MGTSV mining fiber optic cable, also known as flame-retardant communication fiber optic cable for coal mines, is a special communication fiber optic cable designed for harsh scenarios such as coal mines, metal mines, tunnels, and vertical shafts. Its core advantage lies in its efficient signal transmission, flame retardant and explosion-proof properties, and resistance to mechanical damage. It must also pass the Mining Product Safety Mark Certification (MA certification) of the National Coal Mine Safety Supervision Bureau, and is the core transmission carrier for underground monitoring, emergency communication, and intelligent sensor networks in mines.
Safety precautions for laying and installation
The laying quality of MGTSV mining optical cable directly affects the transmission stability and safety of use. It is necessary to strictly follow the coal mine safety regulations and communication system design specifications. The core points are as follows:
1. Preparation before construction
-Environmental survey: Evaluate the slope, humidity, water spraying situation, and potential impact areas of the roadway, avoid gas drainage pipelines, high-voltage cables (spacing ≥ 300mm), and heating equipment; When passing through air doors and sealed walls, it is necessary to reserve wall sleeves and ensure proper sealing;
-Fiber optic cable inspection: Check whether the outer skin is damaged, whether the armor layer is corroded, use OTDR to test the fiber attenuation and length, verify the model, number of cores, and MA certification mark to ensure that the product is qualified;
-Personnel qualifications: Construction personnel must undergo coal mine safety training, hold an electrician certificate or communication engineering operation certificate to work, and test the gas concentration (≤ 1%) before underground operations to ensure good ventilation.
2. Laying process control
-Traction control: Short term maximum traction force ≤ 1500N (steel belt armor), continuous traction force ≤ 600N, use dedicated traction end, and prohibit direct pulling of optical fibers or inner protective layers;
-Bending radius control: Static ≥ 10-15 times the outer diameter of the optical cable, dynamic (during traction) ≥ 20 times the outer diameter to avoid fiber breakage or additional loss;
-Fixed and protected: Flame retardant hooks are used for hanging and laying in tunnels, with a spacing of 0.5-1 meter. Crossing intersections requires lifting to a height of ≥ 2 meters and installing protective sleeves; The vertical shaft is laid from top to bottom, fixed in layers every 5-10 meters, with 2-3 meters of redundancy reserved at the bottom and protected by coils; When laying through pipes, the inner diameter of the pipeline should be ≥ 1.5 times the outer diameter of the optical cable, and corner pulleys should be used at corners to avoid scratches;
-Safe distance: parallel distance with high-voltage cables above 10kV ≥ 500mm, crossing distance ≥ 300mm; maintain a distance of ≥ 200mm from compressed air and drainage pipelines.
3. Handling of connectors and terminals
-Installation of joint box: Choose a mining flame-retardant and explosion-proof joint box (such as Ex ib certification), install it in a dry and water free area, with a height of ≥ 1.5 meters; The remaining length of the fiber after fusion splicing is ≥ 1.5 meters, and the bending radius of the winding is ≥ 30mm;
-Terminal processing: The tail fibers are protected with flame-retardant corrugated tubes and undergo anti rodent bite treatment when introduced into the computer room; Reliable grounding of metal components, with a grounding resistance of ≤ 4 Ω;
-Moisture proof sealing: The end of the optical cable should be sealed with a heat shrink cap or waterproof tape in a timely manner, and the entire water spraying area should be protected with galvanized steel pipes. The interface should be sealed with waterproof adhesive.
4. Testing and Acceptance
-Performance testing: After installation, use OTDR to test the attenuation curve to ensure there are no abnormal loss points; Measure the total loss of the link using an optical power meter, with single-mode ≤ 3dB and multi-mode ≤ 10dB;
-Document record: Draw a fiber optic cable routing diagram, mark the joint position, length, loss value, and maintenance responsible person; Save test reports, product qualification certificates, and concealed engineering acceptance records.