At present, the domestic fire cables are mainly divided into two categories: rigid mineral insulated fire cables and flexible mineral insulated fire cables. Rigid mineral fire cables include (BTTZ, BTTQ, BTTVZ, BTTVQ) and so on, and flexible mineral insulated fire cables (BTLY, BTTW, YTTW, RTTW, TBTRZ, BBTRZ) and so on. Rigid mineral insulated fire protection cables and flexible fire protection cables are two types of cables that are widely used in applications with high fire safety requirements, and they each have their own characteristics and are suitable for different installation environments and needs. Below TST CBLES will elaborate the characteristics, structure and application scenarios of these two types of cables.
I. Rigid mineral insulated cable / BTTZ BTTQ BTTVZ BTTVQ
BTTZ Rigid Mineral Insulated Cable is a kind of cable with national standard in the category of fireproof cable, its fire performance exceeds the BS6387 standard, which has been used in the international market for nearly one hundred years, and after a long period of extensive validation and finally recognized, it is a mature fireproof level and safety performancehigh cable products. Its fire performance, current-carrying capacity, overload capacity, service life, mechanical strength and flexibility are not comparable to any other fireproof cable. When compared with other fire-resistant cables, BTTZ cable can be reduced by one cross-section level to reduce a ground wire for design, its cost is close to ordinary fire-resistant cables, lower than any other fire-resistant cable cost price. Now there are many relevant national standards provide for the use of BTTZ fire-resistant cable. And compared with similar manufacturers, our company mineral insulated cable using porcelain column assembly method of processing and production, the process is more mature, more rigorous Mineral Insulated Cable Brief Description
Mineral insulated cable is a metal copper conductor, mineral magnesium oxide as insulation, seamless copper tube for the sheath of a cable, when the cable is used for copper corrosion of the plant, the outer layer can be added a layer of polyvinyl chloride, and in the building or underground places of the cable has a beautiful or easy to reach places can be added to a layer of halogen-free and low-smoke outer sheath. Cable continuous working temperature of up to 250 ℃, at 950 ℃ ~ 1000 ℃ can be a continuous power supply for 3 hours, a short period of time or very close to the melting point of copper 1083 ℃ work (the melting point of magnesium oxide is 2800 ℃).
Rigid mineral insulated cable main performance
1, fire performance
2, overload protection ability
3, high current-carrying capacity
4, high working temperature
5, waterproof, anti-corrosion, explosion-proof
6, superior shielding performance
7, radiation resistance
8, long service life
9, small external diameter, light weight
10, environmental protection, safety
11, high mechanical strength
12, bending performance
13, good grounding
Rigid mineral insulated cable main application places
A. Public buildings
Public entertainment, high-rise buildings, hotels, restaurants, hospitals, schools, institutions, department stores, warehouses, national monuments and historic buildings, banks, post and telecommunications buildings, libraries, museums, exhibition halls, airport terminals, stations, ports, electric power dispatching building, telecommunications buildings;
B. High temperature occasions, metallurgical industry, coke industry, shipbuilding industry, iron and steel industry, glass industry, other high-temperature occasions of transmission and distribution lines;
C. Explosion-proof systems and fire hazardous areas, petrochemical industry, refineries, gas stations and oil depots, paint and pigment industry, chemical industry, nuclear power plants, offshore oil platforms, natural gas, gas transmission and compression stations, pharmaceutical industry, mining industry, paper industry, military industry;
D. Underground places, subways, underground warehouses, tunnels, underground squares;
E. Transportation and traffic hubs and so on.
Second, flexible mineral insulated cable / YTTW / BTTW / RTTW
This cable is in addition to BTTZ, a building industry association standards of fire protection cables, it is the same with the BTTZ copper core copper sheathed cable, its fire performance, service life, overload capacity, load capacity, etc. with the performance of mineral insulated cables tend to be the same, to overcome some of the shortcomings of the BTTZ cable. It can be customized according to the actual length, and does not require intermediate connectors and related accessories. Installation is basically the same as that of ordinary cables. The comprehensive cost is relatively low.
