Disadvantages of aging wire and cable

What are the common causes of cable aging? The most direct cause of wire and cable aging failure is insulation reduction and damage. According to practical experience, there are many factors that lead to the reduction of sensitive insulation.

1.So what are the reasons for the aging of wires and cables? What are the disadvantages of cable aging?

(1)External force damage. According to the operation analysis in recent years, especially in Haipudong with rapid economic development, quite a few cable failures are caused by mechanical damage. For example, the cable laying and installation construction is not standardized, which is easy to cause mechanical damage; the civil construction of directly buried cables is also easy to damage the running cables. Sometimes if the damage is not serious, it will take several months or even years to cause the damaged part to be completely destroyed.
(2)Insulation is damp. This is also common and usually occurs with cable glands in direct burial or drains. For example, if the cable splice fails, making the splice in a humid climate will allow the splice to enter water or mix with water vapor. For a long time, water branches are formed under the action of the electric field, which gradually damages the insulation strength of the cable and causes failure.
(3)chemical corrosion. The cable is directly buried in the acid-base action area, which often leads to corrosion of the cable armor, lead sheath or outer protective layer. The protective layer suffers from chemical corrosion or electrolytic corrosion for a long time, resulting in the failure of the protective layer, the reduction of insulation, and the failure of the cable.
(4)Long-term overload operation. During overload operation, due to the thermal effect of the current, the conductor will heat up when the load current passes through the cable. At the same time, the skin collection effect of the electric charge and the eddy current loss of the steel armor. The loss of the insulating medium also generates additional heat, which increases the temperature of the cable. During long-term overload operation, the high temperature will accelerate the aging of the insulation, and even the insulation will be broken down. Especially in the hot summer, the temperature rise of the cable often causes the weak point of the cable insulation to be broken down first, so in the summer, the failure of the cable is particularly high.
(5)Faulty cable connector. The cable joint is the weakest link in the cable line, and the cable joint failure is often caused by poor construction. In the process of making cable joints, if there are reasons such as loose joints and insufficient heating, the insulation of the cable head will be reduced, causing accidents.
(6)Environment and temperature. The external environment and heat source can also cause excessive temperature of the cable, insulation breakdown, and even explosion and fire.

2.How to judge wire aging?

(1)Current leakage or even short-circuit fire;
(2)Hardening of insulation. Cracks;
(3)The contact resistance increases, and the joint heats up.

3.Will aging wires increase power consumption?

Aging wires can increase power consumption. After the line is aging, if the outer insulating sheath is damaged, it will not only increase the line consumption, but also cause a circuit fire. need to be replaced in time.
If the temperature of the wire is too high for a long time, it will accelerate the aging, and if the temperature is too high, the outer insulation will ignite and cause a fire. In real life, many people who do not understand the common sense of the circuit just use wire cutters to twist two or three turns without tightening, resulting in a small contact surface between the two wires at the joint. According to physical knowledge, the smaller the cross-sectional area of the conductor, the greater the resistance, and the greater the heat, the greater the resistance, resulting in an increase in heat.

4.How to prevent wire and cable aging?

Pay attention to the safe current carrying capacity of the wires and cables in the circuit during normal use. If the current used seriously exceeds the safe current carrying capacity of the wires and cables, it will easily affect the service life of the realization, although no changes have been seen in a short period of time. However, over time, it is easy to cause short-circuit problems, and it is easy to cause accelerated aging of wires and cables, which will naturally cause serious hidden dangers.
If you want to better prevent the aging and damage of wires and cables, it is recommended that in addition to using them in the correct way, you should also pay attention to regular maintenance. Only in this way can you determine whether the wires and cables are safer, and any small problems can be found in advance. , so that it can be repaired when there is a defect, so as to avoid affecting the normal use of the circuit, and it is likely to cause various safety hazards.