One. General
1. In order to further implement the "Coal Mine Safety Regulations" and the standards and regulations related to explosion-proof electrical, improve the understanding of explosion-proof electrical explosion-proof performance of mechanical and electrical workers, and facilitate the mastery of the application standards in practical work, so as to strengthen the scientific management of explosion-proof electrical in coal mines, improve the quality of maintenance, eliminate electrical explosion, and realize the safe operation of electrical equipment, these "Detailed Rules" are formulated.
2. The selection of all underground electrical equipment (including small electrical appliances) must meet the requirements of Article 444 and Article 7 of the Coal Mine Safety Regulations.
3. Full-time explosion-proof inspectors must be trained and examined by the competent department at a higher level and obtain a certificate. Part-time explosion-proof inspectors must pass the mine-level training examination and obtain a certificate.
4. Explosion-proof electrical equipment must be inspected by a full-time explosion-proof inspector before entering the pit for its "product certificate", "explosion-proof certificate", "safety mark of coal mine products" and safety performance; After passing the inspection and issuing a certificate, the well can be allowed. Explosion-proof electrical equipment for industrial trial operation must have the "industrial test license" issued by the quality supervision and inspection department, and the user unit shall formulate safety measures and be reviewed and approved by the deputy general manager of mine electromechanical, otherwise it is not allowed to go down.
5. When the underground explosion-proof electrical equipment is used and technical transformation is changed, it must be inspected by the mining product quality inspection department authorized by the state.
6. The operation, maintenance and management of underground explosion-proof electrical equipment must meet the technical requirements of explosion-proof performance. Electrical equipment whose explosion-proof performance has been damaged must be disposed of or replaced immediately, and it is strictly forbidden to continue to use it.
7. The maintenance of explosion-proof shell shall be carried out in accordance with the "Coal Mine Explosion-proof Electrical Equipment Shell Repair Regulations", and must be repaired by the unit or manufacturer with explosion-proof maintenance qualification.
8. Strengthen the inspection of explosion-proof electrical performance in underground use:
(1) Explosion-proof electrical maintenance workers (part-time explosion-proof inspectors) shall inspect the explosion-proof electrical equipment under their jurisdiction at least once per shift.
(2) The full-time explosion-proof inspector shall inspect the explosion-proof electrical in the high gas area of the high gas mine or low gas mine at least twice a week. Explosion-proof electrical inspections in low-gas mines are carried out at least once a week.
(3) The staffing of full-time and part-time explosion-proof inspectors must meet the needs of explosion-proof inspection.
II. General Provisions
1. The voltage level of explosion-proof electrical equipment (including small electrical appliances) and cables shall not be higher than its nominal voltage level, otherwise it will be regarded as explosion.
2. If the 9# terminal of the explosion-proof magnetic switch used in high gas, coal and gas outburst mines is grounded or the shell is charged for some reason, it is regarded as a loss of explosion.
3. The use of switch to control the inlet device to enter and exit the power line is regarded as explosion loss (except for the access leak detection relay and the power supply of the control loop).
4. All explosion-proof electrical equipment should be managed in accordance with explosion-proof requirements no matter where it is used in the underground.
3. The flameproof shell must have a clear explosion-proof mark and coal safety mark
Explosion loss occurs in one of the following situations:
1. The shell has cracks, open welding, and serious deformation (the deformation length exceeds 50mm, and the convex and concave depth exceeds 5mm).
2. The rust peeling off inside and outside the explosion-proof shell (the thickness of the rust skin is 0.2mm or more).
3. The transparent plate of the observation hole (window) of the explosion-proof chamber (cavity) is loose, cracked or ordinary glass is used.
4. The flameproof cavity of the explosion-proof equipment is directly penetrated, and the flameproof insulating seat in the junction box of the explosion-proof equipment is removed.
