Application of mineral insulated cable: what other areas besides fire protection?
Since 1991, when the national standard for cables and terminals of mineral insulated cables of 750V and below was promulgated, relevant departments have also issued various electrical design specifications, which have made mineral cables widely developed. Not only for electricity and lighting, but also for control and communication

1. History of mineral insulated cable

The early inventor of mineral cable was Arnold Francois Borel, a Swiss engineer, who put forward the idea of using magnesium oxide powder as insulating material for fire resistance and high temperature resistance at the end of the 19th century, and obtained the invention patent. Later in Britain, France, Italy, the United States, Japan and other developed countries have been a large number of production and application. China promulgated GB13033 "rated voltage 750V and below mineral insulated cable and terminal" national standard in 1991, but the corresponding design standard and specification formulation, revision work failed to keep up with, resulting in the use and promotion of the mineral material cable in China has been slow development, behind the developed countries. New version GB/ t13033-2007 "rated voltage 750V and below mineral insulated cable and terminal" national standard was issued in 2007. In recent years, in order to improve the security level of electrical wiring, electric fire accidents and reduce losses, the national ministry of construction, fire department and some local governments have issued the electrical design specification, and make clear a regulation in some important electrical wiring or place appropriate USES mineral insulated cable, further widen the application range of mineral insulated cable.

2. Mineral insulated cable technology

a. The rated voltage of mineral insulated cable is currently 500V and 750V. Flexible mineral insulated cable (rated domestic voltages 1000V and 600V).
b. The core number of mineral insulated cable is 1,2,3,4,7,12,19 cores, and the maximum core number can reach 24 cores. 1-4 cores are mainly used for power and lighting, and above 7 cores are mainly used for control and communication. Compared with organic cables of the same section, the current carrying capacity of magnesia cable can be improved by more than one section grade. At the same time can withstand considerable overload, its overload capacity up to 100 times more than the normal current. Note BTTZ does not have five cores, other models have five cores.
c, mineral insulated incombustible cable is widely used in nuclear power plants, metallurgy, chemical industry, mine, aerospace, high-rise buildings, airports, docks, underground railway passenger flow centers, such as to safeguard in case a fire pumps, fire elevator, important load, emergency evacuation instructions, as well as prevention, exhaust system important fire fighting equipment such as electricity.
d. The highest normal working temperature of the cable can reach 250℃, and the cable can be normally energized for more than three hours under the condition of burning at 950°C. In a short term, the cable can be operated at 1083 °C, which is close to the melting point of copper. Through and through the rain impact experiment.
e, due to the use of seamless copper tube as sheath, so the mineral insulated cable has waterproof, moisture, oil and some chemical damage performance, copper tube has a considerable mechanical strength, so it has a better explosion-proof performance.
f, mineral insulated cable copper tube sheath layer can be used as a ground wire.
BTTZ structure schematic diagram of mineral insulated cable
Application of mineral insulated cable: what other areas besides fire protection?

3. Application of mineral insulated cable

a, the most afraid of mineral insulation cable laying construction is cable joints affected by moisture, causing short circuit and other electrical faults, many construction projects are due to the installation is not in place, leading to the failure.
b. Mineral cables in rail transit tunnel are mainly used for fire protection system, including tunnel fan, jet fan system power supply, gas fire protection, emergency evacuation lighting and indicating power supply, etc.
c. Mineral insulated cables in high-rise buildings are mainly used for general lighting, emergency lighting, fire alarm, fire electrical circuit, emergency elevator and lifting equipment circuit, computer room control circuit, trunk distribution and distribution system circuit, and dual power supply control circuit
d. Application of mineral cables for ships and warships: transmission lines for generator rooms, fire monitoring system, fire alarm system, flue gas emission and ventilation lines, kitchen power lines, and large power lines
Road, dual power control circuit, emergency lighting, emergency broadcast circuit, computer room control circuit.
e, aerospace mineral insulation cable general lighting, emergency lighting, computer room control circuit, large power circuit, high temperature environment power and control circuit, potentially dangerous explosion area line.