Seven common causes of cable failure
1. External force damage. According to the operation analysis in recent years, especially in cities with rapid economic development, a considerable number of cable faults are caused by mechanical damage.
For example, nonstandard construction during cable laying and installation is easy to cause mechanical damage; Civil construction on directly buried cables is also very easy to damage the cables in operation.
Sometimes, if the damage is not serious, it will take months or even years to cause the complete breakdown of the damaged part to form a fault. Sometimes, if the damage is serious, a short-circuit fault may occur,
It directly affects the safety production of electricity and electricity users.
2. The insulation is damp. This kind of situation is also very common, which usually occurs at the cable joint in the direct burial or row pipe. For example, the production of cable joints is unqualified and joints are made under humid weather conditions,
It will make the joint water or mixed with water vapor, and form water branches under the action of electric field for a long time, which will gradually damage the insulation strength of the cable and cause failure.
3. Chemical corrosion. If the cable is directly buried in the area with acid-base effect, it will often cause the armor, lead skin or outer protective layer of the cable to be corroded, and the protective layer will suffer from chemical corrosion or electrolytic corrosion for a long time,
As a result, the protective layer will fail and the insulation will be reduced, which will also lead to cable failure. Chemical: the cable corrosion of the unit is quite serious.
4. Long term overload operation. During overload operation, due to the thermal effect of current, when the load current passes through the cable, it will inevitably lead to conductor heating. At the same time, the skin effect of charge and the eddy current loss of steel armor
The loss of insulating medium will also produce additional heat, which will increase the temperature of the cable. During long-term overload operation, excessive temperature will accelerate the aging of insulation and even the insulation will be broken down. Especially in hot summer,
The temperature rise of the cable often leads to the breakdown of the weak part of the cable insulation first, so in summer, there are particularly many cable faults.
5. Cable connector failure. The cable joint is the weakest link in the cable line, and the cable joint failure caused by the direct fault of personnel (poor construction) often occurs.
In the process of making cable joints, if there are original nets such as loose crimping and insufficient heating of joints, the insulation of cable heads will be reduced, resulting in accidents.
6. Environment and temperature. The external environment and heat source of the cable will also cause the cable temperature to be too high, insulation breakdown, and even explosion and fire.
7. Normal aging of cable body or natural disasters and other reasons.
1. External force damage. According to the operation analysis in recent years, especially in cities with rapid economic development, a considerable number of cable faults are caused by mechanical damage.
For example, nonstandard construction during cable laying and installation is easy to cause mechanical damage; Civil construction on directly buried cables is also very easy to damage the cables in operation.
Sometimes, if the damage is not serious, it will take months or even years to cause the complete breakdown of the damaged part to form a fault. Sometimes, if the damage is serious, a short-circuit fault may occur,
It directly affects the safety production of electricity and electricity users.
2. The insulation is damp. This kind of situation is also very common, which usually occurs at the cable joint in the direct burial or row pipe. For example, the production of cable joints is unqualified and joints are made under humid weather conditions,
It will make the joint water or mixed with water vapor, and form water branches under the action of electric field for a long time, which will gradually damage the insulation strength of the cable and cause failure.
3. Chemical corrosion. If the cable is directly buried in the area with acid-base effect, it will often cause the armor, lead skin or outer protective layer of the cable to be corroded, and the protective layer will suffer from chemical corrosion or electrolytic corrosion for a long time,
As a result, the protective layer will fail and the insulation will be reduced, which will also lead to cable failure. Chemical: the cable corrosion of the unit is quite serious.
4. Long term overload operation. During overload operation, due to the thermal effect of current, when the load current passes through the cable, it will inevitably lead to conductor heating. At the same time, the skin effect of charge and the eddy current loss of steel armor
The loss of insulating medium will also produce additional heat, which will increase the temperature of the cable. During long-term overload operation, excessive temperature will accelerate the aging of insulation and even the insulation will be broken down. Especially in hot summer,
The temperature rise of the cable often leads to the breakdown of the weak part of the cable insulation first, so in summer, there are particularly many cable faults.
5. Cable connector failure. The cable joint is the weakest link in the cable line, and the cable joint failure caused by the direct fault of personnel (poor construction) often occurs.
In the process of making cable joints, if there are original nets such as loose crimping and insufficient heating of joints, the insulation of cable heads will be reduced, resulting in accidents.
6. Environment and temperature. The external environment and heat source of the cable will also cause the cable temperature to be too high, insulation breakdown, and even explosion and fire.
7. Normal aging of cable body or natural disasters and other reasons.
