check whether the cable terminal filled with cable glue (oil) leaks oil and overflows glue. 2. For bare cables, check whether there is rust or damage on the cable surface, whether there is hook or bracket falling off along the line, and whether there are flammable, explosive and corrosive substances piled up on and near the line. 3. For buried cables, check whether the cover plates along the line are in good condition, whether there are excavation traces and whether the routing signs are complete. 4. Whether there is water and seepage in the cable trench, and whether there are sundries and inflammable and explosive articles piled up. 5, all kinds of grounding on the line are in good condition, with or without looseness, broken strands and corrosion. (III) Safety inspection of workshop distribution lines To do a good job in the safety inspection of workshop distribution lines, we must also fully understand the wiring situation, structural form, conductor model and specification, the location of distribution box and switch, and understand the size of workshop load and the situation of workshop distribution room. When there is a special maintenance electrician in the workshop distribution line, it is generally required to conduct 1 safety inspection every week. The inspection items are as follows: 1. Check the heat of the conductor. 2. Check the load of the line. 3, check the operation of distribution box, junction box, switch, fuse, bus duct and grounding zero device, etc. , focus on checking whether there is any oxidation, overheating, discoloration and corrosion on the bus joint, whether there is any looseness, discharge and singeing on the wiring, and whether there is any tightening on the bolts. 4, check whether there is any abnormal situation on and around the line that affects the safe operation of the line. It is absolutely forbidden to hang objects on insulated wires, and it is forbidden to pile up inflammable and explosive articles on the roadside. 5. For lines laid in damp and corrosive places, the insulation should be checked regularly, and the insulation resistance should generally not be less than 0.5 μ Ω.
Two. Operation, Development and Management of Substations Doing well in the operation and management of substations is an important guarantee to realize safe, reliable, economical and reasonable power supply. Therefore, the substation must be equipped with operating rules and regulations that conform to the actual situation on site, and be handed over to the personnel on duty to learn and strictly abide by them to ensure safe production. (a) 1 operating system. Must seriously implement the system of succession. Handover personnel shall perform handover procedures in strict accordance with regulations, with specific contents and requirements as follows. (1) The successor shall fill in all records in detail and do a good job in environmental sanitation; In case of homework or tasks, you should take the initiative to prepare for the work. (2) The successor shall introduce the following information in detail: 1. The operation mode, renovation and decoration, equipment defects, accident treatment, superior notice and other related matters of the equipment under its jurisdiction; 2 tools, instruments, spare parts and keys are complete. (3) The successor should listen carefully to the handover content and check whether the simulation panel is consistent with the on-site operation mode. After the handover, both parties shall sign the handover record book. (4) During the shift change, try to avoid switching operation and licensing work. In case of any accident or abnormal operation during handover, the handover shall be stopped immediately. In principle, the successor shall be responsible for handling it, and the successor shall take the initiative to assist in handling it. After the accident treatment, continue to handle the handover procedures. (5) In case the successor is drunk or insane, the successor shall refuse to hand over, report to the superior leader in time and make proper arrangements. 2. Patrol inspection system In order to master and monitor the running state of equipment and find anomalies and defects in time, a regular and special patrol inspection system is implemented for the running and standby equipment in the hospital, and it is constantly revised and improved in practice. (1) patrol period. Patrol the substation on duty once every hour, the unattended substation at least once every four hours, and the workshop substation once every shift. Conduct special inspection when necessary. (2) Check the project regularly. 1) Whether the oil level of the refueling equipment is appropriate, whether the oil color is clear and whether there is leakage. 2) Whether the porcelain bottle is damaged or discharged. 3) Whether the connection point is overheated. 4) Whether the sound and temperature of transformer and rotating motor are normal. 5) Whether the cooling device of the transformer works normally. 6) The capacitor has no abnormal sound, and the shell has deformation and expansion. 7) Whether the power cable junction box leaks oil. 8) Whether all kinds of signal indications are normal and whether the positions of circuit breakers and disconnectors in the secondary circuit are correct. 9) relay protection and automatic device linking piece position is correct. 10) Whether the indicator is normal and whether the pointer is bent or stuck; Is the watt-hour meter stopped or down? Whether the DC bus voltage and floating charge current are appropriate. 12) whether the liquid level of the battery is appropriate, whether the color of the polar plate is normal, and whether there are phenomena such as salt formation, bending, fracture, bubble expansion, local short circuit, etc. 13) Whether the equipment defects have developed or changed. (3) Special inspection items. 1) Before the strong wind comes, check the surrounding sundries to prevent them from blowing on the equipment; When the wind is strong, pay attention to whether the distance between the outdoor cord and the ground is too small. 2) After lightning strike, check whether there is any discharge trace on the insulation of porcelain insulator, whether the lightning arrester and lightning rod discharge, and whether the lightning counter operates. 