Statistics of underground accidents show that many major accidents are caused by electricity. A considerable part of the reasons are caused by human factors: either the system is lax, or the management is poor, or there are rules that are not followed and careless. Therefore, how to take various measures to strengthen the management of electrical equipment and put an end to accidents caused by electricity is a major topic of electromechanical work in coal mines at present. 1 Perfect management organization Underground electrical equipment can be roughly divided into four categories: equipment, cables, safety protection devices and small appliances. In accordance with the system, professional institutions such as equipment management, explosion-proof inspection, low-voltage electrical appliances management, small electrical appliances and cable management have been established for centralized and unified management. The equipment management group is responsible for the configuration and maintenance management of all kinds of mechanical and electrical equipment in the whole mine; The explosion-proof inspection team and the low-voltage electrical management team are divided into two or three transformer rooms according to the regional division of labor. All low-voltage equipment supplied by this transformer room is under their overall management, and they are responsible for the inspection and maintenance of electrical equipment, the management of the three major protections, the supervision and implementation of mine power supply, the inspection of explosion-proof performance, and the examination and approval of power supply in each mining area. The small electrical group is responsible for receiving, maintaining, dispatching and managing the bell, button, tee, signal line and power box of 127V system; The cable management group is responsible for the repair, distribution and deployment of power rubber-sheathed cables. Therefore, every piece of equipment, every cable and every small electrical appliance in the underground has a corresponding professional management team full-time staff who are responsible for management respectively. Clear division of labor, no buck passing. At the same time, managers have the right to inspect and accept maintenance units, inspect and supervise users and cut off power, make suggestions on the handover and stop of equipment, and make suggestions on the use of equipment. Each professional management group carries out system management in the form of drawings, cards, boards and accounts (cards), and the equipment management is mainly based on microcomputer management. On the ground, you can see the use and flow direction of underground electrical equipment at a glance. While strengthening professional management, the mine has improved the group management organization. Each mine auxiliary unit is equipped with a deputy section chief of electromechanical department. After passing the technical training and examination, the maintenance monitor of each district serves as the network operator for equipment management and explosion-proof inspection in this area. The responsibility system for mine electromechanical managers has been implemented, and the weekly meeting system of electromechanical district heads and maintenance squad leaders has been established. The combination of professional management and group management has enabled people to be promoted and demoted, reported and communicated. Members of various management networks are distributed in various workplaces and can find problems in time. It has formed an assessment and supervision system with electromechanical mine manager, electromechanical deputy mine manager, section chief, engineer, technician, "four specialized management groups", mine electromechanical district head and maintenance monitor as the backbone. Pay close attention to explosion protection of electrical equipment. First of all, strictly control the "three customs": ① maintenance. After the maintenance of flameproof electrical equipment, the platform must be qualified for explosion protection. After each equipment is put into the well, it should be disassembled for inspection and replaced with vulnerable equipment. The explosion-proof surface is polished, phosphatized and oiled. If the shell is deformed, it should be reshaped, with antirust paint on the outside and arc-resistant paint on the inner cavity. Measure the clearance, effective length and parameters of each explosion-proof surface; Replace the cracked terminal; The operation and suction mechanism should be flexible and reliable; Wait a minute. Then power on for load test. After various electrical tests and quality inspections, it is found that the equipment is safe and qualified, and the parts are complete and complete. Record the maintenance and acceptance, register the technical parameters and maintenance contents, and put a label in each equipment to indicate the maintenance personnel and main technical parameters. It is convenient to find the responsible personnel in time and accurately after the problems appear on site, and enhances the sense of responsibility of maintenance personnel. (2) acceptance. Technicians and explosion-proof inspectors are responsible for the acceptance of the electrical equipment after overhaul, re-conduct the power-on test, determine the explosion-proof technical parameters, make acceptance records, fill in the acceptance personnel and acceptance date on the internal standard, and complete the above procedures before warehousing. The mechanical and electrical department shall organize the finance, planning, auditing, enterprise management and related users for the newly arrived equipment or outsourced maintenance equipment in No.4 Mine, and put them into storage after * * * acceptance, and carry out accounting and card building. (3) Into the well. When the electrical equipment is powered on again before entering the well, the certificate of entering the well with the "Acceptance Sheet for Explosion-proof Electrical Equipment" and "Explosion-proof Qualified Sign" must be issued. The wellhead hook operator is responsible for the verification and custody of this certificate, and shall not go into the well without a license, otherwise the hook operator shall be investigated for responsibility. The special management team shall regularly check the "underground qualification certificate" with the hook operators. 