Advantages of flexible fireproof cable
- excellent fire performance, fire resistance not only meets the national standard GB12666.6 Class A 950 ℃, 90min, but also to meet the British BS6387-1994 in the provisions of the Class A 650 ℃ 3h; Class B 750 ℃ 3h; Class C 950 ℃ 3h requirements; at the same time, in the combustion of the water can also withstand spraying and mechanical impacts;
- long continuous length, whether single-core, or multi-core cable, its length to meet the needs of the power supply length, each continuous length of up to 1,000m.
- large cross-section, single-core cable cross-section of up to 1000mm, multi-core cable cross-section of up to 240mm; 4. flexible, the cable can be used in a variety of ways.
- flexible, the cable can be coiled on the cable tray, its bending radius ≤ 20D, (D is the outer diameter of the cable);
- Smoke-free and non-toxic when burning, insulation using inorganic materials (non-combustible), combustion will not produce any harmful gases, not to mention the occurrence of secondary pollution, said to be environmentally friendly green products.
- large overload capacity, the cable not only has a large flow capacity, but also has a large overload capacity. According to the wiring to show that the cable surface temperature is usually ≤ 70 ℃, if the wiring can not be touched, but also not in contact with combustible building materials, the cable sheath temperature can be increased to 105 ℃. Overload
Flexible fire-rated cable long-term operating temperature of up to 250 ℃; 7. - corrosion-resistant, organically insulated fire-resistant cables sometimes need to wear plastic pipe or iron pipe, plastic pipe is easy to age and become brittle, iron pipe is easy to rust and corrosion, fire cables have a copper sheath does not need to wear a pipe, copper sheath corrosion resistance;
- superior shielding performance, fire-resistant cables and information, control and other lines in the same shaft when laid in the copper sheath shielding, will not signal, control wire and cable transmission of information to produce interference;
- good safety performance, fire cable can be normal in the flame power supply, start fire-fighting equipment, reduce fire losses, personal safety is also particularly reliable, the copper sheath is a good conductor, is ** good grounding PE line, and continuous to the full length of the cable, greatly improving the grounding protection sensitivity and reliability;
- long service life, inorganic insulation materials, high temperature resistance, and is not easy to age, his life than organic insulation cable many times higher, in normal working conditions, its life expectancy can reach more than a century;
- the transportation and installation of flexible fireproof cable including the installation of fittings is similar to ordinary cable, simpler;
- good economy, flexible fireproof cable due to advanced production technology, simple installation, under the same conditions of its comprehensive cost than the mineral insulated cable costs significantly lower.
Flexible fire cable structure
- cable conductor: stranded copper wire, with good bending characteristics. 2.
- insulation: high temperature resistant, non-combustible inorganic insulation materials.
- Copper sheath: copper material, with good bending characteristics after special processing, and used as PE wire. 4.
- outer sheath: low smoke and non-toxic plastic material, with good anti-corrosion properties.
Application scope of flexible fireproof cable
- Power supply for fire-fighting equipments in all kinds of buildings, power supply for fire-fighting elevator, etc;
- Power supply for equipment and lighting system in important buildings or densely populated buildings.
- Places with high ambient temperature, such as steel mills, smelters, glass factories, etc.; and
- Important flammable and explosive occasions, such as petrochemical, coal mining and other equipment power supply;
- Places that require special cleanliness and hygiene, such as: hospitals, food factories and other power supply equipment;
- Important military, national defense, aviation, satellite base equipment power supply.
- Power supply for important equipment in power plants and nuclear power plants.
Isolated flexible mineral insulated cable (BTLY, BBTRZ, TBTRZ)
On the basis of traditional BTTZ mineral insulated cable, we have developed new BTLY, BTLYQ, BTLV, BTLVQ aluminum sheath continuous extruded mineral insulated cable.
1、Isolated flexible mineral insulated cable product structure:
①, the conductor is round copper stranded wire (relative to the BTTZ solid copper rod is softer)
②, the insulation layer is pure gold mica tape (no longer with the extruded insulating material composite composition, so as to exclude the generation of carbon particles, improve the stability of electrical resistance)
③, the metal sleeve for the continuous extrusion of aluminum metal tube (greatly simplifies the BTTZ copper pipe drawing process)
④, isolation sleeve (cross-linked insulation)
⑤. Fire-resistant layer (covered with Mg(OH) or AL(OH), inorganic materials that do not melt or burn under flame and can be expanded and fire-resistant)
⑥, outer sheath plastic (polyolefin or polyvinyl chloride).
