Among special cable types, high-temperature cables and high-temperature cables have become an important development trend. Although high-temperature cables have slightly larger power losses, in some relatively high-temperature places, ordinary cables are easily damaged. High-temperature cables can operate safely and are modern and an indispensable type for military industry.
Heat-resistant and high-temperature wires and cables are generally determined by two requirements. The first one is that the operating temperature of wires and cables is relatively high, and the cables can normally transmit signals or electric energy in high temperature weather for a long time; the other is power transmission cables, which often have the primary purpose of improving interception capabilities.
Cables operating in high temperature environments. When general wires and cables are exposed to high temperatures, it is easy for the cable sheath to age and deteriorate. The used cables lack characteristics and are affected and difficult to use. High-temperature cables can work normally and smoothly in high-current and high-temperature environments with little impact on signal or power transmission characteristics, and can also ensure that the cable has a relatively long service life. This kind of function cable is a common type of high-temperature cable, and its application characteristics are also helpful to know.
The main purpose of increasing the load of high-temperature cables is to reduce the cable aperture and net weight while ensuring the current carrying capacity, and to develop in the direction of lightweighting. Generally speaking, the higher the working temperature of wires and cables, the greater the current carrying capacity of cables with the same cross-section. If the operating temperature rises from 90°C to 155°C, the current carrying capacity will increase by 50%. Under the same cable carrying capacity, the cable network key is reduced by half, and the cost is also reduced to a certain extent. Of course, in addition to high current interception, there will also be some increase in power loss in most cable jacketing materials.
The subjective reason for unsuccessful wire aging is penetration due to insulation degradation. There are many factors that can lead to reduced insulation performance. The following are some of the situations summarized.
External factors and heat sources where wires and cables are located can also cause the cable temperature to be too high, insulation breakdown, and even explosion and fire.
Due to the thermal effect of the current, the load current passing through the cable will cause the conductor to become hot, and the skin effect of the free charge, the eddy current loss of the steel armor, and the insulation loss will also generate additional heat, causing the cable temperature to rise.
Usually, the armored cable, tin drop or outer sheath of the cable will be corroded. The protective layer will be ineffective due to long-term corrosion or electrolytic corrosion, and the insulation layer will be reduced, which will also cause common faults of wires and cables. The corrosion situation of some cables is quite serious.
The cable is directly buried in the area with acid and alkali, which often causes the cable armor, tin drop or external protective layer to be corroded. The protective layer has been subject to chemical corrosion or electrolytic attack for a long time, which makes the protective layer ineffective and reduces the insulation performance. Common cable faults.
The above is the product knowledge of high-temperature wires and cables summarized by Zhengzhou Jinshui Industrial Co., Ltd. Pay attention to relevant details during installation and construction to reduce losses and hazards.