3 On-site inspection There are three main forms to strengthen on-site management inspection: ① All professional managers regularly inspect the equipment, cables and small appliances running Xin, and comprehensively inspect the safety protection devices at least twice a week. For the problems found in the inspection, in addition to informing the maintenance personnel of the unit to solve them on the spot, a "notice of potential safety hazards" will be issued after going down the well. Major problems, such as fire and cracks, will be solved immediately after the power failure. After the inspection, fill in the inspection daily report and send it to the competent technician and section chief for signature, so as to grasp the situation in time, make overall arrangements and focus on handling. (2) the mine organization 3 times a month irregular mechanical and electrical equipment in good condition. During inspection, the number of explosion-proof electrical equipment generally accounts for more than 40% of the equipment used. It is necessary to check not only the explosion-proof equipment, but also the three major protections, small appliances, cables, industrial hygiene, and the suspension of cables and signal lines on the spot, and link the inspection results with economic benefits. (3) The members of the equipment management network and the explosion-proof inspection network of each user shall conduct self-examination. They patrol and check the running equipment every day. Individual work areas have also deployed 1 ~ 2 maintenance personnel, who are specialized in on-site equipment integrity inspection, rectification and cable hanging. We should actively develop and produce mines. The dynamic evaluation method of on-site quality is organized by the electromechanical department, and the inspected units are determined by drawing lots every month, and the best and worst units in the mining face are comprehensively inspected and evaluated, rewarding the excellent and punishing the poor, which greatly improves the on-site management level of the mining face and promotes the underground electrical equipment to be in a qualified state all the time.
To improve the safety protection performance of underground power supply, it is necessary not only to ensure that the parts of the equipment are intact, but also to pay attention to the inspection and management of various safety protection devices, such as leak detection relays and low-voltage feed switches, to ensure their good performance and always in a "standby" state. (1) The leak detection relay should be tried once a day and once every half month. (2) Check the setting value of the running feed switch three times a month, and check the protection coefficient. Calibrate the over-current setting value during downhole maintenance and re-mark. (3) The comprehensive protection of coal electric drill shall be grounded once per shift. The rated value of the primary fuse of the device is not greater than 10A, and the secondary fuse is not greater than 15A. The cable used in the coal electric drill must be a rafter cable with a cross section of not less than 4mm2 and a length of not more than 100m, and a small chain and karan shall be installed at one end of the coal electric drill to avoid "sheep's tail" caused by external force pulling out the rubber sleeve. ④ Regularly check and test the wind power interlocking device. ⑤ The setting value of protection in each magnetic starter should be selected appropriately, and it is not allowed to be too large or too small, and copper wire and iron wire are not allowed to replace or dump protection. All units generally check once a day. All the above inspections and tests should be recorded in detail and filed for future reference. 5. Strengthen plan management. The electromechanical department arranges the mining area design for the newly-built underground mining area and the mine production department, at the same time, carries out the power supply design, incorporates it into the operation procedures, and strictly follows the design and installation. If the load and line change in the production process, the corresponding variable power supply design should be done. Regular maintenance of electrical equipment should be institutionalized and a maintenance plan should be made in advance. Running equipment has running files, which record running time, overhaul date and accident situation in detail, so as to ensure regular overhaul. When the work area is changed between units, mutual acceptance and handover of mechanical and electrical equipment are also carried out. Whether it is equipment, cables or small appliances, as long as they are transferred from one unit to another, they must go through the handover procedures, fill in the handover acceptance form, and be signed by the handover, connection and management parties. This can not only avoid many disputes, but also ensure that the equipment in use can come and go freely and the responsibilities are clear. Grasp the four key links of equipment maintenance, installation, use and recovery, resulting in three opposites: maintenance acceptance, installation and use, and handover and acceptance. Unqualified maintenance will not be accepted, unqualified installation will not be used, unclear or unqualified quality standards will not be handed over. This can supervise each other and improve each other. Strengthening the maintenance of mine mechanical and electrical equipment often leads to more unnecessary accidents due to long running time and neglect of maintenance. So daily maintenance is also a key. Every day, there is a maintenance class in the coal mining face of this mine to inspect and maintain the key parts of electrical equipment, and to deal with or replace the equipment that has abnormal phenomena but is not damaged. Oil the explosion-proof surface frequently, fasten the electrical connectors, clean up the deposits in front of electrical equipment, maintain good heat dissipation conditions and working environment, arrange the hanging lines, and check the sealing condition of the coal electric drill.