What are the advantages of mineral insulated cables?
With the rapid development of cities in recent years, the number of high-rise buildings has increased dramatically, and the demand for electricity in cities has also been rising. In such a densely populated key area, the consequences of a fire will be disastrous. Under such circumstances, mineral insulated cables are becoming more and more popular. Mineral insulated cables are referred to as MI cables. When used as wiring, we usually call them magnesium oxide cables or fireproof cables. It is a copper core copper sheathed cable with mineral material magnesium oxide powder as insulation. Mineral insulated cables are composed of two inorganic materials: copper conductor, magnesium oxide, and copper sheath.
Since this mineral insulated cable is made entirely of inorganic substances (metallic copper and magnesium oxide powder), it itself will not cause a fire, and it is impossible to burn or support combustion. Since the melting point of copper is 1083°C and the melting point of magnesium oxide is 2800°C, this type of cable can continue to maintain power supply in a fire situation close to the melting point of copper. It is a truly fireproof cable. It is much superior to traditional NH cables:
1. Green and environmentally friendly characteristics, which means that the cable structure materials are all made of inorganic mineral materials. The cables do not release smoke or toxic gases in the burning flames; the discarded cables can also be recycled and reused without polluting the natural environment.
2. Strong overload capacity. The normal operating temperature of mineral insulated cables can reach 250℃. Under special circumstances, the cables can maintain operation for a short time at a temperature close to the melting point of the copper sheath. It is very suitable for laying in high-temperature places, such as metallurgy, boilers, glass kilns, blast furnaces and other environments. Its interception capacity is far greater than other cables, because magnesium oxide powder has a better conductor coefficient than plastic, so the same working temperature has a larger interception capacity. For lines above 16mm, one section can be reduced, and for places where people are not allowed to touch, two sections can be reduced.
3. Good bending characteristics. Traditional rigid fireproof cables (BTTZ) are difficult to bend and use. The minimum bending radius of mineral insulated flexible fireproof cables is 6 to 10 times the cable diameter, which reduces the space for installation layout, reduces installation costs, and is easier to lay.
4. Radiation-resistant and non-aging, mineral insulated flexible fireproof cable uses inorganic mineral insulation materials as insulation. Compared with conventional organic insulated cables (YJV, VV), it is not affected by radiation, the material will not age and deteriorate, and the insulation properties will not change; at the same time, the outer sheath of the cable is in the form of copper corrugation, which has excellent sealing, moisture-proof and corrosion-resistant properties. The service life of the cable can reach more than 70 years, which is 2-3 times the life of ordinary cables. Coupled with the inherent characteristics of the copper sheath, the grounding of the cable is better, so the lightning protection grounding measures are effectively implemented, thereby ensuring the safe and reliable operation of the electrical line.
5. High mechanical strength and impact resistance, metal sheath isolation type flexible fireproof cable The mineral insulation layer of the cable is equipped with an aluminum metal layer on the outside, which has the effect of heat insulation, heat insulation, fire and water blocking, and can also prevent objects in the fire environment from hitting and damaging the cable insulation layer. In addition, the cable can be porcelainized. The fireproof layer will form a solid shell at 350°C, which effectively enhances the protection function of the cable.
6. The continuous production length is longer. Due to the use of continuous mechanized production, whether it is single-core or multi-core cable, its length can fully meet the power supply length requirements. The continuous length can reach more than 1000m, without the need for intermediate connection points, which greatly reduces the safety hazards caused by the connection points of the engineering lines.
Mineral insulated cables are special cables that must be used for fire protection in national important facilities, large public areas, high-rise buildings and other places. Their fire resistance, durability, safety, reliability and economy are irreplaceable by traditional power cables. Due to the many excellent characteristics of mineral insulated cables, they have been adopted by many domestic electrical design specifications or standards in recent years, and have also been used in many engineering projects in different industries. It can be expected that the use of mineral insulated cables will increase significantly in the next ten years.
