Wires are conductive metal wires used to carry current. There are various forms such as solid, twisted or foil woven. According to the insulation condition, it can be divided into bare wires and insulated wires. The cable is an insulated conductor composed of one or more mutually insulated conductive wire cores placed in a sealing sheath. The protective cover can be added outside. The difference between wires and cables is that the size of wires is generally small and the structure is relatively simple, but sometimes cables are also included in the broad category of wires.
New energy cable The insulation is damp. This situation is also very common, and generally occurs at the cable joints in the direct burial or pipe. For example, if the cable connector is not made up to standard and is made in a humid climate, water will enter the connector or water vapor will be mixed into the connector. After a long time, water tree will form under the action of electric field, gradually damaging the insulation strength of the cable and causing failure.
There may be two reasons for bubbles generated in insulation, one is during extrusion. The solution is to select the appropriate mold. There are bubbles in the shielding layer. The main reason is that there is water in the material and it should be dried before extrusion. The second reason is that the cooling is not sufficient. At this time, the following will occur. A circle of bubbles will appear on the circumference equidistant from the wire core. The removal method is to strengthen cooling, raise the water level and reduce the temperature of cooling water. Unqualified cable performance: unqualified free discharge and dielectric loss The reasons for unqualified free discharge and dielectric loss are very complex, which are related to external shielding. Whether the insulation contains bubbles and impurities is closely related to the performance of raw materials. The elimination method is to keep the raw materials clean and produce in strict accordance with the process. The insulation breakdown of cables is mainly caused by impurities mixed with insulating materials and external damage. Due to strict avoidance of external damage, try to avoid impurities mixed. Semi finished products are strictly managed to prevent bumping.
The DC resistance of the cable conductor does not meet the requirements, resulting in the heating phenomenon of the cable during operation. Improper selection of cable leads to the fact that the conductor cross section of the applied cable is too small and overload occurs during operation. After a long time of use, the heating and heat dissipation of the cable are uneven, forming a heating scene. The cable device is too densely displayed, the ventilation and heat dissipation effect is poor, or the cable is too close to other heat sources, which affects the normal heat dissipation of the cable, and can also form a heating scene during the operation of the cable. The connector manufacturing technology is not good, and the crimping is not tight, resulting in excessive contact resistance at the connector, which will also cause heating of the cable. The interphase insulation function of the cable is not good, resulting in a small insulation resistance. The heating scene may also occur during the operation. Some sheaths of the armored cable may be damaged. After water ingress, the insulation function will be damaged slowly, resulting in a gradual reduction of the insulation resistance, which will also form a heating scene during the operation of the cable.
The DC resistance of the cable conductor does not meet the requirements, resulting in the heating phenomenon of the cable during operation. Improper selection of cable leads to the fact that the conductor cross section of the applied cable is too small and overload occurs during operation. After a long time of use, the heating and heat dissipation of the cable are uneven, forming a heating scene. The cable device is too densely displayed, the ventilation and heat dissipation effect is poor, or the cable is too close to other heat sources, which affects the normal heat dissipation of the cable, and can also form a heating scene during the operation of the cable. The connector manufacturing technology is not good, and the crimping is not tight, resulting in excessive contact resistance at the connector, which will also cause heating of the cable. The insulation function between the phases of the cable is not good, resulting in a small insulation resistance, and heating may also occur during operation.