3) In fog, rain, snow and other weather, we should pay attention to observe the insulation discharge of porcelain insulator. 4) Under heavy load, check whether the contacts and connectors are overheated. 5) When the operation is abnormal, check the voltage, current and relay protection action. 6) Turn off the lights at night and check whether there is lightning flashover on porcelain insulation and overheating and redness on connection points. (4) Safety regulations that should be observed when patrolling. 1) In general, the inspection of high-voltage distribution equipment should be carried out jointly by two people, and the personnel who pass the examination and are approved by the unit leader are allowed to inspect the high-voltage equipment alone. When patrolling power distribution equipment and entering and leaving the high-voltage room, you must close the door behind you. 2) When patrolling high-voltage equipment, it is forbidden to move or cross obstacles, and no operation is allowed; If it is necessary to move the fence, a guardian must be present and keep the following safe distance: 10kV and below 0.7m 35Kv 1m 3) When the conductive part of the high-voltage equipment is grounded, it shall not be within 4m indoors and 8m outdoors. Personnel entering the above range must wear insulating boots and gloves when touching the equipment shell and frame. 3, equipment defect management system to ensure that the equipment is always in good technical condition is one of the important links to ensure safe operation. In order to fully grasp the health status of equipment, when equipment defects are found, they should be eliminated as soon as possible, and efforts should be made to nip in the bud. At the same time, it also provides a basis for arranging the work plan of equipment maintenance and testing. The following equipment defect management system must be seriously implemented. (1) All electrical equipment of various voltage levels that have been put into operation or standby, including electrical primary and secondary circuit equipment, lightning protection devices, communication equipment, power distribution equipment frames and buildings, etc., belong to the scope of equipment defect management. (2) According to the degree of threat to power supply and use safety, defects can be divided into three categories: I, II and III. Class III defects are emergency defects, which refer to defects that may cause personal injury, large-scale power failure, damage to major equipment or power failure accidents that have political impact. This defect is serious and critical and must be dealt with immediately; ? Class II defects are major defects, which mean that the equipment can continue to operate, but the situation is serious, which has affected the output of the equipment, can not meet the needs of the normal operation of the system, or an accident will occur in a short time, threatening the safe operation; ? Class III defects are general defects, with general nature and slight conditions, which will not endanger the safe operation for the time being, and can be included in the plan for treatment. After finding defects, we should carefully analyze the causes of defects and deal with them according to their nature and situation. When an emergency defect is found, you should immediately try to cut off the power supply and deal with it. At the same time, it should report to the person in charge of the unit and the power supply bureau. When major defects are found, they should be reported to the person in charge of electricity and dealt with as soon as possible; If you can't deal with it immediately, you must arrange a treatment plan within a week. After discovering general defects, we should actively deal with them whether they affect safety or not. For their own defects that are difficult to deal with, they should report to the person in charge of electric power and be included in the planned maintenance to eliminate them. The defects found and eliminated shall be recorded in the defect record book in time and accurately. The main contents of defect record shall include: equipment name and number, main defects, classification and attribution of defects, name and date of discoverer, treatment scheme, treatment result, name and date of handler, etc. The person in charge of electrical equipment should hold regular meetings with relevant personnel to analyze and study the causes, development laws, best treatment methods and preventive measures of equipment defects, and continuously improve the operation and management level. 4. The on-site environmental management system (1) should adhere to civilized production, be clean and tidy regularly, and always keep the on-site environment clean and tidy. (2) The fire control facilities shall be fixed in a convenient location. (3) Equipment operation channels and patrol walkways must be kept clear at any time, and it is forbidden to pile up sundries. (4) Buildings such as control room, switch room, capacitor room and storage battery room should be maintained regularly to meet the requirements of "four precautions and one ventilation" (fire prevention, rain and snow prevention, flood control, prevention of small animal invasion and good ventilation). (5) The cable ditch cover plate shall be intact; There should be no water in the cable trench. (6) Weeds should be removed regularly outdoors. It is forbidden to plant tall or climbing plants in the equipment area. If it is necessary for greening, use shrubs and prune them frequently. (7) Motor vehicles (such as cranes) can only enter the substation area with the approval of the electrical supervisor. Implement safety measures before operation, always keep a safe distance from the live part of the equipment during operation, and have special personnel to monitor it. (II) Technical management Technical management is an important aspect of substation management. Through technical management, operators have rules to follow, it is convenient to accumulate data and analyze operation accidents, which is conducive to improving the technical management level of operators and ensuring the safe