Cable Aging

1, external injury. From the standpoint of operation analysis in recent years, especially in the rapid economic development of Shanghai Pudong, a considerable number of cable fault is caused by mechanical damage.
2, insulated from moisture. This is also common, and generally occur in direct buried or pipe at the cable connector. For example: cable making qualified and in humid weather conditions do joints, joint water or mix with water vapor, r a long time in the electric field formation water tree, gradually damage the insulation of the cable caused failure.
3, chemical corrosion. Direct buried cable in areas with acid-base interaction, tends to cause cable sheathing, lead or outer sheath corrosion and protective chemical or electrolytic corrosion due to long-term, resulting in failure of protective, insulated to reduce, also can cause cable failure. : The unit of cable corrosion situation is very serious
4, load operation for a long time. Overloading due to the thermal effect of the current, load current through the cables will inevitably lead to heating of the conductor, and skin effect of electric charge and steel armor of Eddy current loss, dielectric loss can also produce additional heat at first glance, so that the cable temperature.
5, cable joint fault. Cable connector is the weakest link in the cable line, directly from the fault (bad construction) caused by cable joint fault happens all the time. Construction workers in the process of making cable connectors, if there is inadequate connector crimp tightly, heating and other reasons, will lead to lower cable insulation, causing the accident.
6, environment and temperature. Cable of the external environment and the heat can also cause overheating of electric cables, insulation breakdown or even burst into flames.