Commonly used low-voltage electrical materials

　　(A) the representation of power cables

　　1. Cable model that

　　In order to accurately indicate the use of the cable, the type of structure and name, the national standard "outer sheath of the cable" GB / T 2952-1989 provides the combination of pinyin letters and numbers to indicate the type and type of cable. Model is usually written in uppercase Hanyu Pinyin letters, cable insulation and inside and outside the protective layer with pinyin letters and numbers to represent, not only can fully reflect the type of cable, use, but also the main structure of the cable, materials and applications Other features are clear.

　　Note: Before the cable model with the pinyin letter ZR- said series of fire-retardant, NH- said fire-resistant series.

　　2.

　　(B) the classification of power cables

　　Power cables are generally divided into PVC insulated (plastic) power cables, XLPE insulated power cables, rubber insulated power cables, oil-filled and oil-impregnated paper insulated power cables according to their types of insulation, which can be classified into General power cables, overhead power cables, underground power cables, submarine power cables, anti-fire-resistant flame retardant power cables, and the like.

　　(C) several common cables and their characteristics

　　1. Copper conductor power cable

　　At present, all low-voltage power cables in China are twisted together for each core wire. The cables of this structure have poor anti-interference ability and poor anti-lightning performance. The impedance of the three-phase cables is unbalanced and the zero sequence impedance is large, Electric appliances and other reliable action. Jiangsu Baosheng Cable Factory developed a rated voltage of 0.6kv ~ 1kv and below the copper and aluminum polyvinyl chloride copper conductor power cable to solve the above problems

　　2. XLPE insulated power cables

　　Referred to as XLPE cable, which is the use of chemical or physical methods to make the cable insulation material polyethylene plastic molecules from the linear structure into a three-dimensional network structure, that is, the original thermoplastic polyethylene into thermosetting cross-linked polyethylene Plastic, which greatly improves the cable's heat resistance and service life, still maintain its excellent electrical performance.

　　3. PVC insulated PVC sheathed power cable

　　Long-term operating temperature of PVC insulated PVC sheathed power cables does not exceed 70 ℃, the maximum temperature of cable conductor does not exceed 160 ℃. Shortest longest duration of no more than 5s, laying the minimum temperature of construction shall not be less than 0 ℃.