The operation of wire and cable is one of the important links in our daily life, work and production. The safety of the operation of cable and cable is related to the safety of the production of enterprises and the safety of people's lives and property. Due to long-term use, power cables will also have a certain loss and aging phenomenon. So what are the reasons for the aging of wire and cable? Is there any harm after cable aging? Tianxing cable to explain the causes and hazards of wire and cable aging!

First, the damage of external forces

According to the data analysis in recent years, especially in Shanghai, where the economy is developing rapidly, most cable failures are caused by mechanical damage. For example, the cable is not constructed in accordance with normal norms during the laying and installation process, which is easy to cause mechanical damage; Construction on the directly buried cable is also particularly easy to damage the cable in operation. Sometimes if the damage is not serious, it will lead to complete breakdown of the damage site after several years to form a fault, and sometimes the damage is relatively serious may cause a short circuit fault, which directly affects the safety of the electricity unit.

Second, chemical corrosion

Burying the cable in a place with acid and alkali action is likely to corrode the armor or outer protective layer of the cable. The protective layer is subjected to chemical corrosion or electrolytic corrosion for a long time, making the protective layer ineffective, reducing insulation, and also leading to cable failure.

3. The insulation is damp

This situation is also very easy to happen, generally in the directly buried or row of cable joints. For example, unqualified cable joints and joints are completed in wet conditions, which will cause the joints to enter water or mix with water vapor, and over time will form water branches under the action of electric fields, which will gradually damage the insulation strength of the cable and cause failure.

4. Cable connector failure

The vulnerable link in the cable line is the connector of the cable, and the fault of the cable connector caused by the personnel who do not operate according to the regulations in the construction often occurs. During the process of making cable joints, if the joints are not pressed tightly or heated adequately, the insulation of the cable ends will be reduced, resulting in accidents.

5. Long-term overload operation

Overload operation, due to the thermal effect of the current, the load current will inevitably cause the conductor to heat when passing through the cable, and the skin effect of the charge, the eddy current loss of steel armor, and the loss of the insulating medium will also produce additional heat, thus increasing the cable temperature. Long-term overload operation, too high temperature will accelerate the aging of insulation, and even insulation breakdown. Especially in the hot summer, the temperature rise of the cable often leads to the breakdown of the weak part of the cable insulation, so in the summer, the cable failure is particularly large.

6. Environment and temperature

The environmental factors and heat sources of the cable will also cause the cable temperature to be too high, insulation breakdown, and even explosion and fire.

Damage caused by cable aging

After the aging of the cable, it will consume more power. After the aging of the line, if the outer insulation sheath is damaged, it will not only increase the line consumption and power consumption, but also cause a fire situation, which should be replaced in time. The wire will speed up aging under high temperature for a long time, and the temperature will ignite the outer insulation and cause a fire. In our lives, there are many people who do not understand the common sense of the circuit, when connecting two wires to each other, just use wire cutters to twist two or three circles and do not tighten, which will lead to the contact surface of the two wires at the junction becomes smaller. According to the common sense of physics, the smaller the cross-sectional area of the conductor, the larger the resistance, Q=I square Rt, and the larger the resistance will lead to the increase of the heat.

How to determine wire aging?

1, check whether the current leaks and short-circuit fire;

2. There is no hardening and cracking of insulation skin;

3. Whether the contact resistance becomes larger and the joint heats up.

Suggestion: When the wire and cable have been used for a certain number of years, it is necessary to check or replace it regularly, because there are certain hidden dangers in the aging of the wire and cable, and it is recommended that we should prevent it from happening.


The above content is the content that Tianxing cable shares for you in this issue, I hope it will be helpful to you

Qingdao Tianxing Cable Co., Ltd. is a high-tech enterprise specializing in the production of wire and cable in Shandong Province, with more than 150 sets of domestic excellent cable production equipment and testing equipment, excellent production technology, modern testing equipment, to ensure stable product quality and timely supply. The main products of the company are power cables, low smoke halogen free cables, photovoltaic cables, aluminum alloy cables, shielding cables, radiation crosslinking cables, control cables, computer cables, high life cables, flame retardant series wire and cable.

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