2, Isolated flexible mineral insulated cable features:
（1）Fire resistance standard can be passed BS6387 three tests: that is, 950 ℃ 3h flame does not break through, 650 ℃ after 30min to withstand 15min of water spray (direct immersion can also be), 950 ℃ flame to withstand 15min of knocking vibration without destruction, so that in the fire-resistant performance fully meets the BTT assessment standards.
（2）The product 1.5 ~ 6 square specifications can be produced 1 ~ 37 cores, 10 ~ 240 square specifications can be produced 1 ~ 5 cores, 300 ~ 630 square can be produced in a single core, the length can be according to user needs, the whole root without joints whole disk delivery.
（3）When laying, there is no need to thread the pipe separately, and it has the same waterproof and shockproof function as BTT.
（4） It has good anti-rodent, anti-termite and anti-radiation functions, which can ensure the stability, long life and durability of the cable.
（5）Low working temperature, small wire loss, strong overload resistance, long service life, high security, especially suitable for application in projects with environmental requirements.
（6） Explosion-proof (highly compacted insulating materials in the cable and the cable terminals installed in the specialized sealing jacket can prevent vapors, gases, and flames from entering the electrical equipment connected to the cable, making it practical for use in places where there is a danger of explosion and for connecting a variety of explosion-proof equipment and devices.)
（7）corrosion resistance (BTT (L) series of mineral insulated cable metal jacket has high corrosion resistance, for most of the device, it does not need to take additional protective measures; even in the cable’s metal sheath is vulnerable to corrosion of chemicals or industrial pollution is serious, because the cable outer layer of the protection of the plastic outer sheath, it is still safe.)
（8）high mechanical strength (BTT (L) series of mineral insulated cables are strong and durable, in the case of cable diameter deformation of one-third of the case can still work normally, even if subjected to severe mechanical damage, but also will not damage its electrical properties.)
3, with aluminum as the main material metal tube extrusion instead of copper pipe drawing not only simplifies the process to improve efficiency, but also to make the product cost drops significantly (aluminum is only 1/10 of the overall cost of copper). The reason why the aluminum tube can replace the copper tube, in the high-temperature flame does not melt, thanks to the aluminum tube extrusion covered by the expansion of the fire-resistant layer: in the flame attack under the expansion of the layer of foam curing, the formation of a thick barrier blocking the flame on the aluminum tube of the direct injection. Not only the integrity of the aluminum tube is preserved, but also the heat temperature of the mica tape is reduced to below 600℃, the stability of the insulation of the mica tape is undoubtedly improved (the insulation resistance of the mica tape rises with the reduction of temperature).
The basic characteristics of isolated flexible mineral insulated cable are as follows:
(1), fire-resistant model BTLY: 950 ~ 1000 ℃ / 3h without breakdown, the National Testing Center and Sichuan Fire Institute double report;
(2), 950 ℃ three hours after the aluminum tube does not crack, not melt, the cable can be immersed in water, and continue to maintain the rated voltage;
(3),It has anti-vibration structure, which can resist falling of heavy objects;
(4), the factory test voltage is 3500V/5min, and its allowable operating voltage is 0.6/1kV;
(5),Manufacturing length can meet the user’s needs, without the need to connect with intermediate joints;
(6), 240mm2 and the following specifications can be multi-core cable stranding, large single-core specifications can meet 800mm2 and below;
(7), flame retardant capability over Class A (cable capacity can be unrestricted; fire time: 80min, fire temperature 850 ℃ and above; flame retardant height: less than 0.5m; self-extinguishing time: 5 seconds; light transmittance ≥ 70%);
(8),Cable halogen content is zero;
(9), the terminal using conventional heat shrinkage sealing;
(10), laying bending radius of 15 times the diameter of the cable (multi-core) single-core for 20 times.
