1. Overview.
Mineral insulated cables offer significant advantages in durability and reliability over conventional cables. In addition to its excellent fire resistance, it can operate continuously at temperatures up to 250 °C. In extreme cases, the temperature can even approach the melting point of copper of 1083 for a short period of time. These characteristics make mineral insulated cables particularly suitable for lines with rated voltages up to 1000V. Moreover, due to its large current carrying capacity, waterproof, explosion-proof, corrosion-resistant, and overload protection function, its service life is significantly longer than that of traditional cables.
Second, the structure of mineral insulated cables.
Mineral insulated cable, referred to as MI cable, is often referred to as mineral cable or mineral fireproof cable in China. Its structure is relatively simple, mainly composed of copper and high-purity magnesium oxide. Specifically, it consists of a copper sheath, high-purity magnesium oxide insulation, and copper conductors, sometimes with the addition of an outer sheath. When the high-purity magnesium oxide porcelain column on the outside of the copper conductor is pulled and annealed, a mineral-insulated cable is formed. However, it is worth noting that the production length of such cables is somewhat limited, especially for large size cables.
3. The important role of high-purity magnesium oxide.
The core material of mineral insulated cable is high-purity magnesium oxide, which acts as the main insulating material, providing excellent fire resistance and high temperature stability for the cable. This means that as long as the flame temperature does not exceed the melting point of 1083 of copper, the cable will remain intact. In addition to fire resistance, they also offer excellent resistance to spray and mechanical impacts, making mineral insulated cables ideal for lighting, power supply and control circuitry in fire protection systems. At the same time, due to its high-temperature resistance, it is also suitable for long-term work in the metallurgical industry and other high-temperature environments. Due to these unique properties, mineral insulated cables have been widely used in various places, such as high-rise buildings, petrochemical industries, airports, tunnels, etc.