1. Laying in closed cable channels such as tunnels, trenches, shallow trenches, shafts and mezzanine layers power cable It is not allowed to arrange thermal pipelines, and it is strictly prohibited to cross pipelines with flammable gases or liquids. Cables laid in explosive gas hazardous areas shall meet the following requirements: 1. Cables shall be far away from the explosion release source within the possible range and laid in places with low explosion risk. New energy cable manufacturer Remind you and meet the following requirements:
1) When the flammable gas is heavier than air, the cable shall be buried or laid overhead at a higher place, and the unarmoured cable shall be mechanically protected by threading or placing in trays and boxes.
2) When the flammable gas is lighter than air, the cable shall be laid in the lower pipe and trench, and the unarmoured cable in the trench shall be buried with sand.
2. When the cable is laid in the air along the pipeline conveying flammable gas, it should be arranged on the side of the pipeline with lower risk, and should meet the following requirements:
1) When flammable gas is heavier than air, the cable should be arranged above the pipeline.
2) When flammable gas is lighter than air, the cable should be arranged below the pipeline.
3. Non combustible materials shall be used to tightly block the holes where cables and their pipes and trenches pass through the walls and plates between different areas. 4 There should be no joints in the cable line; If joints are used, they must be explosion-proof. Non armored cables used in the following places and parts shall be protected by pipes or covers with mechanical strength: 1 cable section within 2m above the floor of places where non electrical personnel often live, and 0.3m deep below the floor from the ground. 2 There may be load equipment moving through the section above the cable.
For non outdoor cables other than overhead insulated cables, cover and other sunshade measures should be taken when they are used outdoors.
4 The following measures shall be taken when cables are laid in places with periodic vibration:
1 A gasket made of rubber and other elastic materials is arranged at the supporting cable part.
2 Lay the cable in wave shape with expansion joints. The cable shall not be laid on the terrace or stairway walkway in the pavement of the terrace, dam, bridge deck, underground commercial facilities and the tunnel where pedestrians pass. It is strictly prohibited to lay open cables in the air duct of the factory, the air duct of the building, the inclined shaft ventilation roadway or the shaft of the wooden support shaft that is mechanically lifted in the coal mine except for the conveyor. For a system with power supply above 1kV directly grounded and configured with independent neutral wire and protective ground wire, when cables independent of phase core wire and neutral wire are used as protective ground wire, the laying method of these two parts of cables in the same circuit shall meet the following requirements: 1 In explosive gas environment, they shall be laid in the same structural pipe, trench or box in the same path. 2 In addition to the above situations, they should be laid in the same structure along the same route. The calculated length of the cable shall include the actual path length and additional length. The following factors should be included in the additional length: 1. The height difference change of the cable laying path terrain, expansion joint or detour reserve allowance. 2 The increase of bending influence of 35kV and above cables in serpentine laying. 3. The reserved section for stripping the cable and the length of cable leading to the equipment or device required for terminal or joint fabrication. The additional length of 35kV and below cable laying measurement shall comply with this regulation.
