How to select cable outer sheath?
1 The selection of cable sheath should meet the following requirements:
1.1 For single-core power cables in AC systems, when it is necessary to enhance the cable’s resistance to external forces, non-magnetic metal armor layers should be used, and steel armor without effective non-magnetic treatment should not be used.
1.2 For cables in humid, chemically corrosive environments or susceptible to water immersion, the metal layer, reinforcement layer, and armor should have polyethylene outer sheaths, and the thick steel wire armor of cables in water should have extruded outer sheaths.
2. The selection of the outer sheath of the cable during direct burial laying shall meet the following requirements:
2.1 When the cable is subjected to high pressure or has the risk of mechanical damage, it should have a reinforcement layer or steel tape armor.
2.2 In the soil where displacement may occur, such as quicksand layer and backfill land zone, the cable should be armored with steel wire.
2.3 For extruded cables used in areas seriously endangered by termites, outer sheaths with higher hardness should be selected, or thin outer sheaths with higher hardness can be extruded on ordinary outer sheaths. The material can be nylon or special polyolefin copolymerized Objects, etc., can also be armored with metal sleeves or steel tapes.
3. The selection of cable sheath for fixed laying in the air shall meet the following requirements:
3.1 When the small cross-section extruded plastic insulated cables are directly laid on the arm support, they should be armored with steel tape.
3.2 In places with high safety requirements and serious rodent infestation, such as underground passenger transportation and commercial facilities, plastic insulated cables should be armored with metal tape or steel tape.
3.3 When the cables are under high-drop force conditions, the multi-core cables shall be armored with steel wires, and the AC single-core cables shall comply with the provisions of Item 1
4 The selection of cable sheath for underwater laying shall meet the following requirements:
4.1 Steel tape armoring can be used for cables that do not require armored layers to bear tension in ditches, unnavigable creeks, etc.
4.2 For cables in rivers, lakes and seas, the type of steel wire armor selected should meet the stress conditions. When the laying conditions have protection requirements such as mechanical damage, the outer sheath that meets the protection and corrosion resistance enhancement requirements can be selected.