Reasons for the Reduction of Insulation Performance in Cable Silicone Rubber

Silicone rubber insulated cables, such as wires and cables, power supply and power connection lines, are widely used in various industrial fields due to their characteristics of high temperature resistance, corrosion resistance, etc. However, most of the reasons for the failure of silicone rubber cables are due to the reduction of cable insulation, which leads to breakdown. So what are the reasons for the reduction of cable silicone insulation?

Chemical corrosion affects the insulation degree of cable silicone

When high-temperature silicone rubber cables are buried directly in areas with acid-base actions, it often causes corrosion of the outer protective layer of the high-temperature silicone rubber cable. The protective layer is invalid due to long-term exposure to chemical corrosion or electrolytic corrosion, causing insulation reduction, which can also cause high-temperature silicone rubber cable failure.

Moisture affects the insulation degree of cable silicone

This situation is also very common in cable rubber high-temperature cables, usually occurring at the joint of flattened cables directly buried or in pipe. For example, if the high-temperature silicone rubber cable joint is fabricated improperly or made in humid climate conditions, water or water vapor can seep into the joint, eventually forming a water tree under the action of the electric field, gradually damaging the insulation strength of the high-temperature silicone rubber cable and causing failure.

External damage affects the insulation degree of cable silicone

From the industry operation analysis in recent years, a considerable number of high-temperature silicone rubber cable failures are caused by mechanical damage. For example, if high-temperature silicone rubber cables are not constructed according to standards during installation, they are prone to mechanical damage. Sometimes, if the damage is not serious, it may take a few months or even years to cause the damaged part to be completely broken down and cause a failure. Sometimes, if the damage is severe, a short circuit failure may occur within a short period of time, directly affecting the operation of the equipment and the power-using unit.

Faulty high-temperature silicone rubber cable joints

Cable silicone joints are the weakest part of cable lines, and high-temperature silicone rubber cable joint failures caused by direct operator negligence (poor construction) often occur. During the fabrication of high-temperature silicone rubber cable joints, if the joint is not compressed tightly or heated sufficiently, it will cause insulation reduction of the high-temperature silicone rubber cable head, thereby causing accidents.

Long-term overload operation of cable silicone

During overload operation, due to the thermal effect of current, the current passing through the conductor of high-temperature silicone rubber cable will inevitably cause the conductor to heat up. At the same time, the skin effect of electric charge, eddy current loss of steel armor, and insulation dielectric loss will also generate additional heat, thereby causing the temperature of the cable silicone to rise. During long-term overload operation, the high temperature will accelerate the aging of the insulation, resulting in breakdown of the insulation. Especially in hot summers, the temperature rise of high-temperature silicone rubber cables often causes the weak insulation of high-temperature silicone rubber cables to be broken down first, so there are particularly high failures of high-temperature silicone rubber cables in summers.