operation of equipment. Technical management should do the following work. 1. Collect and establish the original data of equipment files (1), such as substation design book (including electrical and civil facilities), design product manual, acceptance record, startup scheme, existing problems, etc. (2) Primary and secondary wiring and professional data (including development diagram, screen layout diagram, wiring diagram, relay protection device setting book, etc.). (3) Equipment account (including equipment specifications and performance, etc. (4) Equipment maintenance report, test report and relay protection inspection report. (5) Simplified test report and chromatographic analysis report of insulating oil. (6) Load data. (7) Equipment defect record and analysis data. (8) Safety records (including records of accidents and abnormal situations). (9) Operation analysis record. (10) Operation work plan and monthly report. (1 1) equipment regular quota data. 2. The regulations to be established and preserved shall be preserved by the Ministry's Regulations on Electric Safety Work; Transformer operation regulations; Operating rules for power cables; Specification for handover test of electrical equipment; "Substation Operation Regulations" and accident treatment regulations of our hospital. 3. The technical drawings should include lightning protection diagram, grounding device diagram, civil engineering diagram, iron processing diagram and equipment insulation supervision diagram. 4. Hanging charts should be hung with primary system simulation diagram, main transformer joint and operation position diagram, substation patrol inspection road map, equipment classification and defect disclosure table, relay protection setting table, substation quarterly work schedule, personnel list with working ticket issuance right, equipment partition management table and cleaning work area division diagram. 5. There should be record books, such as duty diary, duty operation record book, work ticket register book, equipment defect record book, electric test site record book, relay protection record book, circuit breaker action record book, battery maintenance record book, battery measurement record book, lightning activity record book, superior document registration and superior instruction record book, accident and abnormal situation record book, safety situation record book and foreign personnel entry and exit register book. C. Handover test and acceptance of electrical equipment The newly-built substation or newly-installed or overhauled electrical equipment shall be handed over for test according to regulations, and the user shall go through the handover acceptance formalities with the test department. The handover acceptance items include: whether the completed project meets the design; Whether the project quality meets the specified requirements; Adjust whether the test items and their results meet the electrical equipment handover test standards; Whether all technical data are complete, etc. Electrical equipment handover test is to check whether the performance of newly installed or overhauled electrical equipment meets the requirements of relevant technical standards, to determine whether insulation damage or performance changes occur during transportation and installation of newly installed electrical equipment, or to determine whether the quality of repaired parts meets the requirements after overhaul. For the electrical equipment in operation, the routine test, that is, preventive test, is carried out according to the specified period. Through preventive tests, hidden defects in electrical equipment can be found in time and eliminated together with maintenance, so as to avoid insulation damage of equipment in operation, resulting in power failure or even serious equipment burning accidents. In the electrical handover test, insulation test (such as insulation resistance, leakage current, dielectric loss tangent tg of insulation medium (and gas chromatography analysis in oil)) and characteristic test (such as DC resistance of transformer, transformation ratio, wiring group, contact resistance of circuit breaker, opening and closing time and speed characteristics, etc.) are mainly carried out for primary high-voltage equipment; The secondary loop mainly tests relay protection devices, automation devices and instruments, and tests insulation resistance. The handover test of electrical equipment is generally the responsibility of the electric power department, which requires compliance with the handover test procedures of electrical equipment. Part II Coal Mine Electromechanical Safety 1, Five Natural Disasters in Coal Mine, Main Components of Gas and Conditions of Gas Explosion (1) Water, fire, gas, coal dust and roof are the five natural disasters in coal mine. (2) The main component of gas is methane (CH4), commonly known as biogas, in addition to nitrogen, carbon monoxide and hydrogen sulfide. The methane content in gas is generally above 83%. (3) The three conditions of gas explosion are: a. When the gas reaches a certain concentration, it is generally 5%- 16%, and it can only be burned if it is lower than 5% or higher than 16%. However, when there is coal dust in the mixed gas, the lower explosion limit will drop, because coal dust can release a lot of combustible gas at 300-400℃. B, there is a fire source, the general temperature is between 650-750℃. C, oxygen content, when the oxygen content in the mixed gas is above 12%, it may cause a gas explosion. 2. The importance of explosion-proof of mine electrical equipment Sparks, arcs, hot surfaces and hot particles may appear when the electrical equipment is in normal operation or fault state. They have certain energy and can be used as a fire source for igniting mine gas and coal dust. A large number of statistical data show that the electric fire source is the main ignition source of underground gas explosion, accounting for about 50%. Moreover, with the improvement of underground electrification and the voltage level of underground electrical equipment, electrical equipment accidents are more likely to occur, so it is of great significance to do explosion-proof work of electrical equipment to prevent gas and coal dust explosion. 