Fireproof cables, also known as mineral insulated cables and magnesium oxide cables, are copper core copper sheathed cables insulated with mineral material magnesium oxide powder. Mineral insulated cables are composed of two inorganic materials: copper conductor, magnesium oxide, and copper sheath. Its structure is made of electrician's copper rod as the wire core, smooth gold tube as the sheath, and inorganic mineral magnesium oxide powder processed into insulation material, thus possessing many unique properties.

　　(1) Good fire resistance. The copper used as the sheath and wire core has a melting point of 1083 ℃, and the insulation material magnesium oxide powder will not melt at a high temperature of 2200. Therefore, the entire cable is non combustible and non combustible. Experiments on fire resistance performance have shown that the energized fire resistant cable burns in a flame at 800~1000 ℃. Due to the natural combustion of cables with organic insulation and sheath layers at temperatures ranging from 380 to 430 ℃, a large amount of heat is released during combustion, which helps to increase the temperature and expand the fire. The insulation material loses almost all of its mechanical strength and insulation performance, making it unable to protect the lamp core and can continue to supply power.
　　(2) High temperature resistance. As an insulation material for fire-resistant cables, magnesium oxide powder, protected by a copper sleeve, can ensure normal power supply and undamaged cables in a short period of time under a flame of 1000 ℃.
　　(3) Smokeless and non-toxic. Magnesium oxide insulated fireproof cables do not smoke in flames and do not produce harmful gases.
　　(4) Explosion proof. Magnesium insulation material can be firmly pressed between the copper core and copper sleeve to prevent combustible gases, flammable liquid vapors, and flames from entering the cable.
　　(5) Corrosion resistance. Copper sheaths are corrosion-resistant and generally do not require additional protective measures. Plastic protective layers can be used to protect copper sheaths in severely chemically corrosive locations.
　　(6) Waterproof. The copper sheath has a smooth copper protection control, and can be electrified for a long time even when immersed in water.
　　(7) High carrying capacity. Compared with other types of cables with the same core cross-section, magnesium fire-resistant cables have longer continuous working time, higher current carrying capacity, and stronger overload capacity.
　　(8) High mechanical strength. The sheath is a copper sheath, which is very sturdy and will not cause damage to the structure even under the influence of general mechanical collisions and external forces.
　　(9) Long lifespan. The materials, copper core, copper sleeve, and magnesium oxide powder that make up fireproof cables are inorganic materials with good chemical stability, so there is no insulation aging problem and can be almost used for permanent protection.
　　(10) Safe and reliable. The copper sleeve of the fireproof cable itself is a good grounding wire, ensuring the safety of personnel during work.
Characteristics and Applications of Fireproof Cables
It has the characteristics of small outer diameter, grounding, waterproof and explosion-proof, corrosion resistance, high mechanical strength, large current carrying capacity, and high working temperature. Widely used in high-rise buildings, petrochemical, airports, tunnels, ships, offshore oil platforms, aerospace, steel metallurgy, shopping centers, parking lots, and other occasions.