1、 Peninsula Cable has developed BBTRZ flexible mineral insulation through cooperation with Shanghai Cable Research Institute, Sichuan Fire Research Institute of the Ministry of Public Security and China Fire Protection Association Fireproof cable
2、 At present, in the markets of developed countries such as Europe, America, Japan and Australia, flexible mineral insulated fireproof cables have gradually replaced the first generation of copper tube fireproof products. In the domestic market, this trend is also in full swing and growing.
3、 Introduction to Mineral Insulated (MI) Cables
According to the authoritative data issued by the Ministry of Public Security - the latest version of China Fire Protection Manual in December 2007 - the development history of mineral insulated cables in the world, domestic mineral insulated cable products are divided into two categories:
one Rigid mineral cable. It mainly refers to BTTZ heavy copper core copper sheathed cable, which is made of copper rod as conductor core, magnesium oxide filler as insulation, copper tube as sheath, and is drawn at high temperature for many times.
two Flexible mineral insulated cables. It mainly refers to BBTRZ flexible mineral insulated fireproof cable, which uses copper stranded wire as conductor and inorganic minerals and mineral compounds as insulation and sheath.
These two kinds of mineral insulated cables mainly follow the British BS6387 standard and meet the fire protection requirements of special and first-class buildings, that is, they have 180 min uninterrupted power supply, spray resistance and impact resistance under fire conditions.
BTTZ heavy copper core copper sheathed cable was invented by the Swiss in 1896 and has the characteristics of large current carrying capacity. However, in view of the technical conditions at that time, this product has the limitation of duration. BBTRZ Flexible fireproof cable It was invented by Swiss Stuart in 1894. It not only inherits the characteristics of BTTZ cable in terms of fire prevention and large current carrying capacity, but also makes significant improvements in the structure of BTTZ cable, which is generally considered as an upgrade product of rigid mineral cable.
It is understood that the initial technology introduction and digestion of the above two types of cables were completed by Shanghai Cable Research Institute and Shanghai Cable Factory, and now there are domestic manufacturers that can complete production and supply.
Between the above two kinds of mineral cables, some domestic manufacturers withdraw flexible fireproof cables with transitional metal sheath and copper stranded wire structure.
4、 Comparative advantages of BBTRZ flexible mineral insulated fireproof cable
As BBTRZ flexible mineral insulated fireproof cable has achieved a qualitative breakthrough in material research, it has more advantages in electrical performance, safety, energy saving, easy construction, economy, etc. The main conclusions are as follows:
one Electrical performance
Large current carrying capacity: under the same conditions, the current carrying capacity of BBTRZ cable is larger. The rated current carrying capacity of its conductor at 90 ℃ is basically equivalent to the current carrying value of BBTZ cable at 125 ℃, which is far higher than other cables.
High voltage withstand level: BBTRZ cable follows the national standard GB/T12706, and the voltage withstand level is 1000V; II. The BBTRZ cable complies with the national standard GB/T13033. The withstand voltage level is 750V, and the resistance to impulse voltage (4-6 times of the conventional voltage) is poor, which seriously affects the service life.
two Security
The material has good insulation. BBTRZ cable uses inorganic non-metallic materials as insulation and sheath. It has a multi-layer insulation protection structure, which is both fireproof and waterproof, so it has excellent insulation performance. BTTZ uses magnesium oxide as insulation, and YTTW uses synthetic mica tape as insulation. Both of them are prone to moisture absorption, which can cause the insulation level to decline. They are not suitable for humid environments, cannot contact with air, too many indirect connectors, copper material defects, and various mechanical damages will lead to moisture absorption of the insulation layer, insulation failure, and even major safety accidents.
High line reliability. The maximum cross section of the multi-core structure of BBTRZ cable can reach 300mm2, and it can be customized for continuous large length (theoretically unlimited length), without intermediate joints, so the integrity of the cable is good, and the defect of a single core is overcome.
Grounding is safer. BBTRZ cable adopts special grounding wire to reduce potential safety hazards.
three Energy saving
Because of the inorganic non-metallic insulation and sheath structure of the BBTRZ cable, only three main lines are connected to the small capacitive current of the ground wire, and its value is several to ten milliamperes, which can be ignored.
Less reactive power loss. BBTRZ cable has large current carrying value, low heat generation of conductor, and multi-core large cross-section structure completely counteracts electromagnetic effect. Because the reactive power loss of thermal field and magnetic field is far lower than that of BTTZ and other products.
four Constructability
BBTRZ cable is flexible, and the minimum bending radius is 6D, which is basically the same as the common cable laying process, so the construction is very simple, effective and reliable. At the same time, BBTRZ cable can be laid in the same slot with ordinary cables, saving space, easy to maintain, and suitable for various laying methods.