Third, mineral insulated cable installation and construction methods:
- the cable according to the required length of the first pipe cutter in the above cut a trace line (copper sheath line can not be cut), and then use the diagonal pliers will be sheathed copper skin clamped between the jaws of the clockwise direction of twisting to step by step clamped household sets of copper skin side and at a small angle to rotate to cut away until the cut mark!
- Use clean dry cloth to remove the magnesium oxide insulating material on the exposed wires thoroughly, then put the bundle head on the cable and screw the brass sealing cup vertically on the cable sheath copper skin, at the beginning of the application of the hand bundle screwing and sliding with the bundle head on the sealing cup to check the verticality of the cup. Confirmed vertical and then use the pipe wire pliers to clamp the knurled seat of the sealing cup to continue the installation, until the tiger guard skin end below the sealing cup inside the local thread. 3!
- from about 600mm from the open end of the cable trip with a blowtorch flame to heat the cable, and will continue to move the flame to the open end of the cable, in order to remove the moisture clean, remember to move the flame only to the open end of the cable, otherwise it will drive the moisture to the inside of the cable!
- Measure the insulation resistance between the core and core, core and sheath with an ohmmeter, if the measurement result meets the requirements, the test can be injected into the sealing paste in the sealing cup. Note that the sealing paste should be added gradually from one side, not too fast, in order to exhaust the air. Wait for the sealing paste filled, in the pressure on the cup, followed by heat-shrinkable tubing to the core set, ** after the ohmmeter and then measure the insulation resistance, if the insulation is low, then re-do it again!
Fourth, installation and laying precautions:
In the cable laying project in the production of cable head is an important part of the process, due to the mineral BTTZ cable compared to ordinary cables have their obvious particularities, shaking the insulation resistance after the completion of the laying of the resistance value is too low in 80% of the cases by the cable head production process quality defects caused by the production of the cable head, so the production process of the cable head quality control is even more important.
Mineral cable cable head there are two kinds of cable: cable terminal head and cable intermediate joints, the components of the two joints cable manufacturers can provide a complete set of components in the production of cable joints should also pay attention to a few aspects:
1, the cable insulation resistance shaking value should meet the specification requirements, otherwise dehumidification operation should be carried out; stripping the copper sheath should be careful to avoid damage to the core;
2, after stripping the magnesium oxide powder should use clean cotton gauze to clean up the remaining powder on the wire core, and it is strictly prohibited to blow with the mouth, so as not to make the cable damp;
3, cable joint production must use quality-qualified silicone, sealing paste and ** construction tools; production should be done first from the distribution room where the cable is concentrated, in turn to the load terminal construction.
Intermediate joint production and quality control
Mineral BTTZ cable intermediate connector includes 1 brass tube, 2 brass bundles and 2 brass sealing cups. Quality control main attention points: conductor production, to thoroughly remove the powder debris, so as not to affect the sealing effect. The use of sealing paste or silica gel shall not be contaminated sundries mixed in, in screwing the sealing cup when the buckle wire should be accurate, the force should be uniform, do not do it brute force. In the production of multi-core cable intermediate head should pay special attention to: in the joint before the core should be carefully checked the corresponding phase to avoid phase connection error, in the joint of different phases of the core connection parts should be staggered, filling insulation sealing material should be guaranteed to ensure that the insulation between the various phases.
Mineral insulated cable branch box
Branch box (box) is mainly used for multi-core small cross-section cable control lines in the implementation of ‘radial’ wiring. It can not only connect cables of the same specification, but also different specifications, different types of cables can be transferred through the branch box. Solve the mineral insulated cable in any place, any place branching problem, but also solved the general fire-resistant plastic cable branching at the fire-retardant fire-resistant special.
Global Leading Mineral Insulated Cable Supplier TST CABLES
Behind every brightly lit night, it is the silent guardian of electric power safety. mineral insulated cables from TST CABLES are not only the bridge for transmitting electric current, but also the extension of lifeline. It is fearless rigidity, stands in the flames of the front line of the test, magnesium oxide heart, copper wall iron armor, casting the sea of fire in the green channel of life, to ensure that electric power safety and stability of uninterrupted, light and hope for eternity. If you have needs or questions about high temperature cables（-100℃~+1200℃），mineral insulated cables, please feel free to contact us by e-mail, you can also get free samples.
