The selection shall comply with the following provisions:
1) Under the conditions of service voltage, operating current and their characteristics and environmental conditions, the cable insulation characteristics shall not be less than the conventional expected service life.
2) The selection shall be based on the operation reliability, the simplicity of construction and maintenance, and the comprehensive economy of maximum operating temperature and cost.
3) Should meet the requirements of fire prevention places, and should be conducive to safety.
4) When it is clear that it needs to coordinate with environmental protection, environment-friendly cable insulation type should be selected.
5) The type of crosslinked polyethylene insulation is recommended. For the importance loop of 6kV or the crosslinked polyethylene cables above 6kV, the form of three-layer co-extrusion process featuring inner and outer semi-conductive and insulating layers should be selected.
1) For single-core cables of AC system, non-magnetic metal armor shall be used when it is necessary to strengthen the cable's resistance to external forces, and steel armor without effective non-magnetic treatment shall not be used.
2) Polyethylene outer protective layer is recommended for the metal layer, reinforcement layer and armor of cables laid in damp, chemically corroded environment or vulnerable to water immersion environment.
3) In public facilities with dense personnel and places with low toxic and flame retardant fire requirements, the halogen-free polyolefin coating can be used, but the PVC coating should not be used.
4) PVC outer sheath can be used except for low-temperature environment below -15℃ or places soaked in medicinal chemical liquid and cable extruding outer sheath with low toxicity and non-flammable requirements.
5) Aluminum alloy cables installed in buildings with aluminum alloy interlocking armor can replace the use of bridge, and can improve the bending performance and compressive performance of the cables. If it is used in outdoor wet place, the outer sheath should be squeezed.