Cause of cable failure and external force damage Accord […]
Cause of cable failure and external force damage
According to the operation analysis in recent years, especially in the fast developing sea Pudong sea, quite a lot of cable failures are caused by mechanical damage. For example, cable laying and installation are not standardized, and it is easy to cause mechanical damage. The construction of buried cables is also very easy to damage the running cables. L sometimes, if the damage is not serious, it will take several months or even years to cause the breakdown of the damaged part to form a breakdown. Sometimes, a serious short circuit fault may happen, which directly affects the safety production of the electric power unit.
The cause of the cable failure two, the insulation dampness
This is also common, usually in a cable joint in a direct buried or pipe row. For example, if the cable joint is unqualified and joints are made under wet weather conditions, it will cause the joints to enter or mix with steam. After a long time, the water branches will form under the action of electric field, which will gradually damage the insulation strength of cables and cause failure.
Causes of cable failure three, chemical corrosion
Cables directly buried in acid and alkali areas often cause cable armor, lead skin or outer sheath to be corroded. The protective layer is corroded due to chemical corrosion or electrolytic corrosion for a long time, resulting in failure of protective layer, insulation loss and cable failure.
Cause of cable failure four, long-term overloading operation
Overload operation, due to the thermal effect of current, load current through the cable conductor will inevitably lead to fever, and the skin effect of charge and eddy current loss, dielectric loss of steel armor will produce additional heat at first, so that the cable temperature. In the long run of overload, excessive temperature will accelerate the aging of the insulation, so that the insulation is penetrated. Especially in the hot summer, the temperature rise of the cable often causes the cable insulation to be first broken down, so in the summer, the cable failure is particularly much.
Cause of cable failure five, cable joint failure
The cable joint is the weakest link in the cable line, and the fault of the cable joint caused by the direct negligence of the personnel (bad construction) occurs frequently. In the process of making cable joints, if the joints are not tight enough and the heating is not enough, the insulation of the cable head will be reduced, causing accidents.
Cause of cable failure six, environment and temperature
The external environment and heat source in the cable will also cause the high temperature of the cable, the insulation breakdown, and even the explosion.
Causes of cable failure seven, the normal aging of the cable body or natural disasters, and other reasons.