Technical requirements of explosion proof combined switch and cable in coal mine

Technical requirements of explosion-proof intelligent vacuum combined switch
1. certificate and certificate with relevant qualification.
2. inspection report of qualified unit inspection.
3. the switch shall be provided with coal safety mark and explosion-proof sign.
4. the switch has explosion-proof and explosion resistance.
5. the altitude is 2000 meters.
6. switch protection is sensitive and reliable, with high measurement accuracy and high anti-interference capability; It has overload, over-current, phase break or leakage blocking protection.
7. fully digital, LCD display, fault self diagnosis, memory function, fault simulation test, can be inquired and modified online, with event sequence record, communication transmission, remote operation of shearer or mining face scraper conveyor.
8. when the scraper conveyor of mining face stops running, the shearer must be locked.
9. there is program control on and off operation, and three machines are matched, and full automatic centralized control is implemented.
10. it can be used for the AC 50Hz, 1140V to 3300v power grid, and interface with other automation equipment or system in a centralized control, protection, monitoring and communication.

11. it can realize single machine control, multi loop program control, single machine double speed control and dual speed control.
12. the integrity standard of flameproof joint surface must meet the following table: ① when the diameter of the control rod is d < 6.0mm, l must not be greater than 6.0mm; When d < 25mm, l must be no less than D; d> At 25mm, l must not be greater than 25mm. ② The maximum unilateral clearance m between the shaft and the shaft hole of the rolling bearing structure shall not be greater than 2/3 of the W value.
13. the surface roughness of flameproof joint surface shall not be greater than 6.3; The surface roughness of the control lever shall not be greater than 3.2.
14. the defects of the flameproof joint surface or the raised parts on both sides of the mechanical scar higher than the surface without damage shall not exceed the following provisions after grinding:
③ The local sand holes with diameter no more than 1mm and depth no more than 2mm shall not exceed 5 for each 25px2 on the explosion-proof surface with width of 40, 25 and 15mm; The explosion-proof surface with a width of 10 mm shall not exceed 2. ④ The mechanical scars, width and depth shall not be greater than 0.5mm; The length shall ensure that the effective length of the remaining non injury flameproof surface is not less than 2/3 of the specified length.
15. the explosion-proof surface shall not be rusted or oil stained, and rust proof oil or phosphating shall be carried out. If there is rust, after wiping with cotton yarn, it is qualified to leave the traces of ferrous oxide in green brown color, and those who feel no sense by hand are qualified.
16. the bolt fixed flameproof joint surface shall be tightened to the extent that the flat spring washer is not loose and the clearance is not more than the specified.
17. observe the window hole with good sealing and transparency, without damage and crack.
18. screw explosion-proof structure: thread accuracy shall not be lower than grade 3; The pitch shall not be less than 0.7mm; The minimum number of thread engagement threads and the minimum screw in concentration meet the requirements.
19. the length of the diameter of the control rod and the flameproof joint surface must meet the requirements.
Technical requirements for mine cables
1. flame retardant shielded cable which has passed the inspection by qualified units and obtained safety signs of coal mine products must be selected.
2. qualified cable unit inspection and test report.
3. relevant certificates and certificates with qualification.
4. the number and section of cable cores shall be determined by the supporting manufacturers of three machines according to the power supply rules, and the length shall be determined according to the control location.
5. it is strictly forbidden to use aluminum clad cable and aluminum core cable.
6. aluminum core cable shall not be used for grounding.
7. rubber sleeve soft cable conforming to mt818 standard must be used for high and low voltage cables laid.
8. the number of cores of special control and communication cables shall be selected and reserved with a certain number of spare lines according to the actual requirements of communication, signal and control system.
9. the cable grounding core wire shall not be used for other purposes except for monitoring the grounding circuit.
10. according to the maximum working current actually passed by the cable, it shall not exceed the allowable current for the long time of the AAC Cable.

11. cable section shall be selected according to mechanical strength, and its core section shall not be less than the minimum section specified by various electrical equipment according to the mechanical strength requirements.
12. insulation shake test of cables of different voltage withstand grades must meet the insulation shake test standard.
13. the connection between ABC Cable and electrical equipment must be made with junction box consistent with the performance of electrical equipment. The cable core must be connected to the electrical equipment by means of a tooth shaped crimping plate (claw) or a nose.
14. rubber sleeve cables of different sections are strictly prohibited to be directly connected, and must be connected through the junction box, connector or bus box meeting the requirements.
15. the low-voltage rubber sleeve cable is connected with electrical equipment. The sealing ring is made of rubber with shore hardness of 45-55 degrees, and aging treatment shall be carried out according to the regulations, and it shall meet the requirements of intact.
16. the inlet and outlet nozzles are connected tightly. The fastening degree of fasteners after wiring is qualified that the crimp type nozzle is qualified to take the pulling cable without string operation, and the screw thread nozzle shall screw the compression nut into no more than half circle with five fingers of one hand. The flattening amount of the cable after pressing the cable with the pressure plate type nozzle shall not exceed 10% of the cable diameter.
17. the connection of cable core wire shall be crimped or welded, and binding is strictly prohibited. The joint resistance after connection shall not be greater than 1.1 times of the resistance of the same length of the core, and the tensile strength shall not be less than 80% of the original core.
18. when connecting the shielded cables, the shielding layer of the main wire core must be stripped.