The operation of power cables is an important part of our daily life, work, and production. The safety of cable line operation is related to the safety of enterprise production and the safety of people’s lives and property. Due to long-term use, power cables will also have certain losses and ageing.
So what are the reasons for the cables deteriorate? Are there any hazards after cable aging? Let’s understand the causes and hazards of aging of wires and cables!
Causes of cables deteriorate
External force damage
According to the operation analysis in recent years, many cable failures are now caused by mechanical damage. For example: irregular construction during cable laying and installation can easily cause mechanical damage; civil construction on direct buried cables can also easily damage the running cables.
Insulation dampness
This situation is also very common, generally occurring at the cable joints in direct buried or drainage pipes. For example, if the cable joint is not made properly or the joint is made under humid climate conditions, water or water vapor will enter the joint. Water dendrites (water enters the insulation layer and forms dendrites under the action of the electric field) will be formed under the action of the electric field for a long time, gradually damaging the insulation strength of the cable and causing failure.
Chemical corrosion
When the cable is directly buried in an area with acid and alkali effects, it will often cause the armor, lead or outer sheath of the cable to be corroded. The protective layer will fail due to long-term chemical corrosion or electrolytic corrosion, and the insulation will be reduced, which will also cause cable failure.
Long-term overload operation
Due to the thermal effect of current, the conductor will inevitably heat up when the load current passes through the cable. At the same time, the skin effect of the charge, the eddy current loss of the steel armor, and the insulation medium loss will also generate additional heat, thereby increasing the cable temperature.
When operating under long-term overload, excessively high temperatures will accelerate the aging of the insulation, and even the insulation will be broken down.
Cable joint failure
The cable joint is the weakest link in the cable line. Cable joint failures caused by poor construction often occur. During the process of making cable joints, if the joints are not crimped tightly or heated insufficiently, the insulation of the cable head will be reduced, thus causing accidents.
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.
Hazards
Aging of wires will increase power consumption. After the line is aged, if the outer insulation sheath is damaged, it will not only increase line consumption and power consumption, but also cause circuit fires, and need to be replaced in time. Wires will age faster under long-term high temperatures.
When the temperature is too high, the outer insulation skin will ignite and cause fires. In real life, many people who do not understand circuit common sense only use wire cutters to twist two or three turns when connecting two wires and do not tighten them, which results in a small contact surface between the two wires at the joint.
According to physics knowledge, the smaller the cross-sectional area of the conductor, the greater the resistance, and the heat generation Q=I square Rt. The larger the resistance, the greater the heat generation.
Therefore, we should conduct regular line safety inspections. At least once a year, professional personnel should conduct a comprehensive inspection of wires and electrical equipment, especially for long-term use of the joints. If the wires are found to be aging, damaged, poorly insulated, or other unsafe conditions, they should be repaired and replaced in time to ensure the safety of electricity use.
Finally, we remind you that when purchasing wires and cables, you must identify regular manufacturers and check the quality. Don’t buy some substandard wires just because they are cheap.
Please feel free to contact us for further information on cable wire.
sales5@lifetimecables.com
Tel/Wechat/Whatsapp:+86 19195666830
Post time: Jul-05-2024
