The company is based on the fundamental-strengthening cable quality

After our company has advanced tooling equipment, it should also have a design and development concept that keeps pace with the times. With the progress of equipment and the improvement of the performance of raw and auxiliary materials, the research and development process documents cannot be static, so we need to formulate a reasonable design and development system to institutionalize, process, standardize and rationalize it.

1.Reference Standard

The design of medium and low voltage power cables is mainly in accordance with GB/T 12706, among which the matching foreign standards are IEC60502, BS 6622, BS 7835, VDE 0814, VDE 0266, SANS1339, SANS1507, etc. Although the foreign standards are roughly the same as the domestic standards, the cable naming method, structural nominal, thickness and other indicators are slightly different, so when there are orders referring to foreign standards, be sure to find the corresponding international standards, digest and absorb word by word, and make preparations before production. Maintain efficient communication with the upper cable office and the National Standards Committee to ensure that the latest information on national or industry standards is obtained at the first time.

2.Production process

2.1Conductor wire drawing, annealing, stranding (tin plating) process control

When purchasing copper and aluminum rods, the company must first carry out electrical and mechanical performance tests and visual inspection. GB/T 3956 shall be strictly implemented. The DC resistance, elongation and tensile strength of the conductors shall meet the standard requirements. The surface of the conductors shall be bright and free of oil stains or oxidation spots. The process documents (national standard and non-national standard) shall be strictly implemented during wire drawing, and the diameter, deviation and ovality of monofilament shall conform to the process regulations. Correctly implement the requirements for the use of copper rod classification to ensure that no man-made oxidation occurs before and after the conductor is drawn. Regularly check the emulsion concentration and temperature during the wire drawing process, and regularly check the performance of the wire drawing equipment. Stranding process conditional enterprises can be installed online DC resistance detector, always alert. For the whole process of wire drawing and stranding, the following points should be paid attention:

1) The conductor wire diameter shall not be mixed, fixed positioning management, and records shall be made;

2) Wire drawing and stranding dies shall be kept clean at all times, and anti-rust, dust and physical damage measures shall be taken when not in use;

3) Ensure that wire drawing and stranding equipment are clean, and no sundries are allowed in the annealing furnace;

4) correctly treat the use of copper rod classification, such as: water copper, flat copper, etc;

Tight conductor, non-tight conductor, round conductor, split conductor, special-shaped conductor and other types shall ensure stable stranding pitch, smooth surface of stranding conductor, small concave-convex gap to prevent semi-conductive shielding layer from falling into, and stranded conductor shall not be serpentine to avoid great error of eccentricity;

During conductor welding, the welding point shall be flat and smooth, and the welding point and welding person shall be recorded for tracing.

The stranded copper wire shall be placed for more than one shift, and measures shall be taken to prevent oxidation, dust, moisture and collision.

2.2 XLPEThree-layer co-extrusion process control

In general, the breakdown of XLPE insulated cables is mostly caused by poor co-extrusion of three layers, mainly including: the process temperature is lower than the plasticizing temperature during extrusion of the inner and outer screens, resulting in pre-crosslinking phenomenon, resulting in stiff blocks or scorched particles mixed with the inner and outer screens, impurities mixed with the insulating material, and even the copper tape or copper wire due to uneven field strength distribution or uneven outer screen; The whole three-layer co-extrusion process focuses on the following points:

1) The machine operator must strictly follow the process of production, communicate with the technical personnel in time in case of abnormal phenomena, and do not perfunctory with fluke;

2) Make full use of the conductor preheating device, eccentricity measuring instrument and other online devices, and record the use time of the conductor preheating device when starting up each time;

3) According to the three-layer co-extrusion materials of different manufacturers and different machines (due to their different equipment performance), different process documents are compiled, which is a long-term and effective work;

4) Formulate strict insulation and sheath repair measures, including repair specifications, repair materials, repair meters, repair time and repair implementer;

5) Strictly control the purification level of the feeding room. The purification room must be kept closed. The air shower room works effectively. The feeding person must wear purification clothes and not be perfunctory. Increase the staff's awareness of purification of insulating materials.

2.3Cable appearance identification, transportation and installation

The appearance of the cable is the first standard for customers to judge the quality of the cable, including the smoothness and roundness of the cable, whether the printing is clear and complete, and whether the arrangement of the cable reel is regular and flat. So in the above process should focus on the following points:

1) Strictly implement the sheath extrusion process, the cable end should not be water, the outer protective layer closely covers the cable core, without holes, bulges, unplasticized and scorched defects, the section should be free of visible trachoma, impurities and bubbles, and the surface should be rounded after repair;

2) The apparent printing of the cable shall be clear, discernible and rub-resistant. The flat cable shall be neat and smooth, no kinked arches, etc., and no rubbing, grinding or scratching. The printing requirements of national standards, UL, VDE, SANS and other standards are different. When the production meets the relevant standards, every sentence of the standard must be fully understood to avoid "low-end errors";

3) When setting out construction in areas with harsh environment, loose and even falling off of the trays often occur. Therefore, the company should attach detailed rules for cable construction, with concise text, more pictures, and mark the setting-out direction on the trays.