Product Features and Applications
• Cross-linked polyethylene insulated power cables for 35kV and below are suitable for fixed laying on AC 50Hz power transmission and distribution lines with rated voltage of 35kV and below for electric energy transmission. Compared with PVC power cables, this product not only has excellent electrical properties, mechanical properties, heat aging resistance, environmental stress cracking resistance and chemical corrosion resistance, but also features simple structure, light weight, no laying height difference limitation and high long-term operating temperature (90℃).
• Cross-linked polyethylene insulated power cables have outstanding thermo-mechanical properties, excellent electrical properties and chemical corrosion resistance. They are new-type cables widely used in urban power grids, mines and factories at present. The cable insulation material, cross-linked polyethylene, is made by chemical and physical methods to convert linear molecular structure polyethylene into three-dimensional network cross-linked polyethylene, which greatly improves the thermo-mechanical properties of polyethylene while maintaining excellent electrical properties.
• Rated Voltage Table for Cables in Three-phase System
Manufacturing Standards
• The product is manufactured in accordance with GB/T1270623-2008 《Extruded Insulated Power Cables and Accessories for Rated Voltage from 1kV (Um=1.2kV) up to 35kV (Um=0.5kV)》
• The fire resistance performance of fire-resistant cables complies with the provisions of GB/T19216,21-2003.
• Low-smoke or low (non-) halogen flame-retardant cables are manufactured in accordance with relevant standards. Their flame retardant performance is divided into three different flame retardant categories A, B and C in accordance with GB/1966-2005 standard. The low concentration passes the test specified in GB/T17651-1998, and the P value and conductivity shall comply with the provisions of GB176502-1998.
Product Service Characteristics
• The maximum temperature of cable conductor under normal operation is 90°C.
• Under short-circuit condition (maximum duration not exceeding 5s), the maximum temperature of cable conductor shall not exceed 250°C.
• The ambient temperature during cable laying shall not be lower than 0°C.
• The bending radius during cable laying shall not be less than the following requirements: single-core cable - 20(D+d) mm / multi-core cable - 15(D+d) mm (D and d refer to the outer diameter of cable and nominal diameter of main conductor respectively, unit: mm).
Technical Parameters
• Ambient temperature: 40°C for laying in air; 25°C for direct burial laying.
• Operating temperature of cable conductor: 90°C.
• For direct buried cables, soil thermal resistivity g=1.0 C·m/W. The increase of soil thermal resistivity caused by moisture migration during long-term operation of the cable is not considered. When the cable is laid underground, the distance from cable axis to ground surface is 1000mm.
• For flat laying of multiple cables, the axial spacing S=2D.
