What is the cause of the problem with the high voltage cable?

What is the cause of the problem with the high voltage cable??

The staff of the cable factory will analyze it for you.

The cable is the bridge between the power supply equipment and the electrical equipment, and plays the role of transmitting electric energy. It is widely used, so faults often occur. The following briefly analyzes the causes of common problems of YJV high-voltage cables. According to the causes of faults, they are roughly divided into the following categories: manufacturer's manufacturing reasons, construction quality reasons, design unit design reasons, external forces Destroy four categories.

      1. Reasons for construction quality There are many cases of high-voltage cable system failures caused by construction quality. The main reasons are as follows:

       1. The site conditions are relatively poor. When the cables and connectors are manufactured in the factory, the environment and process requirements are very high, and the temperature, humidity and dust of the construction site are not well controlled.

       2. Small slip marks will inevitably be left on the insulating surface during the construction of the cable, and the semiconductive particles and sand on the emery cloth may also be embedded in the insulation. In addition, the insulation will be inhaled due to the exposure of the insulation to the air during the construction of the joint. Moisture, these leave hidden dangers for long-term safe operation.

       3. The installation did not strictly follow the process construction or the process regulations did not take into account the possible problems.

       4. The DC withstand voltage test is adopted for the completion acceptance, resulting in the formation of a reverse electric field in the joint, resulting in insulation damage.

       5. Caused by poor sealing. The intermediate joint must be sealed with a metal copper shell and a PE or PVC insulation and anti-corrosion layer. The lead seal is tight in the field construction, which effectively ensures the sealing and waterproof performance of the joint.

       2. Reasons for the manufacture of the manufacturer The reasons for the manufacture of the manufacturer are divided into three categories: the cause of the cable body, the cause of the cable joint, and the cause of the cable grounding system according to the different parts of the occurrence.

       1. Reasons for the manufacture of cable joints High-voltage cable joints used to be of wrap-type, die-casting, and molding-type types, which required a large amount of work to be produced on site, and because of the limitations of site conditions and the production process, the insulation tapes cannot be interlayered. Air gaps and impurities are avoided, so problems are prone to occur. The commonly used types in China are the assembled type and the prefabricated type. Cable joints are divided into cable terminal joints and cable intermediate joints. Regardless of the joint form, cable joint failures generally occur at the cable insulation shielding fracture, because this is the place where electrical stress is concentrated, and the cause of cable joint failure due to manufacturing reasons is stress. Cone body manufacturing defects, insulation filler problems, oil leakage from the sealing ring, etc.

       2. Cable grounding system Cable grounding system includes cable grounding box, cable grounding protection box (with sheath protector), cable cross-connection box, sheath protector and other parts. Generally, the problem that is easy to occur is mainly due to the poor sealing of the box body, which leads to multi-point grounding, which causes the induced current of the metal sheath to be too large. In addition, the unreasonable selection of the parameters of the protective layer protector or the poor quality of the zinc oxide crystal is also easy to cause damage to the protective layer protector.

       3. Reasons for the manufacture of the cable body Generally, the problems that are easy to occur in the cable production process include insulation eccentricity, uneven thickness of insulation shielding, impurities in the insulation, protrusions on the inner and outer shielding, uneven cross-linking degree, the cable is damp, and the metal sheath of the cable is sealed. In some cases, failures may occur during the completion test or shortly after being put into operation. Most of them exist in the form of defects in the cable system, causing serious hidden dangers to the long-term safe operation of the cable.

       The above are the common problems of high-voltage cables introduced by the cable factory and the reasons for such problems. Anyone who needs to order cables can consult us.