5. The locking device is incomplete, deformed, or damaged, and cannot play a locking role.
Fourth, the explosion-proof surface should be kept clean and complete, and anti-rust measures should be taken
1. The structural parameters of the flameproof joint surface must meet the following requirements, otherwise it is a loss of explosion:
(1) The maximum clearance corresponding to the explosion-proof joint surface, joystick and shaft of the static part of electrical equipment and the explosion-proof joint surface of the rotating shaft with bearing and the corresponding shell volume must comply with the provisions of Table 1. The most effective length of the flameproof joint surface of the quick-opening type is not less than 25mm.
(2) The average roughness of the flameproof joint surface shall not be higher than 6.3μm.
(3) There is no rust on the explosion-proof surface (after wiping with cotton yarn, there are still rust marks left for rust, and only cloud shadows are left, not rust).
(4) Flameproof surface fastened with bolts:
(1) Bolts and spring washers must be fully fastened (the degree of tightness is to flatten the washer to qualify).
(2) The specifications of the spring washer must be adapted to the bolt, (occasionally when the individual spring washer breaks or loses elasticity, check the explosion-proof clearance, if it does not exceed the limit, the replacement of the qualified spring washer is not a loss of explosion.)
(3) Bolts or bolts can not be slid (except for those with long bolts of the same diameter and nut fastening).
(4) The axial length of the remaining thread on the bolt and the screw hole should be greater than 1.5 times of the thickness of the spring washer after tightening, and the thickness around the screw hole and the bottom should be greater than 3mm.
(5) Bolts in the same part. The specifications of the nut should be consistent, and the depth of the steel fastening bolt into the nut should not be less than the diameter of the bolt.
(6) The length of the counterbore steel fastening bolt into the bolt hole should be greater than the diameter of the bolt, and the cast iron, copper and aluminum parts should not be less than 1.5 times the diameter of the bolt;
(7) The cover of the motor junction box shall not be reversed.
2. On the explosion-proof surface, the defects within the specified length and the shortest effective length from the edge of the screw hole to the edge of the explosion-proof surface shall not exceed the following provisions:
(1) For sand holes with a diameter of no more than 1mm and a depth of no more than 2mm, no more than 5 per square centimeter on the 40, 25 and 15mm explosion-proof surfaces, and no more than 2 explosion-proof surfaces of 10mm.
(2) The depth and width of the occasional mechanical scar shall not be greater than 0.5mm, and the effective length of the remaining non-scarred explosion-proof surface shall not be less than 2/3 of the specified length.
(3) There shall be no paint on the explosion-proof surface (when the paint is found, the clearance of the inspection place does not exceed the regulations, and the length of the explosion-proof surface without paint is not less than 2/3 of the fixed length is not an explosion).
3. Explosion-proof motor:
(1) The flameproof surface of the motor shaft and shaft hole should not be rubbed under normal working conditions. When the cylindrical flameproof joint surface is used, the minimum unilateral clearance between the shaft and the shaft hole shall not be less than 0.075mm.
(2) For the rolling bearing structure, the maximum unilateral clearance between the shaft and the shaft hole shall not be greater than 2/3 of the value specified in Table 1.
5. Cable entry device
The cable entry device should be complete, complete, tightened and well sealed, and one of the following conditions is a loss of explosion:
1. The inner diameter of the sealing ring is greater than the outer diameter of the cable by more than 1mm.
2. The difference between the inner diameter of the inlet nozzle and the outer diameter of the sealing ring exceeds the value specified in Table 2.
3. The width of the sealing ring is less than 0.7 times of the outer diameter of the cable, or the minimum width is less than 10mm.
4. The thickness of the sealing ring is less than 0.3 times of the outer diameter of the cable (except for cables of 70 square millimeters and above), or the minimum thickness is less than 4mm.
5. Multiple cables are passed into a single hole of the sealing ring.
6. Cut the sealing ring and put it on the cable.
7. The hardness of the sealing ring does not meet the Sauer hardness of 45 degrees ~ 55 degrees, and the aging (cracking, stickiness, hardening, softening, chalking, discoloration, etc.) loses elasticity. Permanent deformation, effective size fitting clearance does not meet the requirements, and cannot play a sealing role.
