The standard sheath material is a phosphorus-containing […]
The standard sheath material is a phosphorus-containing deoxidized copper strip (phosphorus-containing copper strip for easy soldering). The dephosphorus copper strip contains no arsenic, antimony content of not more than 50 ppm, and sulfur content of not more than 15 ppm. The sides of the phosphorus-containing deoxidized copper strip must be smooth, clean, bright, burr-free and oil-free, so as to ensure the stability of the weld and the quality of the weld, the smooth rolling can be ensured.
Insulating material of mineral insulated cable Inorganic magnesium oxide - its physical and chemical properties are very stable, non-corrosive to copper, melting point up to 2800 ° C, high electrical strength, high thermal conductivity, non-toxic, the purity of the material can be manufactured up to More than 94%, for special occasions such as nuclear power plants, the purity of materials for magnesium oxide is higher. The magnesium oxide used in the continuous production process of copper strip longitudinal welding mainly considers three aspects of the flow rate, density and particle size distribution of magnesium oxide. 1) The flow rate is controlled between 160 ∽ 210 s / 100 g. 2) The tap density is between 2.13 ∽ 2.33 g/cm 3 . 3) The particle size distribution is directly related to the density. The normal particle size distribution is from +40 to 325 mesh, and the distribution from high to low is decreasing.
Electrical properties of magnesium oxide:
Check the physical and chemical indicators of magnesium oxide powder, the only purpose of which is to ensure good electrical performance. Electrical performance indicators are divided into normal, hot and tidal states.
Normal test refers to the insulation resistance and withstand voltage measured under normal conditions after the pipe is made. It is called normal insulation and normal withstand voltage.
The hot state test is conducted under various setting conditions. Under certain load conditions, the leakage current, resistance and withstand voltage of the tube are observed. Actually, the quality of the magnesium powder is evaluated by these data.
The tidal test is to put the electric or non-passing electric tube into a constant temperature and humidity chamber (wet tank) for a certain period of time to observe the moisture absorption performance of the magnesium oxide. The tube insulation and withstand voltage (representing magnesium oxide insulation and withstand voltage) are generally determined at 42 ° C or 50 ° C for 48 or 72 hours.