3. The basic explosion-proof measures of mine electrical equipment (1) adopt interval explosion-proof technology, such as the explosion-proof switch we use, which puts the electrical equipment that may detonate gas or coal dust in normal operation or fault state in a solid shell with explosion-proof structure, so that when an explosion occurs in the explosion-proof shell, it will not cause the explosion of gas or coal dust outside the shell. (2) Intrinsic safety technology is adopted, which is characterized by limiting the heat of the heat source, so that the electric spark generated by the intrinsically safe equipment can not ignite gas or coal dust in an accident or fault state, but this explosion-proof technology is only applicable to "weak current" systems. (3) Measures to improve the safety level mainly depend on improving the safety level of equipment and reducing the failure rate, thus preventing the occurrence of arc, spark or dangerous temperature. (4) Fast power-off technology, also known as advanced power-off technology, is characterized by taking reliable measures to automatically and quickly cut off fault current, so that the possible spark or arc exists for less than the shortest time required to ignite gas or coal dust. The induction period of gas explosion is generally greater than 10ms, and the induction period of coal dust explosion is generally 40-250 ms 4. Flameproof performance guarantee (1) Flameproof structure shall meet the requirements. The length and gap of flameproof joint surface are directly related to the flameproof performance of flameproof shell. As long as the width is properly designed, the instantaneous deformation and residual deformation of the joint surface will not affect the flame-proof gap under the action of explosion pressure. Flameproof surface should be clean, and the roughness of flameproof surface should also meet the requirements. (2) Anti-rust measures should be taken for the flameproof surface, such as electroplating and vulcanization. , but painting is not allowed, because paint is easy to decompose under the action of high temperature, which makes the joint surface gap larger and affects the flameproof performance of flameproof enclosure. (3) Fastening and locking between flameproof surfaces. (4) Setting of interlocking and warning signs. 5. Prevention of short-circuit fault At present, the shell strength and flameproof parameters of electrical equipment produced in China are based on the test of detonating gas by low-power ignition source. When the shell is short-circuited by arc, its explosion-proof performance cannot be guaranteed. Therefore, short circuit fault of electrical equipment should be prevented as much as possible. Therefore, regular preventive maintenance and reasonable setting of electrical equipment protection are the most effective methods to prevent electrical equipment failure. 6. Power outage maintenance system In order to prevent people from getting an electric shock, it is forbidden to work with electricity when repairing and disassembling electrical equipment. During power failure, power transmission and construction, we should strictly abide by the power failure system, work ticket system, work permit system and the relevant provisions of "Coal Mine Safety Regulations", mainly as follows: (1) Power outage personnel must know the knowledge of safety production, be familiar with electrical equipment and obtain a certificate of approval; (2) Before the power outage, the affected units and places must go through the power outage procedures, and after obtaining the approval, they will operate the power outage with the power outage operation ticket; (3) After a power outage, a power outage sign "No power transmission is allowed when someone is working" must be hung on the control switch, and no one can take off this sign except the power outage personnel; (4) It is forbidden to borrow the machine of whole mine power failure, local power failure or accidental power failure, and touch electrical equipment for maintenance or disassembly without going through the power failure formalities; (5) Where the ventilation is affected by power failure, the tile inspector should check the gas before power failure, and the gas must be checked before power transmission is resumed, and power transmission can only be carried out after permission; (6) After the power failure, before the start of the maintenance work, it is necessary to check the discharge with the corresponding test pen and ground the conductor (where gas may accumulate, it is necessary to check that the gas concentration is below 1% before discharge); (7) During the shift change, if the maintenance work is not completed, it is necessary to explain the power outage and unfinished work to the next shift at the scene; (8) When power transmission is resumed after maintenance, the personnel who originally hung the power outage card and participated in maintenance must remove the power outage card before switching on power transmission. It is forbidden to send electricity when others make an appointment; (9) If there are more than two groups of people working on the same line, they should hang their own power failure cards. After a group of work is completed, it is absolutely forbidden to switch on and send electricity when other power-off cards are not removed. 7. In the underground power supply of coal mine, in order to improve the power supply reliability of the local ventilator and reduce the interference of other factors on the ventilator, the three majors are powered by the mine substation with separate transformers, switches and cables, regardless of other loads. Gas electric locking refers to a locking device that can automatically stop power supply when the gas detector set in the heading face detects that the gas exceeds the specified concentration, and can only send electricity when the gas drops below the specified limit (methane 1%, carbon dioxide 1.5%); Wind power locking means that only when the ventilator is normally ventilated can the tunneling face be officially powered on. Once the wind stopped, the power supply to the working face was cut off. Personnel evacuated in time.