YTTW mineral insulated cable

YTTW mineral insulated cableNH-YJVPR fire-resistant cable

Mineral Insulated Cable, abbreviated as MI cable, is commonly referred to as mineral cable or fire-resistant cable in China when used for wiring. Mineral insulated cables are composed of inorganic materials such as copper conductors, mineral insulation, copper or other metal sheaths.

In 1996, a serious fire broke out in the English Channel Tunnel connecting England and France. The mineral insulated cable system installed inside the tunnel even provided emergency lighting for evacuating passengers after the reinforced concrete and welded steel rails were destroyed, and it withstood the severe test of raging flames and high temperatures. Due to the incomparable quality and performance of mineral insulated cables compared to ordinary cables, their range of use is becoming increasingly widespread.

There are three common products currently available in the Chinese market:

Copper core copper sheathed magnesium oxide insulated cable (without outer sheath BTTZ, BTTQ, with outer sheath BTTVZ, BTTVQ, WD-BTTYZ)

Composed of solid copper rod, magnesium oxide insulation, and seamless copper tube sheath

Flexible inorganic mica with mineral insulation cable (YTTW, RTTZ without outer sheath, with outer sheath) YTTWV、WD-YTTWY、RTTZV、WR-RTTZY、BTTW、BTTRZ）

Composed of copper stranded wire, fluorine mica tape insulation, and copper tape longitudinally wrapped continuous welding sheath

Flexible isolation type aluminum sheathed mineral insulated cable (NG-A, BTLY)

Composed of copper stranded wire, gold mica tape insulation, seamless aluminum tube sheath, oxygen barrier filling, fire-resistant isolation layer, and low smoke halogen-free sheath

The BTTZ series, which has good fire resistance performance, is currently recognized as a mineral insulated cable. It uses high conductivity solid copper core wires as conductors, highly compressed powdered magnesium oxide (MgO) as insulation, and seamless copper tubes as sheaths. It is a modern building wiring cable and a special industry cable (metallurgy, chemical, petroleum, etc.) made by special processes. Due to the special nature of its materials and structure, this product has the electrical, mechanical, environmental resistance, and environmental performance of organic cables (plastic cables). This structure ensures that the melting points of the conductor and insulation material are 1083 ° C and 2800 ° C, respectively. This allows the cable to continue to operate safely under load at temperatures exceeding 1000 ° C even under fire conditions.

The advantages of fire-resistant cables

The service life can reach a hundred years;

● No combustion, no support for combustion, no release of toxic gases, zero combustion energy;

The continuous working temperature can reach 250 ℃, and the short-term working temperature can reach 1083 ℃;

Good fire resistance, the cable can be reused after a fire;

Cable terminals and intermediate connectors are equipped with the cable, enhancing the fire resistance and reliability of the cable;

In a fire, the cable can withstand temperature, impact from falling objects, and fire water spray;

The cable can be used in high-temperature environments;

Waterproof, moisture-proof, oil resistant, and corrosion-resistant;

● No aging, extremely stable cable performance;

The metal sheath of the cable can be used as a grounding circuit;

Excellent mechanical strength and good bending performance, suitable for installation environments with complex structures and limited space;

Due to the particularity of cable structure, its current carrying capacity is large;

The cable has a small outer diameter, easy installation, low overall cost, and does not require conduit protection;

Good explosion-proof performance and excellent resistance to nuclear radiation;

Excellent electromagnetic shielding performance and electromagnetic compatibility performance;

● Can prevent animals from biting.

Regarding price misconceptions

Mineral insulated cables can reduce usage by 1 to 2 specifications and save one ground wire core:

Most people think that mineral insulated cables are expensive and do not use them, but this is not the case. Through the continuous efforts of manufacturing plants and material suppliers in recent years, the price of mineral insulated cables is constantly approaching that of ordinary cables. Mineral insulated cables with a cross-sectional area of 25 mm2 or more are all single core, so their current carrying capacity is higher than that of ordinary cables. This conclusion has also been drawn from simulating the characteristics of solid cables. At the same time, the copper sheath of mineral insulated cables can be directly used as grounding wires, which can reduce one cable core when selecting mineral insulated cables.

The renovation project of the lighting system in the Great Hall of the People of China originally planned to use fire-resistant cable conduit, but later decided to switch to mineral insulated cables. The two proposed cable specifications are the same (both are small-sized cables). The total cost of the final project is 97.59:100 for mineral insulated cables and fire-resistant cables.

Regarding installation issues

With the expansion of the application scope of mineral insulated cables, many installation or construction units have begun to come into contact with mineral insulated cables. Due to their lack of understanding of the construction methods of the products and how to install them, these units have resisted the use of mineral insulated cables in many engineering projects. In fact, the cable laying method is simple and does not require tools or auxiliary facilities; When laying, it can be done through cable trays, brackets, or exposed installation. When installing cable accessories (terminals and connectors), the manufacturer will send professional technicians to the site for guidance and provide construction tools accordingly. The accessories currently in use are all press fit, which are easy to connect and operate. For * contacts, installation and laying techniques can be mastered in less than two hours. In addition, the 99D163 "Mineral Insulated Cable Laying" National Building Standard Design Atlas provides a detailed explanation of the installation and laying methods of mineral insulated cables. As long as the installation unit follows this step of construction, even without the guidance of technical personnel from the manufacturing plant, the cable installation and laying can be completed.

Due to the numerous excellent characteristics of mineral insulated cables and their strong promotion by manufacturing plants, they have been adopted by many electrical design specifications or standards in China in recent years, and have also been used in many engineering projects in different industries. It can be expected that the usage of mineral insulated cables in China will increase significantly in the next decade.