8. The sealing ring is not completely sleeved on the cable sheath (or the lead skin of the armored cable).
9. There are other wrappings between the sealing ring and the cable sheath (or the lead skin of the armored cable); There is a filling between the sealing ring and the inlet nozzle;
10. A plurality of sealing rings are used in a wire inlet nozzle;
11. For the cable entry device with threads, the thread meshing is less than 5 buckles, and the length of the threaded part is less than 8mm and less than 6 buckle threads.
12. The thread accuracy is lower than grade 3, and the pitch is less than 0.7mm.
13. The unused inlet nozzle lacks a sealing ring or baffle; or the baffle is placed inside the sealing ring; The diameter of the baffle is less than 2mm than the inner diameter of the inlet nozzle; The thickness of the baffle is less than 2mm or the diameter of the baffle is 110mm or more, and the thickness is less than 3mm; All baffles should be galvanized;
14. The spiral wire nozzle in use lacks a compression metal ring; The metal ring does not match the inlet nozzle; (Idle cable nozzles can be used without metal rings).
15. After the inlet nozzle is pressed, there is no margin or the inner edge of the inlet nozzle is not tightly pressed and sealed; The contact between the end face of the sealing ring and the wall of the device is not tight; or the seal can be moved;
16. The pressure plate type inlet nozzle lacks a compression bolt or the compression bolt is not tightened, and the inlet nozzle can be shaken obviously with one hand;
17. The nut-type inlet nozzle is not tightened in place due to random buckle, rust and other reasons, or the thumb, index and middle finger of one hand can make the compression nut advance to the tightening direction for more than half a turn;
18. The cable can be pushed with one hand at the inlet of the cable at the inlet of the cable;
19. When the insulating glue is used in the high-voltage armored cable junction box, the insulating glue is not poured above the three forks; There are cracks in the insulating glue that can be active on the surface.
Sixth, the connection of cables
The connection of the cable is deemed to be in the event of a detonation under one of the following conditions:
1. The connection of the cable does not use vulcanization heat repair or cold repair with the same efficiency;
2. If the cable (including communication, lighting, signal, and control cables) uses a junction box, it is not an intrinsically safe equipment, and an explosion-proof junction box is not used (an intrinsically safe control line and communication cable should use an intrinsically safe junction box).
3. The junction box is not used for the connection of the armored cable, and the middle box is not filled with insulating filler or the connector of the core wire is not tightly filled;
4. The end of the cable is not connected to explosion-proof electrical equipment or explosion-proof components;
5. Electrical equipment and cables have exposed conductors;
6. The rubber sleeve and cross-linked polyethylene cable sheath are damaged and the core wire is exposed (except for the shielded cable that exposes the shielding layer or the connecting cable of intrinsically safe equipment exposes the conductor, but it should be repaired in time).
7. Flameproof plug-in device
1. The power supply side of the coal drill bolt should be connected to the socket, which conforms to the side bolt, and the reverse connection is a loss of explosion.
2. The plug-in device lacks a fluttering device to prevent sudden unplugging, and the plug-in device with a power supply voltage of 660~1140V lacks an electrical interlocking device for explosion.
3. At the moment when the bolt is disconnected from the contact, the maximum diameter difference W and the minimum effective length L of the flameproof surface of the shell do not conform to Table 3 and are fixed for explosion loss.
8. Lighting appliances
1. The explosion-proof safety lamp changes the pressure port to the mouth of the mouth for explosion;
2. The interlock device of the transparent cover can only be opened after the power supply of the flameproof lamp is disconnected, and the failure is explosion-loss;
3. One of the loose, cracked and damaged glass covers of explosion-proof lamps is explosion-loss.
9. Miner's lamp
In view of the problems found in this product quality supervision and random inspection, the relevant market supervision departments in various places should do the following work.
The miner's lamp used underground must have explosion-proof signs and safety marks for coal mine products, and one of the following circumstances shall be regarded as explosion-loss:
1. The lamp head is broken, the lamp head ring is loose, the glass is broken, the lamp head is not tightly sealed, and the lamp lock fails;
2. The lamp line is damaged, the exposed core wire, the lamp line introduction device is damaged, and the seal is not tight, and the lamp line moves.
