Oct 20, 2022
Friends all know that the quality of a product is mainly reflected in the appearance quality of the product. No matter what kind of product it is, it pays attention to the appearance quality in the production and manufacture, and has strict management and inspection on it. The sheath is the appearance of the power engineering cable. Its appearance is required to be smooth and shiny, with uniform gloss, no eccentricity (not higher than the required error), no mechanical equipment damage, flattening, and no visible dirt and bubbles. , sand holes, significant particles, round bamboo, hemp flower, etc. In addition to the above quality standards, the thickness of the sheath has a key impact on the quality of power engineering cables.
If the thickness of the sheath is less than the specification, it is not a pass, but if the thickness exceeds the specification, it is not up to the standard. For example: the cable model specification is ZR-KVVP 4*1.5mm2, the average thickness of the sheath is measured to be 1.6mm, and the thickness of this type of model should be 1.2mm as specified in the GB9330-88 specification.
Therefore, this cable was judged to be a substandard cable. The failure of power engineering cables will generally lead to the following types of problems and even product quality problems: (1) Reduce the service life. After the cable is laid, it will be plugged in for a long time, and plugging in will cause energy. The allowable operating temperature of the electrical conductor is 70 °C, and the long-term use temperature of polyethylene cannot exceed 65 °C. If the operating temperature may rise in summer, this temperature may According to the release of the outer sheath, the thickness of the sheath increases, and the energy cannot be released, which may endanger the service life of the cable. Due to the thermal effect of polyethylene, the cable sheath undergoes a series of physical and chemical reactions, which lacks the inherent high quality. performance, resulting in a significant reduction in the performance of the insulating layer, and even short-circuit failures, jeopardizing the normal operation of the equipment.
(2) Disadvantages of raw material performance. The performance of the raw material is not reflected according to the thickness. According to the GB8815-2002 specification, if one of its index values is unqualified, the flame retardant polyethylene raw material, then its flame retardant grade is less than 30.
(3) Problems with cable structure. If the relative density of electrical conductors, cable jackets, and hand-woven fabrics are manipulated according to the specifications, and appropriate fillers are selected to make them shiny, how can the jacket be squeezed so thick?
(4) Improve the difficulty factor of cable laying. Nowadays, cable laying is dominated by cable trays or threading pipes. Nowadays, many companies will implement tight cable regulations and small diameters. There can be gaps in the whole process of laying, release energy, and ensure that the outer sheath of the cables will not be damaged. Otherwise, the construction Units and cabling create certain difficulties.
In general, the thickness of the power engineering cable sheath should be controlled in accordance with the specifications, which not only saves energy, reduces material consumption, and improves the efficiency of the company, but also ensures the quality of power engineering cables and creates high-quality and inexpensive products.